diff --git a/CHANGELOG.md b/CHANGELOG.md
index 196a8292b20918926df4a66fb1081651f0ede66e..4dafc0aa2ec89300f9e0f94260aa038f20ba319b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -7,10 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
-This is an important security update.
-
 ### Added
 
+* Implementation for the ACM GRPC-API
+* Implementation for the EntityACL GRPC-API
+
 ### Changed
 
 ### Deprecated
@@ -19,6 +20,12 @@ This is an important security update.
 
 ### Fixed
 
+* Wrong serialization of date time values in the GRPC-API (resulting in
+  org.caosdb.server.datatime@12347abcd or similar).
+* Missing serialization of file descriptors in the GRPC-API during retrievals.
+* [caosdb-server#131](https://gitlab.com/caosdb/caosdb-server/-/issues/131)
+  Query: AND does not work with sub-properties
+
 ### Security
 
 
diff --git a/README_SETUP.md b/README_SETUP.md
index 5065e3383c4ac2f2d549bfedb15687d0b4124ec0..d46722d26458757a53f081dd1ce9af3db2688283 100644
--- a/README_SETUP.md
+++ b/README_SETUP.md
@@ -58,12 +58,14 @@ libpam0g-dev`. Then try again.
 After a fresh clone of the repository, this is what you need to setup the
 server:
 
-1. Compile the server with `make compile`. This may take a while and there
+1. Install the `proto` submodule (and submodules for those extensions you want, see above):
+   `git submodule update --init caosdb-proto`
+2. Compile the server with `make compile`. This may take a while and there
    needs to be an internet connection as packages are downloaded to be
    integrated in the java file.
    1. It is recommended to run the unit tests with `make test`. It may take a
       while.
-2. Create an SSL certificate somewhere with a `Java Key Store` file.  For
+3. Create an SSL certificate somewhere with a `Java Key Store` file.  For
    self-signed certificates (not recommended for production use) you can do:
    - `mkdir certificates; cd certificates`
    - `keytool -genkey -keyalg RSA -alias selfsigned -keystore caosdb.jks -validity 375 -keysize 2048 -ext san=dns:localhost`
@@ -77,11 +79,11 @@ server:
    Alternatively, you can create a keystore from certificate files that you already have:
    - `openssl pkcs12 -export -inkey privkey.pem -in fullchain.pem -out all-certs.pkcs12`
    - `keytool -importkeystore -srckeystore all-certs.pkcs12 -srcstoretype PKCS12  -deststoretype pkcs12 -destkeystore caosdb.jks`
-3. Install/configure the MySQL back-end: see the `README_SETUP.md` of the
+4. Install/configure the MySQL back-end: see the `README_SETUP.md` of the
    `caosdb-mysqlbackend` repository
-4. Create an authtoken config (e.g. copy `conf/core/authtoken.example.yaml` to
+5. Create an authtoken config (e.g. copy `conf/core/authtoken.example.yaml` to
    `conf/ext/authtoken.yml` and change it)
-5. Copy `conf/core/server.conf` to `conf/ext/server.conf` and change it
+6. Copy `conf/core/server.conf` to `conf/ext/server.conf` and change it
    appropriately:
     * Setup for MySQL back-end:
       specify the fields `MYSQL_USER_NAME`, `MYSQL_USER_PASSWORD`,
@@ -94,7 +96,7 @@ server:
       `CERTIFICATES_KEY_STORE_PATH`, and `CERTIFICATES_KEY_STORE_PASSWORD`.
       Make sure that the conf file is not readable by other users because the
       certificate passwords are stored in plaintext.
-    - Set the path to the authtoken config (see step 4)
+    * Set the path to the authtoken config (see step 4)
     * Set the file system paths:
       - `FILE_SYSTEM_ROOT`: The root for all the files managed by CaosDB.
       - `DROP_OFF_BOX`: Files can be put here for insertion into CaosDB.
@@ -112,8 +114,8 @@ server:
       - `INSERT_FILES_IN_DIR_ALLOWED_DIRS`: add mounted filesystems here that
         shall be accessible by CaosDB
     * Maybe set another `SESSION_TIMEOUT_MS`.
-    * See also [CONFIGURATION.rst](src/doc/administration/configuration.rst)
-6. Copy `conf/core/usersources.ini.template` to `conf/ext/usersources.ini`.
+     * See also [CONFIGURATION.rst](src/doc/administration/configuration.rst)
+7. Copy `conf/core/usersources.ini.template` to `conf/ext/usersources.ini`.
     * You can skip this if you do not want to use an external authentication. 
       Local users (CaosDB realm) are always available.
     * Define the users/groups who you want to include/exclude.
@@ -128,7 +130,7 @@ server:
       Especially that there are no `properties` (aka `keys`) without a
       `value`. An emtpy value can be represented by `""`. Comments are
       everything from `#` or `;` to the end of the line.
-7. Possibly install the PAM caller in `misc/pam_authentication/` if you have 
+8. Possibly install the PAM caller in `misc/pam_authentication/` if you have
    not do so already. See above.
    
 Done!
diff --git a/caosdb-proto b/caosdb-proto
index 533c8e7341d0659e3cc43d834793a7a965703f55..02e56997f29ee3bfc2c079c9776f66659379c58a 160000
--- a/caosdb-proto
+++ b/caosdb-proto
@@ -1 +1 @@
-Subproject commit 533c8e7341d0659e3cc43d834793a7a965703f55
+Subproject commit 02e56997f29ee3bfc2c079c9776f66659379c58a
diff --git a/src/doc/index.rst b/src/doc/index.rst
index 4f63fe07f37a4432a442040ff2f614f01c959472..b5ce9f3235277b613b357dca5dfc3334d80aeb3f 100644
--- a/src/doc/index.rst
+++ b/src/doc/index.rst
@@ -10,6 +10,7 @@ Welcome to caosdb-server's documentation!
 
    Getting started <README_SETUP>
    Concepts <concepts>
+   tutorials
    Query Language <CaosDB-Query-Language>
    administration
    Development <development/devel>
diff --git a/src/doc/tutorials.rst b/src/doc/tutorials.rst
new file mode 100644
index 0000000000000000000000000000000000000000..27aacfb3eb9a4f04ab261b12f904e652c4daf3d3
--- /dev/null
+++ b/src/doc/tutorials.rst
@@ -0,0 +1,10 @@
+Tutorials
+==============
+
+.. toctree::
+   :maxdepth: 1
+   :glob:
+
+   tutorials/*
+
+
diff --git a/src/doc/tutorials/setup_state_model.py b/src/doc/tutorials/setup_state_model.py
new file mode 100755
index 0000000000000000000000000000000000000000..0a1a7daa3b14d7c3e7a5b8eac093857bddfad330
--- /dev/null
+++ b/src/doc/tutorials/setup_state_model.py
@@ -0,0 +1,379 @@
+#!/usr/bin/env python3
+# encoding: utf-8
+#
+# This file is a part of the CaosDB Project.
+#
+# Copyright (C) 2021 Indiscale GmbH <info@indiscale.com>
+# Copyright (C) 2021 Henrik tom Wörden <h.tomwoerden@indiscale.com>
+# Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU Affero General Public License as
+# published by the Free Software Foundation, either version 3 of the
+# License, or (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU Affero General Public License for more details.
+#
+# You should have received a copy of the GNU Affero General Public License
+# along with this program. If not, see <https://www.gnu.org/licenses/>.
+#
+"""
+This is a utility script to setup a publication process in LinkAhead using
+states.
+
+If you start from scratch you should perform the following actions in that
+order:
+
+1. setup_roles
+2. setup_state_data_model
+4. setup_model_publication_cycle
+"""
+from argparse import ArgumentParser, RawDescriptionHelpFormatter
+
+import caosdb as db
+from caosdb.common.administration import generate_password
+
+
+def teardown(args):
+    """fully clears the database"""
+
+    if "yes" != input(
+        "Are you really sure that you want to delete ALL "
+        "ENTITIES in LinkAhead? [yes/No]"
+    ):
+
+        print("Nothing done.")
+
+        return
+    d = db.execute_query("FIND ENTITY WITH ID > 99")
+
+    if len(d) > 0:
+        d.delete(flags={"forceFinalState": "true"})
+
+
+def soft_teardown(args):
+    """ allows to remove state data only """
+    recs = db.execute_query("FIND Entity WITH State")
+
+    for rec in recs:
+        rec.state = None
+    recs.update(flags={"forceFinalState": "true"})
+    db.execute_query("FIND StateModel").delete()
+    db.execute_query("FIND Transition").delete()
+    db.execute_query("FIND State").delete()
+    db.execute_query(
+        "FIND Property WITH name=from or name=to or name=initial or name=final or name=color").delete()
+
+
+def setup_user(args):
+    """Creates a user with given username and adds the given role.
+
+    If the user exists, it is deleted first. A random password is generated
+    and printed in clear text in the console output.
+
+    """
+
+    username, role = args.username, args.role
+    try:
+        db.administration._delete_user(name=username)
+    except Exception:
+        pass
+
+    password = generate_password(10)
+    print("new password for {}:\n{}".format(username, password))
+    db.administration._insert_user(
+        name=username, password=password, status="ACTIVE")
+    db.administration._set_roles(username=username, roles=[role])
+
+
+def remove_user(args):
+    """deletes the given user"""
+    db.administration._delete_user(name=args.username)
+
+
+def setup_role_permissions():
+    """
+    Adds the appropriate permissions to the 'normal' and 'publisher' role.
+
+    The permissions are such that they suit the publication life cycle.
+    """
+    db.administration._set_permissions(
+        role="normal",
+        permission_rules=[
+            db.administration.PermissionRule("Grant", "TRANSACTION:*"),
+            db.administration.PermissionRule(
+                "Grant", "ACM:USER:UPDATE_PASSWORD:?REALM?:?USERNAME?"
+            ),
+            db.administration.PermissionRule("Grant", "STATE:TRANSITION:Edit"),
+            db.administration.PermissionRule("Grant", "UPDATE:PROPERTY:ADD"),
+            db.administration.PermissionRule(
+                "Grant", "UPDATE:PROPERTY:REMOVE"),
+            db.administration.PermissionRule(
+                "Grant", "STATE:TRANSITION:Start Review"),
+            db.administration.PermissionRule(
+                "Grant", "STATE:ASSIGN:Publish Life-cycle"
+            ),
+        ],
+    )
+
+    db.administration._set_permissions(
+        role="publisher",
+        permission_rules=[
+            db.administration.PermissionRule(
+                "Grant", "ACM:USER:UPDATE_PASSWORD:?REALM?:?USERNAME?"
+            ),
+            db.administration.PermissionRule("Grant", "TRANSACTION:*"),
+            db.administration.PermissionRule("Grant", "UPDATE:PROPERTY:ADD"),
+            db.administration.PermissionRule(
+                "Grant", "UPDATE:PROPERTY:REMOVE"),
+            db.administration.PermissionRule("Grant", "STATE:*"),
+        ],
+    )
+
+
+def setup_roles(args):
+    """Creates 'publisher' and 'normla' roles and assigns appropriate
+    permissions
+
+    If those roles exist they are deleted first.
+    """
+
+    for role in ["publisher", "normal"]:
+        try:
+            db.administration._delete_role(name=role)
+        except Exception:
+            print("Could not delete role {}".format(role))
+
+    for role in ["publisher", "normal"]:
+        db.administration._insert_role(name=role, description="")
+
+    setup_role_permissions()
+
+
+def setup_state_data_model(args):
+    """Creates the data model for using states
+
+    RecordTypes: State, StateModel, Transition
+    Properties: from, to, initial, final, color
+    """
+    cont = db.Container().extend(
+        [
+            db.RecordType("State"),
+            db.RecordType("StateModel"),
+            db.RecordType("Transition"),
+            db.Property(name="from", datatype="State"),
+            db.Property(name="to", datatype="State"),
+            db.Property(name="initial", datatype="State"),
+            db.Property(name="final", datatype="State"),
+            db.Property(name="color", datatype=db.TEXT),
+        ]
+    )
+    cont.insert()
+
+
+def setup_model_publication_cycle(args):
+    """Creates States and Transitions for the Publication Life Cycle"""
+    unpublished_acl = db.ACL()
+    unpublished_acl.grant(role="publisher", permission="*")
+    unpublished_acl.grant(role="normal", permission="UPDATE:*")
+    unpublished_acl.grant(role="normal", permission="RETRIEVE:ENTITY")
+    unpublished_acl = db.State.create_state_acl(unpublished_acl)
+
+    unpublished_state = (
+        db.Record(
+            "Unpublished",
+            description="Unpublished entries are only visible to the team "
+            "and may be edited by any team member.",
+        )
+        .add_parent("State")
+        .add_property("color", "#5bc0de")
+    )
+    unpublished_state.acl = unpublished_acl
+    unpublished_state.insert()
+
+    review_acl = db.ACL()
+    review_acl.grant(role="publisher", permission="*")
+    review_acl.grant(role="normal", permission="RETRIEVE:ENTITY")
+
+    review_state = (
+        db.Record(
+            "Under Review",
+            description="Entries under review are not publicly available yet, "
+            "but they can only be edited by the members of the publisher "
+            "group.",
+        )
+        .add_parent("State")
+        .add_property("color", "#FFCC33")
+    )
+    review_state.acl = db.State.create_state_acl(review_acl)
+    review_state.insert()
+
+    published_acl = db.ACL()
+    published_acl.grant(role="guest", permission="RETRIEVE:ENTITY")
+
+    published_state = (
+        db.Record(
+            "Published",
+            description="Published entries are publicly available and "
+            "cannot be edited unless they are unpublished again.",
+        )
+        .add_parent("State")
+        .add_property("color", "#333333")
+    )
+    published_state.acl = db.State.create_state_acl(published_acl)
+    published_state.insert()
+
+    # 1->2
+    (
+        db.Record(
+            "Start Review",
+            description="This transitions denies the permissions to edit an "
+            "entry for anyone but the members of the publisher group. "
+            "However, the entry is not yet publicly available.",
+        )
+        .add_parent("Transition")
+        .add_property("from", "unpublished")
+        .add_property("to", "under review")
+        .add_property("color", "#FFCC33")
+        .insert()
+    )
+
+    # 2->3
+    (
+        db.Record(
+            "Publish",
+            description="Published entries are visible for the public and "
+            "cannot be changed unless they are unpublished again. Only members"
+            " of the publisher group can publish or unpublish entries.",
+        )
+        .add_parent("Transition")
+        .add_property("from", "under review")
+        .add_property("to", "published")
+        .add_property("color", "red")
+        .insert()
+    )
+
+    # 3->1
+    (
+        db.Record(
+            "Unpublish",
+            description="Unpublish this entry to hide it from "
+            "the public. Unpublished entries can be edited by any team "
+            "member.",
+        )
+        .add_parent("Transition")
+        .add_property("from", "published")
+        .add_property("to", "unpublished")
+        .insert()
+    )
+
+    # 2->1
+    (
+        db.Record(
+            "Reject",
+            description="Reject the publishing of this entity.  Afterwards, "
+            "the entity is editable for any team member again.",
+        )
+        .add_parent("Transition")
+        .add_property("from", "under review")
+        .add_property("to", "unpublished")
+        .insert()
+    )
+
+    # 1->1
+    (
+        db.Record(
+            "Edit",
+            description="Edit this entity. The changes are not publicly "
+            "available until this entity will have been reviewed and "
+            "published.",
+        )
+        .add_parent(
+            "Transition",
+        )
+        .add_property("from", "unpublished")
+        .add_property("to", "unpublished")
+        .insert()
+    )
+
+    (
+        db.Record(
+            "Publish Life-cycle",
+            description="The publish life-cycle is a quality assurance tool. "
+            "Database entries can be edited without being publicly available "
+            "until the changes have been reviewed and explicitely published by"
+            " an eligible user.",
+        )
+        .add_parent("StateModel")
+        .add_property(
+            "Transition",
+            datatype=db.LIST("Transition"),
+            value=[
+                "Edit",
+                "Start Review",
+                "Reject",
+                "Publish",
+                "Unpublish",
+            ],
+        )
+        .add_property("initial", "Unpublished")
+        .add_property("final", "Unpublished")
+        .insert()
+    )
+
+
+def parse_args():
+    parser = ArgumentParser(
+        description=__doc__, formatter_class=RawDescriptionHelpFormatter
+    )
+    subparsers = parser.add_subparsers(
+        title="action",
+        metavar="ACTION",
+        description=(
+            "You can perform the following actions. "
+            "Print the detailed help for each command with "
+            "#> setup_state_model ACTION -h"
+        ),
+    )
+
+    subparser = subparsers.add_parser(
+        "setup_state_data_model", help=setup_state_data_model.__doc__
+    )
+    subparser.set_defaults(call=setup_state_data_model)
+
+    subparser = subparsers.add_parser(
+        "setup_model_publication_cycle", help=setup_model_publication_cycle.__doc__
+    )
+    subparser.set_defaults(call=setup_model_publication_cycle)
+
+    subparser = subparsers.add_parser("setup_roles", help=setup_roles.__doc__)
+    subparser.set_defaults(call=setup_roles)
+
+    subparser = subparsers.add_parser("remove_user", help=remove_user.__doc__)
+    subparser.set_defaults(call=remove_user)
+    subparser.add_argument("username")
+
+    subparser = subparsers.add_parser("setup_user", help=setup_user.__doc__)
+    subparser.set_defaults(call=setup_user)
+    subparser.add_argument("username")
+    subparser.add_argument("role")
+
+    subparser = subparsers.add_parser(
+        "teardown", help="Removes ALL ENTITIES from LinkAhead!"
+    )
+    subparser.set_defaults(call=teardown)
+
+    subparser = subparsers.add_parser(
+        "soft_teardown", help=soft_teardown.__doc__
+    )
+    subparser.set_defaults(call=soft_teardown)
+
+    return parser.parse_args()
+
+
+if __name__ == "__main__":
+    args = parse_args()
+    args.call(args)
diff --git a/src/doc/tutorials/statemachine.rst b/src/doc/tutorials/statemachine.rst
new file mode 100644
index 0000000000000000000000000000000000000000..317620423e6221ccaf29297fc1f71f0c008f78a0
--- /dev/null
+++ b/src/doc/tutorials/statemachine.rst
@@ -0,0 +1,34 @@
+
+State Machine
+=============
+
+Prerequisites
+-------------
+
+In order to use the state machine functionality you have to set the
+corresponding server setting: ``EXT_ENTITY_STATE=ENABLED``.
+
+Also, a few RecordTypes and Properties are required. You can use the
+script `setup_state_model.py <https://gitlab.com/caosdb/caosdb-server/-/blob/dev/src/doc/tutorials/setup_state_model.py>`_
+to create those or you may have a look at it to see what is needed (``setup_state_data_model`` function).
+
+Defining the State Machine
+--------------------------
+
+Now you are setup to create your own state machine. You can define States and Transitions
+and bundle it all to a StateModel. The above mentioned ``setup_state_model.py`` script defines
+a publication cycle with the state "Unpublished", "UnderReview" and "Published".
+Again, the ``setup_state_model.py`` script provides orientation on how this
+can be setup (``setup_model_publication_cycle`` function).
+
+Note, that you can provide ACL to the state definition which will be applied to an entity once
+the state is reached. This is for example useful to change the visibility depending on a state change.
+
+If you assign a state to a RecordType, this state will be the initial state
+of Records that have that parent. For example by executing:
+
+.. code-block:: Python
+
+    rt = db.RecordType("Article").retrieve()
+    rt.state = db.State(name="UnPublished", model="Publish Life-cycle")``
+    rt.update()
diff --git a/src/main/java/org/caosdb/datetime/DateTimeFactory2.java b/src/main/java/org/caosdb/datetime/DateTimeFactory2.java
index 103359c7b4ff6f995996866e2283bab47562699c..14088ea5d1033771d8835352b61e5bf430c4ff5f 100644
--- a/src/main/java/org/caosdb/datetime/DateTimeFactory2.java
+++ b/src/main/java/org/caosdb/datetime/DateTimeFactory2.java
@@ -30,6 +30,11 @@ import org.antlr.v4.runtime.CommonTokenStream;
 import org.caosdb.server.query.CQLParsingErrorListener;
 import org.caosdb.server.query.CQLParsingErrorListener.ParsingError;
 
+/**
+ * Factory which parses string into CaosDB's DATETIME values.
+ *
+ * @author tf
+ */
 public class DateTimeFactory2 implements DateTimeFactoryInterface {
 
   private Long millis = null;
@@ -51,6 +56,14 @@ public class DateTimeFactory2 implements DateTimeFactoryInterface {
   private Integer nanosecond = null;
   private TimeZone timeZone = TimeZone.getDefault();
 
+  public DateTimeFactory2(TimeZone timeZone) {
+    this.timeZone = timeZone;
+  }
+
+  public DateTimeFactory2() {
+    this(TimeZone.getDefault());
+  }
+
   @Override
   public void setDate(final String string) {
     this.date = Integer.valueOf(string);
@@ -220,6 +233,16 @@ public class DateTimeFactory2 implements DateTimeFactoryInterface {
   }
 
   public static DateTimeInterface valueOf(final String str) {
+    return valueOf(str, TimeZone.getDefault());
+  }
+
+  public static DateTimeInterface valueOf(final String str, TimeZone timeZone) {
+    final DateTimeFactory2 dtf = new DateTimeFactory2(timeZone);
+
+    return dtf.parse(str);
+  }
+
+  public DateTimeInterface parse(String str) {
     final DateTimeLexer lexer = new DateTimeLexer(CharStreams.fromString(str));
     final CommonTokenStream tokens = new CommonTokenStream(lexer);
 
@@ -230,9 +253,7 @@ public class DateTimeFactory2 implements DateTimeFactoryInterface {
     final CQLParsingErrorListener el = new CQLParsingErrorListener(DateTimeLexer.UNKNOWN_CHAR);
     parser.addErrorListener(el);
 
-    final DateTimeFactory2 dtf = new DateTimeFactory2();
-
-    parser.datetime(dtf);
+    parser.datetime(this);
 
     if (el.hasErrors()) {
       final StringBuilder sb = new StringBuilder();
@@ -243,7 +264,7 @@ public class DateTimeFactory2 implements DateTimeFactoryInterface {
           "Parsing DateTime finished with errors. \n" + sb.toString());
     }
 
-    return dtf.getDateTime();
+    return getDateTime();
   }
 
   @Override
diff --git a/src/main/java/org/caosdb/server/CaosDBServer.java b/src/main/java/org/caosdb/server/CaosDBServer.java
index b445749d68fafaeac74cc398912769acd6841a8b..fab783b765cb8af3c5ffdd1dda8ab2eb5dd0086b 100644
--- a/src/main/java/org/caosdb/server/CaosDBServer.java
+++ b/src/main/java/org/caosdb/server/CaosDBServer.java
@@ -60,6 +60,8 @@ import org.caosdb.server.entity.EntityInterface;
 import org.caosdb.server.entity.Role;
 import org.caosdb.server.entity.container.Container;
 import org.caosdb.server.grpc.GRPCServer;
+import org.caosdb.server.jobs.core.AccessControl;
+import org.caosdb.server.jobs.core.CheckStateTransition;
 import org.caosdb.server.logging.RequestErrorLogMessage;
 import org.caosdb.server.resource.AuthenticationResource;
 import org.caosdb.server.resource.DefaultResource;
@@ -81,6 +83,7 @@ import org.caosdb.server.resource.Webinterface;
 import org.caosdb.server.resource.WebinterfaceBuildNumber;
 import org.caosdb.server.resource.transaction.EntityNamesResource;
 import org.caosdb.server.resource.transaction.EntityResource;
+import org.caosdb.server.scripting.ScriptingPermissions;
 import org.caosdb.server.transaction.ChecksumUpdater;
 import org.caosdb.server.utils.FileUtils;
 import org.caosdb.server.utils.Initialization;
@@ -280,6 +283,16 @@ public class CaosDBServer extends Application {
     // init Shiro (user authentication/authorization and session management)
     final Ini config = getShiroConfig();
     initShiro(config);
+
+    // Init ACMPermissions.ALL -  the whole point is to fill all these
+    // permissions into ACMPermissions.ALL for retrieval by clients. If we don't
+    // do this, every work, but the list of known permissions grows over time
+    // (as soon as these classes are used for the first time)
+    logger.debug("Register permissions: ", ScriptingPermissions.PERMISSION_EXECUTION("*"));
+    logger.debug("Register permissions: ", CheckStateTransition.STATE_PERMISSIONS.toString());
+    logger.debug(
+        "Register permissions: ", CheckStateTransition.PERMISSION_STATE_FORCE_FINAL.toString());
+    logger.debug("Register permissions: ", AccessControl.TRANSACTION_PERMISSIONS.toString());
   }
 
   public static Ini getShiroConfig() {
diff --git a/src/main/java/org/caosdb/server/accessControl/ACMPermissions.java b/src/main/java/org/caosdb/server/accessControl/ACMPermissions.java
index 84844e892297e68d2ad22cbf5dad935612d1c4f4..854fc07f9ed93eda28e8aca99c1ea1983c73f4fe 100644
--- a/src/main/java/org/caosdb/server/accessControl/ACMPermissions.java
+++ b/src/main/java/org/caosdb/server/accessControl/ACMPermissions.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -17,79 +18,257 @@
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
- *
- * ** end header
  */
 package org.caosdb.server.accessControl;
 
-public class ACMPermissions {
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+public class ACMPermissions implements Comparable<ACMPermissions> {
+
+  private static Logger LOGGER = LoggerFactory.getLogger(ACMPermissions.class);
+  public static final String USER_PARAMETER = "?USER?";
+  public static final String REALM_PARAMETER = "?REALM?";
+  public static final String ROLE_PARAMETER = "?ROLE?";
+  public static Set<ACMPermissions> ALL = new HashSet<>();
+  public static final ACMPermissions GENERIC_ACM_PERMISSION =
+      new ACMPermissions(
+          "ACM:*",
+          "Permissions to administrate the access controll management system. That includes managing users, roles, and assigning permissions to roles and roles to users.");
+
+  protected final String permission;
+  protected final String description;
+
+  public ACMPermissions(String permission, String description) {
+    if (permission == null) {
+      throw new NullPointerException("Permission must no be null");
+    }
+    this.permission = permission;
+    this.description = description;
+    ALL.add(this);
+  }
+
+  @Override
+  public final boolean equals(Object obj) {
+    if (obj instanceof ACMPermissions) {
+      ACMPermissions that = (ACMPermissions) obj;
+      return this.permission.equals(that.permission);
+    }
+    return false;
+  }
+
+  @Override
+  public final int hashCode() {
+    return permission.hashCode();
+  }
+
+  @Override
+  public final String toString() {
+    return this.permission;
+  }
+
+  public final String getDescription() {
+    return description;
+  }
+
+  public static final class UserPermission extends ACMPermissions {
+
+    public static final ACMPermissions GENERIC_USER_PERMISSION =
+        new ACMPermissions(
+            "ACM:USER:*",
+            "Permissions to manage users, i.e. create, retrieve, update and delete users.");
+
+    public UserPermission(String permission, String description) {
+      super(permission, description);
+    }
+
+    public String toString(String realm) {
+      return toString().replace(REALM_PARAMETER, realm);
+    }
+
+    public String toString(String realm, String user) {
+      return toString(realm).replace(USER_PARAMETER, user);
+    }
+  }
+
+  public static final class RolePermission extends ACMPermissions {
+
+    public static final ACMPermissions GENERIC_ROLE_PERMISSION =
+        new ACMPermissions(
+            "ACM:ROLE:*",
+            "Permissions to manage roles, i.e. create, retrieve, update and delete roles and assign them to users.");
+
+    public RolePermission(String permission, String description) {
+      super(permission, description);
+    }
 
-  public static final String PERMISSION_ACCESS_SERVER_PROPERTIES = "ACCESS_SERVER_PROPERTIES";
-  public static final String PERMISSION_RETRIEVE_SERVERLOGS = "SERVERLOGS:RETRIEVE";
+    public String toString(String role) {
+      return toString().replace(ROLE_PARAMETER, role);
+    }
+  }
+
+  public static final String PERMISSION_ACCESS_SERVER_PROPERTIES =
+      new ACMPermissions("ACCESS_SERVER_PROPERTIES", "Permission to read the server properties.")
+          .toString();
+
+  @Deprecated
+  public static final String PERMISSION_RETRIEVE_SERVERLOGS =
+      new ACMPermissions("SERVERLOGS:RETRIEVE", "Permission to read the server logs. (DEPRECATED)")
+          .toString();
+
+  private static UserPermission retrieve_user_roles =
+      new UserPermission(
+          "ACM:USER:RETRIEVE:ROLES:" + REALM_PARAMETER + ":" + USER_PARAMETER,
+          "Permission to retrieve the roles of a user");
 
   public static final String PERMISSION_RETRIEVE_USER_ROLES(
       final String realm, final String username) {
-    return "ACM:USER:RETRIEVE:ROLES:" + realm + ":" + username;
+    return retrieve_user_roles.toString(realm, username);
   }
 
+  private static UserPermission retrieve_user_info =
+      new UserPermission(
+          "ACM:USER:RETRIEVE:INFO:" + REALM_PARAMETER + ":" + USER_PARAMETER,
+          "Permission to retrieve the user info (email, entity, status)");
+
   public static final String PERMISSION_RETRIEVE_USER_INFO(
       final String realm, final String username) {
-    return "ACM:USER:RETRIEVE:INFO:" + realm + ":" + username;
+    return retrieve_user_info.toString(realm, username);
   }
 
+  private static UserPermission delete_user =
+      new UserPermission(
+          "ACM:USER:DELETE:" + REALM_PARAMETER + ":" + USER_PARAMETER,
+          "Permission to delete a user");
+
   public static String PERMISSION_DELETE_USER(final String realm, final String username) {
-    return "ACM:USER:DELETE:" + realm + ":" + username;
+    return delete_user.toString(realm, username);
   }
 
+  private static final UserPermission insert_user =
+      new UserPermission(
+          "ACM:USER:INSERT:" + REALM_PARAMETER, "Permission to create a user in the given realm");
+
   public static String PERMISSION_INSERT_USER(final String realm) {
-    return "ACM:USER:INSERT:" + realm;
+    return insert_user.toString(realm);
   }
 
+  private static final UserPermission update_user_password =
+      new UserPermission(
+          "ACM:USER:UPDATE_PASSWORD:" + REALM_PARAMETER + ":" + USER_PARAMETER,
+          "Permission to set the password of a user.");
+
   public static String PERMISSION_UPDATE_USER_PASSWORD(final String realm, final String username) {
-    return "ACM:USER:UPDATE_PASSWORD:" + realm + ":" + username;
+    return update_user_password.toString(realm, username);
   }
 
+  private static final UserPermission update_user_email =
+      new UserPermission(
+          "ACM:USER:UPDATE:EMAIL:" + REALM_PARAMETER + ":" + USER_PARAMETER,
+          "Permission to update the email address of a user.");
+
   public static String PERMISSION_UPDATE_USER_EMAIL(final String realm, final String username) {
-    return "ACM:USER:UPDATE:EMAIL:" + realm + ":" + username;
+    return update_user_email.toString(realm, username);
   }
 
+  private static final UserPermission update_user_status =
+      new UserPermission(
+          "ACM:USER:UPDATE:STATUS:" + REALM_PARAMETER + ":" + USER_PARAMETER,
+          "Permission to update the status of a user, i.e. marking them as ACTIVE or INACTIVE.");
+
   public static String PERMISSION_UPDATE_USER_STATUS(final String realm, final String username) {
-    return "ACM:USER:UPDATE:STATUS:" + realm + ":" + username;
+    return update_user_status.toString(realm, username);
   }
 
+  private static final UserPermission update_user_entity =
+      new UserPermission(
+          "ACM:USER:UPDATE:ENTITY:" + REALM_PARAMETER + ":" + USER_PARAMETER,
+          "Permission to set the entity which is associated with a user.");
+
   public static String PERMISSION_UPDATE_USER_ENTITY(final String realm, final String username) {
-    return "ACM:USER:UPDATE:ENTITY:" + realm + ":" + username;
+    return update_user_entity.toString(realm, username);
   }
 
+  private static final UserPermission update_user_roles =
+      new UserPermission(
+          "ACM:USER:UPDATE:ROLES:" + REALM_PARAMETER + ":" + USER_PARAMETER,
+          "Permission to change the roles of a user.");
+
   public static String PERMISSION_UPDATE_USER_ROLES(final String realm, final String username) {
-    return "ACM:USER:UPDATE:ROLES:" + realm + ":" + username;
+    return update_user_roles.toString(realm, username);
   }
 
+  private static final RolePermission insert_role =
+      new RolePermission("ACM:ROLE:INSERT", "Permission to create a new role.");
+
   public static String PERMISSION_INSERT_ROLE() {
-    return "ACM:ROLE:INSERT";
+    return insert_role.toString();
   }
 
+  private static final RolePermission update_role_description =
+      new RolePermission(
+          "ACM:ROLE:UPDATE:DESCRIPTION:" + ROLE_PARAMETER,
+          "Permission to update the description of a role.");
+
   public static String PERMISSION_UPDATE_ROLE_DESCRIPTION(final String role) {
-    return "ACM:ROLE:UPDATE:DESCRIPTION:" + role;
+    return update_role_description.toString(role);
   }
 
+  private static final RolePermission retrieve_role_description =
+      new RolePermission(
+          "ACM:ROLE:RETRIEVE:DESCRIPTION:" + ROLE_PARAMETER,
+          "Permission to retrieve the description of a role.");
+
   public static String PERMISSION_RETRIEVE_ROLE_DESCRIPTION(final String role) {
-    return "ACM:ROLE:RETRIEVE:DESCRIPTION:" + role;
+    return retrieve_role_description.toString(role);
   }
 
+  private static final RolePermission delete_role =
+      new RolePermission("ACM:ROLE:DELETE:" + ROLE_PARAMETER, "Permission to delete a role.");
+
   public static String PERMISSION_DELETE_ROLE(final String role) {
-    return "ACM:ROLE:DELETE:" + role;
+    return delete_role.toString(role);
   }
 
+  private static final RolePermission update_role_permissions =
+      new RolePermission(
+          "ACM:ROLE:UPDATE:PERMISSIONS:" + ROLE_PARAMETER,
+          "Permission to set the permissions of a role.");
+
   public static String PERMISSION_UPDATE_ROLE_PERMISSIONS(final String role) {
-    return "ACM:ROLE:UPDATE:PERMISSIONS:" + role;
+    return update_role_permissions.toString(role);
   }
 
+  private static final RolePermission retrieve_role_permissions =
+      new RolePermission(
+          "ACM:ROLE:RETRIEVE:PERMISSIONS:" + ROLE_PARAMETER,
+          "Permission to read the permissions of a role.");
+
   public static String PERMISSION_RETRIEVE_ROLE_PERMISSIONS(final String role) {
-    return "ACM:ROLE:RETRIEVE:PERMISSIONS:" + role;
+    return retrieve_role_permissions.toString(role);
   }
 
+  private static final RolePermission assign_role =
+      new RolePermission(
+          "ACM:ROLE:ASSIGN:" + ROLE_PARAMETER, "Permission to assign a role (to a user).");
+
   public static String PERMISSION_ASSIGN_ROLE(final String role) {
-    return "ACM:ROLE:ASSIGN:" + role;
+    return assign_role.toString(role);
+  }
+
+  @Override
+  public int compareTo(ACMPermissions that) {
+    return this.toString().compareToIgnoreCase(that.toString());
+  }
+
+  public static List<ACMPermissions> getAll() {
+    LinkedList<ACMPermissions> result = new LinkedList<>(ALL);
+    Collections.sort(result);
+    return result;
   }
 }
diff --git a/src/main/java/org/caosdb/server/accessControl/AnonymousRealm.java b/src/main/java/org/caosdb/server/accessControl/AnonymousRealm.java
index 006400bf649619390d5eaa642642a73b6a94f337..92b37c0ec15b110670a55ea46b6efa1a418bb597 100644
--- a/src/main/java/org/caosdb/server/accessControl/AnonymousRealm.java
+++ b/src/main/java/org/caosdb/server/accessControl/AnonymousRealm.java
@@ -27,12 +27,19 @@ import org.apache.shiro.authc.AuthenticationToken;
 import org.apache.shiro.authc.SimpleAuthenticationInfo;
 import org.apache.shiro.authc.credential.AllowAllCredentialsMatcher;
 import org.apache.shiro.realm.AuthenticatingRealm;
+import org.caosdb.server.CaosDBServer;
+import org.caosdb.server.ServerProperties;
 
 public class AnonymousRealm extends AuthenticatingRealm {
 
   @Override
   protected AuthenticationInfo doGetAuthenticationInfo(AuthenticationToken token) {
-    return new SimpleAuthenticationInfo(token.getPrincipal(), null, getName());
+
+    if (CaosDBServer.getServerProperty(ServerProperties.KEY_AUTH_OPTIONAL)
+        .equalsIgnoreCase("true")) {
+      return new SimpleAuthenticationInfo(token.getPrincipal(), null, getName());
+    }
+    return null;
   }
 
   public AnonymousRealm() {
diff --git a/src/main/java/org/caosdb/server/accessControl/AuthenticationUtils.java b/src/main/java/org/caosdb/server/accessControl/AuthenticationUtils.java
index e6907f40b57b5ef44dc9c4772327ddf8920df173..dc40e72e44ffdd6fca21824c6f3dd036f0b6f9ed 100644
--- a/src/main/java/org/caosdb/server/accessControl/AuthenticationUtils.java
+++ b/src/main/java/org/caosdb/server/accessControl/AuthenticationUtils.java
@@ -29,6 +29,7 @@ import static org.caosdb.server.utils.Utils.URLDecodeWithUTF8;
 import java.sql.Timestamp;
 import java.util.Collection;
 import java.util.LinkedList;
+import org.apache.shiro.authz.AuthorizationInfo;
 import org.apache.shiro.subject.Subject;
 import org.caosdb.server.CaosDBServer;
 import org.caosdb.server.ServerProperties;
@@ -199,4 +200,8 @@ public class AuthenticationUtils {
         .getRealm()
         .equals(OneTimeAuthenticationToken.REALM_NAME);
   }
+
+  public static AuthorizationInfo getAuthorizationInfo(Subject user) {
+    return new CaosDBAuthorizingRealm().doGetAuthorizationInfo(user.getPrincipals());
+  }
 }
diff --git a/src/main/java/org/caosdb/server/accessControl/CaosDBAuthorizingRealm.java b/src/main/java/org/caosdb/server/accessControl/CaosDBAuthorizingRealm.java
index e10a0b29b38b2e246bde8c89c43a8b82a9307b7e..52f8d3db87f9748a254f7a6f60fc00100a1bef0e 100644
--- a/src/main/java/org/caosdb/server/accessControl/CaosDBAuthorizingRealm.java
+++ b/src/main/java/org/caosdb/server/accessControl/CaosDBAuthorizingRealm.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,8 +19,8 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.accessControl;
 
 import java.util.Collection;
@@ -63,7 +64,7 @@ public class CaosDBAuthorizingRealm extends AuthorizingRealm {
 
     // Find all roles which are associated with this principal in this realm.
     final Set<String> principalRoles =
-        UserSources.resolve((Principal) principals.getPrimaryPrincipal());
+        UserSources.resolveRoles((Principal) principals.getPrimaryPrincipal());
     if (principalRoles != null) {
       authzInfo.addRoles(principalRoles);
     }
diff --git a/src/main/java/org/caosdb/server/accessControl/CaosDBRolePermissionResolver.java b/src/main/java/org/caosdb/server/accessControl/CaosDBRolePermissionResolver.java
index 17637b010a1ddcd7ed88e3ba448e3fa68b894b43..5bc711e17b60309f851e55bf249a22beeec56d61 100644
--- a/src/main/java/org/caosdb/server/accessControl/CaosDBRolePermissionResolver.java
+++ b/src/main/java/org/caosdb/server/accessControl/CaosDBRolePermissionResolver.java
@@ -49,6 +49,7 @@ public class CaosDBRolePermissionResolver {
         throw new AuthenticationException(e);
       }
     }
+
     return new CaosPermission(rules);
   }
 }
diff --git a/src/main/java/org/caosdb/server/accessControl/Principal.java b/src/main/java/org/caosdb/server/accessControl/Principal.java
index fc96fb99670b51d0a128710722e2c10effed152a..7d4144557d89ddf90ec99edb190abb66ec0119aa 100644
--- a/src/main/java/org/caosdb/server/accessControl/Principal.java
+++ b/src/main/java/org/caosdb/server/accessControl/Principal.java
@@ -88,6 +88,6 @@ public class Principal implements ResponsibleAgent {
 
   @Override
   public String toString() {
-    return "[[" + this.realm + "]]" + this.username;
+    return this.username + REALM_SEPARATOR + this.realm;
   }
 }
diff --git a/src/main/java/org/caosdb/server/accessControl/Role.java b/src/main/java/org/caosdb/server/accessControl/Role.java
index 1a34b49974804ae202ceaf4044ff1f620eaa5d12..d1b04918e76ecbe6c94db8b00c6bb50f1c9a351c 100644
--- a/src/main/java/org/caosdb/server/accessControl/Role.java
+++ b/src/main/java/org/caosdb/server/accessControl/Role.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,18 +19,23 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.accessControl;
 
 import java.io.Serializable;
+import java.util.LinkedList;
+import org.caosdb.server.database.proto.ProtoUser;
+import org.caosdb.server.permissions.PermissionRule;
 import org.jdom2.Element;
 
 public class Role implements Serializable {
 
-  private static final long serialVersionUID = 8968219504349206982L;
+  private static final long serialVersionUID = -243913823L;
   public String name = null;
   public String description = null;
+  public LinkedList<PermissionRule> permission_rules = null;
+  public LinkedList<ProtoUser> users = null;
 
   public Element toElement() {
     final Element ret = new Element("Role");
diff --git a/src/main/java/org/caosdb/server/accessControl/SessionTokenRealm.java b/src/main/java/org/caosdb/server/accessControl/SessionTokenRealm.java
index d78ffb405a8470a005da54736e25fbd69340b7e5..270565be3dd8fc25408a1d7992638ef24bcfaa1c 100644
--- a/src/main/java/org/caosdb/server/accessControl/SessionTokenRealm.java
+++ b/src/main/java/org/caosdb/server/accessControl/SessionTokenRealm.java
@@ -36,7 +36,7 @@ public class SessionTokenRealm extends AuthenticatingRealm {
     final SelfValidatingAuthenticationToken sessionToken =
         (SelfValidatingAuthenticationToken) token;
 
-    if (sessionToken.isValid()) {
+    if (sessionToken.isValid() && UserSources.isActive(sessionToken)) {
       return new SimpleAuthenticationInfo(sessionToken, null, getName());
     }
     return null;
diff --git a/src/main/java/org/caosdb/server/accessControl/SinglePermissionSubject.java b/src/main/java/org/caosdb/server/accessControl/SinglePermissionSubject.java
new file mode 100644
index 0000000000000000000000000000000000000000..2c3a3479420c5f0642e0d42bf53b717ab0219571
--- /dev/null
+++ b/src/main/java/org/caosdb/server/accessControl/SinglePermissionSubject.java
@@ -0,0 +1,210 @@
+package org.caosdb.server.accessControl;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.List;
+import java.util.concurrent.Callable;
+import org.apache.shiro.authc.AuthenticationException;
+import org.apache.shiro.authc.AuthenticationToken;
+import org.apache.shiro.authz.AuthorizationException;
+import org.apache.shiro.authz.Permission;
+import org.apache.shiro.authz.permission.WildcardPermission;
+import org.apache.shiro.session.Session;
+import org.apache.shiro.subject.ExecutionException;
+import org.apache.shiro.subject.PrincipalCollection;
+import org.apache.shiro.subject.Subject;
+
+public class SinglePermissionSubject implements Subject {
+
+  private WildcardPermission permission;
+
+  public SinglePermissionSubject(String permission) {
+    this.permission = new WildcardPermission(permission);
+  }
+
+  @Override
+  public Object getPrincipal() {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public PrincipalCollection getPrincipals() {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public boolean isPermitted(String permission) {
+    return this.permission.implies(new WildcardPermission(permission));
+  }
+
+  @Override
+  public boolean isPermitted(Permission permission) {
+    return this.permission.implies(permission);
+  }
+
+  @Override
+  public boolean[] isPermitted(String... permissions) {
+    boolean[] result = new boolean[permissions.length];
+    for (int i = 0; i < result.length; i++) {
+      result[i] = this.permission.implies(new WildcardPermission(permissions[i]));
+    }
+    return result;
+  }
+
+  @Override
+  public boolean[] isPermitted(List<Permission> permissions) {
+    boolean[] result = new boolean[permissions.size()];
+    for (int i = 0; i < result.length; i++) {
+      result[i] = this.permission.implies(permissions.get(i));
+    }
+    return result;
+  }
+
+  @Override
+  public boolean isPermittedAll(String... permissions) {
+    boolean result = true;
+    for (int i = 0; i < permissions.length; i++) {
+      result &= this.permission.implies(new WildcardPermission(permissions[i]));
+    }
+    return result;
+  }
+
+  @Override
+  public boolean isPermittedAll(Collection<Permission> permissions) {
+    Boolean result = true;
+    Iterator<Permission> iterator = permissions.iterator();
+    while (iterator.hasNext()) {
+      result &= this.permission.implies(iterator.next());
+    }
+    return result;
+  }
+
+  @Override
+  public void checkPermission(String permission) throws AuthorizationException {
+    if (!isPermitted(permission)) {
+      throw new AuthenticationException("Not permitted: " + permission);
+    }
+  }
+
+  @Override
+  public void checkPermission(Permission permission) throws AuthorizationException {
+    if (!isPermitted(permission)) {
+      throw new AuthenticationException("Not permitted: " + permission.toString());
+    }
+  }
+
+  @Override
+  public void checkPermissions(String... permissions) throws AuthorizationException {
+    if (!isPermittedAll(permissions)) {
+      throw new AuthenticationException("Not permitted: " + permissions.toString());
+    }
+  }
+
+  @Override
+  public void checkPermissions(Collection<Permission> permissions) throws AuthorizationException {
+    if (!isPermittedAll(permissions)) {
+      throw new AuthenticationException("Not permitted: " + permissions.toString());
+    }
+  }
+
+  @Override
+  public boolean hasRole(String roleIdentifier) {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public boolean[] hasRoles(List<String> roleIdentifiers) {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public boolean hasAllRoles(Collection<String> roleIdentifiers) {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public void checkRole(String roleIdentifier) throws AuthorizationException {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public void checkRoles(Collection<String> roleIdentifiers) throws AuthorizationException {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public void checkRoles(String... roleIdentifiers) throws AuthorizationException {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public void login(AuthenticationToken token) throws AuthenticationException {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public boolean isAuthenticated() {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public boolean isRemembered() {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public Session getSession() {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public Session getSession(boolean create) {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public void logout() {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public <V> V execute(Callable<V> callable) throws ExecutionException {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public void execute(Runnable runnable) {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public <V> Callable<V> associateWith(Callable<V> callable) {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public Runnable associateWith(Runnable runnable) {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public void runAs(PrincipalCollection principals)
+      throws NullPointerException, IllegalStateException {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public boolean isRunAs() {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public PrincipalCollection getPreviousPrincipals() {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+
+  @Override
+  public PrincipalCollection releaseRunAs() {
+    throw new UnsupportedOperationException("This method should never be called");
+  }
+}
diff --git a/src/main/java/org/caosdb/server/accessControl/UserSources.java b/src/main/java/org/caosdb/server/accessControl/UserSources.java
index a7abd1405f3d566bb672befc86b853dcf2a17357..04c2ecab9fee23c62b042657c69911e2d69846a0 100644
--- a/src/main/java/org/caosdb/server/accessControl/UserSources.java
+++ b/src/main/java/org/caosdb/server/accessControl/UserSources.java
@@ -1,11 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
- * Copyright (C) 2020 Indiscale GmbH <info@indiscale.com>
- * Copyright (C) 2020 Timm Fitschen <t.fitschen@indiscale.com>
+ * Copyright (C) 2020-2021 Indiscale GmbH <info@indiscale.com>
+ * Copyright (C) 2020-2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -20,22 +19,26 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.accessControl;
 
 import java.io.FileInputStream;
 import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.Set;
 import org.apache.shiro.authc.AuthenticationException;
+import org.apache.shiro.authz.AuthorizationException;
 import org.apache.shiro.config.Ini;
+import org.apache.shiro.subject.Subject;
 import org.caosdb.server.CaosDBServer;
 import org.caosdb.server.ServerProperties;
 import org.caosdb.server.entity.Message;
 import org.caosdb.server.permissions.Role;
+import org.caosdb.server.transaction.LogUserVisitTransaction;
 import org.caosdb.server.transaction.RetrieveRoleTransaction;
 import org.caosdb.server.transaction.RetrieveUserTransaction;
 import org.caosdb.server.utils.ServerMessages;
@@ -69,6 +72,8 @@ import org.slf4j.LoggerFactory;
  */
 public class UserSources extends HashMap<String, UserSource> {
 
+  public static final String USERNAME_PASSWORD_AUTHENTICATION = "USERNAME_PASSWORD_AUTHENTICATION";
+  private static final Subject transactor = new SinglePermissionSubject("ACM:*:RETRIEVE:*");
   private static final Logger logger = LoggerFactory.getLogger(UserSources.class);
   public static final String KEY_DEFAULT_REALM = "defaultRealm";
   public static final String KEY_REALMS = "realms";
@@ -86,6 +91,14 @@ public class UserSources extends HashMap<String, UserSource> {
    * @return true iff the user identified by the given {@link Principal} exists.
    */
   public static boolean isUserExisting(final Principal principal) {
+    if (principal.getRealm().equals(OneTimeAuthenticationToken.REALM_NAME)) {
+      return true;
+    }
+    if (principal.toString().equals(AnonymousAuthenticationToken.PRINCIPAL.toString())
+        && CaosDBServer.getServerProperty(ServerProperties.KEY_AUTH_OPTIONAL)
+            .equalsIgnoreCase("true")) {
+      return true;
+    }
     UserSource userSource = instance.get(principal.getRealm());
     if (userSource != null) {
       return userSource.isUserExisting(principal.getUsername());
@@ -164,18 +177,23 @@ public class UserSources extends HashMap<String, UserSource> {
    * @return A set of user roles.
    */
   public static Set<String> resolveRoles(String realm, final String username) {
+    if (AnonymousAuthenticationToken.PRINCIPAL.getRealm().equals(realm)
+        && AnonymousAuthenticationToken.PRINCIPAL.getUsername().equals(username)) {
+      return Collections.singleton(Role.ANONYMOUS_ROLE.toString());
+    }
     if (realm == null) {
       realm = guessRealm(username);
     }
 
-    UserSource userSource = instance.get(realm);
-    if (userSource == null) {
-      return null;
+    RetrieveUserTransaction t = new RetrieveUserTransaction(realm, username, transactor);
+    try {
+      t.execute();
+      if (t.getUser() != null) return t.getRoles();
+    } catch (Exception e) {
+      throw new AuthorizationException("Could not resolve roles for " + username + "@" + realm);
     }
-    // find all roles that are associated with this principal in this realm
-    final Set<String> ret = userSource.resolveRolesForUsername(username);
 
-    return ret;
+    return null;
   }
 
   public static String guessRealm(final String username) {
@@ -206,20 +224,28 @@ public class UserSources extends HashMap<String, UserSource> {
     return instance.map.getSectionProperty(Ini.DEFAULT_SECTION_NAME, KEY_DEFAULT_REALM, "CaosDB");
   }
 
-  // @todo Refactor name: resolveRoles(...)?
-  public static Set<String> resolve(final Principal principal) {
+  /**
+   * Return the roles of a given user.
+   *
+   * @param principal
+   * @return A set of role names.
+   */
+  public static Set<String> resolveRoles(final Principal principal) {
     if (AnonymousAuthenticationToken.PRINCIPAL == principal) {
       // anymous has one role
       Set<String> roles = new HashSet<>();
       roles.add(Role.ANONYMOUS_ROLE.toString());
       return roles;
     }
+    if (principal instanceof OneTimeAuthenticationToken) {
+      return new HashSet<>(((OneTimeAuthenticationToken) principal).getRoles());
+    }
 
     return resolveRoles(principal.getRealm(), principal.getUsername());
   }
 
   public static boolean isRoleExisting(final String role) {
-    final RetrieveRoleTransaction t = new RetrieveRoleTransaction(role);
+    final RetrieveRoleTransaction t = new RetrieveRoleTransaction(role, transactor);
     try {
       t.execute();
       return true;
@@ -233,12 +259,20 @@ public class UserSources extends HashMap<String, UserSource> {
     }
   }
 
+  public static UserStatus getDefaultUserStatus(final String realm, String username) {
+    return instance.get(realm).getDefaultUserStatus(username);
+  }
+
   public static UserStatus getDefaultUserStatus(final Principal p) {
-    return instance.get(p.getRealm()).getDefaultUserStatus(p.getUsername());
+    return getDefaultUserStatus(p.getRealm(), p.getUsername());
   }
 
   public static String getDefaultUserEmail(final Principal p) {
-    return instance.get(p.getRealm()).getDefaultUserEmail(p.getUsername());
+    return getDefaultUserEmail(p.getRealm(), p.getUsername());
+  }
+
+  public static String getDefaultUserEmail(String realm, String username) {
+    return instance.get(realm).getDefaultUserEmail(username);
   }
 
   public static UserSource getInternalRealm() {
@@ -251,16 +285,60 @@ public class UserSources extends HashMap<String, UserSource> {
     }
 
     final boolean isValid = instance.get(realm).isValid(username, password);
-    return isValid && isActive(realm, username);
+
+    if (isValid && isActive(realm, username)) {
+      logUserVisit(realm, username, USERNAME_PASSWORD_AUTHENTICATION);
+      return true;
+    }
+    return false;
+  }
+
+  /** Log the current time as the user's last visit. */
+  public static void logUserVisit(String realm, String username, String type) {
+    try {
+      LogUserVisitTransaction t =
+          new LogUserVisitTransaction(System.currentTimeMillis(), realm, username, type);
+      t.execute();
+    } catch (final Exception e) {
+      throw new AuthenticationException(e);
+    }
   }
 
   private static boolean isActive(final String realm, final String username) {
-    final RetrieveUserTransaction t = new RetrieveUserTransaction(realm, username);
+    final RetrieveUserTransaction t = new RetrieveUserTransaction(realm, username, transactor);
     try {
       t.execute();
-      return t.isActive();
+      if (t.getUser() != null) {
+        return t.getUser().status == UserStatus.ACTIVE;
+      } else {
+        return instance.get(realm).getDefaultUserStatus(username) == UserStatus.ACTIVE;
+      }
     } catch (final Exception e) {
       throw new AuthenticationException(e);
     }
   }
+
+  public static boolean isActive(Principal principal) {
+    if (principal.getRealm().equals(OneTimeAuthenticationToken.REALM_NAME)) {
+      return true;
+    }
+    if (principal.getUsername().equals(AnonymousAuthenticationToken.PRINCIPAL.getUsername())
+        && principal.getRealm().equals(AnonymousAuthenticationToken.PRINCIPAL.getRealm())
+        && CaosDBServer.getServerProperty(ServerProperties.KEY_AUTH_OPTIONAL)
+            .equalsIgnoreCase("true")) {
+      return true;
+    }
+    return isActive(principal.getRealm(), principal.getUsername());
+  }
+
+  public static Set<String> getDefaultRoles(String realm, String username) {
+    UserSource userSource = instance.get(realm);
+    if (userSource == null) {
+      return null;
+    }
+    // find all roles that are associated with this principal in this realm
+    final Set<String> ret = userSource.resolveRolesForUsername(username);
+
+    return ret;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/database/BackendTransaction.java b/src/main/java/org/caosdb/server/database/BackendTransaction.java
index 7c26db1ed05e76c30f9d30f0c3d9965ed0c59b6b..5addf3f3f3e34a8e3e6a9152b9511046fe4b6a23 100644
--- a/src/main/java/org/caosdb/server/database/BackendTransaction.java
+++ b/src/main/java/org/caosdb/server/database/BackendTransaction.java
@@ -44,10 +44,14 @@ import org.caosdb.server.database.backend.implementation.MySQL.MySQLInsertRole;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLInsertSparseEntity;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLInsertTransactionHistory;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLIsSubType;
+import org.caosdb.server.database.backend.implementation.MySQL.MySQLListRoles;
+import org.caosdb.server.database.backend.implementation.MySQL.MySQLListUsers;
+import org.caosdb.server.database.backend.implementation.MySQL.MySQLLogUserVisit;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLRegisterSubDomain;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLRetrieveAll;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLRetrieveAllUncheckedFiles;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLRetrieveDatatypes;
+import org.caosdb.server.database.backend.implementation.MySQL.MySQLRetrieveEntityACL;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLRetrieveLogRecord;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLRetrieveParents;
 import org.caosdb.server.database.backend.implementation.MySQL.MySQLRetrievePasswordValidator;
@@ -99,10 +103,14 @@ import org.caosdb.server.database.backend.interfaces.InsertRoleImpl;
 import org.caosdb.server.database.backend.interfaces.InsertSparseEntityImpl;
 import org.caosdb.server.database.backend.interfaces.InsertTransactionHistoryImpl;
 import org.caosdb.server.database.backend.interfaces.IsSubTypeImpl;
+import org.caosdb.server.database.backend.interfaces.ListRolesImpl;
+import org.caosdb.server.database.backend.interfaces.ListUsersImpl;
+import org.caosdb.server.database.backend.interfaces.LogUserVisitImpl;
 import org.caosdb.server.database.backend.interfaces.RegisterSubDomainImpl;
 import org.caosdb.server.database.backend.interfaces.RetrieveAllImpl;
 import org.caosdb.server.database.backend.interfaces.RetrieveAllUncheckedFilesImpl;
 import org.caosdb.server.database.backend.interfaces.RetrieveDatatypesImpl;
+import org.caosdb.server.database.backend.interfaces.RetrieveEntityACLImpl;
 import org.caosdb.server.database.backend.interfaces.RetrieveLogRecordImpl;
 import org.caosdb.server.database.backend.interfaces.RetrieveParentsImpl;
 import org.caosdb.server.database.backend.interfaces.RetrievePasswordValidatorImpl;
@@ -192,6 +200,7 @@ public abstract class BackendTransaction implements Undoable {
       setImpl(FileCheckSize.class, UnixFileSystemCheckSize.class);
       setImpl(InsertRoleImpl.class, MySQLInsertRole.class);
       setImpl(RetrieveRoleImpl.class, MySQLRetrieveRole.class);
+      setImpl(ListRolesImpl.class, MySQLListRoles.class);
       setImpl(DeleteRoleImpl.class, MySQLDeleteRole.class);
       setImpl(SetPermissionRulesImpl.class, MySQLSetPermissionRules.class);
       setImpl(RetrievePermissionRulesImpl.class, MySQLRetrievePermissionRules.class);
@@ -204,6 +213,9 @@ public abstract class BackendTransaction implements Undoable {
       setImpl(InsertEntityDatatypeImpl.class, MySQLInsertEntityDatatype.class);
       setImpl(RetrieveVersionHistoryImpl.class, MySQLRetrieveVersionHistory.class);
       setImpl(SetFileChecksumImpl.class, MySQLSetFileChecksum.class);
+      setImpl(ListUsersImpl.class, MySQLListUsers.class);
+      setImpl(LogUserVisitImpl.class, MySQLLogUserVisit.class);
+      setImpl(RetrieveEntityACLImpl.class, MySQLRetrieveEntityACL.class);
     }
   }
 
diff --git a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLDeleteRole.java b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLDeleteRole.java
index 8fd8d35fda6b99f7d79b245a10ace4ed9521e0ce..b0faa45f96e04e6957ff1d288d034ca9e96cb6d7 100644
--- a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLDeleteRole.java
+++ b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLDeleteRole.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,15 +19,17 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.database.backend.implementation.MySQL;
 
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
+import java.sql.SQLIntegrityConstraintViolationException;
 import org.caosdb.server.database.access.Access;
 import org.caosdb.server.database.backend.interfaces.DeleteRoleImpl;
 import org.caosdb.server.database.exceptions.TransactionException;
+import org.caosdb.server.utils.ServerMessages;
 
 public class MySQLDeleteRole extends MySQLTransaction implements DeleteRoleImpl {
 
@@ -42,6 +45,8 @@ public class MySQLDeleteRole extends MySQLTransaction implements DeleteRoleImpl
       final PreparedStatement stmt = prepareStatement(STMT_DELETE_ROLE);
       stmt.setString(1, role);
       stmt.execute();
+    } catch (final SQLIntegrityConstraintViolationException e) {
+      throw new TransactionException(ServerMessages.ROLE_CANNOT_BE_DELETED);
     } catch (final SQLException e) {
       throw new TransactionException(e);
     } catch (final ConnectionException e) {
diff --git a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLHelper.java b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLHelper.java
index b1f445e2b8ad2d79b756e1dd662296d8e6c9a49c..568e0e53a7b80a76c533229e13c6700c4c4ff47f 100644
--- a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLHelper.java
+++ b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLHelper.java
@@ -35,7 +35,7 @@ import org.caosdb.server.accessControl.Principal;
 import org.caosdb.server.database.misc.DBHelper;
 import org.caosdb.server.transaction.ChecksumUpdater;
 import org.caosdb.server.transaction.TransactionInterface;
-import org.caosdb.server.transaction.WriteTransaction;
+import org.caosdb.server.transaction.WriteTransactionInterface;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -55,7 +55,7 @@ public class MySQLHelper implements DBHelper {
    *
    * <p>In the database, this adds a row to the transaction table with SRID, user and timestamp.
    */
-  public void initTransaction(Connection connection, WriteTransaction transaction)
+  public void initTransaction(Connection connection, WriteTransactionInterface transaction)
       throws SQLException {
     try (CallableStatement call = connection.prepareCall("CALL set_transaction(?,?,?,?,?)")) {
 
@@ -86,10 +86,10 @@ public class MySQLHelper implements DBHelper {
     if (transaction instanceof ChecksumUpdater) {
       connection.setReadOnly(false);
       connection.setAutoCommit(false);
-    } else if (transaction instanceof WriteTransaction) {
+    } else if (transaction instanceof WriteTransactionInterface) {
       connection.setReadOnly(false);
       connection.setAutoCommit(false);
-      initTransaction(connection, (WriteTransaction) transaction);
+      initTransaction(connection, (WriteTransactionInterface) transaction);
     } else {
       connection.setReadOnly(false);
       connection.setAutoCommit(true);
diff --git a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListRoles.java b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListRoles.java
new file mode 100644
index 0000000000000000000000000000000000000000..69ac524eae823d06fdbd4346056979ea15307437
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListRoles.java
@@ -0,0 +1,65 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.implementation.MySQL;
+
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.LinkedList;
+import java.util.List;
+import org.caosdb.server.accessControl.Role;
+import org.caosdb.server.database.access.Access;
+import org.caosdb.server.database.backend.interfaces.ListRolesImpl;
+import org.caosdb.server.database.exceptions.TransactionException;
+
+public class MySQLListRoles extends MySQLTransaction implements ListRolesImpl {
+
+  public MySQLListRoles(Access access) {
+    super(access);
+  }
+
+  public static final String STMT_LIST_ROLES = "SELECT name, description FROM roles";
+
+  @Override
+  public List<Role> execute() {
+    List<Role> roles = new LinkedList<>();
+    try {
+      final PreparedStatement stmt = prepareStatement(STMT_LIST_ROLES);
+      final ResultSet rs = stmt.executeQuery();
+      try {
+        while (rs.next()) {
+          final Role role = new Role();
+          role.name = rs.getString("name");
+          role.description = rs.getString("description");
+          roles.add(role);
+        }
+      } finally {
+        rs.close();
+      }
+    } catch (final SQLException e) {
+      throw new TransactionException(e);
+    } catch (final ConnectionException e) {
+      throw new TransactionException(e);
+    }
+    return roles;
+  }
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListUsers.java b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListUsers.java
new file mode 100644
index 0000000000000000000000000000000000000000..83ebffe679e6625da720fd2933a5d8defb7264c3
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLListUsers.java
@@ -0,0 +1,73 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.implementation.MySQL;
+
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import java.util.LinkedList;
+import java.util.List;
+import org.caosdb.server.accessControl.UserStatus;
+import org.caosdb.server.database.access.Access;
+import org.caosdb.server.database.backend.interfaces.ListUsersImpl;
+import org.caosdb.server.database.exceptions.TransactionException;
+import org.caosdb.server.database.proto.ProtoUser;
+
+public class MySQLListUsers extends MySQLTransaction implements ListUsersImpl {
+
+  public MySQLListUsers(Access access) {
+    super(access);
+  }
+
+  public static final String STMT_LIST_USERS =
+      "SELECT status, realm, name, email, entity FROM user_info";
+
+  @Override
+  public List<ProtoUser> execute() {
+    List<ProtoUser> users = new LinkedList<>();
+    try {
+      final PreparedStatement stmt = prepareStatement(STMT_LIST_USERS);
+      final ResultSet rs = stmt.executeQuery();
+      try {
+        while (rs.next()) {
+          final ProtoUser user = new ProtoUser();
+          user.name = rs.getString("name");
+          user.realm = rs.getString("realm");
+          user.email = rs.getString("email");
+          user.entity = rs.getInt("entity");
+          if (user.entity == 0) {
+            user.entity = null;
+          }
+          user.status = UserStatus.valueOf(rs.getString("status"));
+          users.add(user);
+        }
+      } finally {
+        rs.close();
+      }
+    } catch (final SQLException e) {
+      throw new TransactionException(e);
+    } catch (final ConnectionException e) {
+      throw new TransactionException(e);
+    }
+    return users;
+  }
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLLogUserVisit.java b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLLogUserVisit.java
new file mode 100644
index 0000000000000000000000000000000000000000..23050da87e324026be1eefa02690959d0a0590cc
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLLogUserVisit.java
@@ -0,0 +1,59 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.implementation.MySQL;
+
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import org.caosdb.server.database.access.Access;
+import org.caosdb.server.database.backend.interfaces.LogUserVisitImpl;
+import org.caosdb.server.database.exceptions.TransactionException;
+
+public class MySQLLogUserVisit extends MySQLTransaction implements LogUserVisitImpl {
+
+  public MySQLLogUserVisit(Access access) {
+    super(access);
+  }
+
+  public static final String LOG_USER_VISIT =
+      "SELECT status FROM user_info WHERE realm = ? AND name = ?";
+  // TODO Replace by "UPDATE user_info SET last_seen = ?";
+
+  /** Return true if this is not the first visit of this user. */
+  @Override
+  public boolean logUserReturnIsKnown(long timestamp, String realm, String username, String type) {
+    try (final PreparedStatement stmt = prepareStatement(LOG_USER_VISIT)) {
+      stmt.setString(1, realm);
+      stmt.setString(2, username);
+      ResultSet executeQuery = stmt.executeQuery();
+      if (!executeQuery.next()) {
+        // first login of this user
+        return false;
+      }
+    } catch (final SQLException e) {
+      throw new TransactionException(e);
+    } catch (final ConnectionException e) {
+      throw new TransactionException(e);
+    }
+    return true;
+  }
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLRetrieveEntityACL.java b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLRetrieveEntityACL.java
new file mode 100644
index 0000000000000000000000000000000000000000..5db8ed7597b1c0d357273848fb7c36febdcfed13
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLRetrieveEntityACL.java
@@ -0,0 +1,57 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.implementation.MySQL;
+
+import java.sql.PreparedStatement;
+import java.sql.ResultSet;
+import java.sql.SQLException;
+import org.caosdb.server.database.access.Access;
+import org.caosdb.server.database.backend.interfaces.RetrieveEntityACLImpl;
+import org.caosdb.server.database.exceptions.TransactionException;
+import org.caosdb.server.database.proto.VerySparseEntity;
+
+public class MySQLRetrieveEntityACL extends MySQLTransaction implements RetrieveEntityACLImpl {
+
+  public MySQLRetrieveEntityACL(Access access) {
+    super(access);
+  }
+
+  public static final String STMT =
+      "SELECT a.acl FROM entities AS e LEFT JOIN entity_acl AS a ON (a.id = e.acl) WHERE e.id = ? LIMIT 1";
+
+  @Override
+  public VerySparseEntity execute(Integer id) {
+    try (PreparedStatement stmt = prepareStatement(STMT)) {
+      stmt.setInt(1, id);
+      ResultSet rs = stmt.executeQuery();
+      if (rs.next()) {
+        VerySparseEntity result = new VerySparseEntity();
+        result.id = id;
+        result.acl = rs.getString(1);
+        return result;
+      }
+    } catch (SQLException | ConnectionException e) {
+      throw new TransactionException(e);
+    }
+    return null;
+  }
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLRetrieveRole.java b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLRetrieveRole.java
index f0219040c47bc09fe2052d8e95a3ea83637e6aae..e9ee37c9a55bc07c79abc8b73d8f9bef2a5cde8c 100644
--- a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLRetrieveRole.java
+++ b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLRetrieveRole.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,17 +19,22 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.database.backend.implementation.MySQL;
 
 import java.sql.PreparedStatement;
 import java.sql.ResultSet;
 import java.sql.SQLException;
+import java.util.LinkedList;
+import java.util.Map;
 import org.caosdb.server.accessControl.Role;
 import org.caosdb.server.database.access.Access;
 import org.caosdb.server.database.backend.interfaces.RetrieveRoleImpl;
 import org.caosdb.server.database.exceptions.TransactionException;
+import org.caosdb.server.database.proto.ProtoUser;
+import org.caosdb.server.permissions.PermissionRule;
+import org.eclipse.jetty.util.ajax.JSON;
 
 public class MySQLRetrieveRole extends MySQLTransaction implements RetrieveRoleImpl {
 
@@ -36,30 +42,66 @@ public class MySQLRetrieveRole extends MySQLTransaction implements RetrieveRoleI
     super(access);
   }
 
-  public static final String STMT_RETRIEVE_ROLE = "SELECT description FROM roles WHERE name=?";
+  public static final String STMT_RETRIEVE_ROLE =
+      "SELECT r.description AS description, p.permissions AS permissions FROM roles AS r LEFT JOIN permissions AS p ON (r.name = p.role) WHERE r.name=?";
+  public static final String STMT_RETRIEVE_USERS =
+      "SELECT u.realm, u.user FROM user_roles AS u WHERE u.role = ?";
 
   @Override
   public Role retrieve(final String role) throws TransactionException {
-    try {
-      final PreparedStatement stmt = prepareStatement(STMT_RETRIEVE_ROLE);
+    Role ret = null;
+    try (final PreparedStatement stmt = prepareStatement(STMT_RETRIEVE_ROLE)) {
       stmt.setString(1, role);
       final ResultSet rs = stmt.executeQuery();
-      try {
-        if (rs.next()) {
-          final Role ret = new Role();
-          ret.name = role;
-          ret.description = rs.getString("description");
-          return ret;
-        } else {
-          return null;
+      if (rs.next()) {
+        ret = new Role();
+        ret.name = role;
+        ret.description = rs.getString("description");
+        ret.permission_rules = parse(rs.getString("permissions"));
+      } else {
+        return null;
+      }
+    } catch (final SQLException e) {
+      throw new TransactionException(e);
+    } catch (final ConnectionException e) {
+      throw new TransactionException(e);
+    }
+
+    try (final PreparedStatement stmt = prepareStatement(STMT_RETRIEVE_USERS)) {
+      stmt.setString(1, role);
+      final ResultSet rs = stmt.executeQuery();
+      if (rs.next()) {
+        ret.users = new LinkedList<>();
+
+        ret.users.add(nextUser(rs));
+        while (rs.next()) {
+          ret.users.add(nextUser(rs));
         }
-      } finally {
-        rs.close();
       }
     } catch (final SQLException e) {
       throw new TransactionException(e);
     } catch (final ConnectionException e) {
       throw new TransactionException(e);
     }
+    return ret;
+  }
+
+  private ProtoUser nextUser(ResultSet rs) throws SQLException {
+    ProtoUser nextUser = new ProtoUser();
+    nextUser.realm = rs.getString("realm");
+    nextUser.name = rs.getString("user");
+    return nextUser;
+  }
+
+  @SuppressWarnings("unchecked")
+  private LinkedList<PermissionRule> parse(String string) {
+    if (string == null) return null;
+    final Object[] maps = (Object[]) JSON.parse(string);
+    final LinkedList<PermissionRule> ret = new LinkedList<>();
+    for (final Object map : maps) {
+      ret.add(PermissionRule.parse((Map<String, String>) map));
+    }
+
+    return ret;
   }
 }
diff --git a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLUpdateUserRoles.java b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLUpdateUserRoles.java
index 62cb68bf58fc8269cc365fa167929ff79726499b..6a52ab9d0e7d606d5f92038239be0ccacd03bda6 100644
--- a/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLUpdateUserRoles.java
+++ b/src/main/java/org/caosdb/server/database/backend/implementation/MySQL/MySQLUpdateUserRoles.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,13 +19,12 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
 package org.caosdb.server.database.backend.implementation.MySQL;
 
 import java.sql.PreparedStatement;
 import java.sql.SQLException;
-import java.util.HashSet;
+import java.util.Set;
 import org.caosdb.server.database.access.Access;
 import org.caosdb.server.database.backend.interfaces.UpdateUserRolesImpl;
 import org.caosdb.server.database.exceptions.TransactionException;
@@ -41,7 +41,7 @@ public class MySQLUpdateUserRoles extends MySQLTransaction implements UpdateUser
       "INSERT INTO user_roles (realm, user, role) VALUES (?,?,?);";
 
   @Override
-  public void updateUserRoles(final String realm, final String user, final HashSet<String> roles)
+  public void updateUserRoles(final String realm, final String user, final Set<String> roles)
       throws TransactionException {
     try {
       final PreparedStatement delete_stmt = prepareStatement(STMT_DELETE_USER_ROLES);
diff --git a/src/main/java/org/caosdb/server/database/backend/interfaces/ListRolesImpl.java b/src/main/java/org/caosdb/server/database/backend/interfaces/ListRolesImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..aab9041ae0f4e02d4b601e97d042dff591fbbf85
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/interfaces/ListRolesImpl.java
@@ -0,0 +1,30 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.interfaces;
+
+import java.util.List;
+import org.caosdb.server.accessControl.Role;
+
+public interface ListRolesImpl extends BackendTransactionImpl {
+
+  public List<Role> execute();
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/interfaces/ListUsersImpl.java b/src/main/java/org/caosdb/server/database/backend/interfaces/ListUsersImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..6bdfda92f2b5a78b8b2dfc8b6f20aac3b68c08a9
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/interfaces/ListUsersImpl.java
@@ -0,0 +1,30 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.interfaces;
+
+import java.util.List;
+import org.caosdb.server.database.proto.ProtoUser;
+
+public interface ListUsersImpl extends BackendTransactionImpl {
+
+  List<ProtoUser> execute();
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/interfaces/LogUserVisitImpl.java b/src/main/java/org/caosdb/server/database/backend/interfaces/LogUserVisitImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..38c253e2e76075c83a7874d581f8b97d25a382f5
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/interfaces/LogUserVisitImpl.java
@@ -0,0 +1,26 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package org.caosdb.server.database.backend.interfaces;
+
+public interface LogUserVisitImpl extends BackendTransactionImpl {
+
+  /** Return true if this is not the first visit of this user. */
+  boolean logUserReturnIsKnown(long timestamp, String realm, String username, String type);
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/interfaces/RetrieveEntityACLImpl.java b/src/main/java/org/caosdb/server/database/backend/interfaces/RetrieveEntityACLImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..230d4d34103603d5499532a7dc1a941cf82068e7
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/interfaces/RetrieveEntityACLImpl.java
@@ -0,0 +1,29 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.interfaces;
+
+import org.caosdb.server.database.proto.VerySparseEntity;
+
+public interface RetrieveEntityACLImpl extends BackendTransactionImpl {
+
+  public VerySparseEntity execute(Integer id);
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/interfaces/UpdateUserRolesImpl.java b/src/main/java/org/caosdb/server/database/backend/interfaces/UpdateUserRolesImpl.java
index f2abfbe3cb7846f16e21d8f9a719ad708884841c..891df301e992f42c38f7c52d867353a65cddd1b2 100644
--- a/src/main/java/org/caosdb/server/database/backend/interfaces/UpdateUserRolesImpl.java
+++ b/src/main/java/org/caosdb/server/database/backend/interfaces/UpdateUserRolesImpl.java
@@ -22,11 +22,11 @@
  */
 package org.caosdb.server.database.backend.interfaces;
 
-import java.util.HashSet;
+import java.util.Set;
 import org.caosdb.server.database.exceptions.TransactionException;
 
 public interface UpdateUserRolesImpl extends BackendTransactionImpl {
 
-  public void updateUserRoles(String realm, String user, HashSet<String> roles)
+  public void updateUserRoles(String realm, String user, Set<String> roles)
       throws TransactionException;
 }
diff --git a/src/main/java/org/caosdb/server/database/backend/transaction/ListRoles.java b/src/main/java/org/caosdb/server/database/backend/transaction/ListRoles.java
new file mode 100644
index 0000000000000000000000000000000000000000..75792475c4c5a6ae9091f89c8de1b4ef157aa11f
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/transaction/ListRoles.java
@@ -0,0 +1,42 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.transaction;
+
+import java.util.List;
+import org.caosdb.server.accessControl.Role;
+import org.caosdb.server.database.BackendTransaction;
+import org.caosdb.server.database.backend.interfaces.ListRolesImpl;
+
+public class ListRoles extends BackendTransaction {
+
+  private List<Role> roles;
+
+  @Override
+  protected void execute() {
+    ListRolesImpl t = getImplementation(ListRolesImpl.class);
+    roles = t.execute();
+  }
+
+  public List<Role> getRoles() {
+    return roles;
+  }
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/transaction/ListUsers.java b/src/main/java/org/caosdb/server/database/backend/transaction/ListUsers.java
new file mode 100644
index 0000000000000000000000000000000000000000..9f29a3c5888104140eb6e2c29b83370fc1c56401
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/transaction/ListUsers.java
@@ -0,0 +1,42 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.transaction;
+
+import java.util.List;
+import org.caosdb.server.database.BackendTransaction;
+import org.caosdb.server.database.backend.interfaces.ListUsersImpl;
+import org.caosdb.server.database.proto.ProtoUser;
+
+public class ListUsers extends BackendTransaction {
+
+  private List<ProtoUser> users;
+
+  @Override
+  protected void execute() {
+    ListUsersImpl t = getImplementation(ListUsersImpl.class);
+    users = t.execute();
+  }
+
+  public List<ProtoUser> getUsers() {
+    return users;
+  }
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/transaction/LogUserVisit.java b/src/main/java/org/caosdb/server/database/backend/transaction/LogUserVisit.java
new file mode 100644
index 0000000000000000000000000000000000000000..43fd87495c4e7489e7f15ec8674ce01cb674dd90
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/transaction/LogUserVisit.java
@@ -0,0 +1,66 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.transaction;
+
+import java.util.HashSet;
+import org.caosdb.server.accessControl.UserSources;
+import org.caosdb.server.database.BackendTransaction;
+import org.caosdb.server.database.backend.interfaces.LogUserVisitImpl;
+import org.caosdb.server.database.backend.interfaces.UpdateUserImpl;
+import org.caosdb.server.database.backend.interfaces.UpdateUserRolesImpl;
+import org.caosdb.server.database.exceptions.TransactionException;
+import org.caosdb.server.database.proto.ProtoUser;
+
+public class LogUserVisit extends BackendTransaction {
+
+  private String realm;
+  private String username;
+  private String type;
+  private long timestamp;
+
+  public LogUserVisit(long timestamp, String realm, String username, String type) {
+    this.timestamp = timestamp;
+    this.realm = realm;
+    this.username = username;
+    this.type = type;
+  }
+
+  @Override
+  protected void execute() throws TransactionException {
+    final LogUserVisitImpl t = getImplementation(LogUserVisitImpl.class);
+    if (!t.logUserReturnIsKnown(timestamp, realm, username, type)) {
+      // User is unknown. Make it known
+      ProtoUser user = new ProtoUser();
+      user.realm = realm;
+      user.name = username;
+      user.email = UserSources.getDefaultUserEmail(realm, username);
+      user.status = UserSources.getDefaultUserStatus(realm, username);
+      user.roles = new HashSet<>(UserSources.getDefaultRoles(realm, username));
+
+      UpdateUserImpl insertUser = getImplementation(UpdateUserImpl.class);
+      insertUser.execute(user);
+      UpdateUserRolesImpl setRoles = getImplementation(UpdateUserRolesImpl.class);
+      setRoles.updateUserRoles(user.realm, user.name, user.roles);
+      t.logUserReturnIsKnown(timestamp, realm, username, type);
+    }
+  }
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/transaction/RetrieveEntityACLTransaction.java b/src/main/java/org/caosdb/server/database/backend/transaction/RetrieveEntityACLTransaction.java
new file mode 100644
index 0000000000000000000000000000000000000000..9cb96112532fe249fd81c3e8d10d85ca900293d9
--- /dev/null
+++ b/src/main/java/org/caosdb/server/database/backend/transaction/RetrieveEntityACLTransaction.java
@@ -0,0 +1,71 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.database.backend.transaction;
+
+import org.caosdb.server.database.CacheableBackendTransaction;
+import org.caosdb.server.database.backend.interfaces.RetrieveEntityACLImpl;
+import org.caosdb.server.database.exceptions.TransactionException;
+import org.caosdb.server.database.proto.VerySparseEntity;
+import org.caosdb.server.permissions.EntityACL;
+
+public class RetrieveEntityACLTransaction
+    extends CacheableBackendTransaction<Integer, VerySparseEntity> {
+
+  private Integer id;
+  private EntityACL entityAcl;
+
+  public RetrieveEntityACLTransaction(Integer id) {
+    // TODO
+    super(null);
+    this.id = id;
+  }
+
+  @Override
+  public VerySparseEntity executeNoCache() throws TransactionException {
+    RetrieveEntityACLImpl t = getImplementation(RetrieveEntityACLImpl.class);
+    return t.execute(getKey());
+  }
+
+  @Override
+  protected void process(VerySparseEntity t) throws TransactionException {
+    this.entityAcl = EntityACL.fromJSON(t.acl);
+  }
+
+  @Override
+  protected Integer getKey() {
+    return id;
+  }
+
+  public EntityACL getEntityAcl() {
+    return entityAcl;
+  }
+
+  public RetrieveEntityACLTransaction reuse(Integer id) {
+    this.id = id;
+    this.entityAcl = null;
+    return this;
+  }
+
+  public static void removeCached(Integer id) {
+    // TODO
+  }
+}
diff --git a/src/main/java/org/caosdb/server/database/backend/transaction/RetrieveRole.java b/src/main/java/org/caosdb/server/database/backend/transaction/RetrieveRole.java
index 1e855663590d85610860fcee246a4f1ed78a31b2..f4059832095acc38d3c65b828412c09cc58b3194 100644
--- a/src/main/java/org/caosdb/server/database/backend/transaction/RetrieveRole.java
+++ b/src/main/java/org/caosdb/server/database/backend/transaction/RetrieveRole.java
@@ -24,6 +24,7 @@
  */
 package org.caosdb.server.database.backend.transaction;
 
+import java.util.Set;
 import org.apache.commons.jcs.access.behavior.ICacheAccess;
 import org.caosdb.server.accessControl.Role;
 import org.caosdb.server.caching.Cache;
@@ -66,4 +67,8 @@ public class RetrieveRole extends CacheableBackendTransaction<String, Role> {
   public static void removeCached(final String name) {
     cache.remove(name);
   }
+
+  public static void removeCached(Set<String> roles) {
+    roles.forEach(RetrieveRole::removeCached);
+  }
 }
diff --git a/src/main/java/org/caosdb/server/database/backend/transaction/UpdateSparseEntity.java b/src/main/java/org/caosdb/server/database/backend/transaction/UpdateSparseEntity.java
index 8548fb0477de9d8b52b18b8132af15295dbc9353..837f64b32ca4cd6f035b74d13ee116205c7e82bc 100644
--- a/src/main/java/org/caosdb/server/database/backend/transaction/UpdateSparseEntity.java
+++ b/src/main/java/org/caosdb/server/database/backend/transaction/UpdateSparseEntity.java
@@ -4,8 +4,8 @@
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
- * Copyright (C) 2019 IndiScale GmbH
- * Copyright (C) 2019 Timm Fitschen (t.fitschen@indiscale.com)
+ * Copyright (C) 2019, 2021 IndiScale GmbH
+ * Copyright (C) 2019, 2021 Timm Fitschen (t.fitschen@indiscale.com)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -41,6 +41,7 @@ public class UpdateSparseEntity extends BackendTransaction {
 
   @Override
   public void execute() throws TransactionException {
+    RetrieveEntityACLTransaction.removeCached(this.entity.getId());
     RetrieveSparseEntity.removeCached(this.entity);
     if (entity.hasFileProperties()) {
       GetFileRecordByPath.removeCached(this.entity.getFileProperties().getPath());
diff --git a/src/main/java/org/caosdb/server/database/backend/transaction/UpdateUserRoles.java b/src/main/java/org/caosdb/server/database/backend/transaction/UpdateUserRoles.java
index 66b3cb8e6f03c3abde0ccaa051a1228057d973f7..bbd23aa95d3eb1bed4f2bafc78fa12d112a02169 100644
--- a/src/main/java/org/caosdb/server/database/backend/transaction/UpdateUserRoles.java
+++ b/src/main/java/org/caosdb/server/database/backend/transaction/UpdateUserRoles.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,11 +19,11 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.database.backend.transaction;
 
-import java.util.HashSet;
+import java.util.Set;
 import org.caosdb.server.accessControl.Principal;
 import org.caosdb.server.database.BackendTransaction;
 import org.caosdb.server.database.backend.interfaces.UpdateUserRolesImpl;
@@ -31,10 +32,10 @@ import org.caosdb.server.database.exceptions.TransactionException;
 public class UpdateUserRoles extends BackendTransaction {
 
   private final String user;
-  private final HashSet<String> roles;
+  private final Set<String> roles;
   private final String realm;
 
-  public UpdateUserRoles(final String realm, final String user, final HashSet<String> roles) {
+  public UpdateUserRoles(final String realm, final String user, final Set<String> roles) {
     this.realm = realm;
     this.user = user;
     this.roles = roles;
diff --git a/src/main/java/org/caosdb/server/database/proto/ProtoUser.java b/src/main/java/org/caosdb/server/database/proto/ProtoUser.java
index cafa32d2580c8a09a97e1cd3ee48c2ec59a454cf..643f4250216c7829c8218113a8842ff139b313ec 100644
--- a/src/main/java/org/caosdb/server/database/proto/ProtoUser.java
+++ b/src/main/java/org/caosdb/server/database/proto/ProtoUser.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,24 +19,24 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.database.proto;
 
 import java.io.Serializable;
-import java.util.Set;
+import java.util.HashSet;
 import org.caosdb.server.accessControl.UserStatus;
 
 public class ProtoUser implements Serializable {
 
   public ProtoUser() {}
 
-  private static final long serialVersionUID = -2704114543883567439L;
+  private static final long serialVersionUID = 5381234723597234L;
 
   public UserStatus status = null;
   public String name = null;
   public String email = null;
   public Integer entity = null;
   public String realm = null;
-  public Set<String> roles = null;
+  public HashSet<String> roles = null;
 }
diff --git a/src/main/java/org/caosdb/server/entity/Message.java b/src/main/java/org/caosdb/server/entity/Message.java
index 4c89e1ee23839483f7bed1099c52e8c24a56a6a2..fca6024561ede97c1b5520bc6a07f08f30f7a76a 100644
--- a/src/main/java/org/caosdb/server/entity/Message.java
+++ b/src/main/java/org/caosdb/server/entity/Message.java
@@ -19,6 +19,7 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  */
+
 package org.caosdb.server.entity;
 
 import java.util.HashMap;
@@ -35,6 +36,11 @@ public class Message extends Exception implements Comparable<Message>, ToElement
   private final String description;
   private final String body;
 
+  @Override
+  public String getMessage() {
+    return description;
+  }
+
   @Deprecated private static final Map<String, String> legacy_codes_mapping = new HashMap<>();
 
   static void init() {
diff --git a/src/main/java/org/caosdb/server/grpc/AccessControlManagementServiceImpl.java b/src/main/java/org/caosdb/server/grpc/AccessControlManagementServiceImpl.java
new file mode 100644
index 0000000000000000000000000000000000000000..88429828f27ac843903cfcfc801847c35eedb607
--- /dev/null
+++ b/src/main/java/org/caosdb/server/grpc/AccessControlManagementServiceImpl.java
@@ -0,0 +1,602 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.grpc;
+
+import io.grpc.Status;
+import io.grpc.StatusException;
+import io.grpc.stub.StreamObserver;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.authz.UnauthorizedException;
+import org.apache.shiro.subject.Subject;
+import org.caosdb.api.acm.v1alpha1.AccessControlManagementServiceGrpc.AccessControlManagementServiceImplBase;
+import org.caosdb.api.acm.v1alpha1.CreateSingleRoleRequest;
+import org.caosdb.api.acm.v1alpha1.CreateSingleRoleResponse;
+import org.caosdb.api.acm.v1alpha1.CreateSingleUserRequest;
+import org.caosdb.api.acm.v1alpha1.CreateSingleUserResponse;
+import org.caosdb.api.acm.v1alpha1.DeleteSingleRoleRequest;
+import org.caosdb.api.acm.v1alpha1.DeleteSingleRoleResponse;
+import org.caosdb.api.acm.v1alpha1.DeleteSingleUserRequest;
+import org.caosdb.api.acm.v1alpha1.DeleteSingleUserResponse;
+import org.caosdb.api.acm.v1alpha1.EmailSetting;
+import org.caosdb.api.acm.v1alpha1.EntitySetting;
+import org.caosdb.api.acm.v1alpha1.ListKnownPermissionsRequest;
+import org.caosdb.api.acm.v1alpha1.ListKnownPermissionsResponse;
+import org.caosdb.api.acm.v1alpha1.ListRoleItem;
+import org.caosdb.api.acm.v1alpha1.ListRolesRequest;
+import org.caosdb.api.acm.v1alpha1.ListRolesResponse;
+import org.caosdb.api.acm.v1alpha1.ListUsersRequest;
+import org.caosdb.api.acm.v1alpha1.ListUsersResponse;
+import org.caosdb.api.acm.v1alpha1.PermissionDescription;
+import org.caosdb.api.acm.v1alpha1.PermissionRule;
+import org.caosdb.api.acm.v1alpha1.RetrieveSingleRoleRequest;
+import org.caosdb.api.acm.v1alpha1.RetrieveSingleRoleResponse;
+import org.caosdb.api.acm.v1alpha1.RetrieveSingleUserRequest;
+import org.caosdb.api.acm.v1alpha1.RetrieveSingleUserResponse;
+import org.caosdb.api.acm.v1alpha1.RoleCapabilities;
+import org.caosdb.api.acm.v1alpha1.RolePermissions;
+import org.caosdb.api.acm.v1alpha1.UpdateSingleRoleRequest;
+import org.caosdb.api.acm.v1alpha1.UpdateSingleRoleResponse;
+import org.caosdb.api.acm.v1alpha1.UpdateSingleUserRequest;
+import org.caosdb.api.acm.v1alpha1.UpdateSingleUserResponse;
+import org.caosdb.api.acm.v1alpha1.User;
+import org.caosdb.api.acm.v1alpha1.UserCapabilities;
+import org.caosdb.api.acm.v1alpha1.UserPermissions;
+import org.caosdb.api.acm.v1alpha1.UserStatus;
+import org.caosdb.server.accessControl.ACMPermissions;
+import org.caosdb.server.accessControl.AuthenticationUtils;
+import org.caosdb.server.accessControl.Role;
+import org.caosdb.server.accessControl.UserSources;
+import org.caosdb.server.database.proto.ProtoUser;
+import org.caosdb.server.transaction.DeleteRoleTransaction;
+import org.caosdb.server.transaction.DeleteUserTransaction;
+import org.caosdb.server.transaction.InsertRoleTransaction;
+import org.caosdb.server.transaction.InsertUserTransaction;
+import org.caosdb.server.transaction.ListRolesTransaction;
+import org.caosdb.server.transaction.ListUsersTransaction;
+import org.caosdb.server.transaction.RetrieveRoleTransaction;
+import org.caosdb.server.transaction.RetrieveUserTransaction;
+import org.caosdb.server.transaction.UpdateRoleTransaction;
+import org.caosdb.server.transaction.UpdateUserTransaction;
+import org.caosdb.server.utils.ServerMessages;
+
+public class AccessControlManagementServiceImpl extends AccessControlManagementServiceImplBase {
+
+  /////////////////////////////////// CONVERTERS
+
+  private ProtoUser convert(User user) {
+    ProtoUser result = new ProtoUser();
+    result.realm = user.getRealm();
+    result.name = user.getName();
+    result.email = user.hasEmailSetting() ? user.getEmailSetting().getEmail() : null;
+    result.status = convert(user.getStatus());
+    result.roles = new HashSet<String>();
+    if (user.getRolesCount() >= 0) {
+      user.getRolesList().forEach(result.roles::add);
+    }
+    return result;
+  }
+
+  private org.caosdb.server.accessControl.UserStatus convert(UserStatus status) {
+    switch (status) {
+      case USER_STATUS_ACTIVE:
+        return org.caosdb.server.accessControl.UserStatus.ACTIVE;
+      case USER_STATUS_INACTIVE:
+        return org.caosdb.server.accessControl.UserStatus.INACTIVE;
+      default:
+        break;
+    }
+    return org.caosdb.server.accessControl.UserStatus.INACTIVE;
+  }
+
+  private ListUsersResponse convertUsers(List<ProtoUser> users) {
+    ListUsersResponse.Builder response = ListUsersResponse.newBuilder();
+    users.forEach(
+        user -> {
+          response.addUsers(convert(user));
+        });
+
+    return response.build();
+  }
+
+  private User.Builder convert(ProtoUser user) {
+    User.Builder result = User.newBuilder();
+    result.setRealm(user.realm);
+    result.setName(user.name);
+    if (user.status != null) result.setStatus(convert(user.status));
+    if (user.email != null) {
+      result.setEmailSetting(EmailSetting.newBuilder().setEmail(user.email));
+    }
+    if (user.entity != null) {
+      result.setEntitySetting(
+          EntitySetting.newBuilder().setEntityId(Integer.toString(user.entity)));
+    }
+    if (user.roles != null && !user.roles.isEmpty()) {
+      result.addAllRoles(user.roles);
+    }
+    return result;
+  }
+
+  private UserStatus convert(org.caosdb.server.accessControl.UserStatus status) {
+    switch (status) {
+      case ACTIVE:
+        return UserStatus.USER_STATUS_ACTIVE;
+      case INACTIVE:
+        return UserStatus.USER_STATUS_INACTIVE;
+      default:
+        return UserStatus.USER_STATUS_UNSPECIFIED;
+    }
+  }
+
+  private Role convert(org.caosdb.api.acm.v1alpha1.Role role) {
+    Role result = new Role();
+
+    result.name = role.getName();
+    result.description = role.getDescription();
+    result.permission_rules = convertPermissionRules(role.getPermissionRulesList());
+    return result;
+  }
+
+  private LinkedList<org.caosdb.server.permissions.PermissionRule> convertPermissionRules(
+      List<PermissionRule> permissionRulesList) {
+    LinkedList<org.caosdb.server.permissions.PermissionRule> result = new LinkedList<>();
+    permissionRulesList.forEach((r) -> result.add(convert(r)));
+    return result;
+  }
+
+  private org.caosdb.server.permissions.PermissionRule convert(PermissionRule r) {
+    boolean grant = r.getGrant();
+    boolean priority = r.getPriority();
+    String permission = r.getPermission();
+    return new org.caosdb.server.permissions.PermissionRule(grant, priority, permission);
+  }
+
+  private ListRolesResponse convert(List<Role> roles) {
+    ListRolesResponse.Builder response = ListRolesResponse.newBuilder();
+    roles.forEach(
+        role -> {
+          response.addRoles(convert(role, getRolePermissions(role), getRoleCapabilities(role)));
+        });
+
+    return response.build();
+  }
+
+  private ListRoleItem convert(
+      Role role,
+      Iterable<? extends RolePermissions> rolePermissions,
+      Iterable<? extends RoleCapabilities> roleCapabilities) {
+    return ListRoleItem.newBuilder()
+        .setRole(convert(role))
+        .addAllCapabilities(roleCapabilities)
+        .addAllPermissions(rolePermissions)
+        .build();
+  }
+
+  private org.caosdb.api.acm.v1alpha1.Role.Builder convert(Role role) {
+    org.caosdb.api.acm.v1alpha1.Role.Builder result = org.caosdb.api.acm.v1alpha1.Role.newBuilder();
+    result.setDescription(role.description);
+    result.setName(role.name);
+    if (role.permission_rules != null) result.addAllPermissionRules(convert(role.permission_rules));
+    return result;
+  }
+
+  private PermissionRule convert(org.caosdb.server.permissions.PermissionRule rule) {
+    PermissionRule.Builder result = PermissionRule.newBuilder();
+    result.setGrant(rule.isGrant());
+    result.setPriority(rule.isPriority());
+    result.setPermission(rule.getPermission());
+    return result.build();
+  }
+
+  private Iterable<PermissionRule> convert(
+      LinkedList<org.caosdb.server.permissions.PermissionRule> permission_rules) {
+
+    List<PermissionRule> result = new LinkedList<>();
+    permission_rules.forEach(
+        (rule) -> {
+          result.add(convert(rule));
+        });
+    return result;
+  }
+
+  ////////////////////////////////////// RPC Methods (Implementation)
+
+  private ListKnownPermissionsResponse listKnownPermissions(ListKnownPermissionsRequest request) {
+    ListKnownPermissionsResponse.Builder builder = ListKnownPermissionsResponse.newBuilder();
+    builder.addAllPermissions(listKnownPermissions());
+    return builder.build();
+  }
+
+  private Iterable<PermissionDescription> listKnownPermissions() {
+    List<PermissionDescription> result = new LinkedList<>();
+    for (ACMPermissions p : ACMPermissions.getAll()) {
+      result.add(
+          PermissionDescription.newBuilder()
+              .setPermission(p.toString())
+              .setDescription(p.getDescription())
+              .build());
+    }
+    return result;
+  }
+
+  ////////////////// ... for roles
+
+  private ListRolesResponse listRolesTransaction(ListRolesRequest request) throws Exception {
+    ListRolesTransaction transaction = new ListRolesTransaction();
+    transaction.execute();
+    List<Role> roles = transaction.getRoles();
+
+    return convert(roles);
+  }
+
+  private CreateSingleRoleResponse createSingleRoleTransaction(CreateSingleRoleRequest request)
+      throws Exception {
+    Role role = convert(request.getRole());
+    InsertRoleTransaction transaction = new InsertRoleTransaction(role);
+    transaction.execute();
+
+    return CreateSingleRoleResponse.newBuilder().build();
+  }
+
+  private RetrieveSingleRoleResponse retrieveSingleRoleTransaction(
+      RetrieveSingleRoleRequest request) throws Exception {
+    RetrieveRoleTransaction transaction = new RetrieveRoleTransaction(request.getName());
+    transaction.execute();
+
+    Role role = transaction.getRole();
+    RetrieveSingleRoleResponse.Builder builder =
+        RetrieveSingleRoleResponse.newBuilder().setRole(convert(transaction.getRole()));
+    if (role.users != null && !role.users.isEmpty())
+      role.users.forEach(
+          (u) -> {
+            builder.addUsers(convert(u));
+          });
+    return builder
+        .addAllPermissions(getRolePermissions(role))
+        .addAllCapabilities(getRoleCapabilities(role))
+        .build();
+  }
+
+  /** What can be done with this role. */
+  private Iterable<? extends RoleCapabilities> getRoleCapabilities(Role role) {
+    List<RoleCapabilities> result = new LinkedList<>();
+    if (org.caosdb.server.permissions.Role.ADMINISTRATION.toString().equals(role.name)) {
+      // administration cannot be deleted and the permissions cannot be changed (from *)
+      result.add(RoleCapabilities.ROLE_CAPABILITIES_ASSIGN);
+    } else if (org.caosdb.server.permissions.Role.ANONYMOUS_ROLE.toString().equals(role.name)) {
+      // anonymous cannot be deleted or assigned to any user
+      result.add(RoleCapabilities.ROLE_CAPABILITIES_UPDATE_PERMISSION_RULES);
+    } else {
+      result.add(RoleCapabilities.ROLE_CAPABILITIES_ASSIGN);
+      result.add(RoleCapabilities.ROLE_CAPABILITIES_DELETE);
+      result.add(RoleCapabilities.ROLE_CAPABILITIES_UPDATE_PERMISSION_RULES);
+    }
+    return result;
+  }
+
+  /** The permissions of the current user w.r.t. this role. */
+  private Iterable<? extends RolePermissions> getRolePermissions(Role role) {
+    List<RolePermissions> result = new LinkedList<>();
+    Subject current_user = SecurityUtils.getSubject();
+    if (current_user.isPermitted(ACMPermissions.PERMISSION_DELETE_ROLE(role.name))) {
+      result.add(RolePermissions.ROLE_PERMISSIONS_DELETE);
+    }
+    if (current_user.isPermitted(ACMPermissions.PERMISSION_UPDATE_ROLE_DESCRIPTION(role.name))) {
+      result.add(RolePermissions.ROLE_PERMISSIONS_UPDATE_DESCRIPTION);
+    }
+    if (current_user.isPermitted(ACMPermissions.PERMISSION_UPDATE_ROLE_PERMISSIONS(role.name))) {
+      result.add(RolePermissions.ROLE_PERMISSIONS_UPDATE_PERMISSION_RULES);
+    }
+    if (current_user.isPermitted(ACMPermissions.PERMISSION_ASSIGN_ROLE(role.name))) {
+      result.add(RolePermissions.ROLE_PERMISSIONS_ASSIGN);
+    }
+    return result;
+  }
+
+  private DeleteSingleRoleResponse deleteSingleRoleTransaction(DeleteSingleRoleRequest request)
+      throws Exception {
+    DeleteRoleTransaction transaction = new DeleteRoleTransaction(request.getName());
+    transaction.execute();
+
+    return DeleteSingleRoleResponse.newBuilder().build();
+  }
+
+  private UpdateSingleRoleResponse updateSingleRoleTransaction(UpdateSingleRoleRequest request)
+      throws Exception {
+    Role role = convert(request.getRole());
+    UpdateRoleTransaction transaction = new UpdateRoleTransaction(role);
+    transaction.execute();
+    return UpdateSingleRoleResponse.newBuilder().build();
+  }
+
+  ////////////////// ... for users
+
+  private ListUsersResponse listUsersTransaction(ListUsersRequest request) throws Exception {
+    ListUsersTransaction transaction = new ListUsersTransaction();
+    transaction.execute();
+    List<ProtoUser> users = transaction.getUsers();
+    return convertUsers(users);
+  }
+
+  private CreateSingleUserResponse createSingleUserTransaction(CreateSingleUserRequest request)
+      throws Exception {
+    ProtoUser user = convert(request.getUser());
+    InsertUserTransaction transaction =
+        new InsertUserTransaction(
+            user, request.hasPasswordSetting() ? request.getPasswordSetting().getPassword() : null);
+    transaction.execute();
+
+    return CreateSingleUserResponse.newBuilder().build();
+  }
+
+  private UpdateSingleUserResponse updateSingleUserTransaction(UpdateSingleUserRequest request)
+      throws Exception {
+    ProtoUser user = convert(request.getUser());
+    UpdateUserTransaction transaction =
+        new UpdateUserTransaction(
+            user, request.hasPasswordSetting() ? request.getPasswordSetting().getPassword() : null);
+    transaction.execute();
+
+    return UpdateSingleUserResponse.newBuilder().build();
+  }
+
+  private RetrieveSingleUserResponse retrieveSingleUserTransaction(
+      RetrieveSingleUserRequest request) throws Exception {
+    RetrieveUserTransaction transaction =
+        new RetrieveUserTransaction(request.getRealm(), request.getName());
+    transaction.execute();
+    ProtoUser user = transaction.getUser();
+
+    return RetrieveSingleUserResponse.newBuilder()
+        .setUser(convert(user))
+        .addAllPermissions(getUserPermissions(user.realm, user.name))
+        .addAllCapabilities(getUserCapabilities(user))
+        .build();
+  }
+
+  private Iterable<? extends UserCapabilities> getUserCapabilities(ProtoUser user) {
+    LinkedList<UserCapabilities> result = new LinkedList<>();
+    if (user.realm.equals(UserSources.getInternalRealm().getName())) {
+      result.add(UserCapabilities.USER_CAPABILITIES_DELETE);
+      result.add(UserCapabilities.USER_CAPABILITIES_UPDATE_PASSWORD);
+    }
+    return result;
+  }
+
+  private Iterable<? extends UserPermissions> getUserPermissions(String realm, String name) {
+    LinkedList<UserPermissions> result = new LinkedList<>();
+    Subject current_user = SecurityUtils.getSubject();
+    if (current_user.isPermitted(ACMPermissions.PERMISSION_DELETE_USER(realm, name))) {
+      result.add(UserPermissions.USER_PERMISSIONS_DELETE);
+    }
+    if (current_user.isPermitted(ACMPermissions.PERMISSION_UPDATE_USER_EMAIL(realm, name))) {
+      result.add(UserPermissions.USER_PERMISSIONS_UPDATE_EMAIL);
+    }
+    if (current_user.isPermitted(ACMPermissions.PERMISSION_UPDATE_USER_STATUS(realm, name))) {
+      result.add(UserPermissions.USER_PERMISSIONS_UPDATE_STATUS);
+    }
+    if (current_user.isPermitted(ACMPermissions.PERMISSION_UPDATE_USER_ROLES(realm, name))) {
+      result.add(UserPermissions.USER_PERMISSIONS_UPDATE_ROLES);
+    }
+    if (current_user.isPermitted(ACMPermissions.PERMISSION_UPDATE_USER_PASSWORD(realm, name))) {
+      result.add(UserPermissions.USER_PERMISSIONS_UPDATE_PASSWORD);
+    }
+    return result;
+  }
+
+  private DeleteSingleUserResponse deleteSingleUserTransaction(DeleteSingleUserRequest request)
+      throws Exception {
+    DeleteUserTransaction transaction =
+        new DeleteUserTransaction(request.getRealm(), request.getName());
+    transaction.execute();
+
+    return DeleteSingleUserResponse.newBuilder().build();
+  }
+
+  ///////////////////////////////////// RPC Methods (API)
+
+  @Override
+  public void listUsers(
+      ListUsersRequest request, StreamObserver<ListUsersResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final ListUsersResponse response = listUsersTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void listRoles(
+      ListRolesRequest request, StreamObserver<ListRolesResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final ListRolesResponse response = listRolesTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void createSingleRole(
+      CreateSingleRoleRequest request, StreamObserver<CreateSingleRoleResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final CreateSingleRoleResponse response = createSingleRoleTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void retrieveSingleRole(
+      RetrieveSingleRoleRequest request,
+      StreamObserver<RetrieveSingleRoleResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final RetrieveSingleRoleResponse response = retrieveSingleRoleTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void createSingleUser(
+      CreateSingleUserRequest request, StreamObserver<CreateSingleUserResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final CreateSingleUserResponse response = createSingleUserTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void updateSingleUser(
+      UpdateSingleUserRequest request, StreamObserver<UpdateSingleUserResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final UpdateSingleUserResponse response = updateSingleUserTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void retrieveSingleUser(
+      RetrieveSingleUserRequest request,
+      StreamObserver<RetrieveSingleUserResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final RetrieveSingleUserResponse response = retrieveSingleUserTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void deleteSingleUser(
+      DeleteSingleUserRequest request, StreamObserver<DeleteSingleUserResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final DeleteSingleUserResponse response = deleteSingleUserTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void deleteSingleRole(
+      DeleteSingleRoleRequest request, StreamObserver<DeleteSingleRoleResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final DeleteSingleRoleResponse response = deleteSingleRoleTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void updateSingleRole(
+      UpdateSingleRoleRequest request, StreamObserver<UpdateSingleRoleResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final UpdateSingleRoleResponse response = updateSingleRoleTransaction(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void listKnownPermissions(
+      ListKnownPermissionsRequest request,
+      StreamObserver<ListKnownPermissionsResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final ListKnownPermissionsResponse response = listKnownPermissions(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      handleException(responseObserver, e);
+    }
+  }
+
+  public static void handleException(StreamObserver<?> responseObserver, Exception e) {
+    String description = e.getMessage();
+    if (description == null || description.isBlank()) {
+      description = "Unknown Error. Please Report!";
+    }
+    if (e instanceof UnauthorizedException) {
+      Subject subject = SecurityUtils.getSubject();
+      if (AuthenticationUtils.isAnonymous(subject)) {
+        responseObserver.onError(new StatusException(AuthInterceptor.PLEASE_LOG_IN));
+        return;
+      } else {
+        responseObserver.onError(
+            new StatusException(
+                Status.PERMISSION_DENIED.withCause(e).withDescription(description)));
+        return;
+      }
+    } else if (e == ServerMessages.ROLE_DOES_NOT_EXIST
+        || e == ServerMessages.ACCOUNT_DOES_NOT_EXIST) {
+      responseObserver.onError(
+          new StatusException(Status.NOT_FOUND.withDescription(description).withCause(e)));
+      return;
+    }
+    e.printStackTrace();
+    responseObserver.onError(
+        new StatusException(Status.UNKNOWN.withDescription(description).withCause(e)));
+  }
+}
diff --git a/src/main/java/org/caosdb/server/grpc/AuthInterceptor.java b/src/main/java/org/caosdb/server/grpc/AuthInterceptor.java
index 0b359835c293a9b1ad95b296f1301de93a6fbbfa..ce8a62210d3c8e849397600fc112cd3103f15df4 100644
--- a/src/main/java/org/caosdb/server/grpc/AuthInterceptor.java
+++ b/src/main/java/org/caosdb/server/grpc/AuthInterceptor.java
@@ -1,7 +1,31 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
 package org.caosdb.server.grpc;
 
+import static org.caosdb.server.utils.Utils.URLDecodeWithUTF8;
+
 import io.grpc.Context;
 import io.grpc.Contexts;
+import io.grpc.ForwardingServerCall;
 import io.grpc.Metadata;
 import io.grpc.Metadata.Key;
 import io.grpc.ServerCall;
@@ -10,14 +34,22 @@ import io.grpc.ServerCallHandler;
 import io.grpc.ServerInterceptor;
 import io.grpc.Status;
 import java.util.Base64;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
 import org.apache.shiro.SecurityUtils;
 import org.apache.shiro.authc.AuthenticationException;
 import org.apache.shiro.subject.Subject;
+import org.apache.shiro.util.ThreadContext;
 import org.caosdb.server.CaosDBServer;
 import org.caosdb.server.ServerProperties;
 import org.caosdb.server.accessControl.AnonymousAuthenticationToken;
+import org.caosdb.server.accessControl.AuthenticationUtils;
 import org.caosdb.server.accessControl.RealmUsernamePasswordToken;
+import org.caosdb.server.accessControl.SelfValidatingAuthenticationToken;
+import org.caosdb.server.accessControl.SessionToken;
 import org.caosdb.server.accessControl.UserSources;
+import org.caosdb.server.utils.Utils;
+import org.restlet.data.CookieSetting;
 
 /**
  * ServerInterceptor for Authentication. If the authentication succeeds or if the caller is
@@ -26,12 +58,35 @@ import org.caosdb.server.accessControl.UserSources;
  *
  * @author Timm Fitschen <t.fitschen@indiscale.com>
  */
-class AuthInterceptor implements ServerInterceptor {
+public class AuthInterceptor implements ServerInterceptor {
 
-  private static final Key<String> AUTHENTICATION_HEADER =
+  public static final Status PLEASE_LOG_IN =
+      Status.UNAUTHENTICATED.withDescription("Please log in!");
+  public static final Key<String> AUTHENTICATION_HEADER =
       Key.of("authentication", Metadata.ASCII_STRING_MARSHALLER);
-  private static final Context.Key<Subject> SUBJECT_KEY = Context.key("subject");
-  private static final String BASIC_SCHEME_PREFIX = "Basic ";
+  public static final Key<String> AUTHORIZATION_HEADER =
+      Key.of("Authorization", Metadata.ASCII_STRING_MARSHALLER);
+  public static final Key<String> COOKIE_HEADER =
+      Key.of("Cookie", Metadata.ASCII_STRING_MARSHALLER);
+  public static final Context.Key<Subject> SUBJECT_KEY = Context.key("subject");
+  public static final String BASIC_SCHEME_PREFIX = "Basic ";
+  public static final Pattern SESSION_TOKEN_COOKIE_PREFIX_PATTERN =
+      Pattern.compile("^\\s*" + AuthenticationUtils.SESSION_TOKEN_COOKIE + "\\s*=\\s*");
+  public static final Predicate<String> SESSION_TOKEN_COOKIE_PREFIX_PREDICATE =
+      SESSION_TOKEN_COOKIE_PREFIX_PATTERN.asPredicate();
+
+  @SuppressWarnings("unused")
+  public static Subject bindSubject() {
+    Subject subject = (Subject) SUBJECT_KEY.get();
+    ThreadContext.bind(subject);
+    return subject;
+  }
+
+  public final Metadata expiredSessionMetadata() {
+    Metadata metadata = new Metadata();
+    metadata.put(CookieSetter.SET_COOKIE, CookieSetter.EXPIRED_SESSION_COOKIE);
+    return metadata;
+  }
   /**
    * A no-op listener. This class is used for failed authentications. We couldn't return a null
    * instead because the documentation of the {@link ServerInterceptor} explicitely forbids it.
@@ -56,8 +111,9 @@ class AuthInterceptor implements ServerInterceptor {
     final String username = split[0];
     final String password = split[1];
     final RealmUsernamePasswordToken token =
-        new RealmUsernamePasswordToken(UserSources.getDefaultRealm(), username, password);
-    final org.apache.shiro.subject.Subject subject = SecurityUtils.getSubject();
+        new RealmUsernamePasswordToken(
+            UserSources.guessRealm(username, UserSources.getDefaultRealm()), username, password);
+    final Subject subject = SecurityUtils.getSubject();
     subject.login(token);
     return subject;
   }
@@ -67,25 +123,75 @@ class AuthInterceptor implements ServerInterceptor {
       final ServerCall<ReqT, RespT> call,
       final Metadata headers,
       final ServerCallHandler<ReqT, RespT> next) {
-    final String authentication = headers.get(AUTHENTICATION_HEADER);
+    ThreadContext.remove();
+
+    String authentication = headers.get(AUTHENTICATION_HEADER);
+    if (authentication == null) {
+      authentication = headers.get(AUTHORIZATION_HEADER);
+    }
+    if (authentication == null) {
+      authentication = getSessionToken(headers.get(COOKIE_HEADER));
+    }
     Status status =
         Status.UNKNOWN.withDescription(
             "An unknown error occured during authentication. Please report a bug.");
     if (authentication == null && isAuthOptional()) {
       return anonymous(call, headers, next);
     } else if (authentication == null) {
-      status = Status.UNAUTHENTICATED.withDescription("Please login.");
+      status = PLEASE_LOG_IN;
     } else if (authentication.startsWith(BASIC_SCHEME_PREFIX)) {
       return basicAuth(authentication.substring(BASIC_SCHEME_PREFIX.length()), call, headers, next);
+    } else if (SESSION_TOKEN_COOKIE_PREFIX_PREDICATE.test(authentication)) {
+      return sessionTokenAuth(
+          SESSION_TOKEN_COOKIE_PREFIX_PATTERN.split(authentication, 2)[1], call, headers, next);
     } else {
-      status =
-          Status.UNAUTHENTICATED.withDescription(
-              "Unsupported authentication scheme: " + authentication.split(" ", 2)[0]);
+      status = Status.UNAUTHENTICATED.withDescription("Unsupported authentication scheme.");
     }
-    call.close(status, new Metadata());
+    call.close(status, expiredSessionMetadata());
     return new NoOpListener<ReqT>();
   }
 
+  private String getSessionToken(String cookies) {
+    if (cookies != null)
+      for (String cookie : cookies.split("\\s*;\\s*")) {
+        if (SESSION_TOKEN_COOKIE_PREFIX_PREDICATE.test(cookie)) {
+          return cookie;
+        }
+      }
+    return null;
+  }
+
+  /**
+   * Login via AuthenticationToken and add the resulting subject to the call context.
+   *
+   * @see #updateContext(Subject, ServerCall, Metadata, ServerCallHandler) for more information.
+   */
+  private <ReqT, RespT> Listener<ReqT> sessionTokenAuth(
+      String sessionTokenCookie,
+      ServerCall<ReqT, RespT> call,
+      Metadata headers,
+      ServerCallHandler<ReqT, RespT> next) {
+    try {
+      final String tokenString = URLDecodeWithUTF8(sessionTokenCookie.split(";")[0]);
+
+      final Subject subject = sessionTokenAuth(tokenString);
+      return updateContext(subject, call, headers, next, "sessionToken: " + tokenString);
+    } catch (final AuthenticationException e) {
+      final Status status =
+          Status.UNAUTHENTICATED.withDescription(
+              "Authentication failed. SessionToken was invalid.");
+      call.close(status, expiredSessionMetadata());
+      return new NoOpListener<ReqT>();
+    }
+  }
+
+  /** Login via AuthenticationToken and return the logged-in subject. */
+  private Subject sessionTokenAuth(String tokenString) {
+    Subject subject = SecurityUtils.getSubject();
+    subject.login(SelfValidatingAuthenticationToken.parse(tokenString));
+    return subject;
+  }
+
   /**
    * Login via username and password with the basic authentication scheme and add the resulting
    * subject to the call context.
@@ -99,12 +205,17 @@ class AuthInterceptor implements ServerInterceptor {
       final ServerCallHandler<ReqT, RespT> next) {
     try {
       final Subject subject = basicAuth(base64);
-      return updateContext(subject, call, headers, next);
+      return updateContext(
+          subject,
+          call,
+          headers,
+          next,
+          "basic: " + base64 + " thread: " + Thread.currentThread().getName());
     } catch (final AuthenticationException e) {
       final Status status =
           Status.UNAUTHENTICATED.withDescription(
               "Authentication failed. Username or password wrong.");
-      call.close(status, new Metadata());
+      call.close(status, expiredSessionMetadata());
       return new NoOpListener<ReqT>();
     }
   }
@@ -119,7 +230,7 @@ class AuthInterceptor implements ServerInterceptor {
       final Metadata headers,
       final ServerCallHandler<ReqT, RespT> next) {
     final Subject subject = anonymous();
-    return updateContext(subject, call, headers, next);
+    return updateContext(subject, call, headers, next, "anonymous");
   }
 
   /** Login as anonymous. */
@@ -137,9 +248,66 @@ class AuthInterceptor implements ServerInterceptor {
       final Subject subject,
       final ServerCall<ReqT, RespT> call,
       final Metadata headers,
-      final ServerCallHandler<ReqT, RespT> next) {
-    final Context context = Context.current();
-    context.withValue(SUBJECT_KEY, subject);
-    return Contexts.interceptCall(Context.current(), call, headers, next);
+      final ServerCallHandler<ReqT, RespT> next,
+      final String tag) {
+    final Context context = Context.current().withValue(SUBJECT_KEY, subject);
+    ServerCall<ReqT, RespT> cookieSetter = new CookieSetter<>(call, subject, tag);
+    return Contexts.interceptCall(context, cookieSetter, headers, next);
+  }
+}
+
+final class CookieSetter<ReqT, RespT>
+    extends ForwardingServerCall.SimpleForwardingServerCall<ReqT, RespT> {
+  public static final String EXPIRED_SESSION_COOKIE =
+      AuthenticationUtils.SESSION_TOKEN_COOKIE
+          + "=expired; Path=/; HttpOnly; SameSite=Strict; Max-Age=0";
+  public static final Key<String> SET_COOKIE =
+      Key.of("Set-Cookie", Metadata.ASCII_STRING_MARSHALLER);
+  private Subject subject;
+
+  protected CookieSetter(ServerCall<ReqT, RespT> delegate, Subject subject, String tag) {
+    super(delegate);
+    this.subject = subject;
+  }
+
+  String getSessionTimeoutSeconds() {
+    int ms =
+        Integer.parseInt(CaosDBServer.getServerProperty(ServerProperties.KEY_SESSION_TIMEOUT_MS));
+    int seconds = (int) Math.floor(ms / 1000);
+    return Integer.toString(seconds);
+  }
+
+  @Override
+  public void sendHeaders(Metadata headers) {
+    setSessionCookies(headers);
+    super.sendHeaders(headers);
+  };
+
+  private void setSessionCookies(Metadata headers) {
+    // if authenticated as a normal user: generate and set session cookie.
+    if (subject.isAuthenticated()
+        && !AnonymousAuthenticationToken.PRINCIPAL.equals(subject.getPrincipal())) {
+      final SessionToken sessionToken = SessionToken.generate(subject);
+      if (sessionToken != null && sessionToken.isValid()) {
+
+        final CookieSetting sessionTokenCookie =
+            AuthenticationUtils.createSessionTokenCookie(sessionToken);
+        if (sessionTokenCookie != null) {
+          // TODO add "Secure;" to cookie setting
+          headers.put(
+              SET_COOKIE,
+              AuthenticationUtils.SESSION_TOKEN_COOKIE
+                  + "="
+                  + Utils.URLEncodeWithUTF8(sessionToken.toString())
+                  + "; Path=/; HttpOnly; SameSite=Strict; Max-Age="
+                  + getSessionTimeoutSeconds());
+        }
+      }
+    } else if (AnonymousAuthenticationToken.PRINCIPAL.equals(subject.getPrincipal())) {
+      // this is anonymous, do nothing
+      headers.toString();
+    } else {
+      headers.put(SET_COOKIE, EXPIRED_SESSION_COOKIE);
+    }
   }
 }
diff --git a/src/main/java/org/caosdb/server/grpc/CaosDBToGrpcConverters.java b/src/main/java/org/caosdb/server/grpc/CaosDBToGrpcConverters.java
index aa6a260dfb52b5e36520d130219632d26095b0d1..d9ac193c104c9cb643897a0cabc97ff2f42cbb9a 100644
--- a/src/main/java/org/caosdb/server/grpc/CaosDBToGrpcConverters.java
+++ b/src/main/java/org/caosdb/server/grpc/CaosDBToGrpcConverters.java
@@ -1,15 +1,42 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
 package org.caosdb.server.grpc;
 
 import java.util.Iterator;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.TimeZone;
 import org.caosdb.api.entity.v1.AtomicDataType;
 import org.caosdb.api.entity.v1.CollectionValues;
 import org.caosdb.api.entity.v1.DataType;
 import org.caosdb.api.entity.v1.Entity;
 import org.caosdb.api.entity.v1.Entity.Builder;
+import org.caosdb.api.entity.v1.EntityACL;
+import org.caosdb.api.entity.v1.EntityAclPermission;
+import org.caosdb.api.entity.v1.EntityPermissionRule;
+import org.caosdb.api.entity.v1.EntityPermissionRuleCapability;
 import org.caosdb.api.entity.v1.EntityResponse;
 import org.caosdb.api.entity.v1.EntityRole;
+import org.caosdb.api.entity.v1.FileDescriptor;
 import org.caosdb.api.entity.v1.Importance;
 import org.caosdb.api.entity.v1.ListDataType;
 import org.caosdb.api.entity.v1.MessageCode;
@@ -36,6 +63,7 @@ import org.caosdb.server.datatype.ReferenceValue;
 import org.caosdb.server.datatype.TextDatatype;
 import org.caosdb.server.datatype.Value;
 import org.caosdb.server.entity.EntityInterface;
+import org.caosdb.server.entity.FileProperties;
 import org.caosdb.server.entity.MagicTypes;
 import org.caosdb.server.entity.Message;
 import org.caosdb.server.entity.Role;
@@ -43,9 +71,17 @@ import org.caosdb.server.entity.StatementStatus;
 import org.caosdb.server.entity.container.ParentContainer;
 import org.caosdb.server.entity.container.PropertyContainer;
 import org.caosdb.server.entity.wrapper.Property;
+import org.caosdb.server.permissions.EntityACI;
+import org.caosdb.server.permissions.EntityPermission;
 
 public class CaosDBToGrpcConverters {
 
+  private TimeZone timeZone;
+
+  public CaosDBToGrpcConverters(TimeZone timeZone) {
+    this.timeZone = timeZone;
+  }
+
   /** Get the unit as string. */
   public String getStringUnit(final EntityInterface entity) {
     final Iterator<Property> iterator = entity.getProperties().iterator();
@@ -98,6 +134,9 @@ public class CaosDBToGrpcConverters {
     if (from.hasParents()) {
       entityBuilder.addAllParents(convert(from.getParents()));
     }
+    if (from.hasFileProperties()) {
+      entityBuilder.setFileDescriptor(convert(from.getFileProperties()));
+    }
 
     final EntityResponse.Builder responseBuilder = EntityResponse.newBuilder();
     responseBuilder.setEntity(entityBuilder);
@@ -107,6 +146,13 @@ public class CaosDBToGrpcConverters {
     return responseBuilder;
   }
 
+  private FileDescriptor.Builder convert(FileProperties fileProperties) {
+    FileDescriptor.Builder result = FileDescriptor.newBuilder();
+    result.setPath(fileProperties.getPath());
+    result.setSize(fileProperties.getSize());
+    return result;
+  }
+
   private EntityRole convert(final Role role) {
     switch (role) {
       case RecordType:
@@ -210,7 +256,7 @@ public class CaosDBToGrpcConverters {
     return builder;
   }
 
-  private ScalarValue.Builder convertScalarValue(final Value value) {
+  protected ScalarValue.Builder convertScalarValue(final Value value) {
 
     if (value instanceof BooleanValue) {
       return convertBooleanValue((BooleanValue) value);
@@ -234,20 +280,20 @@ public class CaosDBToGrpcConverters {
     } else if (wrappedValue instanceof Integer) {
       return ScalarValue.newBuilder().setIntegerValue((Integer) wrappedValue);
     } else {
-      return convertStringValue(value);
+      return convertStringValue(value.toString());
     }
   }
 
-  private org.caosdb.api.entity.v1.ScalarValue.Builder convertStringValue(final Value value) {
-    if (value.toString().isEmpty()) {
+  private org.caosdb.api.entity.v1.ScalarValue.Builder convertStringValue(final String value) {
+    if (value.isEmpty()) {
       return ScalarValue.newBuilder().setSpecialValue(SpecialValue.SPECIAL_VALUE_EMPTY_STRING);
     }
-    return ScalarValue.newBuilder().setStringValue(value.toString());
+    return ScalarValue.newBuilder().setStringValue(value);
   }
 
   private org.caosdb.api.entity.v1.ScalarValue.Builder convertDateTimeInterface(
       final DateTimeInterface value) {
-    return convertStringValue(value);
+    return convertStringValue(value.toDateTimeString(timeZone));
   }
 
   private org.caosdb.api.entity.v1.ScalarValue.Builder convertBooleanValue(
@@ -256,7 +302,7 @@ public class CaosDBToGrpcConverters {
   }
 
   private ScalarValue.Builder convertReferenceValue(final ReferenceValue value) {
-    return convertStringValue(value);
+    return convertStringValue(value.toString());
   }
 
   private org.caosdb.api.entity.v1.Value.Builder convertCollectionValue(
@@ -274,6 +320,11 @@ public class CaosDBToGrpcConverters {
   }
 
   private ScalarValue convertScalarValue(final IndexedSingleValue v) {
+    if (v == null || v.getWrapped() == null) {
+      return ScalarValue.newBuilder()
+          .setSpecialValue(SpecialValue.SPECIAL_VALUE_UNSPECIFIED)
+          .build();
+    }
     return convertScalarValue(v.getWrapped()).build();
   }
 
@@ -438,4 +489,56 @@ public class CaosDBToGrpcConverters {
       builder.addAllInfos(convert(from.getMessages(Message.MessageType.Info.toString())));
     }
   }
+
+  public EntityACL convertACL(EntityInterface e) {
+    EntityACL.Builder builder = EntityACL.newBuilder();
+    builder.setId(e.getId().toString());
+    if (e.hasEntityACL()) {
+      builder.addAllRules(convert(e.getEntityACL(), true));
+    }
+    builder.addAllRules(convert(org.caosdb.server.permissions.EntityACL.GLOBAL_PERMISSIONS, false));
+    EntityAclPermission entityAclPermission = getCurrentACLPermission(e);
+    if (entityAclPermission != null) {
+      builder.setPermission(entityAclPermission);
+    }
+    return builder.build();
+  }
+
+  private org.caosdb.api.entity.v1.EntityAclPermission getCurrentACLPermission(EntityInterface e) {
+    if (e.hasPermission(EntityPermission.EDIT_PRIORITY_ACL)) {
+      return EntityAclPermission.ENTITY_ACL_PERMISSION_EDIT_PRIORITY_ACL;
+    }
+    if (e.hasPermission(EntityPermission.EDIT_ACL)) {
+      return EntityAclPermission.ENTITY_ACL_PERMISSION_EDIT_ACL;
+    }
+    return null;
+  }
+
+  private Iterable<? extends EntityPermissionRule> convert(
+      org.caosdb.server.permissions.EntityACL entityACL, boolean deletable) {
+    List<EntityPermissionRule> result = new LinkedList<>();
+    for (EntityACI aci : entityACL.getRules()) {
+      EntityPermissionRule.Builder builder =
+          EntityPermissionRule.newBuilder()
+              .setGrant(aci.isGrant())
+              .setPriority(aci.isPriority())
+              .setRole(aci.getResponsibleAgent().toString())
+              .addAllPermissions(convert(aci));
+      if (deletable) {
+        builder.addCapabilities(
+            EntityPermissionRuleCapability.ENTITY_PERMISSION_RULE_CAPABILITY_DELETE);
+      }
+      result.add(builder.build());
+    }
+    return result;
+  }
+
+  private Iterable<org.caosdb.api.entity.v1.EntityPermission> convert(EntityACI aci) {
+    List<org.caosdb.api.entity.v1.EntityPermission> result = new LinkedList<>();
+
+    for (EntityPermission p : aci.getPermission()) {
+      result.add(p.getMapping());
+    }
+    return result;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/grpc/EntityTransactionServiceImpl.java b/src/main/java/org/caosdb/server/grpc/EntityTransactionServiceImpl.java
index 7062defe36121177976d43bc58355f87f235ff8a..c234e61048ba7af730dd7928d0b64ff587c005cc 100644
--- a/src/main/java/org/caosdb/server/grpc/EntityTransactionServiceImpl.java
+++ b/src/main/java/org/caosdb/server/grpc/EntityTransactionServiceImpl.java
@@ -1,7 +1,29 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
 package org.caosdb.server.grpc;
 
 import io.grpc.stub.StreamObserver;
 import java.util.HashMap;
+import java.util.TimeZone;
 import java.util.UUID;
 import org.apache.shiro.SecurityUtils;
 import org.caosdb.api.entity.v1.DeleteRequest;
@@ -13,8 +35,12 @@ import org.caosdb.api.entity.v1.EntityTransactionServiceGrpc.EntityTransactionSe
 import org.caosdb.api.entity.v1.IdResponse;
 import org.caosdb.api.entity.v1.InsertRequest;
 import org.caosdb.api.entity.v1.InsertResponse;
+import org.caosdb.api.entity.v1.MultiRetrieveEntityACLRequest;
+import org.caosdb.api.entity.v1.MultiRetrieveEntityACLResponse;
 import org.caosdb.api.entity.v1.MultiTransactionRequest;
 import org.caosdb.api.entity.v1.MultiTransactionResponse;
+import org.caosdb.api.entity.v1.MultiUpdateEntityACLRequest;
+import org.caosdb.api.entity.v1.MultiUpdateEntityACLResponse;
 import org.caosdb.api.entity.v1.RetrieveResponse;
 import org.caosdb.api.entity.v1.TransactionRequest;
 import org.caosdb.api.entity.v1.TransactionRequest.WrappedRequestsCase;
@@ -31,12 +57,16 @@ import org.caosdb.server.entity.UpdateEntity;
 import org.caosdb.server.entity.container.RetrieveContainer;
 import org.caosdb.server.entity.container.WritableContainer;
 import org.caosdb.server.transaction.Retrieve;
+import org.caosdb.server.transaction.RetrieveACL;
+import org.caosdb.server.transaction.UpdateACL;
 import org.caosdb.server.transaction.WriteTransaction;
 import org.caosdb.server.utils.ServerMessages;
 
 public class EntityTransactionServiceImpl extends EntityTransactionServiceImplBase {
 
-  private final CaosDBToGrpcConverters caosdbToGrpc = new CaosDBToGrpcConverters();
+  // TODO(tf) let the clients define the time zone of the date time values which are being returned.
+  private final CaosDBToGrpcConverters caosdbToGrpc =
+      new CaosDBToGrpcConverters(TimeZone.getDefault());
   private final GrpcToCaosDBConverters grpcToCaosdb = new GrpcToCaosDBConverters();
   private final FileTransmissionServiceImpl fileTransmissionService;
 
@@ -359,18 +389,67 @@ public class EntityTransactionServiceImpl extends EntityTransactionServiceImplBa
     }
   }
 
+  private MultiRetrieveEntityACLResponse multiRetrieveEntityACL(
+      MultiRetrieveEntityACLRequest request) throws Exception {
+    MultiRetrieveEntityACLResponse.Builder builder = MultiRetrieveEntityACLResponse.newBuilder();
+    RetrieveACL transaction = new RetrieveACL(request.getIdList());
+    transaction.execute();
+    for (EntityInterface e : transaction.getContainer()) {
+      builder.addAcls(caosdbToGrpc.convertACL(e));
+    }
+    return builder.build();
+  }
+
+  private MultiUpdateEntityACLResponse multiUpdateEntityACL(MultiUpdateEntityACLRequest request)
+      throws Exception {
+    MultiUpdateEntityACLResponse.Builder builder = MultiUpdateEntityACLResponse.newBuilder();
+    UpdateACL transaction = new UpdateACL(grpcToCaosdb.convertAcls(request.getAclsList()));
+    transaction.execute();
+    return builder.build();
+  }
+
   @Override
   public void multiTransaction(
       final MultiTransactionRequest request,
       final StreamObserver<MultiTransactionResponse> responseObserver) {
     try {
+      AuthInterceptor.bindSubject();
       final MultiTransactionResponse response = transaction(request);
       responseObserver.onNext(response);
       responseObserver.onCompleted();
 
     } catch (final Exception e) {
-      e.printStackTrace();
-      responseObserver.onError(e);
+      AccessControlManagementServiceImpl.handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void multiRetrieveEntityACL(
+      MultiRetrieveEntityACLRequest request,
+      StreamObserver<MultiRetrieveEntityACLResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final MultiRetrieveEntityACLResponse response = multiRetrieveEntityACL(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      AccessControlManagementServiceImpl.handleException(responseObserver, e);
+    }
+  }
+
+  @Override
+  public void multiUpdateEntityACL(
+      MultiUpdateEntityACLRequest request,
+      StreamObserver<MultiUpdateEntityACLResponse> responseObserver) {
+    try {
+      AuthInterceptor.bindSubject();
+      final MultiUpdateEntityACLResponse response = multiUpdateEntityACL(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      AccessControlManagementServiceImpl.handleException(responseObserver, e);
     }
   }
 }
diff --git a/src/main/java/org/caosdb/server/grpc/FileTransmissionServiceImpl.java b/src/main/java/org/caosdb/server/grpc/FileTransmissionServiceImpl.java
index 0b0c4b50e0851f3298a61c02c5e38e08c29b2601..1f549b37a33f26c2f4ecdc5efc1258a3bb602d50 100644
--- a/src/main/java/org/caosdb/server/grpc/FileTransmissionServiceImpl.java
+++ b/src/main/java/org/caosdb/server/grpc/FileTransmissionServiceImpl.java
@@ -45,6 +45,7 @@ public class FileTransmissionServiceImpl extends FileTransmissionServiceImplBase
 
     @Override
     public void onNext(final FileUploadRequest request) {
+      AuthInterceptor.bindSubject();
       final FileChunk chunk = request.getChunk();
       if (chunk.hasFileTransmissionId()) {
         fileUpload =
@@ -104,6 +105,7 @@ public class FileTransmissionServiceImpl extends FileTransmissionServiceImplBase
       final RegisterFileUploadRequest request,
       final StreamObserver<RegisterFileUploadResponse> responseObserver) {
     try {
+      AuthInterceptor.bindSubject();
       final FileTransmission result = fileUploadRegistration.registerFileUpload();
       final Builder builder = RegisterFileUploadResponse.newBuilder();
       builder.setStatus(result.getRegistrationStatus());
@@ -133,6 +135,7 @@ public class FileTransmissionServiceImpl extends FileTransmissionServiceImplBase
       final FileDownloadRequest request,
       final StreamObserver<FileDownloadResponse> responseObserver) {
     try {
+      AuthInterceptor.bindSubject();
       FileDownloadResponse response =
           fileDownloadRegistration.downloadNextChunk(request.getFileTransmissionId());
       responseObserver.onNext(response);
diff --git a/src/main/java/org/caosdb/server/grpc/GRPCServer.java b/src/main/java/org/caosdb/server/grpc/GRPCServer.java
index 469e4b1048b6139c58d41a46b36c738603e536cf..73356140b85fb09af93bdca034a69685ce8cd4eb 100644
--- a/src/main/java/org/caosdb/server/grpc/GRPCServer.java
+++ b/src/main/java/org/caosdb/server/grpc/GRPCServer.java
@@ -17,6 +17,7 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  */
+
 package org.caosdb.server.grpc;
 
 import io.grpc.Server;
@@ -115,6 +116,12 @@ public class GRPCServer {
   private List<ServerServiceDefinition> getEnabledServices() {
     final List<ServerServiceDefinition> services = new LinkedList<>();
 
+    final AccessControlManagementServiceImpl accessControlManagementService =
+        new AccessControlManagementServiceImpl();
+    services.add(
+        ServerInterceptors.intercept(
+            accessControlManagementService, loggingInterceptor, authInterceptor));
+
     final GeneralInfoServiceImpl generalInfoService = new GeneralInfoServiceImpl();
     services.add(
         ServerInterceptors.intercept(generalInfoService, loggingInterceptor, authInterceptor));
@@ -197,6 +204,7 @@ public class GRPCServer {
       CaosDBServer.addPreShutdownHook(new ServerStopper(server));
       server.start();
       logger.info("Started GRPC (HTTP) on port {}", port_http);
+
     } else if (!started) {
       logger.warn(
           "No GRPC Server has been started. Please configure {} or {} to do so.",
diff --git a/src/main/java/org/caosdb/server/grpc/GeneralInfoServiceImpl.java b/src/main/java/org/caosdb/server/grpc/GeneralInfoServiceImpl.java
index 17d9f4c8e17886f66bc73096487f0b194b350fe8..e47bda9c1783fd9a82703626ad8017c26dbea1fe 100644
--- a/src/main/java/org/caosdb/server/grpc/GeneralInfoServiceImpl.java
+++ b/src/main/java/org/caosdb/server/grpc/GeneralInfoServiceImpl.java
@@ -17,15 +17,27 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  */
+
 package org.caosdb.server.grpc;
 
 import io.grpc.stub.StreamObserver;
+import java.util.Collection;
+import java.util.LinkedList;
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.authz.AuthorizationInfo;
+import org.apache.shiro.authz.Permission;
+import org.apache.shiro.subject.Subject;
 import org.caosdb.api.info.v1.GeneralInfoServiceGrpc.GeneralInfoServiceImplBase;
+import org.caosdb.api.info.v1.GetSessionInfoRequest;
+import org.caosdb.api.info.v1.GetSessionInfoResponse;
 import org.caosdb.api.info.v1.GetVersionInfoRequest;
 import org.caosdb.api.info.v1.GetVersionInfoResponse;
 import org.caosdb.api.info.v1.VersionInfo;
 import org.caosdb.server.CaosDBServer;
 import org.caosdb.server.ServerProperties;
+import org.caosdb.server.accessControl.AuthenticationUtils;
+import org.caosdb.server.accessControl.Principal;
+import org.caosdb.server.permissions.CaosPermission;
 
 /**
  * Implementation of the GeneralInfoService.
@@ -38,10 +50,7 @@ import org.caosdb.server.ServerProperties;
  */
 public class GeneralInfoServiceImpl extends GeneralInfoServiceImplBase {
 
-  @Override
-  public void getVersionInfo(
-      final GetVersionInfoRequest request,
-      final StreamObserver<GetVersionInfoResponse> responseObserver) {
+  private GetVersionInfoResponse getVersionInfo(GetVersionInfoRequest request) {
 
     final String version[] =
         CaosDBServer.getServerProperty(ServerProperties.KEY_PROJECT_VERSION).split("[\\.-]", 4);
@@ -59,10 +68,74 @@ public class GeneralInfoServiceImpl extends GeneralInfoServiceImplBase {
             .setPreRelease(pre_release)
             .setBuild(build)
             .build();
-    final GetVersionInfoResponse response =
-        GetVersionInfoResponse.newBuilder().setVersionInfo(versionInfo).build();
+    return GetVersionInfoResponse.newBuilder().setVersionInfo(versionInfo).build();
+  }
+
+  @Override
+  public void getVersionInfo(
+      final GetVersionInfoRequest request,
+      final StreamObserver<GetVersionInfoResponse> responseObserver) {
+
+    try {
+      AuthInterceptor.bindSubject();
+      GetVersionInfoResponse response = getVersionInfo(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
+
+    } catch (final Exception e) {
+      AccessControlManagementServiceImpl.handleException(responseObserver, e);
+    }
+  }
+
+  private GetSessionInfoResponse getSessionInfo(GetSessionInfoRequest request) {
+    Subject subject = SecurityUtils.getSubject();
+    GetSessionInfoResponse.Builder response = GetSessionInfoResponse.newBuilder();
+
+    Principal principal = (Principal) subject.getPrincipal();
+
+    response.setUsername(principal.getUsername());
+    response.setRealm(principal.getRealm());
+
+    AuthorizationInfo authorizationInfo = AuthenticationUtils.getAuthorizationInfo(subject);
+    Collection<String> roles = authorizationInfo.getRoles();
+    if (roles != null && !roles.isEmpty()) {
+      response.addAllRoles(roles);
+    }
+
+    Collection<String> permissions = new LinkedList<>();
+
+    Collection<String> stringPermissions = authorizationInfo.getStringPermissions();
+    if (stringPermissions != null && !stringPermissions.isEmpty()) {
+      permissions.addAll(stringPermissions);
+    }
+
+    for (Permission p : authorizationInfo.getObjectPermissions()) {
+      if (p instanceof CaosPermission) {
+        permissions.addAll(((CaosPermission) p).getStringPermissions(subject));
+      } else {
+        permissions.add(p.toString());
+      }
+    }
+
+    if (permissions != null && !permissions.isEmpty()) {
+      response.addAllPermissions(permissions);
+    }
+
+    return response.build();
+  }
+
+  @Override
+  public void getSessionInfo(
+      GetSessionInfoRequest request, StreamObserver<GetSessionInfoResponse> responseObserver) {
+
+    try {
+      AuthInterceptor.bindSubject();
+      final GetSessionInfoResponse response = getSessionInfo(request);
+      responseObserver.onNext(response);
+      responseObserver.onCompleted();
 
-    responseObserver.onNext(response);
-    responseObserver.onCompleted();
+    } catch (final Exception e) {
+      AccessControlManagementServiceImpl.handleException(responseObserver, e);
+    }
   }
 }
diff --git a/src/main/java/org/caosdb/server/grpc/GrpcToCaosDBConverters.java b/src/main/java/org/caosdb/server/grpc/GrpcToCaosDBConverters.java
index c2007bebd52f29ce8d1a02fe9e0fcd913a8df798..d7c515a433cfa82f0bea046a1856dd9fb309b915 100644
--- a/src/main/java/org/caosdb/server/grpc/GrpcToCaosDBConverters.java
+++ b/src/main/java/org/caosdb/server/grpc/GrpcToCaosDBConverters.java
@@ -1,12 +1,39 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
 package org.caosdb.server.grpc;
 
+import java.util.ArrayList;
 import java.util.Collection;
 import java.util.LinkedList;
 import java.util.List;
+import java.util.UUID;
+import org.apache.shiro.SecurityUtils;
 import org.caosdb.api.entity.v1.AtomicDataType;
 import org.caosdb.api.entity.v1.CollectionValues;
 import org.caosdb.api.entity.v1.DataType;
 import org.caosdb.api.entity.v1.Entity;
+import org.caosdb.api.entity.v1.EntityACL;
+import org.caosdb.api.entity.v1.EntityPermission;
+import org.caosdb.api.entity.v1.EntityPermissionRule;
 import org.caosdb.api.entity.v1.EntityRole;
 import org.caosdb.api.entity.v1.FileDescriptor;
 import org.caosdb.api.entity.v1.Importance;
@@ -28,7 +55,10 @@ import org.caosdb.server.entity.FileProperties;
 import org.caosdb.server.entity.MagicTypes;
 import org.caosdb.server.entity.Role;
 import org.caosdb.server.entity.StatementStatus;
+import org.caosdb.server.entity.UpdateEntity;
+import org.caosdb.server.entity.container.TransactionContainer;
 import org.caosdb.server.entity.wrapper.Property;
+import org.caosdb.server.permissions.EntityACLFactory;
 import org.caosdb.server.utils.EntityStatus;
 import org.caosdb.server.utils.ServerMessages;
 
@@ -95,7 +125,7 @@ public class GrpcToCaosDBConverters {
     if (from.getParentsCount() > 0) {
       entity.getParents().addAll(convertParents(from.getParentsList()));
     }
-    if (from.hasFileDescriptor()) {
+    if (entity.getRole() == Role.File && from.hasFileDescriptor()) {
       entity.setFileProperties(convert(from.getFileDescriptor()));
     }
     return entity;
@@ -289,4 +319,58 @@ public class GrpcToCaosDBConverters {
     result.setName(e.getName().isBlank() ? null : e.getName());
     return result;
   }
+
+  public TransactionContainer convertAcls(List<EntityACL> aclsList) {
+    TransactionContainer result =
+        new TransactionContainer(
+            SecurityUtils.getSubject(), System.currentTimeMillis(), UUID.randomUUID().toString());
+
+    aclsList.forEach(
+        acl -> {
+          result.add(convert(acl));
+        });
+    return result;
+  }
+
+  private EntityInterface convert(EntityACL acl) {
+    try {
+      Integer id = getId(acl.getId());
+      UpdateEntity result = new UpdateEntity(id, null);
+      result.setEntityACL(convertAcl(acl));
+      return result;
+    } catch (NumberFormatException exc) {
+      UpdateEntity result = new UpdateEntity(null, null);
+      result.addError(ServerMessages.ENTITY_DOES_NOT_EXIST);
+      return result;
+    }
+  }
+
+  private org.caosdb.server.permissions.EntityACL convertAcl(EntityACL acl) {
+    EntityACLFactory fac = new EntityACLFactory();
+    for (EntityPermissionRule rule : acl.getRulesList()) {
+      if (rule.getGrant()) {
+        fac.grant(
+            org.caosdb.server.permissions.Role.create(rule.getRole()),
+            rule.getPriority(),
+            convert(rule.getPermissionsList()));
+      } else {
+        fac.deny(
+            org.caosdb.server.permissions.Role.create(rule.getRole()),
+            rule.getPriority(),
+            convert(rule.getPermissionsList()));
+      }
+    }
+    return fac.remove(org.caosdb.server.permissions.EntityACL.GLOBAL_PERMISSIONS).create();
+  }
+
+  private org.caosdb.server.permissions.EntityPermission[] convert(
+      List<EntityPermission> permissionsList) {
+    ArrayList<org.caosdb.server.permissions.EntityPermission> result =
+        new ArrayList<>(permissionsList.size());
+    permissionsList.forEach(
+        (p) -> {
+          result.add(org.caosdb.server.permissions.EntityPermission.getEntityPermission(p));
+        });
+    return result.toArray(new org.caosdb.server.permissions.EntityPermission[0]);
+  }
 }
diff --git a/src/main/java/org/caosdb/server/jobs/Job.java b/src/main/java/org/caosdb/server/jobs/Job.java
index 9bca9eb2e1b9a78e9e73a79b5f31161b345f2dc1..675686aa797cd2a00cf7a921a29e81ce144db179 100644
--- a/src/main/java/org/caosdb/server/jobs/Job.java
+++ b/src/main/java/org/caosdb/server/jobs/Job.java
@@ -27,8 +27,6 @@ import java.util.HashMap;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Set;
-import org.apache.shiro.authz.AuthorizationException;
-import org.apache.shiro.authz.Permission;
 import org.apache.shiro.subject.Subject;
 import org.caosdb.server.CaosDBException;
 import org.caosdb.server.database.BackendTransaction;
@@ -300,11 +298,6 @@ public abstract class Job {
     return entity;
   }
 
-  protected final void checkPermission(final EntityInterface entity, final Permission permission)
-      throws AuthorizationException {
-    entity.checkPermission(permission);
-  }
-
   /**
    * Create a Job object with the given parameters.
    *
diff --git a/src/main/java/org/caosdb/server/jobs/Schedule.java b/src/main/java/org/caosdb/server/jobs/Schedule.java
index f33400099a951aa8fbcf1975208988085813a8b8..57474da515418745ed0457962596dfce233bff48 100644
--- a/src/main/java/org/caosdb/server/jobs/Schedule.java
+++ b/src/main/java/org/caosdb/server/jobs/Schedule.java
@@ -97,8 +97,8 @@ public class Schedule {
             ? this.jobLists.get(jobclass.getAnnotation(JobAnnotation.class).stage().ordinal())
             : this.jobLists.get(TransactionStage.CHECK.ordinal());
     for (final ScheduledJob scheduledJob : jobs) {
-      if (jobclass.isInstance(scheduledJob.job)) {
-        if (scheduledJob.job.getEntity() == entity) {
+      if (jobclass.isInstance(scheduledJob.getJob())) {
+        if (scheduledJob.getJob().getEntity() == entity) {
           runJob(scheduledJob);
         }
       }
diff --git a/src/main/java/org/caosdb/server/jobs/ScheduledJob.java b/src/main/java/org/caosdb/server/jobs/ScheduledJob.java
index 3affdfd21421961edc4721c25d80f392d914d1bb..0ef0ac143428eaddaf857f063b7953a620f47ee6 100644
--- a/src/main/java/org/caosdb/server/jobs/ScheduledJob.java
+++ b/src/main/java/org/caosdb/server/jobs/ScheduledJob.java
@@ -31,11 +31,14 @@ package org.caosdb.server.jobs;
 public class ScheduledJob {
 
   long runtime = 0;
-  final Job job;
+  private final Job job;
   private long startTime = -1;
 
-  ScheduledJob(final Job j) {
-    this.job = j;
+  ScheduledJob(final Job job) {
+    if (job == null) {
+      throw new NullPointerException("job was null.");
+    }
+    this.job = job;
   }
 
   void run() {
@@ -85,4 +88,8 @@ public class ScheduledJob {
   public boolean skip() {
     return this.job.getTarget().skipJob();
   }
+
+  public Job getJob() {
+    return job;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/jobs/core/AccessControl.java b/src/main/java/org/caosdb/server/jobs/core/AccessControl.java
index 408384f416e1249501d5383ea1028ced56914ded..724dd89844097dad5bd1a6fbf2102c8f2c4ceb8c 100644
--- a/src/main/java/org/caosdb/server/jobs/core/AccessControl.java
+++ b/src/main/java/org/caosdb/server/jobs/core/AccessControl.java
@@ -24,6 +24,7 @@ package org.caosdb.server.jobs.core;
 
 import org.apache.shiro.SecurityUtils;
 import org.apache.shiro.subject.Subject;
+import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.database.backend.transaction.RetrieveSparseEntity;
 import org.caosdb.server.entity.EntityInterface;
 import org.caosdb.server.entity.wrapper.Parent;
@@ -37,12 +38,51 @@ import org.caosdb.server.utils.ServerMessages;
 @JobAnnotation(stage = TransactionStage.INIT)
 public class AccessControl extends ContainerJob {
 
+  public static class TransactionPermission extends ACMPermissions {
+
+    public static final String ENTITY_ROLE_PARAMETER = "?ENTITY_ROLE?";
+
+    public TransactionPermission(String permission, String description) {
+      super(permission, description);
+    }
+
+    public final String toString(String entityRole) {
+      return toString().replace(ENTITY_ROLE_PARAMETER, entityRole);
+    }
+
+    public final String toString(String transaction, String entityRole) {
+      return "TRANSACTION:" + transaction + (entityRole != null ? (":" + entityRole) : "");
+    }
+
+    public static String init() {
+      return TransactionPermission.class.getSimpleName();
+    }
+  }
+
+  public static final TransactionPermission TRANSACTION_PERMISSIONS =
+      new TransactionPermission(
+          "TRANSACTION:*",
+          "Permission to execute any writable transaction. This permission only allows to execute these transactions in general. The necessary entities permissions are not implied.");
+  public static final TransactionPermission UPDATE =
+      new TransactionPermission(
+          "TRANSACTION:UPDATE:" + TransactionPermission.ENTITY_ROLE_PARAMETER,
+          "Permission to update entities of a given role (e.g. Record, File, RecordType, or Property).");
+  public static final TransactionPermission DELETE =
+      new TransactionPermission(
+          "TRANSACTION:DELETE:" + TransactionPermission.ENTITY_ROLE_PARAMETER,
+          "Permission to delete entities of a given role (e.g. Record, File, RecordType, or Property).");
+  public static final TransactionPermission INSERT =
+      new TransactionPermission(
+          "TRANSACTION:INSERT:" + TransactionPermission.ENTITY_ROLE_PARAMETER,
+          "Permission to insert entities of a given role (e.g. Record, File, RecordType, or Property).");
+
   @Override
   protected void run() {
     final Subject subject = SecurityUtils.getSubject();
 
     // subject has complete permissions for this kind of transaction
-    if (subject.isPermitted("TRANSACTION:" + getTransaction().getClass().getSimpleName())) {
+    if (subject.isPermitted(
+        TRANSACTION_PERMISSIONS.toString(getTransaction().getClass().getSimpleName(), null))) {
       return;
     }
 
@@ -54,10 +94,8 @@ public class AccessControl extends ContainerJob {
 
       // per role permission
       if (subject.isPermitted(
-          "TRANSACTION:"
-              + getTransaction().getClass().getSimpleName()
-              + ":"
-              + e.getRole().toString())) {
+          TRANSACTION_PERMISSIONS.toString(
+              getTransaction().getClass().getSimpleName(), e.getRole().toString()))) {
         continue;
       }
 
diff --git a/src/main/java/org/caosdb/server/jobs/core/CheckStateTransition.java b/src/main/java/org/caosdb/server/jobs/core/CheckStateTransition.java
index 1a159910044a079baba3b64c62176883ad31b8ef..a43face9ae14f3fac57890ccb8617e5637c95c16 100644
--- a/src/main/java/org/caosdb/server/jobs/core/CheckStateTransition.java
+++ b/src/main/java/org/caosdb/server/jobs/core/CheckStateTransition.java
@@ -22,6 +22,7 @@ package org.caosdb.server.jobs.core;
 
 import java.util.Map;
 import org.apache.shiro.authz.AuthorizationException;
+import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.entity.DeleteEntity;
 import org.caosdb.server.entity.Message;
 import org.caosdb.server.entity.Message.MessageType;
@@ -42,9 +43,35 @@ import org.caosdb.server.utils.ServerMessages;
 @JobAnnotation(stage = TransactionStage.POST_CHECK, transaction = WriteTransaction.class)
 public class CheckStateTransition extends EntityStateJob {
 
-  private static final String PERMISSION_STATE_FORCE_FINAL = "STATE:FORCE:FINAL";
-  private static final String PERMISSION_STATE_UNASSIGN = "STATE:UNASSIGN:";
-  private static final String PERMISSION_STATE_ASSIGN = "STATE:ASSIGN:";
+  public static final class StateModelPermission extends ACMPermissions {
+
+    public static final String STATE_MODEL_PARAMETER = "?STATE_MODEL?";
+
+    public StateModelPermission(String permission, String description) {
+      super(permission, description);
+    }
+
+    public final String toString(String state_model) {
+      return toString().replace(STATE_MODEL_PARAMETER, state_model);
+    }
+
+    public static String init() {
+      return StateModelPermission.class.getSimpleName();
+    }
+  }
+
+  public static final StateModelPermission PERMISSION_STATE_FORCE_FINAL =
+      new StateModelPermission(
+          "STATE:FORCE:FINAL",
+          "Permission to force to leave a state models specified life-cycle even though the currrent state isn't a final state in the that model.");
+  public static final StateModelPermission PERMISSION_STATE_UNASSIGN =
+      new StateModelPermission(
+          "STATE:UNASSIGN:" + StateModelPermission.STATE_MODEL_PARAMETER,
+          "Permission to unassign a state model.");
+  public static final StateModelPermission PERMISSION_STATE_ASSIGN =
+      new StateModelPermission(
+          "STATE:ASSIGN:" + StateModelPermission.STATE_MODEL_PARAMETER,
+          "Permission to assign a state model.");
   private static final Message TRANSITION_NOT_ALLOWED =
       new Message(MessageType.Error, "Transition not allowed.");
   private static final Message INITIAL_STATE_NOT_ALLOWED =
@@ -167,12 +194,12 @@ public class CheckStateTransition extends EntityStateJob {
   private void checkFinalState(State oldState) throws Message {
     if (!oldState.isFinal()) {
       if (isForceFinal()) {
-        getUser().checkPermission(PERMISSION_STATE_FORCE_FINAL);
+        getUser().checkPermission(PERMISSION_STATE_FORCE_FINAL.toString());
       } else {
         throw FINAL_STATE_NOT_ALLOWED;
       }
     }
-    getUser().checkPermission(PERMISSION_STATE_UNASSIGN + oldState.getStateModelName());
+    getUser().checkPermission(PERMISSION_STATE_UNASSIGN.toString(oldState.getStateModelName()));
   }
 
   /**
@@ -185,7 +212,7 @@ public class CheckStateTransition extends EntityStateJob {
     if (!newState.isInitial()) {
       throw INITIAL_STATE_NOT_ALLOWED;
     }
-    getUser().checkPermission(PERMISSION_STATE_ASSIGN + newState.getStateModelName());
+    getUser().checkPermission(PERMISSION_STATE_ASSIGN.toString(newState.getStateModelName()));
   }
 
   private boolean isForceFinal() {
diff --git a/src/main/java/org/caosdb/server/jobs/core/EntityStateJob.java b/src/main/java/org/caosdb/server/jobs/core/EntityStateJob.java
index e2f59a8827a682df508a26176a45a9fc1a874b4e..16fe593654aad760edc2b8efc2e6889222bfa78e 100644
--- a/src/main/java/org/caosdb/server/jobs/core/EntityStateJob.java
+++ b/src/main/java/org/caosdb/server/jobs/core/EntityStateJob.java
@@ -33,6 +33,7 @@ import java.util.Map.Entry;
 import java.util.Objects;
 import java.util.Set;
 import org.apache.shiro.subject.Subject;
+import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.database.exceptions.EntityDoesNotExistException;
 import org.caosdb.server.datatype.AbstractCollectionDatatype;
 import org.caosdb.server.datatype.CollectionValue;
@@ -82,6 +83,19 @@ import org.jdom2.Element;
  */
 public abstract class EntityStateJob extends EntityJob {
 
+  public static final class TransitionPermission extends ACMPermissions {
+
+    public static final String TRANSITION_PARAMETER = "?TRANSITION?";
+
+    public TransitionPermission(String permission, String description) {
+      super(permission, description);
+    }
+
+    public final String toString(String transition) {
+      return toString().replace(TRANSITION_PARAMETER, transition);
+    }
+  }
+
   protected static final String SERVER_PROPERTY_EXT_ENTITY_STATE = "EXT_ENTITY_STATE";
 
   public static final String TO_STATE_PROPERTY_NAME = "to";
@@ -102,7 +116,13 @@ public abstract class EntityStateJob extends EntityJob {
   public static final String STATE_ATTRIBUTE_DESCRIPTION = "description";
   public static final String STATE_ATTRIBUTE_ID = "id";
   public static final String ENTITY_STATE_ROLE_MARKER = "?STATE?";
-  public static final String PERMISSION_STATE_TRANSION = "STATE:TRANSITION:";
+  public static final ACMPermissions STATE_PERMISSIONS =
+      new ACMPermissions(
+          "STATE:*", "Permissions to manage state models and the states of entities.");
+  public static final TransitionPermission PERMISSION_STATE_TRANSION =
+      new TransitionPermission(
+          "STATE:TRANSITION:" + TransitionPermission.TRANSITION_PARAMETER,
+          "Permission to initiate a transition.");
 
   public static final Message STATE_MODEL_NOT_FOUND =
       new Message(MessageType.Error, "StateModel not found.");
@@ -253,7 +273,7 @@ public abstract class EntityStateJob extends EntityJob {
     }
 
     public boolean isPermitted(Subject user) {
-      return user.isPermitted(PERMISSION_STATE_TRANSION + this.name);
+      return user.isPermitted(PERMISSION_STATE_TRANSION.toString(this.name));
     }
   }
 
diff --git a/src/main/java/org/caosdb/server/permissions/CaosPermission.java b/src/main/java/org/caosdb/server/permissions/CaosPermission.java
index bfbb7eb2e8515f71bb2d611d4fd75916cfae50e7..615b4d1a9c26c1addb955506ab1debddb729db9c 100644
--- a/src/main/java/org/caosdb/server/permissions/CaosPermission.java
+++ b/src/main/java/org/caosdb/server/permissions/CaosPermission.java
@@ -22,12 +22,11 @@
  */
 package org.caosdb.server.permissions;
 
+import java.util.Collection;
 import java.util.HashSet;
-import java.util.Map;
 import org.apache.shiro.SecurityUtils;
 import org.apache.shiro.authz.Permission;
 import org.apache.shiro.subject.Subject;
-import org.eclipse.jetty.util.ajax.JSON;
 
 public class CaosPermission extends HashSet<PermissionRule> implements Permission {
 
@@ -35,16 +34,33 @@ public class CaosPermission extends HashSet<PermissionRule> implements Permissio
     super(rules);
   }
 
-  public CaosPermission() {}
+  public Collection<String> getStringPermissions(Subject subject) {
+    HashSet<String> grant = new HashSet<>();
+    HashSet<String> prio_grant = new HashSet<>();
+    HashSet<String> deny = new HashSet<>();
+    HashSet<String> prio_deny = new HashSet<>();
 
-  public static CaosPermission parseJSON(final String json) {
-    final CaosPermission ret = new CaosPermission();
-    @SuppressWarnings("unchecked")
-    final Map<String, String>[] rules = (Map<String, String>[]) JSON.parse(json);
-    for (final Map<String, String> rule : rules) {
-      ret.add(PermissionRule.parse(rule));
+    for (PermissionRule r : this) {
+      String p = subject == null ? r.getPermission() : r.getPermission(subject).toString();
+      if (r.isGrant()) {
+        if (r.isPriority()) {
+          prio_grant.add(p);
+        } else {
+          grant.add(p);
+        }
+      } else {
+        if (r.isPriority()) {
+          prio_deny.add(p);
+        } else {
+          deny.add(p);
+        }
+      }
     }
-    return ret;
+
+    grant.removeAll(deny);
+    grant.addAll(prio_grant);
+    grant.removeAll(prio_deny);
+    return grant;
   }
 
   private static final long serialVersionUID = 2136265443788256009L;
diff --git a/src/main/java/org/caosdb/server/permissions/EntityACL.java b/src/main/java/org/caosdb/server/permissions/EntityACL.java
index ce76cf5283847ad0e17886daa80b06548541c030..f959ba89bd08cd5996af18540a484292a5046f94 100644
--- a/src/main/java/org/caosdb/server/permissions/EntityACL.java
+++ b/src/main/java/org/caosdb/server/permissions/EntityACL.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,8 +19,8 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.permissions;
 
 import static org.caosdb.server.permissions.Role.OTHER_ROLE;
@@ -152,6 +153,7 @@ public class EntityACL {
       }
     }
     if (acl.isEmpty()) {
+      // There haven't been any rules which apply to this subject. Thus the rules for ?OTHER? apply.
       acl.addAll(forOthers);
     }
     return getPermissionsFromBitSet(getResultingACL(acl));
@@ -360,10 +362,6 @@ public class EntityACL {
     return new EntityACL(newACL);
   }
 
-  public static final void normalize(final Collection<EntityACI> acl) {
-    // every priority denial removes all other items
-  }
-
   public EntityACL getPriorityEntityACL() {
     return getPriorityEntityACL(this);
   }
diff --git a/src/main/java/org/caosdb/server/permissions/EntityPermission.java b/src/main/java/org/caosdb/server/permissions/EntityPermission.java
index 1f84dce34a611f3b25bea5ddaab0d40c9723a280..f8f21a354ef68403f852a1f426e28afed857278d 100644
--- a/src/main/java/org/caosdb/server/permissions/EntityPermission.java
+++ b/src/main/java/org/caosdb/server/permissions/EntityPermission.java
@@ -37,6 +37,11 @@ public class EntityPermission extends Permission {
   private static final long serialVersionUID = -8935713878537140286L;
   private static List<EntityPermission> instances = new ArrayList<>();
   private final int bitNumber;
+  private final org.caosdb.api.entity.v1.EntityPermission mapping;
+  public static final Permission EDIT_PRIORITY_ACL =
+      new Permission(
+          "ADMIN:ENTITY:EDIT:PRIORITY_ACL",
+          "The permission to edit (add/delete) the prioritized rules of an acl of an entity.");
 
   public static ToElementable getAllEntityPermissions() {
     final Element entityPermissionsElement = new Element("EntityPermissions");
@@ -57,9 +62,14 @@ public class EntityPermission extends Permission {
     };
   }
 
-  private EntityPermission(final String shortName, final String description, final int bitNumber) {
+  private EntityPermission(
+      final String shortName,
+      final String description,
+      final int bitNumber,
+      org.caosdb.api.entity.v1.EntityPermission mapping) {
     super(shortName, description);
     this.bitNumber = bitNumber;
+    this.mapping = mapping;
     if (bitNumber > 61) {
       throw new CaosDBException(
           "This bitNumber is too big. This implementation only handles bitNumbers up to 61.");
@@ -102,6 +112,16 @@ public class EntityPermission extends Permission {
     throw new IllegalArgumentException("Permission is not defined.");
   }
 
+  public static EntityPermission getEntityPermission(
+      final org.caosdb.api.entity.v1.EntityPermission permission) {
+    for (final EntityPermission p : instances) {
+      if (p.getMapping() == permission) {
+        return p;
+      }
+    }
+    throw new IllegalArgumentException("Permission not found." + permission.name());
+  }
+
   public long getBitSet() {
     return (long) Math.pow(2, getBitNumber());
   }
@@ -116,78 +136,153 @@ public class EntityPermission extends Permission {
     return ret;
   }
 
+  public org.caosdb.api.entity.v1.EntityPermission getMapping() {
+    return mapping;
+  }
+
   public static final EntityPermission RETRIEVE_ENTITY =
       new EntityPermission(
           "RETRIEVE:ENTITY",
           "Permission to retrieve the full entity (name, description, data type, ...) with all parents and properties (unless prohibited by another rule on the property level).",
-          4);
+          4,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_ENTITY);
   public static final EntityPermission RETRIEVE_ACL =
       new EntityPermission(
-          "RETRIEVE:ACL", "Permission to retrieve the full and final ACL of this entity.", 5);
+          "RETRIEVE:ACL",
+          "Permission to retrieve the full and final ACL of this entity.",
+          5,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_ACL);
   public static final EntityPermission RETRIEVE_HISTORY =
       new EntityPermission(
-          "RETRIEVE:HISTORY", "Permission to retrieve the history of this entity.", 6);
+          "RETRIEVE:HISTORY",
+          "Permission to retrieve the history of this entity.",
+          6,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_HISTORY);
   public static final EntityPermission RETRIEVE_OWNER =
       new EntityPermission(
-          "RETRIEVE:OWNER", "Permission to retrieve the owner(s) of this entity.", 9);
+          "RETRIEVE:OWNER",
+          "Permission to retrieve the owner(s) of this entity.",
+          9,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_OWNER);
   public static final EntityPermission RETRIEVE_FILE =
       new EntityPermission(
-          "RETRIEVE:FILE", "Permission to download the file belonging to this entity.", 10);
+          "RETRIEVE:FILE",
+          "Permission to download the file belonging to this entity.",
+          10,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_FILE);
   public static final EntityPermission DELETE =
-      new EntityPermission("DELETE", "Permission to delete an entity.", 1);
+      new EntityPermission(
+          "DELETE",
+          "Permission to delete an entity.",
+          1,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_DELETE);
   public static final EntityPermission EDIT_ACL =
       new EntityPermission(
           "EDIT:ACL",
           "Permission to change the user-specified part of this entity's ACL. Roles with this Permission are called 'Owners'.",
-          0);
+          0,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_EDIT_ACL);
   public static final EntityPermission UPDATE_DESCRIPTION =
       new EntityPermission(
-          "UPDATE:DESCRIPTION", "Permission to change the value of this entity.", 11);
+          "UPDATE:DESCRIPTION",
+          "Permission to change the value of this entity.",
+          11,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_DESCRIPTION);
   public static final EntityPermission UPDATE_VALUE =
-      new EntityPermission("UPDATE:VALUE", "Permission to change the value of this entity.", 12);
+      new EntityPermission(
+          "UPDATE:VALUE",
+          "Permission to change the value of this entity.",
+          12,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_VALUE);
   public static final EntityPermission UPDATE_ROLE =
-      new EntityPermission("UPDATE:ROLE", "Permission to change the role of this entity.", 13);
+      new EntityPermission(
+          "UPDATE:ROLE",
+          "Permission to change the role of this entity.",
+          13,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_ROLE);
   public static final EntityPermission UPDATE_REMOVE_PARENT =
       new EntityPermission(
-          "UPDATE:PARENT:REMOVE", "Permission  to remove parents from this entity.", 14);
+          "UPDATE:PARENT:REMOVE",
+          "Permission  to remove parents from this entity.",
+          14,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_REMOVE_PARENT);
   public static final EntityPermission UPDATE_ADD_PARENT =
-      new EntityPermission("UPDATE:PARENT:ADD", "Permission to add a parent to this entity.", 15);
+      new EntityPermission(
+          "UPDATE:PARENT:ADD",
+          "Permission to add a parent to this entity.",
+          15,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_ADD_PARENT);
   public static final EntityPermission UPDATE_REMOVE_PROPERTY =
       new EntityPermission(
-          "UPDATE:PROPERTY:REMOVE", "Permission to remove properties from this entity.", 16);
+          "UPDATE:PROPERTY:REMOVE",
+          "Permission to remove properties from this entity.",
+          16,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_REMOVE_PROPERTY);
   public static final EntityPermission UPDATE_ADD_PROPERTY =
       new EntityPermission(
-          "UPDATE:PROPERTY:ADD", "Permission to add a property to this entity.", 17);
+          "UPDATE:PROPERTY:ADD",
+          "Permission to add a property to this entity.",
+          17,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_ADD_PROPERTY);
   public static final EntityPermission UPDATE_NAME =
-      new EntityPermission("UPDATE:NAME", "Permission to change the name of this entity.", 19);
+      new EntityPermission(
+          "UPDATE:NAME",
+          "Permission to change the name of this entity.",
+          19,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_NAME);
   public static final EntityPermission UPDATE_DATA_TYPE =
       new EntityPermission(
-          "UPDATE:DATA_TYPE", "Permission to change the data type of this entity.", 20);
+          "UPDATE:DATA_TYPE",
+          "Permission to change the data type of this entity.",
+          20,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_DATA_TYPE);
   public static final EntityPermission UPDATE_REMOVE_FILE =
       new EntityPermission(
-          "UPDATE:FILE:REMOVE", "Permission to delete the file of this entity.", 21);
+          "UPDATE:FILE:REMOVE",
+          "Permission to delete the file of this entity.",
+          21,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_REMOVE_FILE);
   public static final EntityPermission UPDATE_ADD_FILE =
-      new EntityPermission("UPDATE:FILE:ADD", "Permission to set a file for this entity.", 22);
+      new EntityPermission(
+          "UPDATE:FILE:ADD",
+          "Permission to set a file for this entity.",
+          22,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_ADD_FILE);
   public static final EntityPermission UPDATE_MOVE_FILE =
       new EntityPermission(
-          "UPDATE:FILE:MOVE", "Permission to move an existing file to a new location.", 23);
+          "UPDATE:FILE:MOVE",
+          "Permission to move an existing file to a new location.",
+          23,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_MOVE_FILE);
   public static final EntityPermission USE_AS_REFERENCE =
       new EntityPermission(
-          "USE:AS_REFERENCE", "Permission to refer to this entity via a reference property.", 24);
+          "USE:AS_REFERENCE",
+          "Permission to refer to this entity via a reference property.",
+          24,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_USE_AS_REFERENCE);
   public static final EntityPermission USE_AS_PROPERTY =
       new EntityPermission(
-          "USE:AS_PROPERTY", "Permission to implement this entity as a property.", 25);
+          "USE:AS_PROPERTY",
+          "Permission to implement this entity as a property.",
+          25,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_USE_AS_PROPERTY);
   public static final EntityPermission USE_AS_PARENT =
       new EntityPermission(
-          "USE:AS_PARENT", "Permission to use this entity as a super type for other entities.", 26);
+          "USE:AS_PARENT",
+          "Permission to use this entity as a super type for other entities.",
+          26,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_USE_AS_PARENT);
   public static final EntityPermission USE_AS_DATA_TYPE =
       new EntityPermission(
           "USE:AS_DATA_TYPE",
           "Permission to use this entity as a data type for reference properties.",
-          27);
+          27,
+          org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_USE_AS_DATA_TYPE);
   public static final EntityPermission UPDATE_QUERY_TEMPLATE_DEFINITION =
       new EntityPermission(
           "UPDATE:QUERY_TEMPLATE_DEFINITION",
           "Permission to update the query template definition of this QueryTemplate",
-          28);
+          28,
+          org.caosdb.api.entity.v1.EntityPermission
+              .ENTITY_PERMISSION_UPDATE_QUERY_TEMPLATE_DEFINITION);
 }
diff --git a/src/main/java/org/caosdb/server/permissions/Permission.java b/src/main/java/org/caosdb/server/permissions/Permission.java
index 44eee1c68a073c405233195aee491bcf10fcd38c..e8f33a3ae3f9eb0956bae6bc7c7eceefdc5663b7 100644
--- a/src/main/java/org/caosdb/server/permissions/Permission.java
+++ b/src/main/java/org/caosdb/server/permissions/Permission.java
@@ -28,11 +28,6 @@ public class Permission extends WildcardPermission {
 
   private static final long serialVersionUID = -7471830472441416012L;
 
-  public static final org.apache.shiro.authz.Permission EDIT_PRIORITY_ACL =
-      new Permission(
-          "ADMIN:ENTITY:EDIT:PRIORITY_ACL",
-          "The permission to edit (add/delete) the prioritized rules of an acl of an entity.");
-
   private final String description;
 
   private final String shortName;
diff --git a/src/main/java/org/caosdb/server/permissions/PermissionRule.java b/src/main/java/org/caosdb/server/permissions/PermissionRule.java
index 85d3b62834a67a4fc46ea9b3c38d19e4b8261d74..2e8b6984509761d649acb27b5482c8df7bff9933 100644
--- a/src/main/java/org/caosdb/server/permissions/PermissionRule.java
+++ b/src/main/java/org/caosdb/server/permissions/PermissionRule.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,8 +19,8 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.permissions;
 
 import java.util.HashMap;
@@ -43,6 +44,9 @@ public class PermissionRule {
   public PermissionRule(final boolean grant, final boolean priority, final String permission) {
     this.grant = grant;
     this.priority = priority;
+    if (permission == null) {
+      throw new NullPointerException("permission cannot be null");
+    }
     this.permission = permission;
   }
 
@@ -54,6 +58,10 @@ public class PermissionRule {
     return this.priority;
   }
 
+  public String getPermission() {
+    return permission;
+  }
+
   public Permission getPermission(String realm, String username) {
     return new WildcardPermission(
         permission.replaceAll("\\?REALM\\?", realm).replaceAll("\\?USERNAME\\?", username));
@@ -72,6 +80,31 @@ public class PermissionRule {
     return ret;
   }
 
+  @Override
+  public String toString() {
+    return "PermissionRule("
+        + (priority ? "[P]" : "")
+        + (grant ? "GRANT" : "DENY")
+        + permission
+        + ")";
+  }
+
+  @Override
+  public int hashCode() {
+    return permission.hashCode() + (grant ? 3 : 0) - (priority ? 5 : 0);
+  }
+
+  @Override
+  public boolean equals(Object obj) {
+    if (obj instanceof PermissionRule) {
+      PermissionRule that = (PermissionRule) obj;
+      return this.grant == that.grant
+          && this.priority == that.priority
+          && this.permission.equals(that.permission);
+    }
+    return false;
+  }
+
   public static PermissionRule parse(final Element e) {
     return new PermissionRule(
         e.getName().equalsIgnoreCase("Grant"),
diff --git a/src/main/java/org/caosdb/server/permissions/Role.java b/src/main/java/org/caosdb/server/permissions/Role.java
index 54afefc664c330dfc4465285347a1463d9df0d5e..f7f4e55e195d72ba3a42a8b909d2c87944bcbf81 100644
--- a/src/main/java/org/caosdb/server/permissions/Role.java
+++ b/src/main/java/org/caosdb/server/permissions/Role.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,8 +19,8 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.permissions;
 
 import java.util.HashMap;
@@ -31,6 +32,7 @@ public class Role implements ResponsibleAgent {
   public static final Role OWNER_ROLE = new Role("?OWNER?");
   public static final Role OTHER_ROLE = new Role("?OTHER?");
   public static final Role ANONYMOUS_ROLE = new Role("anonymous");
+  public static final Role ADMINISTRATION = new Role("administration");
 
   private final String role;
 
diff --git a/src/main/java/org/caosdb/server/query/CQLParser.g4 b/src/main/java/org/caosdb/server/query/CQLParser.g4
index c4311ac1cbe03f490b79456e091cc0e73b94c506..f8c2a3b5ea4e7c34f3cc8fd07cdc77c912a5cc7b 100644
--- a/src/main/java/org/caosdb/server/query/CQLParser.g4
+++ b/src/main/java/org/caosdb/server/query/CQLParser.g4
@@ -287,15 +287,36 @@ pov returns [POV filter] locals [Query.Pattern p, String o, String v, String a]
 ;
 
 
-subproperty returns [SubProperty subp] locals [String p]
+subproperty returns [SubProperty subp]
 @init{
-    $p = null;
     $subp = null;
 }
 :
-    entity_filter {$subp = new SubProperty($entity_filter.filter);}
+	subproperty_filter {$subp = new SubProperty($subproperty_filter.filter);}
 ;
 
+subproperty_filter returns [EntityFilterInterface filter]
+    @init{
+        $filter = null;
+    }
+:
+    which_exp
+    (
+        (
+            LPAREN WHITE_SPACE?
+            (
+                filter_expression {$filter = $filter_expression.efi;}
+                | conjunction {$filter = $conjunction.c;}
+                | disjunction {$filter = $disjunction.d;}
+            )
+            RPAREN
+        ) | (
+            filter_expression {$filter = $filter_expression.efi;}
+        )
+    )?
+;
+
+
 backreference returns [Backreference ref] locals [Query.Pattern e, Query.Pattern p]
     @init{
         $e = null;
@@ -328,7 +349,7 @@ storedat returns [StoredAt filter] locals [String loc]
     WHITE_SPACE?
 ;
 
-conjunction returns [Conjunction c] locals [Conjunction dummy]
+conjunction returns [Conjunction c]
     @init{
         $c = new Conjunction();
     }
@@ -493,7 +514,7 @@ number_with_unit
 
 unit
 :
-    (~(WHITE_SPACE | WHICH | HAS_A | WITH | WHERE | DOT | AND | OR ))
+    (~(WHITE_SPACE | WHICH | HAS_A | WITH | WHERE | DOT | AND | OR | RPAREN ))
     (~(WHITE_SPACE))*
     |
     NUM SLASH (~(WHITE_SPACE))+
@@ -510,7 +531,7 @@ atom returns [Query.Pattern ep]
 :
     double_quoted {$ep = $double_quoted.ep;}
     | single_quoted {$ep = $single_quoted.ep;}
-    | (~(WHITE_SPACE | DOT ))+  {$ep = new Query.Pattern($text, Query.Pattern.TYPE_NORMAL);}
+    | (~(WHITE_SPACE | DOT | RPAREN | LPAREN ))+ {$ep = new Query.Pattern($text, Query.Pattern.TYPE_NORMAL);}
 ;
 
 single_quoted returns [Query.Pattern ep] locals [StringBuffer sb, int patternType]
diff --git a/src/main/java/org/caosdb/server/query/Query.java b/src/main/java/org/caosdb/server/query/Query.java
index 95f853d607edffa29b69e4f84657560ba3a52a48..07a165a352ba9a07a345018e7d287cd961f4a00b 100644
--- a/src/main/java/org/caosdb/server/query/Query.java
+++ b/src/main/java/org/caosdb/server/query/Query.java
@@ -47,6 +47,7 @@ import org.antlr.v4.runtime.CommonTokenStream;
 import org.apache.commons.jcs.access.behavior.ICacheAccess;
 import org.apache.shiro.subject.Subject;
 import org.caosdb.api.entity.v1.MessageCode;
+import org.caosdb.datetime.UTCDateTime;
 import org.caosdb.server.CaosDBServer;
 import org.caosdb.server.ServerProperties;
 import org.caosdb.server.caching.Cache;
@@ -1047,4 +1048,9 @@ public class Query implements QueryInterface, ToElementable, TransactionInterfac
       return -1;
     }
   }
+
+  @Override
+  public UTCDateTime getTimestamp() {
+    return null;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/resource/AbstractCaosDBServerResource.java b/src/main/java/org/caosdb/server/resource/AbstractCaosDBServerResource.java
index 876b43a160f673b96a7220a746c9a7dcd4951388..44ebfa22d08c975031f5bf5bfca325d6b706af24 100644
--- a/src/main/java/org/caosdb/server/resource/AbstractCaosDBServerResource.java
+++ b/src/main/java/org/caosdb/server/resource/AbstractCaosDBServerResource.java
@@ -251,6 +251,7 @@ public abstract class AbstractCaosDBServerResource extends ServerResource {
     try {
       return httpPostInChildClass(entity);
     } catch (final Throwable t) {
+      t.printStackTrace();
       return handleThrowable(t);
     }
   }
@@ -388,6 +389,7 @@ public abstract class AbstractCaosDBServerResource extends ServerResource {
   public Representation handleThrowable(final Throwable t) {
     try {
       getRequest().getAttributes().put("THROWN", t);
+      t.printStackTrace();
       throw t;
     } catch (final AuthenticationException e) {
       return error(ServerMessages.UNAUTHENTICATED, Status.CLIENT_ERROR_UNAUTHORIZED);
diff --git a/src/main/java/org/caosdb/server/resource/RolesResource.java b/src/main/java/org/caosdb/server/resource/RolesResource.java
index a89a731950d09a7edbce0a5f67a3e81287c07b2a..ad1544da3a326f1c16e0b01238985d10e93b0581 100644
--- a/src/main/java/org/caosdb/server/resource/RolesResource.java
+++ b/src/main/java/org/caosdb/server/resource/RolesResource.java
@@ -26,7 +26,6 @@ import java.io.IOException;
 import java.security.NoSuchAlgorithmException;
 import java.sql.SQLException;
 import org.caosdb.server.CaosDBException;
-import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.accessControl.Role;
 import org.caosdb.server.database.backend.implementation.MySQL.ConnectionException;
 import org.caosdb.server.entity.Message;
@@ -55,7 +54,6 @@ public class RolesResource extends AbstractCaosDBServerResource {
     if (getRequestedItems().length > 0) {
       final String name = getRequestedItems()[0];
       if (name != null) {
-        getUser().checkPermission(ACMPermissions.PERMISSION_RETRIEVE_ROLE_DESCRIPTION(name));
         final RetrieveRoleTransaction t = new RetrieveRoleTransaction(name);
         try {
           t.execute();
diff --git a/src/main/java/org/caosdb/server/resource/Webinterface.java b/src/main/java/org/caosdb/server/resource/Webinterface.java
index adba714a96e5bbb4bc3ea13b8d72ec69a88cb33b..95901260937a5364a68ed3e9e6849210bd67d6b3 100644
--- a/src/main/java/org/caosdb/server/resource/Webinterface.java
+++ b/src/main/java/org/caosdb/server/resource/Webinterface.java
@@ -81,7 +81,9 @@ public class Webinterface extends ServerResource {
                             ? MediaType.IMAGE_PNG
                             : path.endsWith(".html")
                                 ? MediaType.TEXT_HTML
-                                : path.endsWith(".yaml") ? MediaType.TEXT_YAML : MediaType.TEXT_XML;
+                                : path.endsWith(".yaml")
+                                    ? MediaType.TEXT_YAML
+                                    : path.endsWith(".xml") ? MediaType.TEXT_XML : MediaType.ALL;
 
     final FileRepresentation ret = new FileRepresentation(file, mt);
 
diff --git a/src/main/java/org/caosdb/server/scripting/ScriptingPermissions.java b/src/main/java/org/caosdb/server/scripting/ScriptingPermissions.java
index 78ad99d77d06b681838e455ad391c62e7ce85ca6..0af49e9faf6ec8ad9a4107d72554a44744184661 100644
--- a/src/main/java/org/caosdb/server/scripting/ScriptingPermissions.java
+++ b/src/main/java/org/caosdb/server/scripting/ScriptingPermissions.java
@@ -1,11 +1,29 @@
 package org.caosdb.server.scripting;
 
-public class ScriptingPermissions {
+import org.caosdb.server.accessControl.ACMPermissions;
+
+public class ScriptingPermissions extends ACMPermissions {
+
+  public static final String PATH_PARAMETER = "?PATH?";
+
+  public ScriptingPermissions(String permission, String description) {
+    super(permission, description);
+  }
+
+  public String toString(String path) {
+    return toString().replace(PATH_PARAMETER, path.replace("/", ":"));
+  }
+
+  private static final ScriptingPermissions execution =
+      new ScriptingPermissions(
+          "SCRIPTING:EXECUTE:" + PATH_PARAMETER,
+          "Permission to execute a server-side script under the given path. Note that, for utilizing the wild cards feature, you have to use ':' as path separator. E.g. 'SCRIPTING:EXECUTE:my_scripts:*' would be the permission to execute all executables below the my_scripts directory.");
 
   public static final String PERMISSION_EXECUTION(final String call) {
-    StringBuilder ret = new StringBuilder(18 + call.length());
-    ret.append("SCRIPTING:EXECUTE:");
-    ret.append(call.replace("/", ":"));
-    return ret.toString();
+    return execution.toString(call);
+  }
+
+  public static String init() {
+    return ScriptingPermissions.class.getSimpleName();
   }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/AccessControlTransaction.java b/src/main/java/org/caosdb/server/transaction/AccessControlTransaction.java
index 4897cd65620577e36a98f2db5e5530a42b3f43d0..1cf9f8f70df2eaa384e4074cc3b80a4816a88142 100644
--- a/src/main/java/org/caosdb/server/transaction/AccessControlTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/AccessControlTransaction.java
@@ -22,6 +22,7 @@
  */
 package org.caosdb.server.transaction;
 
+import org.caosdb.datetime.UTCDateTime;
 import org.caosdb.server.database.DatabaseAccessManager;
 import org.caosdb.server.database.access.Access;
 import org.caosdb.server.database.misc.RollBackHandler;
@@ -30,9 +31,11 @@ import org.caosdb.server.entity.Message;
 public abstract class AccessControlTransaction implements TransactionInterface {
 
   private Access access;
+  private UTCDateTime timestamp;
 
   @Override
   public final void execute() throws Exception {
+    this.timestamp = UTCDateTime.SystemMillisToUTCDateTime(System.currentTimeMillis());
     this.access = DatabaseAccessManager.getAccountAccess(this);
 
     try {
@@ -54,4 +57,9 @@ public abstract class AccessControlTransaction implements TransactionInterface {
   }
 
   protected abstract void transaction() throws Exception;
+
+  @Override
+  public UTCDateTime getTimestamp() {
+    return timestamp;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/DeleteRoleTransaction.java b/src/main/java/org/caosdb/server/transaction/DeleteRoleTransaction.java
index ad9a9925f8bed2ef03a1bcf9cd6b8c79adca6345..2e7e5b2a5ad4354b517dc7020f44f5ece459cc35 100644
--- a/src/main/java/org/caosdb/server/transaction/DeleteRoleTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/DeleteRoleTransaction.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,8 +19,8 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.transaction;
 
 import org.apache.shiro.SecurityUtils;
@@ -27,6 +28,8 @@ import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.database.backend.transaction.DeleteRole;
 import org.caosdb.server.database.backend.transaction.RetrieveRole;
 import org.caosdb.server.database.backend.transaction.SetPermissionRules;
+import org.caosdb.server.database.exceptions.TransactionException;
+import org.caosdb.server.entity.Message;
 import org.caosdb.server.utils.ServerMessages;
 
 public class DeleteRoleTransaction extends AccessControlTransaction {
@@ -41,10 +44,19 @@ public class DeleteRoleTransaction extends AccessControlTransaction {
   protected void transaction() throws Exception {
     SecurityUtils.getSubject().checkPermission(ACMPermissions.PERMISSION_DELETE_ROLE(this.name));
 
+    if (this.name == "administration" || this.name == "anonymous") {
+      throw ServerMessages.SPECIAL_ROLE_CANNOT_BE_DELETED;
+    }
     if (execute(new RetrieveRole(this.name), getAccess()).getRole() == null) {
       throw ServerMessages.ROLE_DOES_NOT_EXIST;
     }
     execute(new SetPermissionRules(this.name, null), getAccess());
-    execute(new DeleteRole(this.name), getAccess());
+    try {
+      execute(new DeleteRole(this.name), getAccess());
+    } catch (TransactionException e) {
+      if (e.getCause() == ServerMessages.ROLE_CANNOT_BE_DELETED) {
+        throw (Message) e.getCause();
+      }
+    }
   }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/DeleteUserTransaction.java b/src/main/java/org/caosdb/server/transaction/DeleteUserTransaction.java
index dc935adc9ea0236ce3c8d54b498ed5f6b15a8c42..24aac16b9c529130520518822e6bf3a6a3e8b72d 100644
--- a/src/main/java/org/caosdb/server/transaction/DeleteUserTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/DeleteUserTransaction.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,13 +19,15 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.transaction;
 
 import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.subject.Subject;
 import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.accessControl.CredentialsValidator;
+import org.caosdb.server.accessControl.Principal;
 import org.caosdb.server.accessControl.UserSources;
 import org.caosdb.server.database.backend.transaction.DeletePassword;
 import org.caosdb.server.database.backend.transaction.DeleteUser;
@@ -35,34 +38,41 @@ import org.jdom2.Element;
 
 public class DeleteUserTransaction extends AccessControlTransaction {
 
-  private final String user;
+  private final String name;
   private final String realm;
 
-  public DeleteUserTransaction(final String user) {
-    this.realm = UserSources.getInternalRealm().getName();
-    this.user = user;
+  public DeleteUserTransaction(final String name) {
+    this(UserSources.getInternalRealm().getName(), name);
+  }
+
+  public DeleteUserTransaction(final String realm, final String name) {
+    this.realm = realm;
+    this.name = name;
   }
 
   @Override
   protected void transaction() throws Exception {
-    SecurityUtils.getSubject()
-        .checkPermission(ACMPermissions.PERMISSION_DELETE_USER(this.realm, this.user));
+    Subject subject = SecurityUtils.getSubject();
+    if (subject.getPrincipal().equals(new Principal(realm, name))) {
+      throw ServerMessages.CANNOT_DELETE_YOURSELF();
+    }
+    subject.checkPermission(ACMPermissions.PERMISSION_DELETE_USER(this.realm, this.name));
 
     final CredentialsValidator<String> validator =
-        execute(new RetrievePasswordValidator(this.user), getAccess()).getValidator();
+        execute(new RetrievePasswordValidator(this.name), getAccess()).getValidator();
 
     if (validator == null) {
       throw ServerMessages.ACCOUNT_DOES_NOT_EXIST;
     }
 
-    execute(new DeletePassword(this.user), getAccess());
-    execute(new DeleteUser(this.realm, this.user), getAccess());
+    execute(new DeletePassword(this.name), getAccess());
+    execute(new DeleteUser(this.realm, this.name), getAccess());
   }
 
   public Element getUserElement() {
     final Element ret = new Element("User");
     ret.setAttribute("realm", this.realm);
-    ret.setAttribute("name", this.user);
+    ret.setAttribute("name", this.name);
     ret.addContent(new Message("This user has been deleted.").toElement());
     return ret;
   }
diff --git a/src/main/java/org/caosdb/server/transaction/FileStorageConsistencyCheck.java b/src/main/java/org/caosdb/server/transaction/FileStorageConsistencyCheck.java
index e066feb3028eb6dcb9bf645070cadefa9cc45047..1ce1aa566ad28d048a36f91d50bb297b1a709d14 100644
--- a/src/main/java/org/caosdb/server/transaction/FileStorageConsistencyCheck.java
+++ b/src/main/java/org/caosdb/server/transaction/FileStorageConsistencyCheck.java
@@ -53,6 +53,7 @@ public class FileStorageConsistencyCheck extends Thread
   private Runnable finishRunnable = null;
   private final String location;
   private Long ts = null;
+  private UTCDateTime timestamp = null;
 
   public Exception getException() {
     return this.exception;
@@ -60,6 +61,7 @@ public class FileStorageConsistencyCheck extends Thread
 
   public FileStorageConsistencyCheck(final String location) {
     setDaemon(true);
+    this.timestamp = UTCDateTime.SystemMillisToUTCDateTime(System.currentTimeMillis());
     this.location = location.startsWith("/") ? location.replaceFirst("^/", "") : location;
   }
 
@@ -245,4 +247,9 @@ public class FileStorageConsistencyCheck extends Thread
   public void execute() throws Exception {
     run();
   }
+
+  @Override
+  public UTCDateTime getTimestamp() {
+    return timestamp;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/InsertLogRecordTransaction.java b/src/main/java/org/caosdb/server/transaction/InsertLogRecordTransaction.java
index c1128135b8620ebfe08328cd4901e9c0e6062053..950d9b8d25688e47833b60c01335f8dd525a0630 100644
--- a/src/main/java/org/caosdb/server/transaction/InsertLogRecordTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/InsertLogRecordTransaction.java
@@ -24,6 +24,7 @@ package org.caosdb.server.transaction;
 
 import java.util.List;
 import java.util.logging.LogRecord;
+import org.caosdb.datetime.UTCDateTime;
 import org.caosdb.server.database.DatabaseAccessManager;
 import org.caosdb.server.database.access.Access;
 import org.caosdb.server.database.backend.transaction.InsertLogRecord;
@@ -31,8 +32,10 @@ import org.caosdb.server.database.backend.transaction.InsertLogRecord;
 public class InsertLogRecordTransaction implements TransactionInterface {
 
   private final List<LogRecord> toBeFlushed;
+  private UTCDateTime timestamp;
 
   public InsertLogRecordTransaction(final List<LogRecord> toBeFlushed) {
+    this.timestamp = UTCDateTime.SystemMillisToUTCDateTime(System.currentTimeMillis());
     this.toBeFlushed = toBeFlushed;
   }
 
@@ -45,4 +48,9 @@ public class InsertLogRecordTransaction implements TransactionInterface {
       access.release();
     }
   }
+
+  @Override
+  public UTCDateTime getTimestamp() {
+    return timestamp;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/InsertRoleTransaction.java b/src/main/java/org/caosdb/server/transaction/InsertRoleTransaction.java
index b70e2bd71259645a8f619cb25d36998579e3dca7..44288af5888c2dacbf9e97c235a76e0d9992a969 100644
--- a/src/main/java/org/caosdb/server/transaction/InsertRoleTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/InsertRoleTransaction.java
@@ -22,11 +22,14 @@
  */
 package org.caosdb.server.transaction;
 
+import java.util.Set;
 import org.apache.shiro.SecurityUtils;
 import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.accessControl.Role;
 import org.caosdb.server.database.backend.transaction.InsertRole;
 import org.caosdb.server.database.backend.transaction.RetrieveRole;
+import org.caosdb.server.database.backend.transaction.SetPermissionRules;
+import org.caosdb.server.entity.Message;
 import org.caosdb.server.utils.ServerMessages;
 
 public class InsertRoleTransaction extends AccessControlTransaction {
@@ -37,14 +40,24 @@ public class InsertRoleTransaction extends AccessControlTransaction {
     this.role = role;
   }
 
-  @Override
-  protected void transaction() throws Exception {
+  private void checkPermissions() throws Message {
     SecurityUtils.getSubject().checkPermission(ACMPermissions.PERMISSION_INSERT_ROLE());
 
     if (execute(new RetrieveRole(this.role.name), getAccess()).getRole() != null) {
       throw ServerMessages.ROLE_NAME_IS_NOT_UNIQUE;
     }
+  }
+
+  @Override
+  protected void transaction() throws Exception {
+    checkPermissions();
 
     execute(new InsertRole(this.role), getAccess());
+    if (this.role.permission_rules != null) {
+      execute(
+          new SetPermissionRules(this.role.name, Set.copyOf(this.role.permission_rules)),
+          getAccess());
+    }
+    RetrieveRole.removeCached(this.role.name);
   }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/InsertUserTransaction.java b/src/main/java/org/caosdb/server/transaction/InsertUserTransaction.java
index b91b1aa6b31911822ed9df4c1eaffa87374ede82..09d59e8d84659037da66e11f7b4c0da556d8aa50 100644
--- a/src/main/java/org/caosdb/server/transaction/InsertUserTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/InsertUserTransaction.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,25 +19,27 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.transaction;
 
 import org.apache.shiro.SecurityUtils;
 import org.caosdb.server.accessControl.ACMPermissions;
+import org.caosdb.server.accessControl.Principal;
 import org.caosdb.server.accessControl.UserSources;
 import org.caosdb.server.accessControl.UserStatus;
-import org.caosdb.server.database.backend.transaction.RetrievePasswordValidator;
 import org.caosdb.server.database.backend.transaction.SetPassword;
 import org.caosdb.server.database.backend.transaction.UpdateUser;
+import org.caosdb.server.database.backend.transaction.UpdateUserRoles;
 import org.caosdb.server.database.proto.ProtoUser;
+import org.caosdb.server.entity.Message;
 import org.caosdb.server.utils.ServerMessages;
 import org.caosdb.server.utils.Utils;
 import org.jdom2.Element;
 
 public class InsertUserTransaction extends AccessControlTransaction {
 
-  ProtoUser user = new ProtoUser();
+  private final ProtoUser user;
   private final String password;
 
   public InsertUserTransaction(
@@ -45,11 +48,16 @@ public class InsertUserTransaction extends AccessControlTransaction {
       final String email,
       final UserStatus status,
       final Integer entity) {
+    this(new ProtoUser(), password);
     this.user.realm = UserSources.getInternalRealm().getName();
     this.user.name = username;
     this.user.email = email;
     this.user.status = status;
     this.user.entity = entity;
+  }
+
+  public InsertUserTransaction(ProtoUser user, String password) {
+    this.user = user;
     this.password = password;
   }
 
@@ -58,6 +66,8 @@ public class InsertUserTransaction extends AccessControlTransaction {
     SecurityUtils.getSubject()
         .checkPermission(ACMPermissions.PERMISSION_INSERT_USER(this.user.realm));
 
+    checkUserName(this.user.name);
+
     if (this.user.email != null && !Utils.isRFC822Compliant(this.user.email)) {
       throw ServerMessages.EMAIL_NOT_WELL_FORMED;
     }
@@ -66,15 +76,31 @@ public class InsertUserTransaction extends AccessControlTransaction {
       UpdateUserTransaction.checkEntityExists(this.user.entity);
     }
 
-    if (execute(new RetrievePasswordValidator(this.user.name), getAccess()).getValidator()
-        == null) {
-      if (this.password != null) {
-        Utils.checkPasswordStrength(this.password);
-      }
+    if (this.password != null) {
+      Utils.checkPasswordStrength(this.password);
+    }
+
+    execute(new SetPassword(this.user.name, this.password), getAccess());
+    execute(new UpdateUser(this.user), getAccess());
+    execute(new UpdateUserRoles(this.user.realm, this.user.name, this.user.roles), getAccess());
+  }
+
+  /*
+   * Names should have at least a length of 1, a maximum length of 32 and match
+   * ^[a-zA-Z_][a-zA-Z0-9_-]*$.
+   */
+  private void checkUserName(String name) throws Message {
+    // Make this configurable?
+    final boolean length = name.length() >= 1 && name.length() <= 32;
+    final boolean match =
+        name.matches("^[\\p{Lower}\\p{Upper}_][\\p{Lower}\\p{Upper}\\p{Digit}_-]*$");
+
+    if (!(length && match)) {
+      throw ServerMessages.INVALID_USER_NAME(
+          "User names must have a length from 1 to 32 characters, begin with a latin letter a-z (upper case or lower case) or an underscore (_), and all other characters must be latin letters, arabic numbers, hyphens (-) or undescores (_).");
+    }
 
-      execute(new SetPassword(this.user.name, this.password), getAccess());
-      execute(new UpdateUser(this.user), getAccess());
-    } else {
+    if (UserSources.isUserExisting(new Principal(this.user.realm, this.user.name))) {
       throw ServerMessages.ACCOUNT_NAME_NOT_UNIQUE;
     }
   }
diff --git a/src/main/java/org/caosdb/server/transaction/ListRolesTransaction.java b/src/main/java/org/caosdb/server/transaction/ListRolesTransaction.java
new file mode 100644
index 0000000000000000000000000000000000000000..ed3cd3cc5a154e82946e76f9934ee8608fe6980c
--- /dev/null
+++ b/src/main/java/org/caosdb/server/transaction/ListRolesTransaction.java
@@ -0,0 +1,69 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.transaction;
+
+import java.util.Iterator;
+import java.util.List;
+import java.util.stream.Collectors;
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.subject.Subject;
+import org.caosdb.server.accessControl.ACMPermissions;
+import org.caosdb.server.accessControl.Role;
+import org.caosdb.server.database.backend.transaction.ListRoles;
+import org.caosdb.server.database.proto.ProtoUser;
+
+public class ListRolesTransaction extends AccessControlTransaction {
+
+  private List<Role> roles = null;
+
+  @Override
+  protected void transaction() throws Exception {
+    Subject currentUser = SecurityUtils.getSubject();
+    roles =
+        execute(new ListRoles(), getAccess())
+            .getRoles()
+            .stream()
+            .filter(
+                role ->
+                    currentUser.isPermitted(
+                        ACMPermissions.PERMISSION_RETRIEVE_ROLE_DESCRIPTION(role.name)))
+            .collect(Collectors.toList());
+
+    // remove users. the list will only contain name and description.
+    for (Role role : roles) {
+      if (role.users != null) {
+        Iterator<ProtoUser> iterator = role.users.iterator();
+        while (iterator.hasNext()) {
+          ProtoUser user = iterator.next();
+          if (!currentUser.isPermitted(
+              ACMPermissions.PERMISSION_RETRIEVE_USER_ROLES(user.realm, user.name))) {
+            iterator.remove();
+          }
+        }
+      }
+    }
+  }
+
+  public List<Role> getRoles() {
+    return roles;
+  }
+}
diff --git a/src/main/java/org/caosdb/server/transaction/ListUsersTransaction.java b/src/main/java/org/caosdb/server/transaction/ListUsersTransaction.java
new file mode 100644
index 0000000000000000000000000000000000000000..2ade4e8595f159d1fc6996c1e04913f4195ecd97
--- /dev/null
+++ b/src/main/java/org/caosdb/server/transaction/ListUsersTransaction.java
@@ -0,0 +1,63 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.transaction;
+
+import java.util.List;
+import java.util.stream.Collectors;
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.subject.Subject;
+import org.caosdb.server.accessControl.ACMPermissions;
+import org.caosdb.server.database.backend.transaction.ListUsers;
+import org.caosdb.server.database.proto.ProtoUser;
+
+public class ListUsersTransaction extends AccessControlTransaction {
+
+  private List<ProtoUser> users = null;
+
+  @Override
+  protected void transaction() throws Exception {
+    Subject currentUser = SecurityUtils.getSubject();
+    users =
+        execute(new ListUsers(), getAccess())
+            .getUsers()
+            .stream()
+            .filter(
+                user ->
+                    currentUser.isPermitted(
+                        ACMPermissions.PERMISSION_RETRIEVE_USER_INFO(user.realm, user.name)))
+            .collect(Collectors.toList());
+
+    // remove roles
+    for (ProtoUser user : users) {
+      if (user.roles != null) {
+        if (!currentUser.isPermitted(
+            ACMPermissions.PERMISSION_RETRIEVE_USER_ROLES(user.realm, user.name))) {
+          user.roles = null;
+        }
+      }
+    }
+  }
+
+  public List<ProtoUser> getUsers() {
+    return users;
+  }
+}
diff --git a/src/main/java/org/caosdb/server/transaction/LogUserVisitTransaction.java b/src/main/java/org/caosdb/server/transaction/LogUserVisitTransaction.java
new file mode 100644
index 0000000000000000000000000000000000000000..dff0d34fed5bab445bfd761817aecc474def6025
--- /dev/null
+++ b/src/main/java/org/caosdb/server/transaction/LogUserVisitTransaction.java
@@ -0,0 +1,42 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ */
+package org.caosdb.server.transaction;
+
+import org.caosdb.server.database.backend.transaction.LogUserVisit;
+
+public class LogUserVisitTransaction extends AccessControlTransaction {
+
+  private String realm;
+  private String username;
+  private String type;
+  private long timestamp;
+
+  public LogUserVisitTransaction(long timestamp, String realm, String username, String type) {
+    this.timestamp = timestamp;
+    this.realm = realm;
+    this.username = username;
+    this.type = type;
+  }
+
+  @Override
+  protected void transaction() throws Exception {
+    execute(new LogUserVisit(timestamp, realm, username, type), getAccess());
+  }
+}
diff --git a/src/main/java/org/caosdb/server/transaction/RetrieveACL.java b/src/main/java/org/caosdb/server/transaction/RetrieveACL.java
new file mode 100644
index 0000000000000000000000000000000000000000..cd9c5c0841557da579c3581f876a1180ecd06f8d
--- /dev/null
+++ b/src/main/java/org/caosdb/server/transaction/RetrieveACL.java
@@ -0,0 +1,89 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.transaction;
+
+import com.google.protobuf.ProtocolStringList;
+import java.util.UUID;
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.authz.AuthorizationException;
+import org.caosdb.server.database.backend.transaction.RetrieveEntityACLTransaction;
+import org.caosdb.server.entity.Entity;
+import org.caosdb.server.entity.EntityInterface;
+import org.caosdb.server.entity.container.TransactionContainer;
+import org.caosdb.server.permissions.EntityACL;
+import org.caosdb.server.permissions.EntityPermission;
+
+public class RetrieveACL extends Transaction<TransactionContainer> {
+
+  public RetrieveACL(ProtocolStringList idList) {
+    super(
+        new TransactionContainer(
+            SecurityUtils.getSubject(), System.currentTimeMillis(), UUID.randomUUID().toString()));
+    for (String strId : idList) {
+      getContainer().add(new Entity(Integer.parseInt(strId)));
+    }
+  }
+
+  @Override
+  public boolean logHistory() {
+    return false;
+  }
+
+  @Override
+  protected void init() throws Exception {
+    // acquire weak access
+    setAccess(getAccessManager().acquireReadAccess(this));
+  }
+
+  @Override
+  protected void preCheck() throws InterruptedException, Exception {}
+
+  @Override
+  protected void postCheck() {}
+
+  @Override
+  protected void preTransaction() throws InterruptedException {}
+
+  @Override
+  protected void transaction() throws Exception {
+    RetrieveEntityACLTransaction t = new RetrieveEntityACLTransaction(null);
+    for (EntityInterface e : getContainer()) {
+      EntityACL acl = execute(t.reuse(e.getId()), getAccess()).getEntityAcl();
+      if (acl != null && acl.isPermitted(getTransactor(), EntityPermission.RETRIEVE_ACL)) {
+        e.setEntityACL(acl);
+      } else if (acl != null
+          && acl.isPermitted(getTransactor(), EntityPermission.RETRIEVE_ENTITY)) {
+        throw new AuthorizationException("You are not permitted to update this entity's ACL.");
+      } else {
+        e.addError(org.caosdb.server.utils.ServerMessages.ENTITY_DOES_NOT_EXIST);
+      }
+    }
+  }
+
+  @Override
+  protected void postTransaction() throws Exception {}
+
+  @Override
+  protected void cleanUp() {
+    getAccess().release();
+  }
+}
diff --git a/src/main/java/org/caosdb/server/transaction/RetrieveLogRecordTransaction.java b/src/main/java/org/caosdb/server/transaction/RetrieveLogRecordTransaction.java
index 7e6c527865566795c397377409b1fc63020ca1dd..2f6cafd6e4e55ab868f69f1d3414a2196f0a4fea 100644
--- a/src/main/java/org/caosdb/server/transaction/RetrieveLogRecordTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/RetrieveLogRecordTransaction.java
@@ -26,6 +26,7 @@ import java.util.List;
 import java.util.logging.Level;
 import java.util.logging.LogRecord;
 import org.apache.shiro.SecurityUtils;
+import org.caosdb.datetime.UTCDateTime;
 import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.database.DatabaseAccessManager;
 import org.caosdb.server.database.access.Access;
@@ -37,10 +38,12 @@ public class RetrieveLogRecordTransaction implements TransactionInterface {
   private final String logger;
   private final Level level;
   private final String message;
+  private UTCDateTime timestamp;
 
   public RetrieveLogRecordTransaction(
       final String logger, final Level level, final String message) {
     this.level = level;
+    this.timestamp = UTCDateTime.SystemMillisToUTCDateTime(System.currentTimeMillis());
     if (message != null && message.isEmpty()) {
       this.message = null;
     } else if (message != null) {
@@ -73,4 +76,9 @@ public class RetrieveLogRecordTransaction implements TransactionInterface {
   public List<LogRecord> getLogRecords() {
     return this.logRecords;
   }
+
+  @Override
+  public UTCDateTime getTimestamp() {
+    return timestamp;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/RetrieveRoleTransaction.java b/src/main/java/org/caosdb/server/transaction/RetrieveRoleTransaction.java
index c7c251ba9847fe29f84589297f846f436f2a1309..8e92a347f869b2a6a3e6f2be58d9124e6a9442d7 100644
--- a/src/main/java/org/caosdb/server/transaction/RetrieveRoleTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/RetrieveRoleTransaction.java
@@ -22,25 +22,50 @@
  */
 package org.caosdb.server.transaction;
 
+import java.util.Iterator;
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.authz.AuthorizationException;
+import org.apache.shiro.subject.Subject;
+import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.accessControl.Role;
 import org.caosdb.server.database.backend.transaction.RetrieveRole;
+import org.caosdb.server.database.proto.ProtoUser;
 import org.caosdb.server.utils.ServerMessages;
 
 public class RetrieveRoleTransaction extends AccessControlTransaction {
 
   private final String name;
   private Role role;
+  private Subject transactor;
 
-  public RetrieveRoleTransaction(final String name) {
+  public RetrieveRoleTransaction(final String name, Subject transactor) {
+    this.transactor = transactor;
     this.name = name;
   }
 
+  public RetrieveRoleTransaction(final String name) {
+    this(name, SecurityUtils.getSubject());
+  }
+
   @Override
   protected void transaction() throws Exception {
+    if (!transactor.isPermitted(ACMPermissions.PERMISSION_RETRIEVE_ROLE_DESCRIPTION(this.name))) {
+      throw new AuthorizationException("You are not permitted to retrieve this role");
+    }
     this.role = execute(new RetrieveRole(this.name), getAccess()).getRole();
     if (this.role == null) {
       throw ServerMessages.ROLE_DOES_NOT_EXIST;
     }
+    if (this.role.users != null) {
+      Iterator<ProtoUser> iterator = this.role.users.iterator();
+      while (iterator.hasNext()) {
+        ProtoUser user = iterator.next();
+        if (!transactor.isPermitted(
+            ACMPermissions.PERMISSION_RETRIEVE_USER_ROLES(user.realm, user.name))) {
+          iterator.remove();
+        }
+      }
+    }
   }
 
   public Role getRole() {
diff --git a/src/main/java/org/caosdb/server/transaction/RetrieveUserRolesTransaction.java b/src/main/java/org/caosdb/server/transaction/RetrieveUserRolesTransaction.java
index 97e518d06ac9ad5766b3801be8b1f1403cf8af3f..e26e29830a6e3c5f135b467f4622febda195da89 100644
--- a/src/main/java/org/caosdb/server/transaction/RetrieveUserRolesTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/RetrieveUserRolesTransaction.java
@@ -23,6 +23,7 @@
 package org.caosdb.server.transaction;
 
 import java.util.Set;
+import org.caosdb.datetime.UTCDateTime;
 import org.caosdb.server.accessControl.Principal;
 import org.caosdb.server.accessControl.UserSources;
 import org.caosdb.server.utils.ServerMessages;
@@ -33,8 +34,10 @@ public class RetrieveUserRolesTransaction implements TransactionInterface {
   private final String user;
   private Set<String> roles;
   private final String realm;
+  private UTCDateTime timestamp;
 
   public RetrieveUserRolesTransaction(final String realm, final String user) {
+    this.timestamp = UTCDateTime.SystemMillisToUTCDateTime(System.currentTimeMillis());
     this.realm = realm;
     this.user = user;
   }
@@ -67,4 +70,9 @@ public class RetrieveUserRolesTransaction implements TransactionInterface {
   public Set<String> getRoles() {
     return this.roles;
   }
+
+  @Override
+  public UTCDateTime getTimestamp() {
+    return timestamp;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/RetrieveUserTransaction.java b/src/main/java/org/caosdb/server/transaction/RetrieveUserTransaction.java
index 228b1585233ae71d3b7130196f68c3b9f83f5ed2..eb24fb24db4f1b6a50a279cfcd9e158003a70948 100644
--- a/src/main/java/org/caosdb/server/transaction/RetrieveUserTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/RetrieveUserTransaction.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,14 +19,16 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.transaction;
 
 import java.util.Set;
+import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.subject.Subject;
+import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.accessControl.Principal;
 import org.caosdb.server.accessControl.UserSources;
-import org.caosdb.server.accessControl.UserStatus;
 import org.caosdb.server.database.backend.transaction.RetrieveUser;
 import org.caosdb.server.database.proto.ProtoUser;
 import org.caosdb.server.utils.ServerMessages;
@@ -35,28 +38,32 @@ public class RetrieveUserTransaction extends AccessControlTransaction {
 
   private final Principal principal;
   private ProtoUser user;
+  private final Subject currentUser;
 
   public RetrieveUserTransaction(final String realm, final String name) {
-    this.principal = new Principal(realm, name);
+    this(realm, name, SecurityUtils.getSubject());
+  }
+
+  public RetrieveUserTransaction(String realm, String username, Subject transactor) {
+    currentUser = transactor;
+    this.principal = new Principal(realm, username);
   }
 
   @Override
   protected void transaction() throws Exception {
-    if (!UserSources.isUserExisting(this.principal)) {
+    if (!UserSources.isUserExisting(this.principal)
+        || !currentUser.isPermitted(
+            ACMPermissions.PERMISSION_RETRIEVE_USER_INFO(
+                this.principal.getRealm(), this.principal.getUsername()))) {
       throw ServerMessages.ACCOUNT_DOES_NOT_EXIST;
     }
     this.user = execute(new RetrieveUser(this.principal), getAccess()).getUser();
 
-    if (this.user == null) {
-      this.user = new ProtoUser();
-      this.user.name = this.principal.getUsername();
-      this.user.realm = this.principal.getRealm();
-    }
-    if (this.user.status == null) {
-      this.user.status = UserSources.getDefaultUserStatus(this.principal);
-    }
-    if (this.user.email == null) {
-      this.user.email = UserSources.getDefaultUserEmail(this.principal);
+    if (user != null && user.roles != null) {
+      if (!currentUser.isPermitted(
+          ACMPermissions.PERMISSION_RETRIEVE_USER_ROLES(user.realm, user.name))) {
+        user.roles = null;
+      }
     }
   }
 
@@ -86,7 +93,7 @@ public class RetrieveUserTransaction extends AccessControlTransaction {
     return this.user.roles;
   }
 
-  public boolean isActive() {
-    return this.user.status == UserStatus.ACTIVE;
+  public ProtoUser getUser() {
+    return user;
   }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/TransactionInterface.java b/src/main/java/org/caosdb/server/transaction/TransactionInterface.java
index d56407ca854c756a956fe11d9bc98a72f05a4b50..8e01c7d9b407927ebdb6a0528f7dcbc6d5bea40d 100644
--- a/src/main/java/org/caosdb/server/transaction/TransactionInterface.java
+++ b/src/main/java/org/caosdb/server/transaction/TransactionInterface.java
@@ -22,6 +22,7 @@
  */
 package org.caosdb.server.transaction;
 
+import org.caosdb.datetime.UTCDateTime;
 import org.caosdb.server.database.BackendTransaction;
 import org.caosdb.server.database.access.Access;
 import org.caosdb.server.database.misc.RollBackHandler;
@@ -48,4 +49,6 @@ public interface TransactionInterface {
     t.executeTransaction();
     return t;
   }
+
+  public UTCDateTime getTimestamp();
 }
diff --git a/src/main/java/org/caosdb/server/transaction/UpdateACL.java b/src/main/java/org/caosdb/server/transaction/UpdateACL.java
new file mode 100644
index 0000000000000000000000000000000000000000..84c73080550d8899f4f1a5156bebb2a44c39df6a
--- /dev/null
+++ b/src/main/java/org/caosdb/server/transaction/UpdateACL.java
@@ -0,0 +1,146 @@
+/*
+ * This file is a part of the CaosDB Project.
+ *
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
+ *
+ */
+
+package org.caosdb.server.transaction;
+
+import static org.caosdb.server.query.Query.clearCache;
+
+import org.apache.shiro.authz.AuthorizationException;
+import org.caosdb.server.database.backend.transaction.RetrieveFullEntityTransaction;
+import org.caosdb.server.database.backend.transaction.UpdateEntityTransaction;
+import org.caosdb.server.entity.EntityInterface;
+import org.caosdb.server.entity.UpdateEntity;
+import org.caosdb.server.entity.container.TransactionContainer;
+import org.caosdb.server.jobs.Job;
+import org.caosdb.server.jobs.core.CheckEntityACLRoles;
+import org.caosdb.server.jobs.core.JobFailureSeverity;
+import org.caosdb.server.permissions.EntityACL;
+import org.caosdb.server.permissions.EntityPermission;
+import org.caosdb.server.utils.EntityStatus;
+
+public class UpdateACL extends Transaction<TransactionContainer>
+    implements WriteTransactionInterface {
+
+  public UpdateACL(TransactionContainer t) {
+    super(t);
+  }
+
+  @Override
+  public boolean logHistory() {
+    return false;
+  }
+
+  @Override
+  protected void init() throws Exception {
+    getSchedule()
+        .add(
+            Job.getJob(
+                CheckEntityACLRoles.class.getSimpleName(), JobFailureSeverity.ERROR, null, this));
+    // reserve write access. Other thread may read until the write access is
+    // actually acquired.
+    setAccess(getAccessManager().reserveWriteAccess(this));
+  }
+
+  @Override
+  protected void preCheck() throws InterruptedException, Exception {
+    TransactionContainer oldContainer = new TransactionContainer();
+
+    for (EntityInterface e : getContainer()) {
+      oldContainer.add(new UpdateEntity(e.getId(), null));
+    }
+
+    RetrieveFullEntityTransaction t = new RetrieveFullEntityTransaction(oldContainer);
+    execute(t, getAccess());
+
+    // the entities in this container only have an id and an ACL. -> Replace
+    // with full entity and move ACL to full entity if permissions are
+    // sufficient, otherwise add an error.
+    getContainer()
+        .replaceAll(
+            (e) -> {
+              EntityInterface result = oldContainer.getEntityById(e.getId());
+
+              // Check ACL update is permitted (against the old ACL) and set the new ACL afterwards.
+              EntityACL oldAcl = result.getEntityACL();
+              EntityACL newAcl = e.getEntityACL();
+              if (oldAcl != null
+                  && oldAcl.isPermitted(getTransactor(), EntityPermission.EDIT_ACL)) {
+                if (oldAcl.equals(newAcl)) {
+                  // nothing to be done
+                  result.setEntityStatus(EntityStatus.IGNORE);
+                } else {
+                  if (!oldAcl.getPriorityEntityACL().equals(newAcl.getPriorityEntityACL())
+                      && !oldAcl.isPermitted(getTransactor(), EntityPermission.EDIT_PRIORITY_ACL)) {
+                    throw new AuthorizationException(
+                        "You are not permitted to change prioritized permission rules of this entity.");
+                  }
+
+                  // we're good to go. set new entity acl
+                  result.setEntityACL(newAcl);
+                  result.setEntityStatus(EntityStatus.QUALIFIED);
+                }
+              } else if (oldAcl != null
+                  && oldAcl.isPermitted(getTransactor(), EntityPermission.RETRIEVE_ENTITY)) {
+                // the user knows that this entity exists
+                throw new AuthorizationException(
+                    "You are not permitted to change permission rules of this entity.");
+              } else {
+                // we pretend this entity doesn't exist
+                result.addError(org.caosdb.server.utils.ServerMessages.ENTITY_DOES_NOT_EXIST);
+              }
+              return result;
+            });
+  }
+
+  @Override
+  protected void postCheck() {}
+
+  @Override
+  protected void preTransaction() throws InterruptedException {
+
+    setAccess(getAccessManager().acquireWriteAccess(this));
+  }
+
+  @Override
+  protected void transaction() throws Exception {
+    UpdateEntityTransaction t = new UpdateEntityTransaction(getContainer());
+    execute(t, getAccess());
+  }
+
+  @Override
+  protected void postTransaction() throws Exception {}
+
+  @Override
+  protected void cleanUp() {
+    getAccess().release();
+  }
+
+  @Override
+  protected void commit() throws Exception {
+    getAccess().commit();
+    clearCache();
+  }
+
+  @Override
+  public String getSRID() {
+    return getContainer().getRequestId();
+  }
+}
diff --git a/src/main/java/org/caosdb/server/transaction/UpdateRoleTransaction.java b/src/main/java/org/caosdb/server/transaction/UpdateRoleTransaction.java
index 7e1632f8a0a9252c6e400d352bb63e133f6ae9e6..a62aff5bb6e90120e6cfd6651acde231cf3519b1 100644
--- a/src/main/java/org/caosdb/server/transaction/UpdateRoleTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/UpdateRoleTransaction.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,36 +19,62 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.transaction;
 
+import java.util.Set;
 import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.subject.Subject;
 import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.accessControl.Role;
-import org.caosdb.server.accessControl.UserSources;
 import org.caosdb.server.database.backend.transaction.InsertRole;
 import org.caosdb.server.database.backend.transaction.RetrieveRole;
+import org.caosdb.server.database.backend.transaction.SetPermissionRules;
+import org.caosdb.server.entity.Message;
+import org.caosdb.server.permissions.PermissionRule;
 import org.caosdb.server.utils.ServerMessages;
 
 public class UpdateRoleTransaction extends AccessControlTransaction {
 
   private final Role role;
+  private Set<PermissionRule> newPermissionRules = null;
 
   public UpdateRoleTransaction(final Role role) {
     this.role = role;
   }
 
-  @Override
-  protected void transaction() throws Exception {
-    SecurityUtils.getSubject()
-        .checkPermission(ACMPermissions.PERMISSION_UPDATE_ROLE_DESCRIPTION(this.role.name));
+  private void checkPermissions() throws Message {
 
-    if (!UserSources.isRoleExisting(this.role.name)) {
+    Subject subject = SecurityUtils.getSubject();
+    subject.checkPermission(ACMPermissions.PERMISSION_UPDATE_ROLE_DESCRIPTION(this.role.name));
+
+    Role oldRole = execute(new RetrieveRole(this.role.name), getAccess()).getRole();
+    if (oldRole == null) {
       throw ServerMessages.ROLE_DOES_NOT_EXIST;
     }
 
+    if (this.role.permission_rules != null) {
+      Set<PermissionRule> oldPermissions = Set.copyOf(oldRole.permission_rules);
+      Set<PermissionRule> newPermissions = Set.copyOf(role.permission_rules);
+      if (!oldPermissions.equals(newPermissions)) {
+        if (org.caosdb.server.permissions.Role.ADMINISTRATION.toString().equals(this.role.name)) {
+          throw ServerMessages.SPECIAL_ROLE_PERMISSIONS_CANNOT_BE_CHANGED();
+        }
+        subject.checkPermission(ACMPermissions.PERMISSION_UPDATE_ROLE_PERMISSIONS(this.role.name));
+        this.newPermissionRules = newPermissions;
+      }
+    }
+  }
+
+  @Override
+  protected void transaction() throws Exception {
+    checkPermissions();
+
     execute(new InsertRole(this.role), getAccess());
+    if (this.newPermissionRules != null) {
+      execute(new SetPermissionRules(this.role.name, newPermissionRules), getAccess());
+    }
     RetrieveRole.removeCached(this.role.name);
   }
 }
diff --git a/src/main/java/org/caosdb/server/transaction/UpdateUserTransaction.java b/src/main/java/org/caosdb/server/transaction/UpdateUserTransaction.java
index 330ce5907f601b4b4345c26b1d483029f7d049b1..6e945118c9b0eef7460f41b5062ccb308b0fd956 100644
--- a/src/main/java/org/caosdb/server/transaction/UpdateUserTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/UpdateUserTransaction.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,21 +19,27 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.transaction;
 
+import java.util.HashSet;
+import java.util.Set;
 import org.apache.shiro.SecurityUtils;
+import org.apache.shiro.subject.Subject;
 import org.caosdb.server.accessControl.ACMPermissions;
 import org.caosdb.server.accessControl.Principal;
 import org.caosdb.server.accessControl.UserSources;
 import org.caosdb.server.accessControl.UserStatus;
+import org.caosdb.server.database.backend.transaction.RetrieveRole;
 import org.caosdb.server.database.backend.transaction.RetrieveUser;
 import org.caosdb.server.database.backend.transaction.SetPassword;
 import org.caosdb.server.database.backend.transaction.UpdateUser;
+import org.caosdb.server.database.backend.transaction.UpdateUserRoles;
 import org.caosdb.server.database.exceptions.TransactionException;
 import org.caosdb.server.database.proto.ProtoUser;
 import org.caosdb.server.entity.Entity;
+import org.caosdb.server.entity.Message;
 import org.caosdb.server.entity.RetrieveEntity;
 import org.caosdb.server.entity.container.RetrieveContainer;
 import org.caosdb.server.utils.EntityStatus;
@@ -40,10 +47,15 @@ import org.caosdb.server.utils.ServerMessages;
 import org.caosdb.server.utils.Utils;
 import org.jdom2.Element;
 
+/**
+ * This transaction also checks if the current user has sufficient permissions to make the update.
+ */
 public class UpdateUserTransaction extends AccessControlTransaction {
 
   private final String password;
-  private final ProtoUser user = new ProtoUser();
+  private final ProtoUser user;
+  private HashSet<String> newRoles;
+  private Set<String> oldRoles;
 
   public UpdateUserTransaction(
       final String realm,
@@ -52,6 +64,7 @@ public class UpdateUserTransaction extends AccessControlTransaction {
       final String email,
       final Integer entity,
       final String password) {
+    this.user = new ProtoUser();
     this.user.realm =
         (realm == null
             ? UserSources.guessRealm(username, UserSources.getInternalRealm().getName())
@@ -63,9 +76,19 @@ public class UpdateUserTransaction extends AccessControlTransaction {
     this.password = password;
   }
 
-  @Override
-  protected void transaction() throws Exception {
-    if (!UserSources.isUserExisting(new Principal(this.user.realm, this.user.name))) {
+  public UpdateUserTransaction(ProtoUser user, String password) {
+    this.user = user;
+    if (this.user.realm == null) {
+      this.user.realm =
+          UserSources.guessRealm(this.user.name, UserSources.getInternalRealm().getName());
+    }
+    this.password = password;
+  }
+
+  private void checkPermissions() throws Message {
+    Principal principal = new Principal(this.user.realm, this.user.name);
+    ProtoUser oldUser = execute(new RetrieveUser(principal), getAccess()).getUser();
+    if (oldUser == null) {
       throw ServerMessages.ACCOUNT_DOES_NOT_EXIST;
     }
 
@@ -94,29 +117,51 @@ public class UpdateUserTransaction extends AccessControlTransaction {
       }
     }
 
+    if (this.user.roles != null) {
+      Set<String> oldRoles = oldUser.roles;
+      if (!this.user.roles.equals(oldRoles)) {
+        SecurityUtils.getSubject()
+            .checkPermission(
+                ACMPermissions.PERMISSION_UPDATE_USER_ROLES(this.user.realm, this.user.name));
+      }
+      this.oldRoles = oldRoles;
+      this.newRoles = this.user.roles;
+    }
+  }
+
+  @Override
+  protected void transaction() throws Exception {
+    checkPermissions();
+
     if (isToBeUpdated()) {
       execute(new UpdateUser(this.user), getAccess());
     }
+    if (this.newRoles != null) {
+      execute(new UpdateUserRoles(this.user.realm, this.user.name, this.user.roles), getAccess());
+      RetrieveRole.removeCached(newRoles);
+      if (this.oldRoles != null) {
+        RetrieveRole.removeCached(oldRoles);
+      }
+    }
   }
 
   private boolean isToBeUpdated() throws Exception {
+    Subject current_user = SecurityUtils.getSubject();
     boolean isToBeUpdated = false;
     final ProtoUser validUser =
         execute(new RetrieveUser(new Principal(this.user.realm, this.user.name)), getAccess())
             .getUser();
     if (this.user.status != null && (validUser == null || this.user.status != validUser.status)) {
-      SecurityUtils.getSubject()
-          .checkPermission(
-              ACMPermissions.PERMISSION_UPDATE_USER_STATUS(this.user.realm, this.user.name));
+      current_user.checkPermission(
+          ACMPermissions.PERMISSION_UPDATE_USER_STATUS(this.user.realm, this.user.name));
       isToBeUpdated = true;
     } else if (validUser != null) {
       this.user.status = validUser.status;
     }
     if (this.user.email != null
         && (validUser == null || !this.user.email.equals(validUser.email))) {
-      SecurityUtils.getSubject()
-          .checkPermission(
-              ACMPermissions.PERMISSION_UPDATE_USER_EMAIL(this.user.realm, this.user.name));
+      current_user.checkPermission(
+          ACMPermissions.PERMISSION_UPDATE_USER_EMAIL(this.user.realm, this.user.name));
       if (!Utils.isRFC822Compliant(this.user.email)) {
         throw ServerMessages.EMAIL_NOT_WELL_FORMED;
       }
@@ -127,9 +172,8 @@ public class UpdateUserTransaction extends AccessControlTransaction {
     }
     if (this.user.entity != null
         && (validUser == null || !this.user.entity.equals(validUser.entity))) {
-      SecurityUtils.getSubject()
-          .checkPermission(
-              ACMPermissions.PERMISSION_UPDATE_USER_ENTITY(this.user.realm, this.user.name));
+      current_user.checkPermission(
+          ACMPermissions.PERMISSION_UPDATE_USER_ENTITY(this.user.realm, this.user.name));
       isToBeUpdated = true;
 
       if (this.user.entity.equals(0)) {
diff --git a/src/main/java/org/caosdb/server/transaction/WriteTransaction.java b/src/main/java/org/caosdb/server/transaction/WriteTransaction.java
index 5c730a19ee0cc7e09278a3e7c184884cb4ff1c3e..334e408a82ddc343ed634979dc76e0b11f33a94b 100644
--- a/src/main/java/org/caosdb/server/transaction/WriteTransaction.java
+++ b/src/main/java/org/caosdb/server/transaction/WriteTransaction.java
@@ -377,7 +377,7 @@ public class WriteTransaction extends Transaction<WritableContainer>
           .getPriorityEntityACL()
           .equals(oldEntity.getEntityACL().getPriorityEntityACL())) {
         // priority acl is to be changed?
-        oldEntity.checkPermission(Permission.EDIT_PRIORITY_ACL);
+        oldEntity.checkPermission(EntityPermission.EDIT_PRIORITY_ACL);
       }
       updatetable = true;
     } else if (!newEntity.hasEntityACL()) {
@@ -578,6 +578,7 @@ public class WriteTransaction extends Transaction<WritableContainer>
     return null;
   }
 
+  @Override
   public String getSRID() {
     return getContainer().getRequestId();
   }
diff --git a/src/main/java/org/caosdb/server/transaction/WriteTransactionInterface.java b/src/main/java/org/caosdb/server/transaction/WriteTransactionInterface.java
index 165acb408776a720c6887d31b550cf57e3d6fa0c..4e2938e18d061cbd1a7575baa59322356731859a 100644
--- a/src/main/java/org/caosdb/server/transaction/WriteTransactionInterface.java
+++ b/src/main/java/org/caosdb/server/transaction/WriteTransactionInterface.java
@@ -1,8 +1,13 @@
 package org.caosdb.server.transaction;
 
+import org.apache.shiro.subject.Subject;
 import org.caosdb.server.database.access.Access;
 
 public interface WriteTransactionInterface extends TransactionInterface {
 
   public Access getAccess();
+
+  public Subject getTransactor();
+
+  public String getSRID();
 }
diff --git a/src/main/java/org/caosdb/server/utils/Info.java b/src/main/java/org/caosdb/server/utils/Info.java
index 18ee09828006c0394dec315ca77483f8298ba86b..644239fc662c1b6a05dc1aac37af1bfe26e7972e 100644
--- a/src/main/java/org/caosdb/server/utils/Info.java
+++ b/src/main/java/org/caosdb/server/utils/Info.java
@@ -28,6 +28,7 @@ import java.sql.SQLException;
 import java.util.LinkedList;
 import org.apache.logging.log4j.LogManager;
 import org.apache.logging.log4j.Logger;
+import org.caosdb.datetime.UTCDateTime;
 import org.caosdb.server.CaosDBServer;
 import org.caosdb.server.FileSystem;
 import org.caosdb.server.database.DatabaseAccessManager;
@@ -46,6 +47,7 @@ public class Info extends AbstractObservable implements Observer, TransactionInt
   public static final String SYNC_DATABASE_EVENT = "SyncDatabaseEvent";
   private final Access access;
   public Logger logger = LogManager.getLogger(getClass());
+  private UTCDateTime timestamp;
 
   @Override
   public boolean notifyObserver(final String e, final Observable o) {
@@ -58,6 +60,7 @@ public class Info extends AbstractObservable implements Observer, TransactionInt
   }
 
   private Info() {
+    this.timestamp = UTCDateTime.SystemMillisToUTCDateTime(System.currentTimeMillis());
     this.access = DatabaseAccessManager.getInfoAccess(this);
     try {
       syncDatabase();
@@ -246,4 +249,9 @@ public class Info extends AbstractObservable implements Observer, TransactionInt
   public void execute() throws Exception {
     syncDatabase();
   }
+
+  @Override
+  public UTCDateTime getTimestamp() {
+    return timestamp;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/utils/Initialization.java b/src/main/java/org/caosdb/server/utils/Initialization.java
index cb1a36307928a72b9da95b48737196e569c43346..4f28f206bd5f272887fb78b661c6dc46d5cff6bc 100644
--- a/src/main/java/org/caosdb/server/utils/Initialization.java
+++ b/src/main/java/org/caosdb/server/utils/Initialization.java
@@ -24,6 +24,7 @@
  */
 package org.caosdb.server.utils;
 
+import org.caosdb.datetime.UTCDateTime;
 import org.caosdb.server.database.DatabaseAccessManager;
 import org.caosdb.server.database.access.Access;
 import org.caosdb.server.transaction.TransactionInterface;
@@ -31,9 +32,11 @@ import org.caosdb.server.transaction.TransactionInterface;
 public final class Initialization implements TransactionInterface, AutoCloseable {
 
   private Access access;
+  private UTCDateTime timestamp;
   private static final Initialization instance = new Initialization();
 
   private Initialization() {
+    this.timestamp = UTCDateTime.SystemMillisToUTCDateTime(System.currentTimeMillis());
     this.access = DatabaseAccessManager.getInitAccess(this);
   }
 
@@ -55,4 +58,9 @@ public final class Initialization implements TransactionInterface, AutoCloseable
       this.access = null;
     }
   }
+
+  @Override
+  public UTCDateTime getTimestamp() {
+    return timestamp;
+  }
 }
diff --git a/src/main/java/org/caosdb/server/utils/ServerMessages.java b/src/main/java/org/caosdb/server/utils/ServerMessages.java
index 4197f2cf78cedb3fcf9dc0ea6648b6c3335a9da8..151f55face7edbfab793606474f183a65f0468be 100644
--- a/src/main/java/org/caosdb/server/utils/ServerMessages.java
+++ b/src/main/java/org/caosdb/server/utils/ServerMessages.java
@@ -1,22 +1,26 @@
 /*
- * ** header v3.0 This file is a part of the CaosDB Project.
+ * This file is a part of the CaosDB Project.
  *
- * Copyright (C) 2018 Research Group Biomedical Physics, Max-Planck-Institute for Dynamics and
- * Self-Organization Göttingen
+ * Copyright (C) 2018 Research Group Biomedical Physics, Max-Planck-Institute
+ * for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
- * This program is free software: you can redistribute it and/or modify it under the terms of the
- * GNU Affero General Public License as published by the Free Software Foundation, either version 3
- * of the License, or (at your option) any later version.
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
  *
- * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without
- * even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Affero General Public License for more details.
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
  *
- * You should have received a copy of the GNU Affero General Public License along with this program.
- * If not, see <https://www.gnu.org/licenses/>.
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.utils;
 
 import org.caosdb.api.entity.v1.MessageCode;
@@ -267,6 +271,25 @@ public class ServerMessages {
           MessageCode.MESSAGE_CODE_UNKNOWN,
           "Role name is already in use. Choose a different name.");
 
+  public static final Message ROLE_CANNOT_BE_DELETED =
+      new Message(
+          MessageType.Error,
+          MessageCode.MESSAGE_CODE_UNKNOWN,
+          "Role cannot be deleted because there are still users with this role.");
+
+  public static final Message SPECIAL_ROLE_CANNOT_BE_DELETED =
+      new Message(
+          MessageType.Error,
+          MessageCode.MESSAGE_CODE_UNKNOWN,
+          "This special role cannot be deleted. Ever.");
+
+  public static final Message SPECIAL_ROLE_PERMISSIONS_CANNOT_BE_CHANGED() {
+    return new Message(
+        MessageType.Error,
+        MessageCode.MESSAGE_CODE_UNKNOWN,
+        "This special role's permissions cannot be changed. Ever.");
+  }
+
   public static final Message QUERY_EXCEPTION =
       new Message(
           MessageType.Error,
@@ -336,7 +359,9 @@ public class ServerMessages {
 
   public static final Message AUTHORIZATION_ERROR =
       new Message(
-          MessageType.Error, MessageCode.MESSAGE_CODE_UNKNOWN, "You are not allowed to do this.");
+          MessageType.Error,
+          MessageCode.MESSAGE_CODE_AUTHORIZATION_ERROR,
+          "You are not allowed to do this.");
 
   public static final Message REFERENCE_IS_NOT_ALLOWED_BY_DATATYPE =
       new Message(
@@ -579,4 +604,16 @@ public class ServerMessages {
           MessageType.Error,
           MessageCode.MESSAGE_CODE_INTEGRITY_VIOLATION,
           "This entity caused an unexpected integrity violation. This is a strong indicator for a server bug. Please report.");
+
+  public static final Message INVALID_USER_NAME(String policy) {
+    return new Message(
+        MessageType.Error,
+        MessageCode.MESSAGE_CODE_UNKNOWN,
+        "The user name does not comply with the policies for user names: " + policy);
+  }
+
+  public static final Message CANNOT_DELETE_YOURSELF() {
+    return new Message(
+        MessageType.Error, MessageCode.MESSAGE_CODE_UNKNOWN, "You cannot delete yourself.");
+  }
 }
diff --git a/src/test/java/org/caosdb/server/authentication/AuthTokenTest.java b/src/test/java/org/caosdb/server/authentication/AuthTokenTest.java
index ca19603230bf6aa989c495fbadabd0989c2a9790..0b19b414517769ee1d6c3882658e870d50193225 100644
--- a/src/test/java/org/caosdb/server/authentication/AuthTokenTest.java
+++ b/src/test/java/org/caosdb/server/authentication/AuthTokenTest.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,12 +19,13 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.authentication;
 
 import static org.junit.Assert.assertArrayEquals;
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
 
 import com.fasterxml.jackson.databind.ObjectMapper;
 import com.fasterxml.jackson.databind.ObjectReader;
@@ -53,10 +55,11 @@ import org.caosdb.server.database.backend.interfaces.RetrievePasswordValidatorIm
 import org.caosdb.server.database.backend.interfaces.RetrievePermissionRulesImpl;
 import org.caosdb.server.database.backend.interfaces.RetrieveRoleImpl;
 import org.caosdb.server.database.backend.interfaces.RetrieveUserImpl;
+import org.caosdb.server.grpc.AuthInterceptor;
 import org.caosdb.server.resource.TestScriptingResource.RetrievePasswordValidator;
 import org.caosdb.server.resource.TestScriptingResource.RetrievePermissionRules;
-import org.caosdb.server.resource.TestScriptingResource.RetrieveRole;
-import org.caosdb.server.resource.TestScriptingResource.RetrieveUser;
+import org.caosdb.server.resource.TestScriptingResource.RetrieveRoleMockup;
+import org.caosdb.server.resource.TestScriptingResource.RetrieveUserMockUp;
 import org.junit.Assert;
 import org.junit.Before;
 import org.junit.BeforeClass;
@@ -71,9 +74,9 @@ public class AuthTokenTest {
 
   @BeforeClass
   public static void setupShiro() throws IOException {
-    BackendTransaction.setImpl(RetrieveRoleImpl.class, RetrieveRole.class);
+    BackendTransaction.setImpl(RetrieveRoleImpl.class, RetrieveRoleMockup.class);
     BackendTransaction.setImpl(RetrievePermissionRulesImpl.class, RetrievePermissionRules.class);
-    BackendTransaction.setImpl(RetrieveUserImpl.class, RetrieveUser.class);
+    BackendTransaction.setImpl(RetrieveUserImpl.class, RetrieveUserMockUp.class);
     BackendTransaction.setImpl(
         RetrievePasswordValidatorImpl.class, RetrievePasswordValidator.class);
 
@@ -393,6 +396,7 @@ public class AuthTokenTest {
     OneTimeAuthenticationToken.initConfig(new CharSequenceInputStream(testYaml, "utf-8"));
 
     Subject anonymous = SecurityUtils.getSubject();
+    CaosDBServer.setProperty(ServerProperties.KEY_AUTH_OPTIONAL, "true");
     anonymous.login(AnonymousAuthenticationToken.getInstance());
 
     OneTimeAuthenticationToken token =
@@ -448,4 +452,10 @@ public class AuthTokenTest {
     assertEquals(9223372036854775000L, config.getExpiresAfter());
     assertEquals(922337203685477000L, config.getReplayTimeout());
   }
+
+  @Test
+  public void testSessionTokenCookiePattern() {
+    String cookie = "SessionToken=%5B%22S%22%22%5D";
+    assertTrue(AuthInterceptor.SESSION_TOKEN_COOKIE_PREFIX_PATTERN.matcher(cookie).find());
+  }
 }
diff --git a/src/test/java/org/caosdb/server/grpc/CaosDBToGrpcConvertersTest.java b/src/test/java/org/caosdb/server/grpc/CaosDBToGrpcConvertersTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..6b21c9b1a5aa4afbe4b018029bf938ae2edd997e
--- /dev/null
+++ b/src/test/java/org/caosdb/server/grpc/CaosDBToGrpcConvertersTest.java
@@ -0,0 +1,56 @@
+package org.caosdb.server.grpc;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+import java.util.TimeZone;
+import org.caosdb.datetime.DateTimeFactory2;
+import org.caosdb.server.datatype.Value;
+import org.caosdb.server.entity.FileProperties;
+import org.caosdb.server.entity.RetrieveEntity;
+import org.junit.Test;
+
+public class CaosDBToGrpcConvertersTest {
+
+  @Test
+  public void testConvertScalarValue_Datetime() {
+    TimeZone timeZone = TimeZone.getTimeZone("UTC");
+    DateTimeFactory2 factory = new DateTimeFactory2(timeZone);
+    CaosDBToGrpcConverters converters = new CaosDBToGrpcConverters(timeZone);
+    Value value = null;
+    assertNull(converters.convertScalarValue(value));
+    value = factory.parse("2022");
+    assertEquals(converters.convertScalarValue(value).toString(), "string_value: \"2022\"\n");
+    value = factory.parse("2022-12");
+    assertEquals(converters.convertScalarValue(value).toString(), "string_value: \"2022-12\"\n");
+    value = factory.parse("2022-12-24");
+    assertEquals(converters.convertScalarValue(value).toString(), "string_value: \"2022-12-24\"\n");
+    value = factory.parse("2022-12-24T18:15:00");
+    assertEquals(
+        converters.convertScalarValue(value).toString(),
+        "string_value: \"2022-12-24T18:15:00+0000\"\n");
+    value = factory.parse("2022-12-24T18:15:00.999999");
+    assertEquals(
+        converters.convertScalarValue(value).toString(),
+        "string_value: \"2022-12-24T18:15:00.999999+0000\"\n");
+    value = factory.parse("2022-12-24T18:15:00.999999UTC");
+    assertEquals(
+        converters.convertScalarValue(value).toString(),
+        "string_value: \"2022-12-24T18:15:00.999999+0000\"\n");
+    value = factory.parse("2022-12-24T18:15:00.999999+0200");
+    assertEquals(
+        converters.convertScalarValue(value).toString(),
+        "string_value: \"2022-12-24T16:15:00.999999+0000\"\n");
+  }
+
+  @Test
+  public void testConvertEntity_FileDescriptor() {
+    RetrieveEntity entity = new RetrieveEntity(null);
+    CaosDBToGrpcConverters converters = new CaosDBToGrpcConverters(null);
+    assertEquals(converters.convert(entity).toString(), "entity {\n}\n");
+    entity.setFileProperties(new FileProperties("checksum1234", "the/path", 1024L));
+    assertEquals(
+        converters.convert(entity).toString(),
+        "entity {\n  file_descriptor {\n    path: \"the/path\"\n    size: 1024\n  }\n}\n");
+  }
+}
diff --git a/src/test/java/org/caosdb/server/permissions/EntityACLTest.java b/src/test/java/org/caosdb/server/permissions/EntityACLTest.java
index 28b4322333f771a3480e4d386b7e77fb2977590b..30c0cd992573c0c083d863a6d60750dd77d6e035 100644
--- a/src/test/java/org/caosdb/server/permissions/EntityACLTest.java
+++ b/src/test/java/org/caosdb/server/permissions/EntityACLTest.java
@@ -35,17 +35,23 @@ import java.util.Set;
 import org.apache.shiro.SecurityUtils;
 import org.apache.shiro.subject.Subject;
 import org.caosdb.server.CaosDBServer;
+import org.caosdb.server.ServerProperties;
 import org.caosdb.server.accessControl.AnonymousAuthenticationToken;
 import org.caosdb.server.accessControl.AuthenticationUtils;
 import org.caosdb.server.accessControl.Config;
+import org.caosdb.server.accessControl.CredentialsValidator;
 import org.caosdb.server.accessControl.OneTimeAuthenticationToken;
+import org.caosdb.server.accessControl.Principal;
 import org.caosdb.server.accessControl.Role;
 import org.caosdb.server.database.BackendTransaction;
 import org.caosdb.server.database.access.Access;
+import org.caosdb.server.database.backend.interfaces.RetrievePasswordValidatorImpl;
 import org.caosdb.server.database.backend.interfaces.RetrievePermissionRulesImpl;
 import org.caosdb.server.database.backend.interfaces.RetrieveRoleImpl;
+import org.caosdb.server.database.backend.interfaces.RetrieveUserImpl;
 import org.caosdb.server.database.exceptions.TransactionException;
 import org.caosdb.server.database.misc.TransactionBenchmark;
+import org.caosdb.server.database.proto.ProtoUser;
 import org.caosdb.server.resource.AbstractCaosDBServerResource;
 import org.caosdb.server.resource.AbstractCaosDBServerResource.XMLParser;
 import org.caosdb.server.utils.Utils;
@@ -103,6 +109,54 @@ public class EntityACLTest {
     }
   }
 
+  public static class RetrievePasswordValidatorMockup implements RetrievePasswordValidatorImpl {
+
+    public RetrievePasswordValidatorMockup(Access a) {}
+
+    @Override
+    public void setTransactionBenchmark(TransactionBenchmark b) {}
+
+    @Override
+    public TransactionBenchmark getBenchmark() {
+      return null;
+    }
+
+    @Override
+    public CredentialsValidator<String> execute(String name) throws TransactionException {
+      if (name.equals("anonymous")) {
+        return new CredentialsValidator<String>() {
+
+          @Override
+          public boolean isValid(String credential) {
+            return false;
+          }
+        };
+      }
+      return null;
+    }
+  }
+
+  public static class RetrieveUserMockup implements RetrieveUserImpl {
+
+    public RetrieveUserMockup(Access a) {}
+
+    @Override
+    public void setTransactionBenchmark(TransactionBenchmark b) {}
+
+    @Override
+    public TransactionBenchmark getBenchmark() {
+      return null;
+    }
+
+    @Override
+    public ProtoUser execute(Principal principal) throws TransactionException {
+      if (principal.getUsername().equals("anonymous")) {
+        return new ProtoUser();
+      }
+      return null;
+    }
+  }
+
   @BeforeClass
   public static void init() throws IOException {
     CaosDBServer.initServerProperties();
@@ -112,6 +166,9 @@ public class EntityACLTest {
     BackendTransaction.setImpl(
         RetrievePermissionRulesImpl.class, RetrievePermissionRulesMockup.class);
     BackendTransaction.setImpl(RetrieveRoleImpl.class, RetrieveRoleMockup.class);
+    BackendTransaction.setImpl(
+        RetrievePasswordValidatorImpl.class, RetrievePasswordValidatorMockup.class);
+    BackendTransaction.setImpl(RetrieveUserImpl.class, RetrieveUserMockup.class);
   }
 
   @Test
@@ -272,6 +329,7 @@ public class EntityACLTest {
   @Test
   public void testEntityACLForAnonymous() {
     Subject anonymous = SecurityUtils.getSubject();
+    CaosDBServer.setProperty(ServerProperties.KEY_AUTH_OPTIONAL, "true");
     anonymous.login(AnonymousAuthenticationToken.getInstance());
     assertTrue(AuthenticationUtils.isAnonymous(anonymous));
     EntityACL acl = EntityACL.getOwnerACLFor(anonymous);
@@ -279,35 +337,6 @@ public class EntityACLTest {
     assertTrue(acl.getOwners().isEmpty());
   }
 
-  //   @Test
-  //   public void testParseFromElement() throws JDOMException, IOException {
-  //   Assert.assertEquals("[]",
-  //   EntityACL.serialize(EntityACL.parseFromElement(stringToJdom("<ACL></ACL>"))));
-  //   Assert.assertEquals("[]", EntityACL.serialize(EntityACL
-  //   .parseFromElement(stringToJdom("<ACL><Grant></Grant></ACL>"))));
-  //   Assert.assertEquals("[]", EntityACL.serialize(EntityACL
-  //   .parseFromElement(stringToJdom("<ACL><Deny></Deny></ACL>"))));
-  //   Assert.assertEquals("[]", EntityACL.serialize(EntityACL
-  //   .parseFromElement(stringToJdom("<ACL><Grant role='bla'></Grant></ACL>"))));
-  //   Assert.assertEquals("[]", EntityACL.serialize(EntityACL
-  //   .parseFromElement(stringToJdom("<ACL><Deny role='bla'></Deny></ACL>"))));
-  //   Assert.assertEquals(
-  //   "{bla:2;}",
-  //   EntityACL.serialize(EntityACL
-  //   .parseFromElement(stringToJdom("<ACL><Grant role='bla'><Permission
-  // name='DELETE'/></Grant></ACL>"))));
-  //   Assert.assertEquals(
-  //   "{bla:" + (Long.MIN_VALUE + 2) + ";}",
-  //   EntityACL.serialize(EntityACL
-  //   .parseFromElement(stringToJdom("<ACL><Deny role='bla'><Permission name='DELETE'
-  // /></Deny></ACL>"))));
-  //   Assert.assertEquals(
-  //   "{bla:32;}",
-  //   EntityACL.serialize(EntityACL
-  //   .parseFromElement(stringToJdom("<ACL><Grant role='bla'><Permission name='RETRIEVE:ACL'
-  // /></Grant></ACL>"))));
-  //   }
-
   @Test
   public void testFactory() {
     final AbstractEntityACLFactory<EntityACL> f = new EntityACLFactory();
@@ -420,6 +449,7 @@ public class EntityACLTest {
     EntityACL acl = f.create();
 
     Subject anonymous = SecurityUtils.getSubject();
+    CaosDBServer.setProperty(ServerProperties.KEY_AUTH_OPTIONAL, "true");
     anonymous.login(AnonymousAuthenticationToken.getInstance());
     assertTrue(AuthenticationUtils.isAnonymous(anonymous));
 
diff --git a/src/test/java/org/caosdb/server/permissions/EntityPermissionTest.java b/src/test/java/org/caosdb/server/permissions/EntityPermissionTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..fd7c3e8e7e9a66a8b99ac09487bfa02767497e22
--- /dev/null
+++ b/src/test/java/org/caosdb/server/permissions/EntityPermissionTest.java
@@ -0,0 +1,92 @@
+package org.caosdb.server.permissions;
+
+import static org.junit.Assert.*;
+
+import org.junit.Test;
+
+public class EntityPermissionTest {
+
+  @Test
+  public void testGRPCMapping() {
+    assertEquals(
+        EntityPermission.EDIT_ACL.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_EDIT_ACL);
+
+    assertEquals(
+        EntityPermission.DELETE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_DELETE);
+
+    assertEquals(
+        EntityPermission.USE_AS_DATA_TYPE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_USE_AS_DATA_TYPE);
+    assertEquals(
+        EntityPermission.USE_AS_PARENT.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_USE_AS_PARENT);
+    assertEquals(
+        EntityPermission.USE_AS_PROPERTY.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_USE_AS_PROPERTY);
+    assertEquals(
+        EntityPermission.USE_AS_REFERENCE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_USE_AS_REFERENCE);
+
+    assertEquals(
+        EntityPermission.RETRIEVE_ENTITY.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_ENTITY);
+    assertEquals(
+        EntityPermission.RETRIEVE_ACL.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_ACL);
+    assertEquals(
+        EntityPermission.RETRIEVE_OWNER.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_OWNER);
+    assertEquals(
+        EntityPermission.RETRIEVE_HISTORY.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_HISTORY);
+    assertEquals(
+        EntityPermission.RETRIEVE_FILE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_RETRIEVE_FILE);
+
+    assertEquals(
+        EntityPermission.UPDATE_VALUE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_VALUE);
+    assertEquals(
+        EntityPermission.UPDATE_DESCRIPTION.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_DESCRIPTION);
+    assertEquals(
+        EntityPermission.UPDATE_DATA_TYPE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_DATA_TYPE);
+    assertEquals(
+        EntityPermission.UPDATE_NAME.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_NAME);
+    assertEquals(
+        EntityPermission.UPDATE_QUERY_TEMPLATE_DEFINITION.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission
+            .ENTITY_PERMISSION_UPDATE_QUERY_TEMPLATE_DEFINITION);
+    assertEquals(
+        EntityPermission.UPDATE_ROLE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_ROLE);
+
+    assertEquals(
+        EntityPermission.UPDATE_ADD_PARENT.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_ADD_PARENT);
+    assertEquals(
+        EntityPermission.UPDATE_REMOVE_PARENT.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_REMOVE_PARENT);
+
+    assertEquals(
+        EntityPermission.UPDATE_ADD_PROPERTY.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_ADD_PROPERTY);
+    assertEquals(
+        EntityPermission.UPDATE_REMOVE_PROPERTY.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_REMOVE_PROPERTY);
+
+    assertEquals(
+        EntityPermission.UPDATE_ADD_FILE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_ADD_FILE);
+    assertEquals(
+        EntityPermission.UPDATE_REMOVE_FILE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_REMOVE_FILE);
+    assertEquals(
+        EntityPermission.UPDATE_MOVE_FILE.getMapping(),
+        org.caosdb.api.entity.v1.EntityPermission.ENTITY_PERMISSION_UPDATE_MOVE_FILE);
+  }
+}
diff --git a/src/test/java/org/caosdb/server/query/TestCQL.java b/src/test/java/org/caosdb/server/query/TestCQL.java
index cf54bf71b69ea5f539744bd4bbe30fd1c37edcf4..ff1be776b041490aac7c434acdee73c96a9e88f9 100644
--- a/src/test/java/org/caosdb/server/query/TestCQL.java
+++ b/src/test/java/org/caosdb/server/query/TestCQL.java
@@ -264,6 +264,13 @@ public class TestCQL {
   String queryMR56 = "FIND ENTITY WITH ((p0 = v0 OR p1=v1) AND p2=v2)";
 
   String versionedQuery1 = "FIND ANY VERSION OF ENTITY e1";
+  // https://gitlab.com/caosdb/caosdb-server/-/issues/131
+  String issue131a = "FIND ename WITH pname1.x AND pname2";
+  String issue131b = "FIND ename WITH (pname1.x < 10) AND (pname1.x)";
+  String issue131c = "FIND ename WITH pname2 AND pname1.x ";
+  String issue131d = "FIND ename WITH (pname1.x) AND pname2";
+  String issue131e = "FIND ename WITH (pname1.pname2 > 30) AND (pname1.pname2 < 40)";
+  String issue131f = "FIND ename WITH (pname1.pname2 > 30) AND pname1.pname2 < 40";
 
   @Test
   public void testQuery1()
@@ -4341,7 +4348,7 @@ public class TestCQL {
     assertEquals("THE GREATEST ID", conjunction.getChild(3).getText());
   }
 
-  /** String query31 = "FIND PROPERTIES WHICH ARE INSERTED TODAY"; */
+  /** String query31 = "FIND PROPERTIES WHICH WERE INSERTED TODAY"; */
   @Test
   public void testQuery31() {
     CQLLexer lexer;
@@ -6740,4 +6747,163 @@ public class TestCQL {
     // must not throw ParsingException
     new Query(this.queryIssue131).parse();
   }
+
+  /** String issue131a = "FIND ename WITH pname1.x AND pname2"; */
+  @Test
+  public void testIssue131a() {
+    CQLLexer lexer;
+    lexer = new CQLLexer(CharStreams.fromString(this.issue131a));
+    final CommonTokenStream tokens = new CommonTokenStream(lexer);
+
+    final CQLParser parser = new CQLParser(tokens);
+    final CqContext sfq = parser.cq();
+
+    System.out.println(sfq.toStringTree(parser));
+
+    assertTrue(sfq.filter instanceof Conjunction);
+    LinkedList<EntityFilterInterface> filters = ((Conjunction) sfq.filter).getFilters();
+    assertEquals(filters.size(), 2);
+    assertTrue(filters.get(0) instanceof POV);
+    assertTrue(filters.get(1) instanceof POV);
+    POV pov1 = ((POV) filters.get(0));
+    POV pov2 = ((POV) filters.get(1));
+    assertEquals("POV(pname1,null,null)", pov1.toString());
+    assertEquals("POV(pname2,null,null)", pov2.toString());
+    assertTrue(pov1.hasSubProperty());
+    assertFalse(pov2.hasSubProperty());
+    assertEquals("POV(x,null,null)", pov1.getSubProperty().getFilter().toString());
+  }
+
+  /** String issue131b = "FIND ename WITH (pname1.x < 10) AND (pname1.x)"; */
+  @Test
+  public void testIssue131b() {
+    CQLLexer lexer;
+    lexer = new CQLLexer(CharStreams.fromString(this.issue131b));
+    final CommonTokenStream tokens = new CommonTokenStream(lexer);
+
+    final CQLParser parser = new CQLParser(tokens);
+    final CqContext sfq = parser.cq();
+
+    System.out.println(sfq.toStringTree(parser));
+
+    assertTrue(sfq.filter instanceof Conjunction);
+    LinkedList<EntityFilterInterface> filters = ((Conjunction) sfq.filter).getFilters();
+    assertEquals(filters.size(), 2);
+    assertTrue(filters.get(0) instanceof POV);
+    assertTrue(filters.get(1) instanceof POV);
+    POV pov1 = ((POV) filters.get(0));
+    POV pov2 = ((POV) filters.get(1));
+    assertEquals("POV(pname1,null,null)", pov1.toString());
+    assertEquals("POV(pname1,null,null)", pov2.toString());
+    assertTrue(pov1.hasSubProperty());
+    assertTrue(pov2.hasSubProperty());
+    assertEquals("POV(x,<,10)", pov1.getSubProperty().getFilter().toString());
+    assertEquals("POV(x,null,null)", pov2.getSubProperty().getFilter().toString());
+  }
+
+  /** String issue131c = "FIND ename WITH pname2 AND pname1.x "; */
+  @Test
+  public void testIssue131c() {
+    CQLLexer lexer;
+    lexer = new CQLLexer(CharStreams.fromString(this.issue131c));
+    final CommonTokenStream tokens = new CommonTokenStream(lexer);
+
+    final CQLParser parser = new CQLParser(tokens);
+    final CqContext sfq = parser.cq();
+
+    System.out.println(sfq.toStringTree(parser));
+
+    assertTrue(sfq.filter instanceof Conjunction);
+    LinkedList<EntityFilterInterface> filters = ((Conjunction) sfq.filter).getFilters();
+    assertEquals(filters.size(), 2);
+    assertTrue(filters.get(0) instanceof POV);
+    assertTrue(filters.get(1) instanceof POV);
+    POV pov1 = ((POV) filters.get(0));
+    POV pov2 = ((POV) filters.get(1));
+    assertEquals("POV(pname2,null,null)", pov1.toString());
+    assertEquals("POV(pname1,null,null)", pov2.toString());
+    assertFalse(pov1.hasSubProperty());
+    assertTrue(pov2.hasSubProperty());
+    assertEquals("POV(x,null,null)", pov2.getSubProperty().getFilter().toString());
+  }
+
+  /** String issue131d = "FIND ename WITH (pname1.x) AND pname2"; */
+  @Test
+  public void testIssue131d() {
+    CQLLexer lexer;
+    lexer = new CQLLexer(CharStreams.fromString(this.issue131d));
+    final CommonTokenStream tokens = new CommonTokenStream(lexer);
+
+    final CQLParser parser = new CQLParser(tokens);
+    final CqContext sfq = parser.cq();
+
+    System.out.println(sfq.toStringTree(parser));
+
+    assertTrue(sfq.filter instanceof Conjunction);
+    LinkedList<EntityFilterInterface> filters = ((Conjunction) sfq.filter).getFilters();
+    assertEquals(filters.size(), 2);
+    assertTrue(filters.get(0) instanceof POV);
+    assertTrue(filters.get(1) instanceof POV);
+    POV pov1 = ((POV) filters.get(0));
+    POV pov2 = ((POV) filters.get(1));
+    assertEquals("POV(pname1,null,null)", pov1.toString());
+    assertEquals("POV(pname2,null,null)", pov2.toString());
+    assertTrue(pov1.hasSubProperty());
+    assertFalse(pov2.hasSubProperty());
+    assertEquals("POV(x,null,null)", pov1.getSubProperty().getFilter().toString());
+  }
+
+  /** String issue131e = "FIND ename WITH (pname1.pname2 > 30) AND (pname1.pname2 < 40)"; */
+  @Test
+  public void testIssue131e() {
+    CQLLexer lexer;
+    lexer = new CQLLexer(CharStreams.fromString(this.issue131e));
+    final CommonTokenStream tokens = new CommonTokenStream(lexer);
+
+    final CQLParser parser = new CQLParser(tokens);
+    final CqContext sfq = parser.cq();
+
+    System.out.println(sfq.toStringTree(parser));
+
+    assertTrue(sfq.filter instanceof Conjunction);
+    LinkedList<EntityFilterInterface> filters = ((Conjunction) sfq.filter).getFilters();
+    assertEquals(filters.size(), 2);
+    assertTrue(filters.get(0) instanceof POV);
+    assertTrue(filters.get(1) instanceof POV);
+    POV pov1 = ((POV) filters.get(0));
+    POV pov2 = ((POV) filters.get(1));
+    assertEquals("POV(pname1,null,null)", pov1.toString());
+    assertEquals("POV(pname1,null,null)", pov2.toString());
+    assertTrue(pov1.hasSubProperty());
+    assertTrue(pov2.hasSubProperty());
+    assertEquals("POV(pname2,>,30)", pov1.getSubProperty().getFilter().toString());
+    assertEquals("POV(pname2,<,40)", pov2.getSubProperty().getFilter().toString());
+  }
+
+  /** String issue131f = "FIND ename WITH (pname1.pname2 > 30) AND pname1.pname2 < 40"; */
+  @Test
+  public void testIssue131f() {
+    CQLLexer lexer;
+    lexer = new CQLLexer(CharStreams.fromString(this.issue131f));
+    final CommonTokenStream tokens = new CommonTokenStream(lexer);
+
+    final CQLParser parser = new CQLParser(tokens);
+    final CqContext sfq = parser.cq();
+
+    System.out.println(sfq.toStringTree(parser));
+
+    assertTrue(sfq.filter instanceof Conjunction);
+    LinkedList<EntityFilterInterface> filters = ((Conjunction) sfq.filter).getFilters();
+    assertEquals(filters.size(), 2);
+    assertTrue(filters.get(0) instanceof POV);
+    assertTrue(filters.get(1) instanceof POV);
+    POV pov1 = ((POV) filters.get(0));
+    POV pov2 = ((POV) filters.get(1));
+    assertEquals("POV(pname1,null,null)", pov1.toString());
+    assertEquals("POV(pname1,null,null)", pov2.toString());
+    assertTrue(pov1.hasSubProperty());
+    assertTrue(pov2.hasSubProperty());
+    assertEquals("POV(pname2,>,30)", pov1.getSubProperty().getFilter().toString());
+    assertEquals("POV(pname2,<,40)", pov2.getSubProperty().getFilter().toString());
+  }
 }
diff --git a/src/test/java/org/caosdb/server/resource/TestAbstractCaosDBServerResource.java b/src/test/java/org/caosdb/server/resource/TestAbstractCaosDBServerResource.java
index 5d81ca738d507bcfd75dbe137756135cede3989b..226c9aaac077a56fa96535480418762d30bbb6e9 100644
--- a/src/test/java/org/caosdb/server/resource/TestAbstractCaosDBServerResource.java
+++ b/src/test/java/org/caosdb/server/resource/TestAbstractCaosDBServerResource.java
@@ -89,6 +89,7 @@ public class TestAbstractCaosDBServerResource {
   @Test
   public void testReponseRootElement() throws IOException {
     final Subject user = new DelegatingSubject(new DefaultSecurityManager(new AnonymousRealm()));
+    CaosDBServer.setProperty(ServerProperties.KEY_AUTH_OPTIONAL, "true");
     user.login(AnonymousAuthenticationToken.getInstance());
     AbstractCaosDBServerResource s =
         new AbstractCaosDBServerResource() {
diff --git a/src/test/java/org/caosdb/server/resource/TestScriptingResource.java b/src/test/java/org/caosdb/server/resource/TestScriptingResource.java
index 7f7434528678dbd2e1886fade2116d0c9f766740..566c8a09ee301f628bfe9232dde75ad5a66c0207 100644
--- a/src/test/java/org/caosdb/server/resource/TestScriptingResource.java
+++ b/src/test/java/org/caosdb/server/resource/TestScriptingResource.java
@@ -1,9 +1,10 @@
 /*
- * ** header v3.0
  * This file is a part of the CaosDB Project.
  *
  * Copyright (C) 2018 Research Group Biomedical Physics,
  * Max-Planck-Institute for Dynamics and Self-Organization Göttingen
+ * Copyright (C) 2021 IndiScale GmbH <info@indiscale.com>
+ * Copyright (C) 2021 Timm Fitschen <t.fitschen@indiscale.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Affero General Public License as
@@ -18,8 +19,8 @@
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <https://www.gnu.org/licenses/>.
  *
- * ** end header
  */
+
 package org.caosdb.server.resource;
 
 import static org.junit.Assert.assertEquals;
@@ -31,6 +32,7 @@ import java.util.List;
 import org.apache.shiro.SecurityUtils;
 import org.apache.shiro.subject.Subject;
 import org.caosdb.server.CaosDBServer;
+import org.caosdb.server.ServerProperties;
 import org.caosdb.server.accessControl.AnonymousAuthenticationToken;
 import org.caosdb.server.accessControl.CredentialsValidator;
 import org.caosdb.server.accessControl.Principal;
@@ -64,9 +66,9 @@ import org.restlet.representation.StringRepresentation;
 
 public class TestScriptingResource {
 
-  public static class RetrieveRole implements RetrieveRoleImpl {
+  public static class RetrieveRoleMockup implements RetrieveRoleImpl {
 
-    public RetrieveRole(Access a) {}
+    public RetrieveRoleMockup(Access a) {}
 
     @Override
     public Role retrieve(String role) throws TransactionException {
@@ -107,9 +109,9 @@ public class TestScriptingResource {
     public void setTransactionBenchmark(TransactionBenchmark b) {}
   }
 
-  public static class RetrieveUser implements RetrieveUserImpl {
+  public static class RetrieveUserMockUp implements RetrieveUserImpl {
 
-    public RetrieveUser(Access a) {}
+    public RetrieveUserMockUp(Access a) {}
 
     @Override
     public ProtoUser execute(Principal principal) throws TransactionException {
@@ -154,9 +156,9 @@ public class TestScriptingResource {
     CaosDBServer.initServerProperties();
     CaosDBServer.initShiro();
 
-    BackendTransaction.setImpl(RetrieveRoleImpl.class, RetrieveRole.class);
+    BackendTransaction.setImpl(RetrieveRoleImpl.class, RetrieveRoleMockup.class);
     BackendTransaction.setImpl(RetrievePermissionRulesImpl.class, RetrievePermissionRules.class);
-    BackendTransaction.setImpl(RetrieveUserImpl.class, RetrieveUser.class);
+    BackendTransaction.setImpl(RetrieveUserImpl.class, RetrieveUserMockUp.class);
     BackendTransaction.setImpl(
         RetrievePasswordValidatorImpl.class, RetrievePasswordValidator.class);
 
@@ -204,6 +206,7 @@ public class TestScriptingResource {
   @Test
   public void testAnonymousWithOutPermission() {
     Subject user = SecurityUtils.getSubject();
+    CaosDBServer.setProperty(ServerProperties.KEY_AUTH_OPTIONAL, "true");
     user.login(AnonymousAuthenticationToken.getInstance());
     Form form = new Form("call=anonymous_no_permission");
     Representation entity = form.getWebRepresentation();
@@ -221,6 +224,7 @@ public class TestScriptingResource {
   @Test
   public void testAnonymousWithPermission() {
     Subject user = SecurityUtils.getSubject();
+    CaosDBServer.setProperty(ServerProperties.KEY_AUTH_OPTIONAL, "true");
     user.login(AnonymousAuthenticationToken.getInstance());
     Form form = new Form("call=anonymous_ok");
     Representation entity = form.getWebRepresentation();
@@ -253,6 +257,7 @@ public class TestScriptingResource {
   @Test
   public void testHandleForm() throws Message, IOException {
     Subject user = SecurityUtils.getSubject();
+    CaosDBServer.setProperty(ServerProperties.KEY_AUTH_OPTIONAL, "true");
     user.login(AnonymousAuthenticationToken.getInstance());
     Form form = new Form("call=anonymous_ok");
     assertEquals(0, resource.handleForm(form));
diff --git a/src/test/java/org/caosdb/server/resource/TestSharedFileResource.java b/src/test/java/org/caosdb/server/resource/TestSharedFileResource.java
index 8dbbd5b1ec25843c3a5b28d46a2fa784f169330d..bff03a45e908419bbaef3a8988df7d9d382a0e8a 100644
--- a/src/test/java/org/caosdb/server/resource/TestSharedFileResource.java
+++ b/src/test/java/org/caosdb/server/resource/TestSharedFileResource.java
@@ -122,16 +122,10 @@ public class TestSharedFileResource {
 
     provideUserSourcesFile();
     final Subject user = new DelegatingSubject(new DefaultSecurityManager(new AnonymousRealm()));
+    CaosDBServer.setProperty(ServerProperties.KEY_AUTH_OPTIONAL, "true");
     user.login(AnonymousAuthenticationToken.getInstance());
     SharedFileResource resource =
         new SharedFileResource() {
-          // @Override
-          // protected Representation httpGetInChildClass()
-          //     throws ConnectionException, IOException, SQLException, CaosDBException,
-          //         NoSuchAlgorithmException, Exception {
-          //   // TODO Auto-generated method stub
-          //   return super.httpGetInChildClass();
-          // }
 
           @Override
           public String getSRID() {