Merge branch 'f-cert' into 'dev'

DOC: note on cert

See merge request caosdb/caosdb-server!67

README_SETUP.md

@@ -75,7 +75,8 @@ server:
    - `keytool -genkey -keyalg RSA -alias selfsigned -keystore caosdb.jks -validity 375 -keysize 2048 -ext san=dns:localhost`
      Replace `localhost` by your host name, if you want.
    - `keytool -importkeystore -srckeystore caosdb.jks -destkeystore caosdb.p12 -deststoretype PKCS12 -srcalias selfsigned`
-   - `openssl pkcs12 -in caosdb.p12 -nokeys -out cert.pem`
+   - Export the public part only: `openssl pkcs12 -in caosdb.p12 -nokeys -out cert.pem`.
+	 The resulting ``cert.pem` can safely be given to users to allow ssl verification.
    - You can check the content of the certificate with `openssl x509 -in cert.pem -text`
 
    Alternatively, you can create a keystore from certificate files that you already have: