Unable to login with a SQL Authenticator

For a project, we are migrating Forms to ADF.
There is also a number of reports which are not to be migrated yet.
Therefore, we need to keep the users in the database.
As we do not want to maintain two user stores, we thought it to be a good idea to create an authenticator in WebLogic to authenticate to the database.
There are loads of blog posts / support notes on how to configure a SQL Authenticator, so I won't repeat this procedure.
Take a look at Oracle Support Document 1342157.1 or a post from Edwin Biemond


However, we noticed a flaw in these (old) references.


In WebLogic 12c, when we create a SQL Authenticaotr, there is a filed named Identity Domain.
From the Oracle documentation, we learn:
All Authentication providers included in WebLogic Server support identity domains. If the identity domain attribute is set on an Authentication provider, that Authentication provider can authenticate only users who are defined in that identity domain.
...
An identity domain is a logical namespace for users and groups, typically representing a discrete set of users and groups in the physical datastore. Identity domains are used to identify the users associated with particular partitions.


As we do not use partitions in our domain, there is no use for an Identity domain.
But we did not know that when we setup the authenticator (and who reads the entire manual right??)


So following the previously mentioned resources, we created the SQL authenticator and entered the domain name in the Identity Domain field.
This resulted in a not working authenticator.
Symptoms:

• When a user tried to login using database credentials, the autentication faild Always
• No error message in the log
• No activity in the datase (no query was executed to check the credentials)

To further analyse the issue, we added som Java options to the Admin server, using the setDomainEnv script:

JAVA_OPTIONS="${JAVA_OPTIONS} -Dweblogic.kernel.debug=true -Dweblogic.log.StdoutSeverity=Debug -Dweblogic.log.LogSeverity=Debug -Dweblogic.StdoutDebugEnabled=true -Dweblogic.log.LoggerSeverity=Debug -Dweblogic.debug.DebugSecurityAtn=true" 
 export JAVA_OPTIONS 

This gave us more insight in the issue. The log file now revealled:

####<23-aug-2016 15:13:02 uur CEST> <Debug> <SecurityAtn> <BSCC6112> <DefaultServer> <[ACTIVE] ExecuteThread: '5' for queue: 'weblogic.kernel.Default (self-tuning)'> <<WLS Kernel>> <> <d489addb-c960-41f1-babb-f912aec329bc-00000036> <1471957982959> <[severity-value: 128] [rid: 0] [partition-id: 0] [partition-name: DOMAIN] > <BEA-000000> <weblogic.security.providers.authentication.shared.DBMSAtnLoginModuleImpl.login exception: 
java.security.PrivilegedActionException: javax.security.auth.login.LoginException: javax.security.auth.callback.UnsupportedCallbackException: Unrecognized Callback: class weblogic.security.auth.callback.IdentityDomainUserCallback 
weblogic.security.auth.callback.IdentityDomainUserCallback@31789514
 at java.security.AccessController.doPrivileged(Native Method)
 at com.bea.common.security.internal.service.LoginModuleWrapper.login(LoginModuleWrapper.java:114)
 at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
 at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
 at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
 at java.lang.reflect.Method.invoke(Method.java:497)
 at javax.security.auth.login.LoginContext.invoke(LoginContext.java:755)
...

Unfortunately, we still had no clue.
As you have read from the beginning of the post, you might think that setting the Identity Domain field to DOMAIN might solve the issue (the log states partition-name: DOMAIN) but no, that's no solution either.

The trick is to leave the Identity Domain filed blank. After that the authenticator worked like a charm.