IllegalStateException is thrown when Liberty tries to update a readOnly subject

[una-tapa]

Describe the bug

The java.lang.IllegalStateException is thrown with the reason Subject is read-only. The error is thrown when TAI authenticator tries to check and remove an internal property that is no longer used.

Caused by: java.lang.IllegalStateException: Subject is read-only
        at javax.security.auth.Subject$SecureSet$1.remove(Subject.java:1297)
        at javax.security.auth.Subject$SecureSet.remove(Subject.java:1386)
        at java.util.Collections$SynchronizedCollection.remove(Collections.java:2051)
        at com.ibm.ws.webcontainer.security.internal.TAIAuthenticator.removeInternalProps(TAIAuthenticator.java:388)
        at com.ibm.ws.webcontainer.security.internal.TAIAuthenticator.authenticateWithSubject(TAIAuthenticator.java:374)
        at com.ibm.ws.webcontainer.security.internal.TAIAuthenticator.loginWithTAIUserName(TAIAuthenticator.java:351)
        at com.ibm.ws.webcontainer.security.internal.TAIAuthenticator.authenticateWithTAIResult(TAIAuthenticator.java:313)
        at com.ibm.ws.webcontainer.security.internal.TAIAuthenticator.handleTaiResult(TAIAuthenticator.java:252)
        at com.ibm.ws.webcontainer.security.internal.TAIAuthenticator.authenticate(TAIAuthenticator.java:167)
        at com.ibm.ws.webcontainer.security.WebProviderAuthenticatorProxy.handleTAI(WebProviderAuthenticatorProxy.java:337)
        at com.ibm.ws.webcontainer.security.WebProviderAuthenticatorProxy.authenticate(WebProviderAuthenticatorProxy.java:454)
        at com.ibm.ws.webcontainer.security.WebAuthenticatorProxy.authenticate(WebAuthenticatorProxy.java:68)
        at com.ibm.ws.webcontainer.security.WebAppSecurityCollaboratorImpl.authenticateRequest(WebAppSecurityCollaboratorImpl.java:1233)
        at com.ibm.ws.webcontainer.security.WebAppSecurityCollaboratorImpl.determineWebReply(WebAppSecurityCollaboratorImpl.java:989)
        at com.ibm.ws.webcontainer.security.WebAppSecurityCollaboratorImpl.performSecurityChecks(WebAppSecurityCollaboratorImpl.java:678)
        at com.ibm.ws.webcontainer.security.WebAppSecurityCollaboratorImpl.preInvoke(WebAppSecurityCollaboratorImpl.java:596)
        at com.ibm.wsspi.webcontainer.collaborator.CollaboratorHelper.preInvokeCollaborators(CollaboratorHelper.java:459)

Steps to Reproduce
Unfortunately, no recreation steps are found.

Expected behavior
Liberty should check isReadOnly() before accessing the Subject.

Diagnostic information:

• OpenLiberty Version: 20.0.0.12
• Java Version: The issue is irrelevant to the Java version. Reported on 8.0.6.25.
• server.xml configuration The error is thrown from TAI related method. The TAI configuration looks like below.

 <trustAssociation id="myTrustAssociation" invokeForUnprotectedURI="false" failOverToAppAuthType="false">
   <interceptors id="myTAI" enabled="true" className="com.ibm.mysecurity.myTAI" invokeBeforeSSO="true" invokeAfterSSO="false" libraryRef="myLib">
   </interceptors>
 </trustAssociation>

[una-tapa]

I had the same fix and the same green build. Somehow I did not ask for review - closing. We will go with # 17586,

[mshah0722]

Opening to link issue. Then closing right after.