How to define mappers for keycloak identity providers?

Question

I defined an Identity Provider in Keycloak that connects to a PingFederate IDP. The SAML assertion flow fails on NullPointerException. Specific error at the bottom. I debugged the code and have a suspicion that it's related to not defining mappers.

I see that the username is being set by some strange ID instead of the one provided by the saml assertion: identity.setUsername(subjectNameID.getValue())

I can't find examples nor tutorials on defining keycloak identity provider mappers.

Can anyone help? Thanks.

Error:

13:58:04,386 ERROR [io.undertow.request] (default task-1) UT005023: Exception handling request to /auth/realms/master/broker/sanity-idp/endpoint: org.jboss.resteasy.spi.UnhandledException: org.keycloak.broker.provider.IdentityBrokerException: Could not process response from SAML identity provider.
    at org.jboss.resteasy.core.ExceptionHandler.handleApplicationException(ExceptionHandler.java:76)
    at org.jboss.resteasy.core.ExceptionHandler.handleException(ExceptionHandler.java:212)
    at org.jboss.resteasy.core.SynchronousDispatcher.writeException(SynchronousDispatcher.java:168)
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:411)
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:202)
    at org.jboss.resteasy.plugins.server.servlet.ServletContainerDispatcher.service(ServletContainerDispatcher.java:221)
    at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:56)
    at org.jboss.resteasy.plugins.server.servlet.HttpServletDispatcher.service(HttpServletDispatcher.java:51)
    at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
    at io.undertow.servlet.handlers.ServletHandler.handleRequest(ServletHandler.java:85)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:129)
    at org.keycloak.services.filters.KeycloakSessionServletFilter.doFilter(KeycloakSessionServletFilter.java:90)
    at io.undertow.servlet.core.ManagedFilter.doFilter(ManagedFilter.java:60)
    at io.undertow.servlet.handlers.FilterHandler$FilterChainImpl.doFilter(FilterHandler.java:131)
    at io.undertow.servlet.handlers.FilterHandler.handleRequest(FilterHandler.java:84)
    at io.undertow.servlet.handlers.security.ServletSecurityRoleHandler.handleRequest(ServletSecurityRoleHandler.java:62)
    at io.undertow.servlet.handlers.ServletDispatchingHandler.handleRequest(ServletDispatchingHandler.java:36)
    at org.wildfly.extension.undertow.security.SecurityContextAssociationHandler.handleRequest(SecurityContextAssociationHandler.java:78)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.servlet.handlers.security.SSLInformationAssociationHandler.handleRequest(SSLInformationAssociationHandler.java:131)
    at io.undertow.servlet.handlers.security.ServletAuthenticationCallHandler.handleRequest(ServletAuthenticationCallHandler.java:57)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.security.handlers.AbstractConfidentialityHandler.handleRequest(AbstractConfidentialityHandler.java:46)
    at io.undertow.servlet.handlers.security.ServletConfidentialityConstraintHandler.handleRequest(ServletConfidentialityConstraintHandler.java:64)
    at io.undertow.security.handlers.AuthenticationMechanismsHandler.handleRequest(AuthenticationMechanismsHandler.java:60)
    at io.undertow.servlet.handlers.security.CachedAuthenticatedSessionHandler.handleRequest(CachedAuthenticatedSessionHandler.java:77)
    at io.undertow.security.handlers.NotificationReceiverHandler.handleRequest(NotificationReceiverHandler.java:50)
    at io.undertow.security.handlers.AbstractSecurityContextAssociationHandler.handleRequest(AbstractSecurityContextAssociationHandler.java:43)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at org.wildfly.extension.undertow.security.jacc.JACCContextIdHandler.handleRequest(JACCContextIdHandler.java:61)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.server.handlers.PredicateHandler.handleRequest(PredicateHandler.java:43)
    at io.undertow.servlet.handlers.ServletInitialHandler.handleFirstRequest(ServletInitialHandler.java:284)
    at io.undertow.servlet.handlers.ServletInitialHandler.dispatchRequest(ServletInitialHandler.java:263)
    at io.undertow.servlet.handlers.ServletInitialHandler.access$000(ServletInitialHandler.java:81)
    at io.undertow.servlet.handlers.ServletInitialHandler$1.handleRequest(ServletInitialHandler.java:174)
    at io.undertow.server.Connectors.executeRootHandler(Connectors.java:202)
    at io.undertow.server.HttpServerExchange$1.run(HttpServerExchange.java:793)
    at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
    at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
    at java.lang.Thread.run(Thread.java:748)
Caused by: org.keycloak.broker.provider.IdentityBrokerException: Could not process response from SAML identity provider.
    at org.keycloak.broker.saml.SAMLEndpoint$Binding.handleLoginResponse(SAMLEndpoint.java:445)
    at org.keycloak.broker.saml.SAMLEndpoint$Binding.handleSamlResponse(SAMLEndpoint.java:480)
    at org.keycloak.broker.saml.SAMLEndpoint$Binding.execute(SAMLEndpoint.java:239)
    at org.keycloak.broker.saml.SAMLEndpoint.postBinding(SAMLEndpoint.java:159)
    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:498)
    at org.jboss.resteasy.core.MethodInjectorImpl.invoke(MethodInjectorImpl.java:139)
    at org.jboss.resteasy.core.ResourceMethodInvoker.invokeOnTarget(ResourceMethodInvoker.java:295)
    at org.jboss.resteasy.core.ResourceMethodInvoker.invoke(ResourceMethodInvoker.java:249)
    at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:138)
    at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:107)
    at org.jboss.resteasy.core.ResourceLocatorInvoker.invokeOnTargetObject(ResourceLocatorInvoker.java:133)
    at org.jboss.resteasy.core.ResourceLocatorInvoker.invoke(ResourceLocatorInvoker.java:101)
    at org.jboss.resteasy.core.SynchronousDispatcher.invoke(SynchronousDispatcher.java:395)
    ... 37 more
Caused by: java.lang.NullPointerException
    at java.util.regex.Matcher.getTextLength(Matcher.java:1283)
    at java.util.regex.Matcher.reset(Matcher.java:309)
    at java.util.regex.Matcher.<init>(Matcher.java:229)
    at java.util.regex.Pattern.matcher(Pattern.java:1093)
    at java.util.regex.Pattern.split(Pattern.java:1206)
    at org.keycloak.broker.provider.util.IdentityBrokerState.decode(IdentityBrokerState.java:75)
    at org.keycloak.broker.provider.util.IdentityBrokerState.getDecodedState(IdentityBrokerState.java:54)
    at org.keycloak.services.resources.IdentityBrokerService.parseEncodedSessionCode(IdentityBrokerService.java:970)
    at org.keycloak.services.resources.IdentityBrokerService.authenticated(IdentityBrokerService.java:485)
    at org.keycloak.broker.saml.SAMLEndpoint$Binding.handleLoginResponse(SAMLEndpoint.java:441)
    ... 52 more

Answer 1

Defined the following mapper and it worked. EMAIL (with capital) is the key coming from the IDP.

The email (lowercase) is the key defined in the client. See below.