I get this at the end of a stack trace:

Caused by: javax.security.auth.login.LoginException: Don't know how to obtain X509Certificate from: class java.lang.String

    at org.jboss.security.auth.spi.BaseCertLoginModule.getAliasAndCert(BaseCertLoginModule.java:320)

    at org.jboss.security.auth.spi.BaseCertLoginModule.login(BaseCertLoginModule:194)

    ...

I'm trying to use BaseCertLoginModule to authenticate.

Can anyone suggest what the cause of this is and how I might be able to fix it? I've tried checking the documentation for the login module and after a few days I'm not really get anywhere.

Thanks