When I try to use the BaseCertLoginModule, it fails with this error: anonymous wrote : Don't know how to obtain X509Certificate from: class java.lang.String I looked at the source code and the failure occurs when the getAliasAndCert() method tries to read a X509 cert from ObjectCallback.getCredential(). Somehow the client cert is not being loaded in the credentials when the callback is done. Here is my login-config.xml; it is almost exactly as given in the manual: <login-module code="org.jboss.security.auth.spi.BaseCertLoginModule" | flag = "required"> | <module-option name="password-stacking">useFirstPass</module-option> | <module-option name="securityDomain">java:/jaas/encrypt-keystore-password</module-option> | <module-option name="unauthenticatedIdentity">guest</module-option> | <module-option name="verifier">org.jboss.security.auth.certs.AnyCertVerifier</module-option> | </login-module> | View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4221404#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...