question: public static boolean useSubjectCredsOnly ( GSSCaller caller ) { if ( caller instanceof HttpCaller ) { return false ; } String propValue = AccessController . doPrivileged ( new GetPropertyAction ( "javax.security.auth.useSubjectCredsOnly" , "true" ) ) ; return ( ! propValue . equalsIgnoreCase ( "false" ) ) ; }
target:  Determines if the application doesn't mind if the mechanism obtains the required credentials from outside of the current Subject. Our Kerberos v5 mechanism would do a JAAS login on behalf of the application if this were the case. The application indicates this by explicitly setting the system property javax.security.auth.useSubjectCredsOnly to false.