success = PasswordUtility.isSame(((CredentialsImpl) userCreds).getPasswordHash(), creds.getPassword());
}
checkSuccess(success, "UserId/Password mismatch.");
} else if (credentials instanceof ImpersonationCredentials) {
ImpersonationCredentials ipCreds = (ImpersonationCredentials) credentials;
AuthInfo info = ipCreds.getImpersonatorInfo();
success = equalUserId(ipCreds) && impersonate(info, user);
checkSuccess(success, "Impersonation not allowed.");
} else {
// guest login is allowed if an anonymous user exists in the content (see get user above)
success = (credentials instanceof GuestCredentials);