def CheckErrorLoggable(self, token): """Verify that the error strings we log are valid, loggable strings.""" try: users_id_token._verify_signed_jwt_with_certs( token, self._SAMPLE_TIME_NOW, self.cache) self.fail('Expected exception.') except users_id_token._AppIdentityError, e: # Make sure this works without an exception. try: str(e).decode('utf-8') except UnicodeDecodeError: printable = ''.join(c if c in string.printable else '\\x%02x' % ord(c) for c in str(e)) self.fail('Unsafe error sent to log: %s' % printable)