def validate(self, auth_rest):
if len(auth_rest) == <NUM_LIT:0>:<EOL><INDENT>raise ValueError("<STR_LIT>")<EOL><DEDENT>return dict(hash=auth_rest)<EOL>
Validate user credentials whether format is right for Plaintext

        :param auth_rest: User credentials' part without auth_type
        :return: Dict with a hash part of user credentials
        :raises ValueError: If credentials' part has zero length