Take a minion id and a string signed with the minion private key
        The string needs to verify as 'salt' with the minion public key

        :param str id_: A minion ID
        :param str token: A string signed with the minion private key

        :rtype: bool
        :return: Boolean indicating whether or not the token can be verified.

def __verify_minion(self, id_, token):
        '''
        Take a minion id and a string signed with the minion private key
        The string needs to verify as 'salt' with the minion public key

        :param str id_: A minion ID
        :param str token: A string signed with the minion private key

        :rtype: bool
        :return: Boolean indicating whether or not the token can be verified.
        '''
        if not salt.utils.verify.valid_id(self.opts, id_):
            return False
        pub_path = os.path.join(self.opts['pki_dir'], 'minions', id_)

        try:
            pub = salt.crypt.get_rsa_pub_key(pub_path)
        except (IOError, OSError):
            log.warning(
                'Salt minion claiming to be %s attempted to communicate with '
                'master, but key could not be read and verification was denied.',
                id_
            )
            return False
        except (ValueError, IndexError, TypeError) as err:
            log.error('Unable to load public key "%s": %s', pub_path, err)
        try:
            if salt.crypt.public_decrypt(pub, token) == b'salt':
                return True
        except ValueError as err:
            log.error('Unable to decrypt token: %s', err)

        log.error(
            'Salt minion claiming to be %s has attempted to communicate with '
            'the master and could not be verified', id_
        )
        return False