def check_hmac(self, message):
'''Check message's hmac for validity'''
return (calc_hmac(self.hmac_key, message).digest() ==
message.header.hmac)
def hmac_and_send(self, message):
'''Calculate HMAC, insert into message, and send'''
message.header.hmac = calc_hmac(self.hmac_key, message).digest()
self.conn.write_message(
message.SerializeToString(), binary=True)
