def METHOD_NAME(self, backend, params):
    key1 = params["key1"]
    key2 = params["key2"]
    key3 = params["key3"]
    key = key1 + key2 + key3
    message = params["message"]
    output = params["output"]
    cmac = CMAC(TripleDES(binascii.unhexlify(key)), backend)
    cmac.update(binascii.unhexlify(message))
    cmac.verify(binascii.unhexlify(output))