def test_signature(self): k1 = new_key() k2 = new_key() k3 = new_key() sender = Encryptor(k1, k2.publickey()) receiver = Encryptor(k2, k1.publickey()) deceiver = Encryptor(k3, k2.publickey()) message = b"Erised stra ehru oyt ube cafru oyt on wohsi" with print_key_on_error(sender, receiver, deceiver): cipher_text = sender.encrypt(message) decrypted_message, signature = receiver.decrypt(cipher_text) self.assertTrue(receiver.verify_message(decrypted_message, signature)) deceiver_text = deceiver.encrypt(message) decrypted_message, signature = receiver.decrypt(deceiver_text) self.assertFalse(receiver.verify_message(decrypted_message, signature)) _, real_encrypted_message, _ = receiver.split_cipher_text(cipher_text) deceiver_aes, _, deceiver_signature = receiver.split_cipher_text(deceiver_text) cipher_text = deceiver_aes + real_encrypted_message + deceiver_signature decrypted_message, signature = receiver.decrypt(cipher_text) self.assertFalse(receiver.verify_message(decrypted_message, signature))