noise_protocol_nn_handshake_encrypted_message_exchange.py

1from noise.connection import NoiseConnection
2
3# 1. Setup the initiator
4proto_initiator = NoiseConnection.from_name(b'Noise_NN_25519_ChaChaPoly_BLAKE2b')
5proto_initiator.set_as_initiator()
6proto_initiator.start_handshake()
7
8# 2. Setup the responder
9proto_responder = NoiseConnection.from_name(b'Noise_NN_25519_ChaChaPoly_BLAKE2b')
10proto_responder.set_as_responder()
11proto_responder.start_handshake()
12
13# 3. Perform handshake
14# Initiator sends the first handshake message
15message_to_responder = proto_initiator.write_message()
16# Responder receives the handshake message
17proto_responder.read_message(message_to_responder)
18
19# Responder sends the second handshake message
20message_to_initiator = proto_responder.write_message()
21# Initiator receives the handshake message
22proto_initiator.read_message(message_to_initiator)
23
24# Handshake is finished
25assert proto_initiator.handshake_finished
26assert proto_responder.handshake_finished
27
28# 4. Exchange encrypted data
29# Initiator encrypts a message
30ciphertext = proto_initiator.encrypt(b'Hello world!')
31# Responder decrypts the message
32plaintext = proto_responder.decrypt(ciphertext)
33
34print(f'Decrypted: {plaintext.decode()}')