spake2

import os from spake2 import SPAKE2_A, SPAKE2_B from spake2.parameters.all import ParamsEd25519 # Or other parameter sets like Params3072 def run_spake2_exchange(password: bytes, idA: bytes, idB: bytes): # Alice (Side A) alice = SPAKE2_A(password, idA=idA, idB=idB, params=ParamsEd25519) alice_msg = alice.start() # Bob (Side B) bob = SPAKE2_B(password, idA=idA, idB=idB, params=ParamsEd25519) bob_msg = bob.start() # Exchange messages # In a real application, alice_msg would be sent to Bob, and bob_msg to Alice. # For this example, we directly pass them. # Alice processes Bob's message alice_key = alice.finish(bob_msg) # Bob processes Alice's message bob_key = bob.finish(alice_msg) print(f"Alice's derived key: {alice_key.hex()}") print(f"Bob's derived key: {bob_key.hex()}") if alice_key == bob_key: print("\nShared secret derived successfully!") return alice_key else: print("\nFailed to derive shared secret. Keys do not match.") return None if __name__ == "__main__": # Example usage shared_password = os.environ.get('SPAKE2_PASSWORD', 'test-password').encode('utf-8') alice_id = b"Alice" bob_id = b"BobServer" print(f"Using password: {shared_password.decode('utf-8')}") print(f"Alice ID: {alice_id.decode('utf-8')}, Bob ID: {bob_id.decode('utf-8')}") derived_key = run_spake2_exchange(shared_password, alice_id, bob_id) if derived_key: # The derived key can then be used for symmetric encryption, HMAC, or fed into HKDF. print(f"Using derived key for subsequent secure communication.")