tls.py

from tinyec import registry
import secrets


def compress(pubKey):
    return hex(pubKey.x) + hex(pubKey.y)[2:]


curve = registry.get_curve('secp256r1')

alicePrivKey = secrets.randbelow(curve.field.n)
alicePubKey = alicePrivKey * curve.g
print("Alice public key:", compress(alicePubKey))

bobPrivKey = secrets.randbelow(curve.field.n)
bobPubKey = bobPrivKey * curve.g
print("Bob public key:", compress(bobPubKey))

print("Now exchange the public keys (e.g. through Internet)")

aliceSharedKey = alicePrivKey * bobPubKey
print("Alice shared key:", compress(aliceSharedKey))

bobSharedKey = bobPrivKey * alicePubKey
print("Bob shared key:", compress(bobSharedKey))

print("Equal shared keys:", aliceSharedKey == bobSharedKey)


# # mallory
# alicePrivKey = secrets.randbelow(curve.field.n)
# alicePubKey = alicePrivKey * curve.g

# bobPrivKey = secrets.randbelow(curve.field.n)
# bobPubKey = bobPrivKey * curve.g

# mallory1PrivKey = secrets.randbelow(curve.field.n)
# mallory1PubKey = mallory1PrivKey * curve.g

# mallory2PrivKey = secrets.randbelow(curve.field.n)
# mallory2PubKey = mallory2PrivKey * curve.g


# aliceMallorySharedKey = alicePrivKey * mallory1PubKey
# print("Alice Mallory shared key:", compress(aliceMallorySharedKey))

# malloryAliceSharedKey = mallory1PrivKey * alicePubKey
# print("Mallory Alice shared key:", compress(malloryAliceSharedKey))

# print("Equal shared keys:", aliceMallorySharedKey == malloryAliceSharedKey)

# bobSharedKey = bobPrivKey * mallory2PubKey
# print("Bob shared key:", compress(bobSharedKey))