def derive(private_key: PrivateKey, peer_public_key: PublicKey) -> bytes:
"""
Key exchange between private key and peer's public key,
`derive(k1, k2.public_key)` should be equal to `derive(k2, k1.public_key)`.
Parameters
----------
private_key: coincurve.PrivateKey
A secp256k1 private key
peer_public_key: coincurve.PublicKey
Peer's public key
Returns
-------
bytes
A secret key used for symmetric encryption
>>> from coincurve import PrivateKey
>>> ke1 = generate_eth_key()
>>> ke2 = generate_eth_key()
>>> k1 = hex2prv(ke1.to_hex())
>>> k2 = hex2prv(ke2.to_hex())
>>> derive(k1, k2.public_key) == derive(k2, k1.public_key)
True
"""
return private_key.ecdh(peer_public_key.format())
def derive(private_key: PrivateKey, peer_public_key: PublicKey) -> bytes:
return private_key.ecdh(peer_public_key.format())
