def create_stub_enr(pubkey: datatypes.PublicKey, address: AddressAPI) -> ENR:
return ENR(
0, {
IDENTITY_SCHEME_ENR_KEY: V4CompatIdentityScheme.id,
V4CompatIdentityScheme.public_key_enr_key:
pubkey.to_compressed_bytes(),
IP_V4_ADDRESS_ENR_KEY: address.ip_packed,
UDP_PORT_ENR_KEY: address.udp_port,
TCP_PORT_ENR_KEY: address.tcp_port,
},
signature=b'')
def ecdh_agree(private_key: bytes, public_key: bytes) -> bytes:
"""Perform the ECDH key agreement.
The public key is expected in uncompressed format and the resulting secret point will be
formatted as a 0x02 or 0x03 prefix (depending on the sign of the secret's y component)
followed by 32 bytes of the x component.
"""
# We cannot use `cryptography.hazmat.primitives.asymmetric.ec.ECDH only gives us the x
# component of the shared secret point, but we need both x and y.
public_key_eth_keys = PublicKey(public_key)
public_key_compressed = public_key_eth_keys.to_compressed_bytes()
public_key_coincurve = coincurve.keys.PublicKey(public_key_compressed)
secret_coincurve = public_key_coincurve.multiply(private_key)
return secret_coincurve.format()
def from_pubkey_and_addr(cls: Type[TNode], pubkey: datatypes.PublicKey,
address: AddressAPI) -> TNode:
enr = ENR(0, {
IDENTITY_SCHEME_ENR_KEY:
V4CompatIdentityScheme.id,
V4CompatIdentityScheme.public_key_enr_key:
pubkey.to_compressed_bytes(),
IP_V4_ADDRESS_ENR_KEY:
address.ip_packed,
UDP_PORT_ENR_KEY:
address.udp_port,
TCP_PORT_ENR_KEY:
address.tcp_port,
},
signature=b'')
return cls(enr)
