def encode_signature(tx_v, tx_r, tx_s) -> bytes:
"""
Calculates byte representation of ECC signature from parameters
:param tx_v:
:param tx_r:
:param tx_s:
:return: bytes of ECC signature
"""
if not isinstance(tx_v, int):
raise ValueError("v is expected to be int")
if tx_v > eth_common_constants.EIP155_CHAIN_ID_OFFSET:
if tx_v % 2 == 0:
tx_v = 28
else:
tx_v = 27
if tx_v not in (27, 28):
raise ValueError("v is expected to be int or long in range (27, 28)")
# pyre-fixme[16]: Module `bitcoin` has no attribute `encode`.
# pyre-fixme[16]: Module `bitcoin` has no attribute `encode`.
v_bytes, r_bytes, s_bytes = rlp_utils.ascii_chr(tx_v - 27), bitcoin.encode(
tx_r, 256), bitcoin.encode(tx_s, 256)
return _left_0_pad_32(r_bytes) + _left_0_pad_32(s_bytes) + v_bytes
def create_auth_message(self):
"""
Generates authentication message bytes
1. initiator generates ecdhe-random and nonce and creates auth
2. initiator connects to remote and sends auth
New:
E(remote-pubk,
S(ephemeral-privk, ecdh-shared-secret ^ nonce) ||
H(ephemeral-pubk) || pubk || nonce || 0x0
)
Known:
E(remote-pubk,
S(ephemeral-privk, token ^ nonce) || H(ephemeral-pubk) || pubk || nonce || 0x1)
:param remote_pubkey: public key of remote node
:param nonce: nonce
:return: authentication message bytes
"""
assert self._is_initiator
ecdh_shared_secret = self._ecc.get_ecdh_key(self._remote_pubkey)
token = ecdh_shared_secret
flag = 0x0
self._initiator_nonce = eth_common_utils.keccak_hash(
rlp_utils.int_to_big_endian(random.randint(0, sys.maxsize)))
assert len(
self._initiator_nonce) == eth_common_constants.SHA3_LEN_BYTES
token_xor_nonce = crypto_utils.string_xor(token, self._initiator_nonce)
assert len(token_xor_nonce) == eth_common_constants.SHA3_LEN_BYTES
ephemeral_pubkey = self._ephemeral_ecc.get_raw_public_key()
assert len(ephemeral_pubkey) == eth_common_constants.PUBLIC_KEY_LEN
if not self._ecc.is_valid_key(ephemeral_pubkey):
raise InvalidKeyError("Invalid ephemeral pubkey")
# S(ephemeral-privk, ecdh-shared-secret ^ nonce)
S = self._ephemeral_ecc.sign(token_xor_nonce)
assert len(S) == eth_common_constants.SIGNATURE_LEN
# S || H(ephemeral-pubk) || pubk || nonce || 0x0
auth_message = S + eth_common_utils.keccak_hash(ephemeral_pubkey) + self._ecc.get_raw_public_key() + \
self._initiator_nonce + rlp_utils.ascii_chr(flag)
return auth_message