mirror of
https://github.com/trezor/trezor-firmware.git
synced 2024-11-13 19:18:56 +00:00
115 lines
3.7 KiB
Python
115 lines
3.7 KiB
Python
from trezor import utils, wire
|
|
from trezor.crypto import bip32, hashlib, hmac
|
|
|
|
from apps.common.keychain import Keychain
|
|
from apps.common.readers import read_bitcoin_varint
|
|
from apps.common.writers import (
|
|
empty_bytearray,
|
|
write_bitcoin_varint,
|
|
write_bytes_fixed,
|
|
write_uint8,
|
|
)
|
|
|
|
from . import common
|
|
from .scripts import read_bip322_signature_proof, write_bip322_signature_proof
|
|
from .verification import SignatureVerifier
|
|
|
|
if False:
|
|
from typing import List, Optional, Tuple
|
|
from trezor.messages.MultisigRedeemScriptType import MultisigRedeemScriptType
|
|
from trezor.messages.TxInputType import EnumTypeInputScriptType
|
|
from apps.common.coininfo import CoinInfo
|
|
|
|
# This module implements the SLIP-0019 proof of ownership format.
|
|
|
|
_VERSION_MAGIC = b"SL\x00\x19"
|
|
_FLAG_USER_CONFIRMED = 0x01
|
|
_OWNERSHIP_ID_LEN = 32
|
|
_OWNERSHIP_ID_KEY_PATH = [b"SLIP-0019", b"Ownership identification key"]
|
|
|
|
|
|
def generate_proof(
|
|
node: bip32.HDNode,
|
|
script_type: EnumTypeInputScriptType,
|
|
multisig: MultisigRedeemScriptType,
|
|
coin: CoinInfo,
|
|
user_confirmed: bool,
|
|
ownership_ids: List[bytes],
|
|
script_pubkey: bytes,
|
|
commitment_data: Optional[bytes],
|
|
) -> Tuple[bytes, bytes]:
|
|
flags = 0
|
|
if user_confirmed:
|
|
flags |= _FLAG_USER_CONFIRMED
|
|
|
|
proof = empty_bytearray(4 + 1 + 1 + len(ownership_ids) * _OWNERSHIP_ID_LEN)
|
|
|
|
write_bytes_fixed(proof, _VERSION_MAGIC, 4)
|
|
write_uint8(proof, flags)
|
|
write_bitcoin_varint(proof, len(ownership_ids))
|
|
for ownership_id in ownership_ids:
|
|
write_bytes_fixed(proof, ownership_id, _OWNERSHIP_ID_LEN)
|
|
|
|
sighash = hashlib.sha256(proof)
|
|
sighash.update(script_pubkey)
|
|
if commitment_data:
|
|
sighash.update(commitment_data)
|
|
signature = common.ecdsa_sign(node, sighash.digest())
|
|
public_key = node.public_key()
|
|
write_bip322_signature_proof(
|
|
proof, script_type, multisig, coin, public_key, signature
|
|
)
|
|
|
|
return proof, signature
|
|
|
|
|
|
def verify_nonownership(
|
|
proof: bytes,
|
|
script_pubkey: bytes,
|
|
commitment_data: bytes,
|
|
keychain: Keychain,
|
|
coin: CoinInfo,
|
|
) -> bool:
|
|
try:
|
|
r = utils.BufferReader(proof)
|
|
if r.read(4) != _VERSION_MAGIC:
|
|
raise wire.DataError("Unknown format of proof of ownership")
|
|
|
|
flags = r.get()
|
|
if flags & 0b1111_1110:
|
|
raise wire.DataError("Unknown flags in proof of ownership")
|
|
|
|
# Determine whether our ownership ID appears in the proof.
|
|
id_count = read_bitcoin_varint(r)
|
|
ownership_id = get_identifier(script_pubkey, keychain)
|
|
not_owned = True
|
|
for _ in range(id_count):
|
|
if utils.consteq(ownership_id, r.read(_OWNERSHIP_ID_LEN)):
|
|
not_owned = False
|
|
|
|
# Verify the BIP-322 SignatureProof.
|
|
|
|
proof_body = proof[: r.offset]
|
|
sighash = hashlib.sha256(proof_body)
|
|
sighash.update(script_pubkey)
|
|
sighash.update(commitment_data)
|
|
script_sig, witness = read_bip322_signature_proof(r)
|
|
|
|
# We don't call verifier.ensure_hash_type() to avoid possible compatibility
|
|
# issues between implementations, because the hash type doesn't influence
|
|
# the digest and the value to use is not defined in BIP-322.
|
|
verifier = SignatureVerifier(script_pubkey, script_sig, witness, coin)
|
|
verifier.verify(sighash.digest())
|
|
except (ValueError, EOFError):
|
|
raise wire.DataError("Invalid proof of ownership")
|
|
|
|
return not_owned
|
|
|
|
|
|
def get_identifier(script_pubkey: bytes, keychain: Keychain) -> bytes:
|
|
# k = Key(m/"SLIP-0019"/"Ownership identification key")
|
|
node = keychain.derive_slip21(_OWNERSHIP_ID_KEY_PATH)
|
|
|
|
# id = HMAC-SHA256(key = k, msg = scriptPubKey)
|
|
return hmac.Hmac(node.key(), script_pubkey, hashlib.sha256).digest()
|