firmware/testing/bip322.py
scgbckbone 0edb093201 move
2026-03-16 13:48:28 -04:00

319 lines
11 KiB
Python

# (c) Copyright 2026 by Coinkite Inc. This file is covered by license found in COPYING-CC.
#
# construct Proof of Reserves transaction according to BIP-322
#
import pytest, struct, hashlib
from ckcc_protocol.protocol import MAX_TXN_LEN
from psbt import BasicPSBT, BasicPSBTInput, BasicPSBTOutput
from io import BytesIO
from helpers import hash160, taptweak, str_to_path
from bip32 import BIP32Node, PublicKey
from constants import simulator_fixed_tprv, AF_P2WSH, AF_P2WSH_P2SH, AF_P2SH
from ctransaction import CTransaction, COutPoint, CTxIn, CTxOut, uint256_from_str
def bip322_msg_hash(msg):
tag_hash = hashlib.sha256(b'BIP0322-signed-message').digest()
return hashlib.sha256(tag_hash + tag_hash + msg).digest()
@pytest.fixture
def create_msg_file(sim_root_dir, garbage_collector):
def doit(msg, msg_hash):
# carelessly overwrites
fpath = f"{sim_root_dir}/MicroSD/{msg_hash.hex()}.txt"
with open(fpath, "w") as f:
f.write(msg.decode())
garbage_collector.append(fpath)
return doit
@pytest.fixture
def bip322_txn(dev, pytestconfig, create_msg_file):
def doit(inputs, msg=b"POR", addr_fmt="p2wpkh", input_amount=1E8, to_sign_lock_time=0,
sighash=None, psbt_hacker=None, witness_utxo=[], to_sign_nVersion=0):
msg_challenge = None
num_ins = len(inputs)
psbt = BasicPSBT()
to_sign = CTransaction()
to_sign.nLockTime = to_sign_lock_time
# must be set to 2 if BIP-68 is used (relative tx level lock)
to_sign.nVersion = to_sign_nVersion
master_xpub = dev.master_xpub or simulator_fixed_tprv
# we have a key; use it to provide "plausible" value inputs
mk = BIP32Node.from_wallet_key(master_xpub)
mfp = mk.fingerprint()
psbt.inputs = [BasicPSBTInput(idx=i) for i in range(num_ins)]
psbt.outputs = []
for i, inp in enumerate(inputs):
sp = f"0/{i}"
af = addr_fmt
ia = input_amount
pubkey = None # public key
try:
if inp[0] is not None:
af = inp[0]
if inp[1] is not None:
sp = inp[1]
if inp[2] is not None:
ia = inp[2]
if inp[3] is not None:
pubkey = inp[3]
except:
pass
if pubkey:
int_path = [0]
sec = pubkey
else:
int_path = str_to_path(sp)
sec = mk.subkey_for_path(sp).sec()
subkey = PublicKey.parse(sec)
assert len(sec) == 33, "expect compressed"
if af == "p2tr":
tweaked_xonly = taptweak(sec[1:])
psbt.inputs[i].taproot_bip32_paths[sec[1:]] = b"\x00" + mfp + struct.pack(f'<{"I" * len(int_path)}',
*int_path)
scr = bytes([81, 32]) + tweaked_xonly
elif af in ("p2wpkh", "p2sh-p2wpkh", "p2wpkh-p2sh"):
psbt.inputs[i].bip32_paths[sec] = mfp + struct.pack(f'<{"I" * len(int_path)}', *int_path)
scr = bytes([0x00, 0x14]) + subkey.h160()
if af != "p2wpkh":
# use classic p2wpkh (from above) as redeem script
psbt.inputs[i].redeem_script = scr
scr = bytes([0xa9, 0x14]) + hash160(scr) + bytes([0x87])
elif af == "p2pkh":
psbt.inputs[i].bip32_paths[sec] = mfp + struct.pack(f'<{"I" * len(int_path)}', *int_path)
scr = bytes([0x76, 0xa9, 0x14]) + subkey.h160() + bytes([0x88, 0xac])
else:
raise ValueError("unknown addr_fmt %s" % af)
if i == 0:
# first input always spends to_spend
to_spend = CTransaction()
to_spend.nVersion = 0
out_point = COutPoint(hash=0, n=0xffffffff)
msg_hash = bip322_msg_hash(msg)
create_msg_file(msg, msg_hash)
to_spend.vin = [CTxIn(out_point, scriptSig=b'\x00\x20' + msg_hash)]
to_spend.vout = [CTxOut(0, scr)] # always zero val
msg_challenge = scr
else:
# other outputs that we want to prove ownership
to_spend = CTransaction()
to_spend.nVersion = 0
out_point = COutPoint(
uint256_from_str(struct.pack('4Q', 0xdead, 0xbeef, 0, i)),
73
)
to_spend.vin = [CTxIn(out_point, nSequence=0xffffffff)]
to_spend.vout.append(CTxOut(int(ia), scr))
if sighash is not None:
psbt.inputs[i].sighash = sighash
to_spend.calc_sha256()
if i in witness_utxo:
psbt.inputs[i].witness_utxo = to_spend.vout[-1].serialize()
else:
psbt.inputs[i].utxo = to_spend.serialize_with_witness()
if to_sign_lock_time and not i:
seq = 0xfffffffd
else:
seq = 0xffffffff
spendable = CTxIn(COutPoint(to_spend.sha256, 0), nSequence=seq)
to_sign.vin.append(spendable)
# just one zero amount output with script null data OP_RETURN
op_ret_o = BasicPSBTOutput(idx=0)
op_return_out = CTxOut(0, b'\x6a')
to_sign.vout.append(op_return_out)
psbt.outputs.append(op_ret_o)
psbt.txn = to_sign.serialize_with_witness()
# last minute chance to mod PSBT object
if psbt_hacker:
psbt_hacker(psbt)
rv = BytesIO()
psbt.serialize(rv)
assert rv.tell() <= MAX_TXN_LEN, 'too fat'
return rv.getvalue(), msg_challenge
return doit
@pytest.fixture
def bip322_ms_txn(pytestconfig, create_msg_file):
from test_multisig import make_ms_address
def doit(num_ins, M, keys, msg=b"POR", inp_af=AF_P2WSH, input_amount=1E8, path_mapper=None,
lock_time=0, with_sigs=False, sighash=None, hack_psbt=None, to_sign_nVersion=0):
msg_challenge = None
psbt = BasicPSBT()
txn = CTransaction()
txn.nVersion = to_sign_nVersion
txn.nLockTime = lock_time
psbt.inputs = [BasicPSBTInput(idx=i) for i in range(num_ins)]
psbt.outputs = []
for i in range(num_ins):
# make a fake txn to supply each of the inputs
# - each input is 1BTC
# addr where the fake money will be stored.
addr, scriptPubKey, script, details = make_ms_address(
M, keys, idx=i, addr_fmt=inp_af, path_mapper=path_mapper
)
if inp_af == AF_P2WSH:
psbt.inputs[i].witness_script = script
elif inp_af == AF_P2SH:
psbt.inputs[i].redeem_script = script
else:
assert inp_af == AF_P2WSH_P2SH
psbt.inputs[i].witness_script = script
psbt.inputs[i].redeem_script = b'\0\x20' + hashlib.sha256(script).digest()
for pubkey, xfp_path in details:
psbt.inputs[i].bip32_paths[pubkey] = b''.join(struct.pack('<I', j) for j in xfp_path)
if with_sigs and (xfp_path[0] != keys[-1][0]): # only cosigner signatures are added
psbt.inputs[i].part_sigs[pubkey] = b"\x30" + 70*b"a"
if i == 0:
to_spend = CTransaction()
to_spend.nVersion = 0
out_point = COutPoint(hash=0, n=0xffffffff)
msg_hash = bip322_msg_hash(msg)
create_msg_file(msg, msg_hash)
to_spend.vin = [CTxIn(out_point, scriptSig=b'\x00\x20' + msg_hash)]
to_spend.vout.append(CTxOut(0, scriptPubKey))
msg_challenge = scriptPubKey
else:
# other outputs that we want to prove ownership
to_spend = CTransaction()
to_spend.nVersion = 0
out_point = COutPoint(
uint256_from_str(struct.pack('4Q', 0xdead, 0xbeef, 0, i)),
73
)
to_spend.vin = [CTxIn(out_point, nSequence=0xffffffff)]
to_spend.vout.append(CTxOut(int(input_amount), scriptPubKey))
# always add whole txn as utxo
psbt.inputs[i].utxo = to_spend.serialize_with_witness()
if sighash is not None and (i != 0):
psbt.inputs[i].sighash = sighash
to_spend.calc_sha256()
if lock_time and not i:
seq = 0xfffffffd
else:
seq = 0xffffffff
spendable = CTxIn(COutPoint(to_spend.sha256, 0), nSequence=seq)
txn.vin.append(spendable)
# just one zero amount output with script null data OP_RETURN
op_ret_o = BasicPSBTOutput(idx=0)
op_return_out = CTxOut(0, b'\x6a')
txn.vout.append(op_return_out)
psbt.outputs.append(op_ret_o)
if hack_psbt:
hack_psbt(psbt)
psbt.txn = txn.serialize_with_witness()
rv = BytesIO()
psbt.serialize(rv)
assert rv.tell() <= MAX_TXN_LEN, 'too fat'
return rv.getvalue(), msg_challenge
return doit
@pytest.fixture
def bip322_from_classic_tx(dev, create_msg_file):
def doit(psbt, msg=b"POR"):
# takes in any PSBT and creates BIP-322 PSBT with all inputs as POR
# ignores & drops all outputs and replaces with one 0 val OP_RETURN
# 0th input is adjusted as specified in BIP-322 (to_spend)
po = BasicPSBT().parse(psbt)
to_sign = CTransaction()
to_sign.deserialize(BytesIO(po.txn))
to_sign.nVersion = 0 # required
to_sign.vout = [] # drop all outputs
# just one zero amount output with script null data OP_RETURN
op_ret_o = BasicPSBTOutput(idx=0)
op_return_out = CTxOut(0, b'\x6a')
to_sign.vout.append(op_return_out)
po.outputs = [op_ret_o]
if po.inputs[0].utxo:
i0_utxo = CTransaction()
i0_utxo.deserialize(BytesIO(po.inputs[0].utxo))
scriptPubKey = i0_utxo.vout[to_sign.vin[0].prevout.n].scriptPubKey
else:
assert po.inputs[0].witness_utxo
i0_wutxo = CTxOut()
i0_wutxo.deserialize(BytesIO(po.inputs[0].witness_utxo))
scriptPubKey = i0_wutxo.scriptPubKey
to_spend = CTransaction()
to_spend.nVersion = 0
out_point = COutPoint(hash=0, n=0xffffffff)
msg_hash = bip322_msg_hash(msg)
create_msg_file(msg, msg_hash)
to_spend.vin = [CTxIn(out_point, scriptSig=b'\x00\x20' + msg_hash)]
to_spend.vout.append(CTxOut(0, scriptPubKey))
msg_challenge = scriptPubKey
to_spend.calc_sha256()
to_sign.vin[0] = CTxIn(COutPoint(to_spend.sha256, 0), nSequence=0xffffffff)
po.inputs[0].utxo = to_spend.serialize_with_witness()
# if it has witness UTXO - get rid of it
po.inputs[0].witness_utxo = None
po.txn = to_sign.serialize_with_witness()
rv = BytesIO()
po.serialize(rv)
return rv.getvalue(), msg_challenge
return doit