def sign_input(tx, input_index, utxo):
"""Sign an input of transaction.
Single-signature signing with SIGHASH_ALL"""
key = utxo['key']
src_addr = CCoinAddress(utxo['address'])
script_for_sighash = CScript(
[OP_DUP, OP_HASH160,
Hash160(key.pub), OP_EQUALVERIFY, OP_CHECKSIG])
assert isinstance(src_addr, (P2PKHCoinAddress, P2SHCoinAddress,
P2WPKHCoinAddress)),\
'only p2pkh, p2wpkh and p2sh_p2wpkh addresses are supported'
if isinstance(src_addr, P2PKHCoinAddress):
sigversion = SIGVERSION_BASE
else:
sigversion = SIGVERSION_WITNESS_V0
if 'amountcommitment' in utxo:
amountcommitment = CConfidentialValue(x(utxo['amountcommitment']))
else:
amountcommitment = CConfidentialValue(coins_to_satoshi(utxo['amount']))
sighash = script_for_sighash.sighash(tx,
input_index,
SIGHASH_ALL,
amount=amountcommitment,
sigversion=sigversion)
sig = key.sign(sighash) + bytes([SIGHASH_ALL])
if isinstance(src_addr, P2PKHCoinAddress):
tx.vin[input_index].scriptSig = CScript(
[CScript(sig), CScript(key.pub)])
scriptpubkey = src_addr.to_scriptPubKey()
elif isinstance(src_addr, P2WPKHCoinAddress):
tx.vin[input_index].scriptSig = CScript()
tx.wit.vtxinwit[input_index] = CTxInWitness(
CScriptWitness([CScript(sig), CScript(key.pub)]))
scriptpubkey = src_addr.to_scriptPubKey()
else:
# Assume that this is p2sh-wrapped p2wpkh address
inner_scriptPubKey = CScript([0, Hash160(key.pub)])
tx.vin[input_index].scriptSig = CScript([inner_scriptPubKey])
tx.wit.vtxinwit[input_index] = CTxInWitness(
CScriptWitness([CScript(sig), CScript(key.pub)]))
scriptpubkey = inner_scriptPubKey.to_p2sh_scriptPubKey()
VerifyScript(tx.vin[input_index].scriptSig,
scriptpubkey,
tx,
input_index,
amount=amountcommitment,
flags=(SCRIPT_VERIFY_P2SH, ))
def test_immutable_tx_creation_with_mutable_parts_specified(self):
tx = CTransaction(
vin=[CMutableTxIn(prevout=COutPoint(hash=b'a' * 32, n=0))],
vout=[CMutableTxOut(nValue=1)],
witness=CMutableTxWitness(
[CMutableTxInWitness(CScriptWitness([CScript([0])]))]))
def check_immutable_parts(tx):
self.assertTrue(tx.vin[0].is_immutable())
self.assertTrue(tx.vin[0].is_immutable())
self.assertTrue(tx.vout[0].is_immutable())
self.assertTrue(tx.wit.is_immutable())
self.assertTrue(tx.wit.vtxinwit[0].is_immutable())
check_immutable_parts(tx)
# Test that if we deserialize with CTransaction,
# all the parts are immutable
tx = CTransaction.deserialize(tx.serialize())
check_immutable_parts(tx)
# Test some parts separately, because when created via
# CMutableTransaction instantiation, they are created with from_*
# methods, and not directly
txin = CTxIn(prevout=CMutableOutPoint(hash=b'a' * 32, n=0))
self.assertTrue(txin.prevout.is_immutable())
wit = CTxWitness((CMutableTxInWitness(), ))
self.assertTrue(wit.vtxinwit[0].is_immutable())
def VerifySignature(txFrom, txTo, inIdx):
"""Verify a scriptSig signature can spend a txout
Verifies that the scriptSig in txTo.vin[inIdx] is a valid scriptSig for the
corresponding COutPoint in transaction txFrom.
"""
if inIdx < 0:
raise VerifySignatureError("inIdx negative")
if inIdx >= len(txTo.vin):
raise VerifySignatureError("inIdx >= len(txTo.vin)")
txin = txTo.vin[inIdx]
if txin.prevout.n < 0:
raise VerifySignatureError("txin prevout.n negative")
if txin.prevout.n >= len(txFrom.vout):
raise VerifySignatureError("txin prevout.n >= len(txFrom.vout)")
txout = txFrom.vout[txin.prevout.n]
if txin.prevout.hash != txFrom.GetTxid():
raise VerifySignatureError("prevout hash does not match txFrom")
witness = None
if txTo.wit:
witness = txTo.wit.vtxinwit[inIdx].scriptWitness
VerifyScript(txin.scriptSig,
txout.scriptPubKey,
txTo,
inIdx,
amount=txout.nValue,
witness=witness or CScriptWitness([]))
def test_repr(self):
def T(txout, expected):
actual = repr(txout)
self.assertEqual(actual, expected)
T(CMutableTxInWitness(CScriptWitness([1])),
"CBitcoinMutableTxInWitness(CScriptWitness([x('01')]))")
def test_repr(self) -> None:
def T(txinwitness: CTxInWitness, expected: str) -> None:
actual = repr(txinwitness)
self.assertEqual(actual, expected)
T(CMutableTxInWitness(CScriptWitness([1])),
"CBitcoinMutableTxInWitness(CScriptWitness([x('01')]))")
def generate_transaction(amount, txin_txid, txin_vout, txout_addr,
redeem_list):
txin = CMutableTxIn(COutPoint(txin_txid, txin_vout))
txout = CMutableTxOut(amount * COIN, txout_addr.addr.to_scriptPubKey())
witness_script = CScriptWitness(tuple(redeem_list))
witness = CTxWitness(tuple([CTxInWitness(witness_script)]))
tx = CMutableTransaction(vin=[txin], vout=[txout], witness=witness)
return tx
def create_btc_spend_tx(dst_addr,
txid,
vout_n,
btc_contract,
spend_key=None,
branch_condition=True):
# In real application, the fees should not be static, of course
out_amount = (coins_to_satoshi(pre_agreed_amount) -
coins_to_satoshi(fixed_fee_amount))
tx = CMutableTransaction(
vin=[CTxIn(prevout=COutPoint(hash=lx(txid), n=vout_n))],
vout=[
CTxOut(nValue=out_amount, scriptPubKey=dst_addr.to_scriptPubKey())
])
if branch_condition is True:
cond = b'\x01'
else:
tx.vin[0].nSequence = bitcoin_contract_timeout
cond = b''
in_amount = coins_to_satoshi(pre_agreed_amount)
# We used P2WSHCoinAddress to create the address that we sent bitcoin to,
# so we know that we need to use SIGVERSION_WITNESS_V0
sighash = btc_contract.sighash(tx,
0,
SIGHASH_ALL,
amount=in_amount,
sigversion=SIGVERSION_WITNESS_V0)
spend_sig = spend_key.sign(sighash) + bytes([SIGHASH_ALL])
# This is script witness, not script. The condition for OP_IF
# in our script is directly encoded as data in the witness.
# We cannot use OP_TRUE/OP_FALSE here. We use DATA guard is to ensure that.
witness = CScriptWitness([spend_sig, DATA(cond), btc_contract])
# empty scriptSig, because segwit
tx.vin[0].scriptSig = CBitcoinScript([])
# all data to check the spend conditions is in the witness
tx.wit.vtxinwit[0] = CTxInWitness(witness)
# Cannot use VerifyScript for now,
# because it does not support CHECKSEQUENCEVERIFY yet
#
# from_addr = P2WSHBitcoinAddress.from_redeemScript(btc_contract)
# VerifyScript(tx.vin[0].scriptSig, from_addr.to_scriptPubKey(),
# tx, 0, amount=in_amount)
return tx
def sign_transaction(tx, privkeys):
witness_list = list(tx.witness.vtxinwit[0].scriptWitness.stack)
sighash = SignatureHash(tx.witness, tx, 0, SIGHASH_ALL)
signatures = []
for privkey in privkeys:
privkey = CBitcoinSecret.from_bytes(privkey)
for privkey in privkeys:
signatures.append(privkey.sign(sighash) + bytes([SIGHASH_ALL]))
counter = 0
for signature in signatures:
witness_list.insert(counter, signature)
counter = counter + 1
witness_script = CScriptWitness(tuple(witness_list))
tx.witness = CTxWitness(tuple([CTxInWitness(witness_script)]))
return tx.serialize()
def VerifyScript(
scriptSig,
scriptPubKey,
txTo,
inIdx, # noqa
flags=None,
amount=0,
witness=None):
"""Verify a scriptSig satisfies a scriptPubKey
scriptSig - Signature
scriptPubKey - PubKey
txTo - Spending transaction
inIdx - Index of the transaction input containing scriptSig
Raises a ValidationError subclass if the validation fails.
"""
assert isinstance(scriptSig, CScript)
assert type(scriptSig) == type(scriptPubKey),\
"scriptSig and scriptPubKey must be of the same script class"
script_class = scriptSig.__class__
if flags is None:
flags = STANDARD_SCRIPT_VERIFY_FLAGS - UNHANDLED_SCRIPT_VERIFY_FLAGS
else:
flags = set(flags) # might be passed as tuple
if flags & UNHANDLED_SCRIPT_VERIFY_FLAGS:
raise VerifyScriptError(
"some of the flags cannot be handled by current code: {}".format(
script_verify_flags_to_string(
flags & UNHANDLED_SCRIPT_VERIFY_FLAGS)))
stack = []
EvalScript(stack, scriptSig, txTo, inIdx, flags=flags)
if SCRIPT_VERIFY_P2SH in flags:
stackCopy = list(stack)
EvalScript(stack, scriptPubKey, txTo, inIdx, flags=flags)
if len(stack) == 0:
raise VerifyScriptError("scriptPubKey left an empty stack")
if not _CastToBool(stack[-1]):
raise VerifyScriptError("scriptPubKey returned false")
hadWitness = False
if witness is None:
witness = CScriptWitness([])
if SCRIPT_VERIFY_WITNESS in flags and scriptPubKey.is_witness_scriptpubkey(
):
hadWitness = True
if scriptSig:
raise VerifyScriptError("scriptSig is not empty")
VerifyWitnessProgram(witness,
scriptPubKey.witness_version(),
scriptPubKey.witness_program(),
txTo,
inIdx,
flags=flags,
amount=amount,
script_class=script_class)
# Bypass the cleanstack check at the end. The actual stack is obviously not clean
# for witness programs.
stack = stack[:1]
# Additional validation for spend-to-script-hash transactions
if SCRIPT_VERIFY_P2SH in flags and scriptPubKey.is_p2sh():
if not scriptSig.is_push_only():
raise VerifyScriptError("P2SH scriptSig not is_push_only()")
# restore stack
stack = stackCopy
# stack cannot be empty here, because if it was the
# P2SH HASH <> EQUAL scriptPubKey would be evaluated with
# an empty stack and the EvalScript above would return false.
assert len(stack)
pubKey2 = script_class(stack.pop())
EvalScript(stack, pubKey2, txTo, inIdx, flags=flags)
if not len(stack):
raise VerifyScriptError(
"P2SH inner scriptPubKey left an empty stack")
if not _CastToBool(stack[-1]):
raise VerifyScriptError("P2SH inner scriptPubKey returned false")
# P2SH witness program
if SCRIPT_VERIFY_WITNESS in flags and pubKey2.is_witness_scriptpubkey(
):
hadWitness = True
if scriptSig != script_class([pubKey2]):
raise VerifyScriptError(
"scriptSig is not exactly a single push of the redeemScript"
)
VerifyWitnessProgram(witness,
pubKey2.witness_version(),
pubKey2.witness_program(),
txTo,
inIdx,
flags=flags,
amount=amount,
script_class=script_class)
# Bypass the cleanstack check at the end. The actual stack is obviously not clean
# for witness programs.
stack = stack[:1]
if SCRIPT_VERIFY_CLEANSTACK in flags:
assert SCRIPT_VERIFY_P2SH in flags
if len(stack) == 0:
raise VerifyScriptError("scriptPubKey left an empty stack")
elif len(stack) != 1:
raise VerifyScriptError("scriptPubKey left extra items on stack")
if SCRIPT_VERIFY_WITNESS in flags:
# We can't check for correct unexpected witness data if P2SH was off, so require
# that WITNESS implies P2SH. Otherwise, going from WITNESS->P2SH+WITNESS would be
# possible, which is not a softfork.
assert SCRIPT_VERIFY_P2SH in flags, "SCRIPT_VERIFY_WITNESS requires SCRIPT_VERIFY_P2SH"
if not hadWitness and witness:
raise VerifyScriptError("Unexpected witness")
script_for_sighash = CScript(
[OP_DUP, OP_HASH160,
Hash160(key.pub), OP_EQUALVERIFY, OP_CHECKSIG])
sighash = script_for_sighash.sighash(tx,
input_index,
SIGHASH_ALL,
amount=utxo.nValue,
sigversion=SIGVERSION_WITNESS_V0)
sig = key.sign(sighash) + bytes([SIGHASH_ALL])
inner_scriptPubKey = CScript([0, Hash160(key.pub)])
tx.vin[input_index].scriptSig = CScript([inner_scriptPubKey])
tx.wit.vtxinwit[input_index] = CTxInWitness(
CScriptWitness([CScript(sig), CScript(key.pub)]))
scriptpubkey = inner_scriptPubKey.to_p2sh_scriptPubKey()
VerifyScript(tx.vin[input_index].scriptSig,
scriptpubkey,
tx,
input_index,
amount=utxo.nValue,
flags=(SCRIPT_VERIFY_P2SH, ))
sys.stderr.write("Successfully signed\n")
# Print out blinded and signed transaction, hex-encoded.
print(b2x(tx.serialize()))
script_for_sighash = CElementsScript(
[OP_DUP, OP_HASH160,
Hash160(key.pub), OP_EQUALVERIFY, OP_CHECKSIG])
sighash = script_for_sighash.sighash(tx,
input_index,
SIGHASH_ALL,
amount=utxo.nValue,
sigversion=SIGVERSION_WITNESS_V0)
sig = key.sign(sighash) + bytes([SIGHASH_ALL])
inner_scriptPubKey = CScript([0, Hash160(key.pub)])
tx.vin[input_index].scriptSig = CScript([inner_scriptPubKey])
tx.wit.vtxinwit[input_index] = CElementsTxInWitness(
CScriptWitness([CScript(sig), CScript(key.pub)])).to_mutable()
scriptpubkey = inner_scriptPubKey.to_p2sh_scriptPubKey()
# VerifyScript does not know about confidential values.
# Somewhen we might have VerifyElementsScript.
# but for now, ignore the type error.
VerifyScript(
tx.vin[input_index].scriptSig,
scriptpubkey,
tx,
input_index,
amount=utxo.nValue, # type: ignore
flags=(SCRIPT_VERIFY_P2SH, ))
sys.stderr.write("Successfully signed\n")
def test_immutable(self):
wit = CTxInWitness(CScriptWitness([1]))
with self.assertRaises(AttributeError):
wit.scriptWitness = CScriptWitness()
def test_clone(self):
wit = CMutableTxWitness([CTxInWitness(CScriptWitness([1]))])
self.assertEqual(wit.serialize(), wit.clone().serialize())
def test_immutable(self):
wit = CTxWitness([CTxInWitness(CScriptWitness([1]))])
with self.assertRaises(AttributeError):
wit.vtxinwit = []
def _create_transaction(self, sources: List[Address],
recipients: List[Address], values, n_locktime,
n_sequence):
# save cospends
self.cospends.union_all([str(x.address) for x in sources])
if not values:
values = [recipient.value for recipient in recipients]
tx_ins = [
CMutableTxIn(COutPoint(source.txid, source.vout),
nSequence=n_sequence) for source in sources
]
tx_outs = []
cnt = 0
for recipient, value in zip(recipients, values):
if value == 0:
self.log.warning("Creating output with 0 BTC")
recipient.vout = cnt
tx_outs.append(
CMutableTxOut(
Coin(value).satoshi(),
recipient.address.to_scriptPubKey()))
cnt += 1
tx = CMutableTransaction(tx_ins, tx_outs, nLockTime=n_locktime)
in_idx = 0
witnesses = []
for txin, source in zip(tx_ins, sources):
key = source.key
if source.type == 'p2pkh':
script = source.address.to_redeemScript()
elif source.type == 'p2sh':
script = CScript([key.pub, OP_CHECKSIG])
elif source.type == 'p2wpkh':
script = source.address.to_redeemScript()
elif source.type == 'p2wsh':
script = source.witness_program
else:
raise UnsupportedAddressTypeError()
# Create signature
amount = Coin(source.value).satoshi()
sig = self._sign(script, tx, in_idx, amount, key, source.type)
# Add signature to input or witness
if source.type == 'p2pkh':
txin.scriptSig = CScript([sig, key.pub])
witnesses.append(CTxInWitness())
elif source.type == 'p2sh':
txin.scriptSig = CScript([sig, script])
witnesses.append(CTxInWitness())
elif source.type == 'p2wpkh':
txin.scriptSig = CScript()
witnesses.append(CTxInWitness(CScriptWitness([sig, key.pub])))
elif source.type == 'p2wsh':
txin.scriptSig = CScript()
witnesses.append(CTxInWitness(CScriptWitness([sig, script])))
in_idx += 1
tx.wit = CTxWitness(witnesses)
return tx
def T(required: int,
total: int,
alt_total: Optional[int] = None) -> None:
amount = 10000
keys = [
CKey.from_secret_bytes(os.urandom(32)) for _ in range(total)
]
pubkeys = [k.pub for k in keys]
if alt_total is not None:
total = alt_total # for assertRaises checks
redeem_script = standard_multisig_redeem_script(total=total,
required=required,
pubkeys=pubkeys)
# Test with P2SH
scriptPubKey = redeem_script.to_p2sh_scriptPubKey()
(_, tx) = self.create_test_txs(CScript(), scriptPubKey,
CScriptWitness([]), amount)
tx = tx.to_mutable()
sighash = redeem_script.sighash(tx,
0,
SIGHASH_ALL,
amount=amount,
sigversion=SIGVERSION_BASE)
sigs = [
k.sign(sighash) + bytes([SIGHASH_ALL]) for k in keys[:required]
]
tx.vin[0].scriptSig = CScript(
standard_multisig_witness_stack(sigs, redeem_script))
VerifyScript(tx.vin[0].scriptSig, scriptPubKey, tx, 0,
(SCRIPT_VERIFY_P2SH, ))
# Test with P2WSH
scriptPubKey = redeem_script.to_p2wsh_scriptPubKey()
(_, tx) = self.create_test_txs(CScript(), scriptPubKey,
CScriptWitness([]), amount)
tx = tx.to_mutable()
sighash = redeem_script.sighash(tx,
0,
SIGHASH_ALL,
amount=amount,
sigversion=SIGVERSION_WITNESS_V0)
sigs = [
k.sign(sighash) + bytes([SIGHASH_ALL]) for k in keys[:required]
]
witness_stack = standard_multisig_witness_stack(
sigs, redeem_script)
tx.vin[0].scriptSig = CScript([])
tx.wit.vtxinwit[0] = CTxInWitness(
CScriptWitness(witness_stack)).to_mutable()
VerifyScript(tx.vin[0].scriptSig,
scriptPubKey,
tx,
0,
flags=(SCRIPT_VERIFY_WITNESS, SCRIPT_VERIFY_P2SH),
amount=amount,
witness=tx.wit.vtxinwit[0].scriptWitness)
# Test with P2SH_P2WSH
scriptPubKey = redeem_script.to_p2wsh_scriptPubKey()
(_, tx) = self.create_test_txs(CScript(), scriptPubKey,
CScriptWitness([]), amount)
tx = tx.to_mutable()
sighash = redeem_script.sighash(tx,
0,
SIGHASH_ALL,
amount=amount,
sigversion=SIGVERSION_WITNESS_V0)
sigs = [
k.sign(sighash) + bytes([SIGHASH_ALL]) for k in keys[:required]
]
witness_stack = standard_multisig_witness_stack(
sigs, redeem_script)
tx.vin[0].scriptSig = CScript([scriptPubKey])
tx.wit.vtxinwit[0] = CTxInWitness(
CScriptWitness(witness_stack)).to_mutable()
VerifyScript(tx.vin[0].scriptSig,
scriptPubKey.to_p2sh_scriptPubKey(),
tx,
0,
flags=(SCRIPT_VERIFY_WITNESS, SCRIPT_VERIFY_P2SH),
amount=amount,
witness=tx.wit.vtxinwit[0].scriptWitness)
def load_test_vectors(
name: str,
skip_fixme: bool = True
) -> Iterator[Tuple[CScript, CScript, CScriptWitness, int,
Set[ScriptVerifyFlag_Type], str, str, str]]:
logging.basicConfig()
log = logging.getLogger("Test_EvalScript")
with open(os.path.dirname(__file__) + '/data/' + name, 'r') as fd:
fixme_comment = None
num_skipped = 0
for test_case in json.load(fd):
if len(test_case) == 1:
continue # comment
if len(test_case) == 2:
if not skip_fixme:
assert test_case[0].startswith('FIXME'),\
"we do not expect anything other than FIXME* here"
continue
if test_case[0] == 'FIXME':
fixme_comment = test_case[1]
continue
if test_case[0] == 'FIXME_END':
log.warning("SKIPPED {} tests: {}".format(
num_skipped, fixme_comment))
fixme_comment = None
num_skipped = 0
continue
if fixme_comment:
num_skipped += 1
continue
to_unpack = test_case.copy()
witness = CScriptWitness()
nValue = 0
if isinstance(to_unpack[0], list):
wdata = to_unpack.pop(0)
stack = [CScript(x(d)) for d in wdata[:-1]]
witness = CScriptWitness(stack)
nValue = int(round(wdata[-1] * 1e8))
if len(to_unpack) == 4:
to_unpack.append('') # add missing comment
assert len(
to_unpack) == 5, "unexpected test data format: {}".format(
to_unpack)
scriptSig_str, scriptPubKey_str, flags, expected_result, comment = to_unpack
scriptSig = parse_script(scriptSig_str)
scriptPubKey = parse_script(scriptPubKey_str)
flag_set = set()
for flag in flags.split(','):
if flag == '' or flag == 'NONE':
pass
else:
try:
flag = SCRIPT_VERIFY_FLAGS_BY_NAME[flag]
except IndexError:
raise Exception('Unknown script verify flag %r' % flag)
flag_set.add(flag)
yield (scriptSig, scriptPubKey, witness, nValue, flag_set,
expected_result, comment, test_case)
if fixme_comment is not None:
raise Exception('Unbalanced FIXME blocks in test data')
def test_clone(self):
txinwit = CMutableTxInWitness(CScriptWitness([1]))
self.assertEqual(txinwit.serialize(), txinwit.clone().serialize())
