def test_chain_params_context_manager(self):
with ChainParams(BitcoinRegtestParams) as p1:
assert isinstance(p1, BitcoinRegtestParams)
with ChainParams(BitcoinSignetParams) as p2:
assert isinstance(p2, BitcoinSignetParams)
assert isinstance(get_current_chain_params(),
BitcoinSignetParams)
assert isinstance(get_current_chain_params(), BitcoinRegtestParams)
def test_parse_config(self):
conf_file_contents = """
listen=1
server=1
rpcpassword=somepass # should be overriden
regtest.rpcport = 8123
rpcport = 8888
[main]
rpcuser=someuser1
rpcpassword=somepass1
rpcconnect=127.0.0.10
[test]
rpcpassword=somepass2
rpcconnect=127.0.0.11
rpcport = 9999
[regtest]
rpcuser=someuser3
rpcpassword=somepass3
rpcconnect=127.0.0.12
"""
rpc = RPCCaller(conf_file_contents=conf_file_contents)
self.assertEqual(rpc._RPCCaller__service_url, 'http://127.0.0.10:8888')
authpair = "someuser1:somepass1"
authhdr = "Basic " + base64.b64encode(
authpair.encode('utf8')).decode('utf8')
self.assertEqual(rpc._RPCCaller__auth_header, authhdr)
with ChainParams('bitcoin/testnet'):
rpc = RPCCaller(conf_file_contents=conf_file_contents)
self.assertEqual(rpc._RPCCaller__service_url,
'http://127.0.0.11:9999')
authpair = ":somepass2" # no user specified
authhdr = "Basic " + base64.b64encode(
authpair.encode('utf8')).decode('utf8')
self.assertEqual(rpc._RPCCaller__auth_header, authhdr)
with ChainParams('bitcoin/regtest'):
rpc = RPCCaller(conf_file_contents=conf_file_contents)
self.assertEqual(rpc._RPCCaller__service_url,
'http://127.0.0.12:8123')
authpair = "someuser3:somepass3"
authhdr = "Basic " + base64.b64encode(
authpair.encode('utf8')).decode('utf8')
self.assertEqual(rpc._RPCCaller__auth_header, authhdr)
def test_MoneyRangeCustomParams(self):
class CoreHighMaxClassDispatcher(CoreBitcoinClassDispatcher):
...
class CoreHighMaxParams(CoreBitcoinParams, CoreBitcoinClass):
@classgetter
def MAX_MONEY(self):
return 22000000 * self.COIN
class WalletHighMaxClassDispatcher(WalletBitcoinClassDispatcher):
...
class HighMaxParams(BitcoinMainnetParams):
NAME = 'high_maxmoney'
WALLET_DISPATCHER = WalletHighMaxClassDispatcher
with ChainParams(HighMaxParams):
self.assertFalse(MoneyRange(-1))
with self.assertRaises(ValueError):
coins_to_satoshi(-1)
with self.assertRaises(ValueError):
satoshi_to_coins(-1)
self.assertTrue(MoneyRange(0))
self.assertTrue(MoneyRange(100000))
max_satoshi = coins_to_satoshi(22000000)
self.assertTrue(
MoneyRange(max_satoshi)) # Maximum money on Bitcoin network
self.assertFalse(MoneyRange(max_satoshi + 1))
with self.assertRaises(ValueError):
coins_to_satoshi(max_satoshi + 1)
with self.assertRaises(ValueError):
satoshi_to_coins(max_satoshi + 1)
def test_legacy_p2sh(self):
with ChainParams('litecoin', allow_legacy_p2sh=True):
a = CCoinAddress('3F1c6UWAs9RLN2Mbt5bAJue12VhVCorXzs')
self.assertIsInstance(a, P2SHLitecoinLegacyAddress)
with ChainParams('litecoin'):
with self.assertRaises(CCoinAddressError):
a = CCoinAddress('3F1c6UWAs9RLN2Mbt5bAJue12VhVCorXzs')
l_addr = '3N4DqfrHhStCao4NjwroxoegjydkJk3P9Z'
c_addr = 'MUGN9ZGFeZjdPJLGqpr9nSu64gECLRzQrx'
self.assertEqual(
str(
P2SHLitecoinAddress.from_scriptPubKey(
P2SHLitecoinLegacyAddress(l_addr).to_scriptPubKey())),
c_addr)
def test_valid_bip341_scriptpubkeys_addresses():
with ChainParams("bitcoin"):
with open(os.path.join(testdir, "bip341_wallet_test_vectors.json"),
"r") as f:
json_data = json.loads(f.read())
for x in json_data["scriptPubKey"]:
sPK = hextobin(x["expected"]["scriptPubKey"])
addr = x["expected"]["bip350Address"]
res, message = validate_address(addr)
assert res, message
print("address {} was valid bech32m".format(addr))
# test this specific conversion because this is how
# our human readable outputs work:
assert str(CCoinAddress.from_scriptPubKey(
btc.CScript(sPK))) == addr
print("and it converts correctly from scriptPubKey: {}".format(
btc.CScript(sPK)))
def test_address_implementations(test,
paramclasses=None,
extra_addr_testfunc=lambda *args: False):
pub = CPubKey(
x('0378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71')
)
if paramclasses is None:
paramclasses = bitcointx.get_registered_chain_params()
for paramclass in paramclasses:
with ChainParams(paramclass):
def recursive_check(aclass):
test.assertTrue(issubclass(aclass, CCoinAddress))
if extra_addr_testfunc(aclass, pub):
pass
else:
a = None
if getattr(aclass, 'from_pubkey', None):
a = aclass.from_pubkey(pub)
elif getattr(aclass, 'from_redeemScript', None):
a = aclass.from_redeemScript(
CScript(b'\xa9' + Hash160(pub) + b'\x87'))
else:
assert len(dispatcher_mapped_list(aclass)) > 0,\
("dispatcher mapped list for {} "
"must not be empty".format(aclass))
if a is not None:
spk = a.to_scriptPubKey()
test.assertEqual(a, aclass.from_scriptPubKey(spk))
a2 = aclass.from_bytes(a)
test.assertEqual(bytes(a), bytes(a2))
test.assertEqual(str(a), str(a2))
a3 = aclass(str(a))
test.assertEqual(bytes(a), bytes(a3))
test.assertEqual(str(a), str(a3))
for next_aclass in dispatcher_mapped_list(aclass):
recursive_check(next_aclass)
recursive_check(CCoinAddress)
def test_MoneyRangeCustomParams(self) -> None:
class CoreHighMaxClassDispatcher(CoreBitcoinClassDispatcher):
...
class CoreHighMaxClass(CoreBitcoinClass,
metaclass=CoreHighMaxClassDispatcher):
...
class CoreHighMaxParams(CoreBitcoinParams, CoreHighMaxClass):
@classgetter
def MAX_MONEY(self) -> int:
return 10**100 * self.COIN
class WalletHighMaxClassDispatcher(WalletBitcoinClassDispatcher,
depends=[
CoreHighMaxClassDispatcher
]):
...
class HighMaxParams(BitcoinMainnetParams):
NAME = 'high_maxmoney'
WALLET_DISPATCHER = WalletHighMaxClassDispatcher
with self.assertRaises(ValueError):
coins_to_satoshi(10**100)
with ChainParams(HighMaxParams):
self.assertFalse(MoneyRange(-1))
with self.assertRaises(ValueError):
coins_to_satoshi(-1)
with self.assertRaises(ValueError):
satoshi_to_coins(-1)
self.assertTrue(MoneyRange(0))
self.assertTrue(MoneyRange(100000))
max_satoshi = coins_to_satoshi(10**100)
self.assertEqual(satoshi_to_coins(max_satoshi), 10**100)
self.assertTrue(MoneyRange(max_satoshi))
self.assertFalse(MoneyRange(max_satoshi + 1))
with self.assertRaises(ValueError):
coins_to_satoshi(max_satoshi + 1)
with self.assertRaises(ValueError):
satoshi_to_coins(max_satoshi + 1)
def test_get_output_size(self):
pub1 = CPubKey(
x('0378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71'
))
pub2 = CPubKey(
x('02546c76587482cd2468b76768da70c0166ecb2aa2eb1038624f4fedc138b042bc'
))
for chainparam in get_params_list():
with ChainParams(chainparam):
smpl = get_unconfidential_address_samples(pub1, pub2)
# 1 byte for 'no asset', 1 byte for 'no nonce',
# 9 bytes for explicit value,
# minus 8 bytes of len of bitcoin nValue
elements_unconfidential_size_extra = 1 + 1 + 9 - 8
# 33 bytes for asset, 33 bytes for nonce,
# 33 bytes for confidential value,
# minus 8 bytes of len of bitcoin nValue
elements_confidential_size_extra = 33 + 33 + 33 - 8
self.assertEqual(smpl.p2pkh.get_output_size(),
34 + elements_unconfidential_size_extra)
self.assertEqual(smpl.p2wpkh.get_output_size(),
31 + elements_unconfidential_size_extra)
self.assertEqual(smpl.p2sh.get_output_size(),
32 + elements_unconfidential_size_extra)
self.assertEqual(smpl.p2wsh.get_output_size(),
43 + elements_unconfidential_size_extra)
self.assertEqual(smpl.conf_p2pkh.get_output_size(),
34 + elements_confidential_size_extra)
self.assertEqual(smpl.conf_p2wpkh.get_output_size(),
31 + elements_confidential_size_extra)
self.assertEqual(smpl.conf_p2sh.get_output_size(),
32 + elements_confidential_size_extra)
self.assertEqual(smpl.conf_p2wsh.get_output_size(),
43 + elements_confidential_size_extra)
def test_from_to_unconfidential(self): #noqa
pub1 = CPubKey(
x('02546c76587482cd2468b76768da70c0166ecb2aa2eb1038624f4fedc138b042bc'
))
pub2 = CPubKey(
x('0378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71'
))
params_list = get_params_list()
for pl_index, chainparam in enumerate(params_list):
next_chainparam = (params_list[0] if pl_index + 1
== len(params_list) else params_list[pl_index +
1])
with ChainParams(chainparam):
mapped_cls_list = dispatcher_mapped_list(
CCoinConfidentialAddress)
assert len(mapped_cls_list) == 1
chain_specific_cls = mapped_cls_list[0]
with ChainParams(next_chainparam):
mapped_cls_list = dispatcher_mapped_list(
CCoinConfidentialAddress)
assert len(mapped_cls_list) == 1
next_chain_specific_cls = mapped_cls_list[0]
assert next_chain_specific_cls is not chain_specific_cls
smpl = get_unconfidential_address_samples(pub1, pub2)
for uct in unconf_types:
for ct in conf_types:
unconf = getattr(smpl, uct)
conf = getattr(smpl, ct)
with self.assertRaises(TypeError):
next_chain_specific_cls.from_unconfidential(
unconf, pub2)
if ct.endswith(uct):
self.assertEqual(str(conf.to_unconfidential()),
str(unconf))
self.assertEqual(
str(conf.from_unconfidential(unconf, pub2)),
str(conf))
self.assertNotEqual(
str(conf.from_unconfidential(unconf, pub1)),
str(conf))
self.assertEqual(
str(
CCoinConfidentialAddress.
from_unconfidential(unconf, pub2)),
str(conf))
self.assertEqual(
str(
chain_specific_cls.from_unconfidential(
unconf, pub2)), str(conf))
if ct.endswith('p2pkh'):
self.assertEqual(
str(
CBase58CoinConfidentialAddress.
from_unconfidential(unconf, pub2)),
str(conf))
self.assertEqual(
str(
P2PKHCoinConfidentialAddress.
from_unconfidential(unconf, pub2)),
str(conf))
elif ct.endswith('p2sh'):
self.assertEqual(
str(
CBase58CoinConfidentialAddress.
from_unconfidential(unconf, pub2)),
str(conf))
self.assertEqual(
str(
P2SHCoinConfidentialAddress.
from_unconfidential(unconf, pub2)),
str(conf))
elif ct.endswith('p2wpkh'):
self.assertEqual(
str(
CBlech32CoinConfidentialAddress.
from_unconfidential(unconf, pub2)),
str(conf))
self.assertEqual(
str(
P2WPKHCoinConfidentialAddress.
from_unconfidential(unconf, pub2)),
str(conf))
elif ct.endswith('p2wsh'):
self.assertEqual(
str(
CBlech32CoinConfidentialAddress.
from_unconfidential(unconf, pub2)),
str(conf))
self.assertEqual(
str(
P2WSHCoinConfidentialAddress.
from_unconfidential(unconf, pub2)),
str(conf))
else:
assert 0, "unexpected addr type"
if issubclass(conf.__class__,
CBlech32CoinConfidentialAddress):
with self.assertRaises(
CConfidentialAddressError):
CBase58CoinConfidentialAddress.from_unconfidential(
unconf, pub2)
elif issubclass(conf.__class__,
CBase58CoinConfidentialAddress):
with self.assertRaises(
CConfidentialAddressError):
CBlech32CoinConfidentialAddress.from_unconfidential(
unconf, pub2)
else:
assert 0, "unexpected conf.__class__"
for ct2 in conf_types:
if ct != ct2:
conf_cls = getattr(smpl, ct2).__class__
with self.assertRaises(TypeError):
conf_cls.from_unconfidential(
unconf, pub2)
else:
self.assertNotEqual(str(conf.to_unconfidential()),
str(unconf))
with self.assertRaises(TypeError):
conf.from_unconfidential(unconf, pub2)
def participant(func, name, pipe, bitcoin_config_path, elements_config_path):
"""Prepares environment for participants, run their functions,
and handles the errors they did not bother to hanlde"""
def say(msg):
participant_says(name, msg)
# Custom exception class to distinguish a case when
# participant calss die() from other exceptions
class ProtocolFailure(Exception):
...
def do_last_wish(msg):
global last_wish_func
lwf = last_wish_func
if lwf:
say("Going to die because '{}', "
"but I still have something to do before that.".format(msg))
last_wish_func = None
lwf()
def die(msg, peacefully=False):
do_last_wish(msg)
if peacefully:
sys.exit(-1)
raise ProtocolFailure(msg)
def recv(expected_type, timeout=60):
if not pipe.poll(timeout):
die('No messages received in {} seconds'.format(timeout))
msg = pipe.recv()
if msg[0] == 'bye!':
msg = 'Communication finished unexpectedly'
say(msg + ', exiting.')
do_last_wish(msg)
sys.exit(-1)
if msg[0] != expected_type:
die("unexpected message type '{}', expected '{}'".format(
msg[0], expected_type))
return msg[1]
def send(msg_type, data=None):
pipe.send([msg_type, data])
# Ignore keyboard interrupt, parent process handles it.
signal.signal(signal.SIGINT, signal.SIG_IGN)
try:
# Connect to Elements or Bitcoin RPC with specified path
# Do it with context params switch, so that appropriate values
# from config files will be used (there may be regtest.port=N, etc)
with ChainParams(bitcoin_chain_name):
btc_rpc = connect_rpc(say, bitcoin_config_path)
with ChainParams(elements_chain_name):
elt_rpc = connect_rpc(say, elements_config_path)
# Execute participant's function
func(say, recv, send, die, btc_rpc, elt_rpc)
except Exception as e:
say('FAIL with {}: {}'.format(type(e).__name__, e))
say("Traceback:")
print("=" * 80)
traceback.print_tb(sys.exc_info()[-1])
print("=" * 80)
do_last_wish(e.__class__.__name__)
send('bye!')
sys.exit(-1)
def bob(say, recv, send, die, btc_rpc, elt_rpc):
"""A function that implements the logic
of the Bitcoin-side participant
of confidential cross-chain atomic swap"""
global last_wish_func
# Default chain for Bob will be Bitcoin
# To handle bitcoin-related objects, either
# `with ChainParams(elements_chain_name):` have to be used, or
# concrete classes, like CElementsAddress, CElementsTransaction, etc.
select_chain_params(bitcoin_chain_name)
say('Waiting for blinding key from Alice')
alice_btc_pub_raw, alice_elt_exit_pub_raw = recv('pubkeys')
blinding_key = CKey.from_secret_bytes(recv('blinding_key'))
say("Pubkey for blinding key: {}".format(b2x(blinding_key.pub)))
# Let's create the key that would lock the coins on Bitcoin side
contract_key = CKey.from_secret_bytes(os.urandom(32))
# And the key for Elements side
bob_elt_spend_key = CKey.from_secret_bytes(os.urandom(32))
# And the key for 'timeout' case on btc side
bob_btc_exit_key = CKey.from_secret_bytes(os.urandom(32))
key_to_reveal_pub = CPubKey.add(contract_key.pub, blinding_key.pub)
say("The pubkey of the combined key to be revealed: {}".format(
b2x(key_to_reveal_pub)))
say('Sending my pubkeys to Alice')
send('pubkeys',
(contract_key.pub, bob_elt_spend_key.pub, bob_btc_exit_key.pub))
combined_btc_spend_pubkey = CPubKey.add(contract_key.pub,
CPubKey(alice_btc_pub_raw))
say('combined_btc_spend_pubkey: {}'.format(b2x(combined_btc_spend_pubkey)))
btc_contract = make_btc_contract(combined_btc_spend_pubkey,
bob_btc_exit_key.pub)
btc_contract_addr = P2WSHCoinAddress.from_redeemScript(btc_contract)
say("Created Bitcoin-side swap contract, size: {}".format(
len(btc_contract)))
say("Contract address: {}".format(btc_contract_addr))
say('Sending {} to {}'.format(pre_agreed_amount, btc_contract_addr))
btc_txid = btc_rpc.sendtoaddress(str(btc_contract_addr), pre_agreed_amount)
def bob_last_wish_func():
try_reclaim_btc(say, btc_rpc, btc_txid, btc_contract, bob_btc_exit_key,
die)
last_wish_func = bob_last_wish_func
wait_confirm(say, 'Bitcoin', btc_txid, die, btc_rpc, num_confirms=6)
send('btc_txid', btc_txid)
elt_txid = recv('elt_txid')
elt_contract = make_elt_cntract(key_to_reveal_pub, bob_elt_spend_key.pub,
alice_elt_exit_pub_raw)
with ChainParams(elements_chain_name):
elt_contract_addr = P2SHCoinAddress.from_redeemScript(elt_contract)
say('Got Elements contract address from Alice: {}'.format(
elt_contract_addr))
say('Looking for this address in transaction {} in Elements'.format(
elt_txid))
tx_json = elt_rpc.getrawtransaction(elt_txid, 1)
if tx_json['confirmations'] < 2:
die('Transaction does not have enough confirmations')
elt_commit_tx = CElementsTransaction.deserialize(x(tx_json['hex']))
vout_n, unblind_result = find_and_unblind_vout(say, elt_commit_tx,
elt_contract_addr,
blinding_key, die)
if unblind_result.amount != coins_to_satoshi(pre_agreed_amount):
die('the amount {} found at the output in the offered transaction '
'does not match the expected amount {}'.format(
satoshi_to_coins(unblind_result.amount), pre_agreed_amount))
say('The asset and amount match expected values. lets spend it.')
with ChainParams(elements_chain_name):
dst_addr = CCoinAddress(elt_rpc.getnewaddress())
assert isinstance(dst_addr, CCoinConfidentialAddress)
say('I will claim my Elements-BTC to {}'.format(dst_addr))
elt_claim_tx = create_elt_spend_tx(
dst_addr,
elt_txid,
vout_n,
elt_contract,
die,
spend_key=bob_elt_spend_key,
contract_key=contract_key,
blinding_key=blinding_key,
blinding_factor=unblind_result.blinding_factor,
asset_blinding_factor=unblind_result.asset_blinding_factor)
# Cannot use VerifyScript for now,
# because it does not support CHECKSIGFROMSTACK yet
#
# VerifyScript(tx.vin[0].scriptSig,
# elt_contract_addr.to_scriptPubKey(),
# tx, 0, amount=amount)
say('Sending my spend-reveal transaction')
sr_txid = elt_rpc.sendrawtransaction(b2x(elt_claim_tx.serialize()))
wait_confirm(say, 'Elements', sr_txid, die, elt_rpc, num_confirms=2)
say('Got my Elements-BTC. Swap successful (at least for me :-)')
def alice(say, recv, send, die, btc_rpc, elt_rpc):
"""A function that implements the logic
of the Elements-side participant
of confidential cross-chain atomic swap"""
global last_wish_func
# Default chain for Alice will be Elements
# To handle bitcoin-related objects, either
# `with ChainParams(bitcoin_chain_name):` have to be used, or
# concrete classes, like CBitcoinAddress, CBitcoinTransaction, etc.
select_chain_params(elements_chain_name)
# Let's create the shared blinding key
blinding_key = CKey.from_secret_bytes(os.urandom(32))
# And the key for btc spend
alice_btc_key = CKey.from_secret_bytes(os.urandom(32))
# And the key for the 'timeout' branch of the contract
alice_elt_exit_key = CKey.from_secret_bytes(os.urandom(32))
say('Sending pubkeys to Bob')
send('pubkeys', (alice_btc_key.pub, alice_elt_exit_key.pub))
say('Sending the blinding key to Bob')
send('blinding_key', blinding_key.secret_bytes)
(contract_pubkey_raw, bob_elt_pubkey_raw,
bob_btc_exit_pub_raw) = recv('pubkeys')
say("Pubkey of the key to be revealed: {}".format(
b2x(contract_pubkey_raw)))
say("Bob's Elements-side pubkey: {}".format(b2x(bob_elt_pubkey_raw)))
contract_pubkey = CPubKey(contract_pubkey_raw)
key_to_reveal_pub = CPubKey.add(contract_pubkey, blinding_key.pub)
elt_contract = make_elt_cntract(key_to_reveal_pub, bob_elt_pubkey_raw,
alice_elt_exit_key.pub)
elt_contract_addr = P2SHCoinAddress.from_redeemScript(elt_contract)
confidential_contract_addr = P2SHCoinConfidentialAddress.from_unconfidential(
elt_contract_addr, blinding_key.pub)
assert isinstance(confidential_contract_addr, CElementsConfidentialAddress)
say("Created Elemets-side swap contract, size: {}".format(
len(elt_contract)))
say("Contract address:\n\tconfidential: {}\n\tunconfidential: {}".format(
confidential_contract_addr, elt_contract_addr))
btc_txid = recv('btc_txid')
combined_btc_spend_pubkey = CPubKey.add(contract_pubkey, alice_btc_key.pub)
btc_contract = make_btc_contract(combined_btc_spend_pubkey,
bob_btc_exit_pub_raw)
tx_json = btc_rpc.getrawtransaction(btc_txid, 1)
if tx_json['confirmations'] < 6:
die('Transaction does not have enough confirmations')
# We use ChainParams, and not P2WSHBitcoinAddress here,
# because bitcoin_chain_name might be 'bitcoin/regtest', for example,
# and then the address would need to be P2WSHBitcoinRegtestAddress.
# with ChainParams we leverage the 'frontend class' magic, P2WSHCoinAddress
# will give us appropriate instance.
with ChainParams(bitcoin_chain_name):
btc_contract_addr = P2WSHCoinAddress.from_redeemScript(btc_contract)
say('Looking for this address in transaction {} in Bitcoin'.format(
btc_txid))
# CTransaction subclasses do not change between mainnet/testnet/regtest,
# so we can directly use CBitcoinTransaction.
# That might not be true for other chains, though.
# You might also want to use CTransaction within `with ChainParams(...):`
btc_tx = CBitcoinTransaction.deserialize(x(tx_json['hex']))
for n, vout in enumerate(btc_tx.vout):
if vout.scriptPubKey == btc_contract_addr.to_scriptPubKey():
say("Found the address at output {}".format(n))
btc_vout_n = n
break
else:
die('Did not find contract address in transaction')
if vout.nValue != coins_to_satoshi(pre_agreed_amount):
die('the amount {} found at the output in the offered transaction '
'does not match the expected amount {}'.format(
satoshi_to_coins(vout.nValue), pre_agreed_amount))
say('Bitcoin amount match expected values')
say('Sending {} to {}'.format(pre_agreed_amount,
confidential_contract_addr))
contract_txid = elt_rpc.sendtoaddress(str(confidential_contract_addr),
pre_agreed_amount)
def alice_last_wish_func():
try_reclaim_elt(say, elt_rpc, contract_txid, elt_contract,
alice_elt_exit_key, blinding_key, die)
last_wish_func = alice_last_wish_func
wait_confirm(say, 'Elements', contract_txid, die, elt_rpc, num_confirms=2)
send('elt_txid', contract_txid)
sr_txid = wait_spend_reveal_transaction(say, contract_txid, die, elt_rpc)
say('Got txid for spend-reveal transaction from Bob ({})'.format(sr_txid))
tx_json = elt_rpc.getrawtransaction(sr_txid, 1)
wait_confirm(say, 'Elements', sr_txid, die, elt_rpc, num_confirms=2)
sr_tx = CTransaction.deserialize(x(tx_json['hex']))
for n, vin in enumerate(sr_tx.vin):
if vin.prevout.hash == lx(contract_txid)\
and vin.scriptSig[-(len(elt_contract)):] == elt_contract:
say('Transaction input {} seems to contain a script '
'we can recover the key from'.format(n))
reveal_script_iter = iter(vin.scriptSig)
break
else:
die('Spend-reveal transaction does not have input that spends '
'the contract output')
next(reveal_script_iter) # skip Bob's spend signature
try:
# 2 skipped bytes are tag and len
sig_s = ecdsa.util.string_to_number(next(reveal_script_iter)[2:])
except (ValueError, StopIteration):
die('Reveal script is invalid')
k, r = get_known_k_r()
order = ecdsa.SECP256k1.order
mhash = ecdsa.util.string_to_number(hashlib.sha256(b'\x01').digest())
r_inverse = ecdsa.numbertheory.inverse_mod(r, order)
for s in (-sig_s, sig_s):
secret_exponent = (((s * k - mhash) % order) * r_inverse) % order
recovered_key = CKey.from_secret_bytes(
ecdsa.util.number_to_string(secret_exponent, order))
if recovered_key.pub == key_to_reveal_pub:
break
else:
die('Key recovery failed. Should not happen - the sig was already '
'verified when transaction was accepted into mempool. '
'Must be a bug.')
say('recovered key pubkey: {}'.format(b2x(recovered_key.pub)))
contract_key = CKey.sub(recovered_key, blinding_key)
say('recovered unblined key pubkey: {}'.format(b2x(contract_key.pub)))
combined_btc_spend_key = CKey.add(contract_key, alice_btc_key)
say('Successfully recovered the key. Can now spend Bitcoin from {}'.format(
btc_contract_addr))
with ChainParams(bitcoin_chain_name):
dst_addr = CCoinAddress(btc_rpc.getnewaddress())
btc_claim_tx = create_btc_spend_tx(dst_addr,
btc_txid,
btc_vout_n,
btc_contract,
spend_key=combined_btc_spend_key)
say('Sending my Bitcoin-claim transaction')
btc_claim_txid = btc_rpc.sendrawtransaction(b2x(btc_claim_tx.serialize()))
wait_confirm(say, 'Bitcoin', btc_claim_txid, die, btc_rpc, num_confirms=3)
say('Got my Bitcoin. Swap successful!')
