def get_dst_addr(say, rpc):
"""Generate an address and retrieve blinding key for it"""
# Note that we could generate our own keys, and make
# addresses from them, and then derive the blinding keys,
# but then we would have to decide how to store the keys
# for the user to be able to do own exploration
# after example finishes working. We choose the easiest path.
#
# Note that if we have master blinding key
# (Elements will include master blinding key in wallet dump
# in future versions), we could derive the blinding key
# from the master key and the address, with this code:
# addr.to_scriptPubKey().derive_blinding_key(blinding_derivation_key)
# derive_blinding_key() follows the logic of blinding key
# derivation in Elements Core source.
if say:
say('Generating new address and retrieving blinding key for it')
addr_str = rpc.getnewaddress()
# Retrieve the blinding key
blinding_key = CCoinKey.from_secret_bytes(x(rpc.dumpblindingkey(addr_str)))
return CCoinAddress(addr_str), blinding_key
f = sys.argv[1]
#with open(sys.argv[1]) as f:
# We could use CTransaction here, but if we want to
# use mypy to do static checking, we need to use the elements-specific
# classes. mypy does cannot know about dynamic class dispatch.
#tx = CElementsTransaction.deserialize(x(f.readline().rstrip())) [16/1870]
tx = CElementsTransaction.deserialize(x(f))
# Read in the blinding key, expected to be in WIF format.
f = sys.argv[2]
#with open(sys.argv[2]) as f:
#bkey = CCoinKey.from_secret_bytes(x(f.readline().rstrip()))
bkey = CCoinKey.from_secret_bytes(x(f))
# Iterate through transaction ouptputs, and unblind what we can.
print("")
for n, vout in enumerate(tx.vout):
# Note that nValue of vout in Elements is not a simple int,
# but CConfidentialValue, which can either be explicit, and can be
# converted to satoshis with to_amount(), or it can be blinded, in
# which case you need to unblind the output to know its value.
if vout.nValue.is_explicit():
# The output is not blinded, we can access the values right away
assert vout.nAsset.is_explicit(), "unblinding just the asset is not supported"
if vout.is_fee():
print("vout {}: fee".format(n))
else:
sys.exit(-1)
# Switch the chain parameters to Elements
select_chain_params('elements')
# Read in and decode the blinded transaction.
# expected to be hex-encoded as one line.
with open(sys.argv[1]) as f:
# We could use CTransaction here, but if we want to
# use mypy to do static checking, we need to use the elements-specific
# classes. mypy does cannot know about dynamic class dispatch.
tx = CElementsTransaction.deserialize(x(f.readline().rstrip()))
# Read in the blinding key, expected to be in WIF format.
with open(sys.argv[2]) as f:
bkey = CCoinKey.from_secret_bytes(x(f.readline().rstrip()))
# Iterate through transaction ouptputs, and unblind what we can.
print("")
for n, vout in enumerate(tx.vout):
# Note that nValue of vout in Elements is not a simple int,
# but CConfidentialValue, which can either be explicit, and can be
# converted to satoshis with to_amount(), or it can be blinded, in
# which case you need to unblind the output to know its value.
if vout.nValue.is_explicit():
# The output is not blinded, we can access the values right away
assert vout.nAsset.is_explicit(
), "unblinding just the asset is not supported"
if vout.is_fee():
print("vout {}: fee".format(n))
else:
# Read in and decode the blinded transaction.
# expected to be hex-encoded as one line.
with open(sys.argv[1]) as f:
# We could use CTransaction here, but if we want to
# use mypy to do static checking, we need to use the elements-specific
# classes. mypy does cannot know about dynamic class dispatch.
input_tx = CElementsTransaction.deserialize(x(f.readline().rstrip()))
# Read in the key, expected to be in WIF format.
with open(sys.argv[2]) as f:
key = CCoinKey(f.readline().rstrip())
# Read in the unblinding key, expected to be in HEX format.
with open(sys.argv[3]) as f:
bkey = CCoinKey.from_secret_bytes(x(f.readline().rstrip()))
dst_addr = CElementsAddress(sys.argv[4])
# Construct P2SH_P2WPKH address from the loaded key
spk = CScript([0, Hash160(key.pub)]).to_p2sh_scriptPubKey()
src_addr = P2SHCoinAddress.from_scriptPubKey(spk)
sys.stderr.write(
'\nSearching for ouptut with address {}\n'.format(src_addr))
utxo = None
fee_asset = None
# Search for output in the transaction that spends to the address that
# we have. We are going to spend the first output that we find.
for in_n, in_vout in enumerate(input_tx.vout):
elif args.verbosity >= 1:
logging.root.setLevel(logging.DEBUG)
elif args.verbosity == -1:
logging.root.setLevel(logging.WARNING)
elif args.verbosity <= -2:
logging.root.setLevel(logging.ERROR)
if args.testnet:
bitcointx.select_chain_params('bitcoin/testnet')
elif args.regtest:
bitcointx.select_chain_params('bitcoin/regtest')
rpc = bitcointx.rpc.RPCCaller(allow_default_conf=True)
if args.privkey is None:
args.privkey = CCoinKey.from_secret_bytes(os.urandom(32))
else:
args.privkey = CCoinKey(args.privkey)
logging.info('Using keypair %s %s' % (b2x(args.privkey.pub), args.privkey))
# Turn the text file into padded lines
if args.fd is sys.stdin:
# work around a bug where even though we specified binary encoding we get
# the sys.stdin instead.
args.fd = sys.stdin.buffer
raw_padded_lines = [
b'\x00' + line.rstrip().ljust(args.min_len) + b'\x00'
for line in args.fd.readlines()
]