def _unblind(self):
if not self.descriptor.is_blinded:
return
b = self.tx
mbpk = self.descriptor.blinding_key.key
net = self.network
values = [0 for out in b.vout]
assets = [b"\xFF" * 32 for out in b.vout]
datas = []
# search for datas encoded in rangeproofs
for i, out in enumerate(b.vout):
# unblinded
if isinstance(out.value, int):
values[i] = out.value
assets[i] = out.asset
continue
pk = slip77.blinding_key(mbpk, out.script_pubkey)
try:
res = out.unblind(pk.secret, message_length=1000)
value, asset, vbf, abf, extra, *_ = res
if len(extra.rstrip(b"\x00")) > 0:
datas.append(extra)
values[i] = value
assets[i] = asset
except Exception as e:
logger.warn(e) # TODO: remove, it's ok
pass
# to calculate blinding seed
tx = PSET(b)
seed = tagged_hash("liquid/blinding_seed", mbpk.secret)
txseed = tx.txseed(seed)
pubkeys = {}
for extra in datas:
s = BytesIO(extra)
while True:
k = read_string(s)
if len(k) == 0:
break
v = read_string(s)
if k[0] == 1 and len(k) == 5:
idx = int.from_bytes(k[1:], "little")
pubkeys[idx] = v
elif k == b"\x01\x00":
txseed = v
for i, out in enumerate(b.vout):
if out.witness.range_proof.is_empty:
continue
if i in pubkeys and len(pubkeys[i]) in [33, 65]:
nonce = tagged_hash("liquid/range_proof",
txseed + i.to_bytes(4, "little"))
if out.ecdh_pubkey == PrivateKey(nonce).sec():
try:
res = unblind(
pubkeys[i],
nonce,
out.witness.range_proof.data,
out.value,
out.asset,
out.script_pubkey,
)
value, asset, vbf, abf, extra, min_value, max_value = res
assets[i] = asset
values[i] = value
except Exception as e:
logger.warn(f"Failed at unblinding output {i}: {e}")
else:
logger.warn(f"Failed at unblinding: {e}")
for i, out in enumerate(b.vout):
out.asset = assets[i]
out.value = values[i]
out.witness = TxOutWitness()
def decoderawtransaction(self, tx):
unblinded = self.unblindrawtransaction(tx)["hex"]
obj = super().__getattr__("decoderawtransaction")(unblinded)
try:
# unblind the rest of outputs
b = LTransaction.from_string(tx)
mbpk = PrivateKey(bytes.fromhex(self.dumpmasterblindingkey()))
net = get_network(self.getblockchaininfo().get("chain"))
outputs = obj["vout"]
datas = []
fee = 0
# search for datas encoded in rangeproofs
for i, out in enumerate(b.vout):
o = outputs[i]
if isinstance(out.value, int):
if "value" in o:
assert o["value"] == round(out.value * 1e-8, 8)
else:
o["value"] = round(out.value * 1e-8, 8)
if "asset" in o:
assert o["asset"] == bytes(reversed(
out.asset[-32:])).hex()
else:
o["asset"] = bytes(reversed(out.asset[-32:])).hex()
try:
o["scriptPubKey"]["addresses"] = [
liquid_address(out.script_pubkey, network=net)
]
except:
pass
if out.script_pubkey.data == b"":
# fee negative?
fee -= out.value
pk = slip77.blinding_key(mbpk, out.script_pubkey)
try:
res = out.unblind(pk.secret, message_length=1000)
value, asset, vbf, abf, extra, min_value, max_value = res
if "value" in o:
assert o["value"] == round(value * 1e-8, 8)
else:
o["value"] = round(value * 1e-8, 8)
if "asset" in o:
assert o["asset"] == bytes(reversed(asset[-32:])).hex()
else:
o["asset"] = bytes(reversed(asset[-32:])).hex()
try:
o["scriptPubKey"]["addresses"] = [
liquid_address(out.script_pubkey, pk, network=net)
]
except:
pass
if len(extra.rstrip(b"\x00")) > 0:
datas.append(extra)
except Exception as e:
pass
# should be changed with seed from tx
tx = PSET(b)
seed = tagged_hash("liquid/blinding_seed", mbpk.secret)
txseed = tx.txseed(seed)
pubkeys = {}
for extra in datas:
s = BytesIO(extra)
while True:
k = read_string(s)
if len(k) == 0:
break
v = read_string(s)
if k[0] == 1 and len(k) == 5:
idx = int.from_bytes(k[1:], "little")
pubkeys[idx] = v
elif k == b"\x01\x00":
txseed = v
for i, out in enumerate(outputs):
o = out
if i in pubkeys and len(pubkeys[i]) in [33, 65]:
nonce = tagged_hash("liquid/range_proof",
txseed + i.to_bytes(4, "little"))
if b.vout[i].ecdh_pubkey == PrivateKey(nonce).sec():
try:
res = unblind(
pubkeys[i],
nonce,
b.vout[i].witness.range_proof.data,
b.vout[i].value,
b.vout[i].asset,
b.vout[i].script_pubkey,
)
value, asset, vbf, abf, extra, min_value, max_value = res
if "value" in o:
assert o["value"] == round(value * 1e-8, 8)
else:
o["value"] = round(value * 1e-8, 8)
if "asset" in o:
assert o["asset"] == bytes(
reversed(asset[-32:])).hex()
else:
o["asset"] = bytes(reversed(asset[-32:])).hex()
try:
o["scriptPubKey"]["addresses"] = [
liquid_address(
b.vout[i].script_pubkey,
PublicKey.parse(pubkeys[i]),
network=net,
)
]
except:
pass
except Exception as e:
logger.warn(
f"Failed at unblinding output {i}: {e}")
else:
logger.warn(f"Failed at unblinding: {e}")
if fee != 0:
obj["fee"] = round(-fee * 1e-8, 8)
except Exception as e:
logger.warn(f"Failed at unblinding transaction: {e}")
return obj
