def sign_transaction(self, tx, password):
if tx.is_complete():
return
# previous transactions used as inputs
prev_tx = {}
# path of the xpubs that are involved
xpub_path = {}
for txin in tx.inputs():
pubkeys, x_pubkeys = tx.get_sorted_pubkeys(txin)
tx_hash = txin['prevout_hash']
if txin.get('prev_tx') is None and not Transaction.is_segwit_input(txin):
raise UserFacingException(_('Offline signing with {} is not supported for legacy inputs.').format(self.device))
prev_tx[tx_hash] = txin['prev_tx']
for x_pubkey in x_pubkeys:
if not is_xpubkey(x_pubkey):
continue
xpub, s = parse_xpubkey(x_pubkey)
if xpub == self.get_master_public_key():
xpub_path[xpub] = self.get_derivation()
self.plugin.sign_transaction(self, tx, prev_tx, xpub_path)
def build_psbt(self, tx: Transaction, wallet=None, xfp=None):
# Render a PSBT file, for upload to Coldcard.
#
if xfp is None:
# need fingerprint of MASTER xpub, not the derived key
xfp = self.ckcc_xfp
inputs = tx.inputs()
if 'prev_tx' not in inputs[0]:
# fetch info about inputs, if needed?
# - needed during export PSBT flow, not normal online signing
assert wallet, 'need wallet reference'
wallet.add_hw_info(tx)
# wallet.add_hw_info installs this attr
assert tx.output_info is not None, 'need data about outputs'
# Build map of pubkey needed as derivation from master, in PSBT binary format
# 1) binary version of the common subpath for all keys
# m/ => fingerprint LE32
# a/b/c => ints
base_path = pack('<I', xfp)
for x in self.get_derivation()[2:].split('/'):
if x.endswith("'"):
x = int(x[:-1]) | 0x80000000
else:
x = int(x)
base_path += pack('<I', x)
# 2) all used keys in transaction
subkeys = {}
derivations = self.get_tx_derivations(tx)
for xpubkey in derivations:
pubkey = xpubkey_to_pubkey(xpubkey)
# assuming depth two, non-harded: change + index
aa, bb = derivations[xpubkey]
assert 0 <= aa < 0x80000000
assert 0 <= bb < 0x80000000
subkeys[bfh(pubkey)] = base_path + pack('<II', aa, bb)
for txin in inputs:
if txin['type'] == 'coinbase':
self.give_error("Coinbase not supported")
if txin['type'] in ['p2sh', 'p2wsh-p2sh', 'p2wsh']:
self.give_error('No support yet for inputs of type: ' +
txin['type'])
# Construct PSBT from start to finish.
out_fd = io.BytesIO()
out_fd.write(b'psbt\xff')
def write_kv(ktype, val, key=b''):
# serialize helper: write w/ size and key byte
out_fd.write(my_var_int(1 + len(key)))
out_fd.write(bytes([ktype]) + key)
if isinstance(val, str):
val = bfh(val)
out_fd.write(my_var_int(len(val)))
out_fd.write(val)
# global section: just the unsigned txn
class CustomTXSerialization(Transaction):
@classmethod
def input_script(cls, txin, estimate_size=False):
return ''
unsigned = bfh(
CustomTXSerialization(
tx.serialize()).serialize_to_network(witness=False))
write_kv(PSBT_GLOBAL_UNSIGNED_TX, unsigned)
# end globals section
out_fd.write(b'\x00')
# inputs section
for txin in inputs:
if Transaction.is_segwit_input(txin):
utxo = txin['prev_tx'].outputs()[txin['prevout_n']]
spendable = txin['prev_tx'].serialize_output(utxo)
write_kv(PSBT_IN_WITNESS_UTXO, spendable)
else:
write_kv(PSBT_IN_NON_WITNESS_UTXO, str(txin['prev_tx']))
pubkeys, x_pubkeys = tx.get_sorted_pubkeys(txin)
pubkeys = [bfh(k) for k in pubkeys]
for k in pubkeys:
write_kv(PSBT_IN_BIP32_DERIVATION, subkeys[k], k)
if txin['type'] == 'p2wpkh-p2sh':
assert len(
pubkeys
) == 1, 'can be only one redeem script per input'
pa = hash_160(k)
assert len(pa) == 20
write_kv(PSBT_IN_REDEEM_SCRIPT, b'\x00\x14' + pa)
out_fd.write(b'\x00')
# outputs section
for o in tx.outputs():
# can be empty, but must be present, and helpful to show change inputs
# wallet.add_hw_info() adds some data about change outputs into tx.output_info
if o.address in tx.output_info:
# this address "is_mine" but might not be change (I like to sent to myself)
output_info = tx.output_info.get(o.address)
index, xpubs = output_info.address_index, output_info.sorted_xpubs
if index[0] == 1 and len(index) == 2:
# it is a change output (based on our standard derivation path)
assert len(xpubs) == 1 # not expecting multisig
xpubkey = xpubs[0]
# document its bip32 derivation in output section
aa, bb = index
assert 0 <= aa < 0x80000000
assert 0 <= bb < 0x80000000
deriv = base_path + pack('<II', aa, bb)
pubkey = bfh(self.get_pubkey_from_xpub(xpubkey, index))
write_kv(PSBT_OUT_BIP32_DERIVATION, deriv, pubkey)
if output_info.script_type == 'p2wpkh-p2sh':
pa = hash_160(pubkey)
assert len(pa) == 20
write_kv(PSBT_OUT_REDEEM_SCRIPT, b'\x00\x14' + pa)
out_fd.write(b'\x00')
return out_fd.getvalue()
def sign_transaction(self, tx, password):
if tx.is_complete():
return
client = self.get_client()
inputs = []
inputsPaths = []
pubKeys = []
chipInputs = []
redeemScripts = []
signatures = []
changePath = ""
output = None
p2shTransaction = False
segwitTransaction = False
pin = ""
self.get_client(
) # prompt for the PIN before displaying the dialog if necessary
# Fetch inputs of the transaction to sign
derivations = self.get_tx_derivations(tx)
for txin in tx.inputs():
if txin['type'] == 'coinbase':
self.give_error(
"Coinbase not supported") # should never happen
if txin['type'] in ['p2sh']:
p2shTransaction = True
if txin['type'] in ['p2wpkh-p2sh', 'p2wsh-p2sh']:
if not self.get_client_electrum().supports_segwit():
self.give_error(MSG_NEEDS_FW_UPDATE_SEGWIT)
segwitTransaction = True
if txin['type'] in ['p2wpkh', 'p2wsh']:
if not self.get_client_electrum().supports_native_segwit():
self.give_error(MSG_NEEDS_FW_UPDATE_SEGWIT)
segwitTransaction = True
pubkeys, x_pubkeys = tx.get_sorted_pubkeys(txin)
for i, x_pubkey in enumerate(x_pubkeys):
if x_pubkey in derivations:
signingPos = i
s = derivations.get(x_pubkey)
hwAddress = "%s/%d/%d" % (self.get_derivation()[2:], s[0],
s[1])
break
else:
self.give_error("No matching x_key for sign_transaction"
) # should never happen
redeemScript = Transaction.get_preimage_script(txin)
txin_prev_tx = txin.get('prev_tx')
if txin_prev_tx is None and not Transaction.is_segwit_input(txin):
raise Exception(
_('Offline signing with {} is not supported for legacy inputs.'
).format(self.device))
txin_prev_tx_raw = txin_prev_tx.raw if txin_prev_tx else None
inputs.append([
txin_prev_tx_raw, txin['prevout_n'], redeemScript,
txin['prevout_hash'], signingPos,
txin.get('sequence', 0xffffffff - 1),
txin.get('value')
])
inputsPaths.append(hwAddress)
pubKeys.append(pubkeys)
# Sanity check
if p2shTransaction:
for txin in tx.inputs():
if txin['type'] != 'p2sh':
self.give_error(
"P2SH / regular input mixed in same transaction not supported"
) # should never happen
txOutput = var_int(len(tx.outputs()))
for o in tx.outputs():
output_type, addr, amount, name_op = o.type, o.address, o.value, o.name_op
txOutput += int_to_hex(amount, 8)
script = tx.pay_script(output_type, addr, name_op)
txOutput += var_int(len(script) // 2)
txOutput += script
txOutput = bfh(txOutput)
# Recognize outputs
# - only one output and one change is authorized (for hw.1 and nano)
# - at most one output can bypass confirmation (~change) (for all)
if not p2shTransaction:
if not self.get_client_electrum().supports_multi_output():
if len(tx.outputs()) > 2:
self.give_error(
"Transaction with more than 2 outputs not supported")
has_change = False
any_output_on_change_branch = is_any_tx_output_on_change_branch(tx)
for o in tx.outputs():
assert o.type == TYPE_ADDRESS
info = tx.output_info.get(o.address)
if (info is not None) and len(tx.outputs()) > 1 \
and not has_change:
index = info.address_index
on_change_branch = index[0] == 1
# prioritise hiding outputs on the 'change' branch from user
# because no more than one change address allowed
if on_change_branch == any_output_on_change_branch:
changePath = self.get_derivation(
)[2:] + "/%d/%d" % index
has_change = True
else:
output = o.address
else:
output = o.address
self.handler.show_message(
_("Confirm Transaction on your Ledger device..."))
try:
# Get trusted inputs from the original transactions
for utxo in inputs:
sequence = int_to_hex(utxo[5], 4)
if segwitTransaction:
tmp = bfh(utxo[3])[::-1]
tmp += bfh(int_to_hex(utxo[1], 4))
tmp += bfh(int_to_hex(utxo[6], 8)) # txin['value']
chipInputs.append({
'value': tmp,
'witness': True,
'sequence': sequence
})
redeemScripts.append(bfh(utxo[2]))
elif not p2shTransaction:
txtmp = bitcoinTransaction(bfh(utxo[0]))
trustedInput = self.get_client().getTrustedInput(
txtmp, utxo[1])
trustedInput['sequence'] = sequence
chipInputs.append(trustedInput)
redeemScripts.append(txtmp.outputs[utxo[1]].script)
else:
tmp = bfh(utxo[3])[::-1]
tmp += bfh(int_to_hex(utxo[1], 4))
chipInputs.append({'value': tmp, 'sequence': sequence})
redeemScripts.append(bfh(utxo[2]))
# Sign all inputs
firstTransaction = True
inputIndex = 0
rawTx = tx.serialize_to_network()
self.get_client().enableAlternate2fa(False)
if segwitTransaction:
self.get_client().startUntrustedTransaction(
True, inputIndex, chipInputs, redeemScripts[inputIndex])
# we don't set meaningful outputAddress, amount and fees
# as we only care about the alternateEncoding==True branch
outputData = self.get_client().finalizeInput(
b'', 0, 0, changePath, bfh(rawTx))
outputData['outputData'] = txOutput
if outputData['confirmationNeeded']:
outputData['address'] = output
self.handler.finished()
pin = self.handler.get_auth(
outputData
) # does the authenticate dialog and returns pin
if not pin:
raise UserWarning()
if pin != 'paired':
self.handler.show_message(
_("Confirmed. Signing Transaction..."))
while inputIndex < len(inputs):
singleInput = [chipInputs[inputIndex]]
self.get_client().startUntrustedTransaction(
False, 0, singleInput, redeemScripts[inputIndex])
inputSignature = self.get_client().untrustedHashSign(
inputsPaths[inputIndex], pin, lockTime=tx.locktime)
inputSignature[0] = 0x30 # force for 1.4.9+
signatures.append(inputSignature)
inputIndex = inputIndex + 1
else:
while inputIndex < len(inputs):
self.get_client().startUntrustedTransaction(
firstTransaction, inputIndex, chipInputs,
redeemScripts[inputIndex])
# we don't set meaningful outputAddress, amount and fees
# as we only care about the alternateEncoding==True branch
outputData = self.get_client().finalizeInput(
b'', 0, 0, changePath, bfh(rawTx))
outputData['outputData'] = txOutput
if outputData['confirmationNeeded']:
outputData['address'] = output
self.handler.finished()
pin = self.handler.get_auth(
outputData
) # does the authenticate dialog and returns pin
if not pin:
raise UserWarning()
if pin != 'paired':
self.handler.show_message(
_("Confirmed. Signing Transaction..."))
else:
# Sign input with the provided PIN
inputSignature = self.get_client().untrustedHashSign(
inputsPaths[inputIndex], pin, lockTime=tx.locktime)
inputSignature[0] = 0x30 # force for 1.4.9+
signatures.append(inputSignature)
inputIndex = inputIndex + 1
if pin != 'paired':
firstTransaction = False
except UserWarning:
self.handler.show_error(_('Cancelled by user'))
return
except BTChipException as e:
if e.sw == 0x6985: # cancelled by user
return
elif e.sw == 0x6982:
raise # pin lock. decorator will catch it
else:
traceback.print_exc(file=sys.stderr)
self.give_error(e, True)
except BaseException as e:
traceback.print_exc(file=sys.stdout)
self.give_error(e, True)
finally:
self.handler.finished()
for i, txin in enumerate(tx.inputs()):
signingPos = inputs[i][4]
tx.add_signature_to_txin(i, signingPos, bh2u(signatures[i]))
tx.raw = tx.serialize()