def compose_transaction(args, message_name, param_names):
args = prepare_args(args, message_name)
common_params = common_args(args)
params = extract_args(args, param_names)
params.update(common_params)
# Get provided pubkeys from params.
pubkeys = []
for address_name in ['source', 'destination']:
if address_name in params:
address = params[address_name]
if not script.is_p2sh(address) and (script.is_multisig(address) or address_name != 'destination'): # We don’t need the pubkey for a mono‐sig destination.
pubkeys += get_pubkeys(address)
params['pubkey'] = pubkeys
method = 'create_{}'.format(message_name)
unsigned_tx_hex = util.api(method, params)
# check_transaction(method, params, unsigned_tx_hex)
return unsigned_tx_hex
def construct (db, tx_info, encoding='auto',
fee_per_kb=config.DEFAULT_FEE_PER_KB,
estimate_fee_per_kb=None, estimate_fee_per_kb_nblocks=config.ESTIMATE_FEE_NBLOCKS,
regular_dust_size=config.DEFAULT_REGULAR_DUST_SIZE,
multisig_dust_size=config.DEFAULT_MULTISIG_DUST_SIZE,
op_return_value=config.DEFAULT_OP_RETURN_VALUE,
exact_fee=None, fee_provided=0, provided_pubkeys=None, dust_return_pubkey=None,
allow_unconfirmed_inputs=False, unspent_tx_hash=None, custom_inputs=None, disable_utxo_locks=False):
if estimate_fee_per_kb is None:
estimate_fee_per_kb = config.ESTIMATE_FEE_PER_KB
global UTXO_LOCKS
desired_encoding = encoding
(source, destination_outputs, data) = tx_info
if dust_return_pubkey:
dust_return_pubkey = binascii.unhexlify(dust_return_pubkey)
# Source.
# If public key is necessary for construction of (unsigned)
# transaction, use the public key provided, or find it from the
# blockchain.
if source:
script.validate(source)
source_is_p2sh = script.is_p2sh(source)
# Sanity checks.
if exact_fee and not isinstance(exact_fee, int):
raise exceptions.TransactionError('Exact fees must be in satoshis.')
if not isinstance(fee_provided, int):
raise exceptions.TransactionError('Fee provided must be in satoshis.')
if UTXO_LOCKS is None and config.UTXO_LOCKS_MAX_ADDRESSES > 0: # initialize if configured
UTXO_LOCKS = util.DictCache(size=config.UTXO_LOCKS_MAX_ADDRESSES)
'''Destinations'''
# Destination outputs.
# Replace multi‐sig addresses with multi‐sig pubkeys. Check that the
# destination output isn’t a dust output. Set null values to dust size.
destination_outputs_new = []
for (address, value) in destination_outputs:
# Value.
if script.is_multisig(address):
dust_size = multisig_dust_size
else:
dust_size = regular_dust_size
if value == None:
value = dust_size
elif value < dust_size:
raise exceptions.TransactionError('Destination output is dust.')
# Address.
script.validate(address)
if script.is_multisig(address):
destination_outputs_new.append((backend.multisig_pubkeyhashes_to_pubkeys(address, provided_pubkeys), value))
else:
destination_outputs_new.append((address, value))
destination_outputs = destination_outputs_new
destination_btc_out = sum([value for address, value in destination_outputs])
'''Data'''
if data:
# Data encoding methods (choose and validate).
if encoding == 'auto':
if len(data) + len(config.PREFIX) <= config.OP_RETURN_MAX_SIZE:
encoding = 'opreturn'
else:
encoding = 'multisig'
elif encoding not in ('pubkeyhash', 'multisig', 'opreturn'):
raise exceptions.TransactionError('Unknown encoding‐scheme.')
if encoding == 'multisig':
# dust_return_pubkey should be set or explicitly set to False to use the default configured for the node
# the default for the node is optional so could fail
if (source_is_p2sh and dust_return_pubkey is None) or (dust_return_pubkey is False and config.P2SH_DUST_RETURN_PUBKEY is None):
raise exceptions.TransactionError("Can't use multisig encoding when source is P2SH and no dust_return_pubkey is provided.")
elif dust_return_pubkey is False:
dust_return_pubkey = binascii.unhexlify(config.P2SH_DUST_RETURN_PUBKEY)
# Divide data into chunks.
if encoding == 'pubkeyhash':
# Prefix is also a suffix here.
chunk_size = 20 - 1 - 8
elif encoding == 'multisig':
# Two pubkeys, minus length byte, minus prefix, minus two nonces,
# minus two sign bytes.
chunk_size = (33 * 2) - 1 - 8 - 2 - 2
elif encoding == 'opreturn':
chunk_size = config.OP_RETURN_MAX_SIZE
if len(data) + len(config.PREFIX) > chunk_size:
raise exceptions.TransactionError('One `OP_RETURN` output per transaction.')
data_array = list(chunks(data, chunk_size))
# Data outputs.
if encoding == 'multisig':
data_value = multisig_dust_size
elif encoding == 'opreturn':
data_value = op_return_value
else:
# Pay‐to‐PubKeyHash, e.g.
data_value = regular_dust_size
data_output = (data_array, data_value)
if not dust_return_pubkey:
if encoding == 'multisig':
dust_return_pubkey = get_dust_return_pubkey(source, provided_pubkeys, encoding)
else:
dust_return_pubkey = None
else:
data_array = []
data_output = None
dust_return_pubkey = None
data_btc_out = sum([data_value for data_chunk in data_array])
'''Inputs'''
# Calculate collective size of outputs, for fee calculation.
p2pkhsize = 25 + 9
if encoding == 'multisig':
data_output_size = 81 # 71 for the data
elif encoding == 'opreturn':
data_output_size = 90 # 80 for the data
else:
data_output_size = p2pkhsize # Pay‐to‐PubKeyHash (25 for the data?)
outputs_size = (p2pkhsize * len(destination_outputs)) + (len(data_array) * data_output_size)
# Get inputs.
multisig_inputs = not data
use_inputs = custom_inputs # Array of UTXOs, as retrieved by listunspent function from bitcoind
if custom_inputs is None:
if unspent_tx_hash is not None:
unspent = backend.get_unspent_txouts(source, unconfirmed=allow_unconfirmed_inputs, unspent_tx_hash=unspent_tx_hash, multisig_inputs=multisig_inputs)
else:
unspent = backend.get_unspent_txouts(source, unconfirmed=allow_unconfirmed_inputs, multisig_inputs=multisig_inputs)
# filter out any locked UTXOs to prevent creating transactions that spend the same UTXO when they're created at the same time
if UTXO_LOCKS is not None and source in UTXO_LOCKS:
unspentkeys = {make_outkey(output) for output in unspent}
filtered_unspentkeys = unspentkeys - UTXO_LOCKS[source].keys()
unspent = [output for output in unspent if make_outkey(output) in filtered_unspentkeys]
unspent = backend.sort_unspent_txouts(unspent)
logger.debug('Sorted candidate UTXOs: {}'.format([print_coin(coin) for coin in unspent]))
use_inputs = unspent
# use backend estimated fee_per_kb
if estimate_fee_per_kb:
estimated_fee_per_kb = backend.fee_per_kb(estimate_fee_per_kb_nblocks)
if estimated_fee_per_kb is not None:
fee_per_kb = max(estimated_fee_per_kb, fee_per_kb) # never drop below the default fee_per_kb
logger.debug('Fee/KB {:.8f}'.format(fee_per_kb / config.UNIT))
inputs = []
btc_in = 0
change_quantity = 0
sufficient_funds = False
final_fee = fee_per_kb
desired_input_count = 1
if encoding == 'multisig' and data_array and util.enabled('bytespersigop'):
desired_input_count = len(data_array) * 2
for coin in use_inputs:
logger.debug('New input: {}'.format(print_coin(coin)))
inputs.append(coin)
btc_in += round(coin['amount'] * config.UNIT)
size = 181 * len(inputs) + outputs_size + 10
necessary_fee = int(size / 1000 * fee_per_kb)
# If exact fee is specified, use that. Otherwise, calculate size of tx
# and base fee on that (plus provide a minimum fee for selling BTC).
if exact_fee:
final_fee = exact_fee
else:
final_fee = max(fee_provided, necessary_fee)
# Check if good.
btc_out = destination_btc_out + data_btc_out
change_quantity = btc_in - (btc_out + final_fee)
logger.debug('Size: {} Fee: {:.8f} Change quantity: {:.8f} BTC'.format(size, final_fee / config.UNIT, change_quantity / config.UNIT))
# If change is necessary, must not be a dust output.
if change_quantity == 0 or change_quantity >= regular_dust_size:
sufficient_funds = True
if len(inputs) >= desired_input_count:
break
if not sufficient_funds:
# Approximate needed change, fee by with most recently calculated
# quantities.
btc_out = destination_btc_out + data_btc_out
total_btc_out = btc_out + max(change_quantity, 0) + final_fee
raise exceptions.BalanceError('Insufficient {} at address {}. (Need approximately {} {}.) To spend unconfirmed coins, use the flag `--unconfirmed`. (Unconfirmed coins cannot be spent from multi‐sig addresses.)'.format(config.BTC, source, total_btc_out / config.UNIT, config.BTC))
# Lock the source's inputs (UTXOs) chosen for this transaction
if UTXO_LOCKS is not None and not disable_utxo_locks:
if source not in UTXO_LOCKS:
UTXO_LOCKS[source] = cachetools.TTLCache(
UTXO_LOCKS_PER_ADDRESS_MAXSIZE, config.UTXO_LOCKS_MAX_AGE)
for input in inputs:
UTXO_LOCKS[source][make_outkey(input)] = input
logger.debug("UTXO locks: Potentials ({}): {}, Used: {}, locked UTXOs: {}".format(
len(unspent), [make_outkey(coin) for coin in unspent],
[make_outkey(input) for input in inputs], list(UTXO_LOCKS[source].keys())))
'''Finish'''
# Change output.
if change_quantity:
if script.is_multisig(source):
change_address = backend.multisig_pubkeyhashes_to_pubkeys(source, provided_pubkeys)
else:
change_address = source
change_output = (change_address, change_quantity)
else:
change_output = None
# in bitcoin core v0.12.1 a -bytespersigop was added that messes with bare multisig transactions,
# as a safeguard we fall back to pubkeyhash encoding when unsure
# when len(inputs) > len(data_outputs) there's more bytes:sigops ratio and we can safely continue
if encoding == 'multisig' and inputs and data_output and len(inputs) < len(data_array) * 2 and util.enabled('bytespersigop'):
# if auto encoding we can do pubkeyhash encoding instead
if desired_encoding == 'auto':
return construct(db, tx_info,
encoding='pubkeyhash',
fee_per_kb=fee_per_kb,
regular_dust_size=regular_dust_size,
multisig_dust_size=multisig_dust_size,
op_return_value=op_return_value,
exact_fee=exact_fee, fee_provided=fee_provided, provided_pubkeys=provided_pubkeys,
allow_unconfirmed_inputs=allow_unconfirmed_inputs, unspent_tx_hash=unspent_tx_hash, custom_inputs=custom_inputs)
# otherwise raise exception
else:
raise exceptions.EncodingError("multisig will be rejected by Bitcoin Core >= v0.12.1, you should use `encoding=auto` or `encoding=pubkeyhash`")
# Serialise inputs and outputs.
unsigned_tx = serialise(encoding, inputs, destination_outputs,
data_output, change_output,
dust_return_pubkey=dust_return_pubkey)
unsigned_tx_hex = binascii.hexlify(unsigned_tx).decode('utf-8')
'''Sanity Check'''
from counterpartylib.lib import blocks
# Desired transaction info.
(desired_source, desired_destination_outputs, desired_data) = tx_info
desired_source = script.make_canonical(desired_source)
desired_destination = script.make_canonical(desired_destination_outputs[0][0]) if desired_destination_outputs else ''
# NOTE: Include change in destinations for BTC transactions.
# if change_output and not desired_data and desired_destination != config.UNSPENDABLE:
# if desired_destination == '':
# desired_destination = desired_source
# else:
# desired_destination += '-{}'.format(desired_source)
# NOTE
if desired_data == None:
desired_data = b''
# Parsed transaction info.
try:
parsed_source, parsed_destination, x, y, parsed_data = blocks._get_tx_info(unsigned_tx_hex)
except exceptions.BTCOnlyError:
# Skip BTC‐only transactions.
return unsigned_tx_hex
desired_source = script.make_canonical(desired_source)
# Check desired info against parsed info.
desired = (desired_source, desired_destination, desired_data)
parsed = (parsed_source, parsed_destination, parsed_data)
if desired != parsed:
# Unlock (revert) UTXO locks
if UTXO_LOCKS is not None:
for input in inputs:
UTXO_LOCKS[source].pop(make_outkey(input), None)
raise exceptions.TransactionError('Constructed transaction does not parse correctly: {} ≠ {}'.format(desired, parsed))
return unsigned_tx_hex
def construct(db,
tx_info,
encoding='auto',
fee_per_kb=config.DEFAULT_FEE_PER_KB,
estimate_fee_per_kb=None,
estimate_fee_per_kb_nblocks=config.ESTIMATE_FEE_NBLOCKS,
regular_dust_size=config.DEFAULT_REGULAR_DUST_SIZE,
multisig_dust_size=config.DEFAULT_MULTISIG_DUST_SIZE,
op_return_value=config.DEFAULT_OP_RETURN_VALUE,
exact_fee=None,
fee_provided=0,
provided_pubkeys=None,
dust_return_pubkey=None,
allow_unconfirmed_inputs=False,
unspent_tx_hash=None,
custom_inputs=None,
disable_utxo_locks=False):
if estimate_fee_per_kb is None:
estimate_fee_per_kb = config.ESTIMATE_FEE_PER_KB
global UTXO_LOCKS
desired_encoding = encoding
(source, destination_outputs, data) = tx_info
if dust_return_pubkey:
dust_return_pubkey = binascii.unhexlify(dust_return_pubkey)
# Source.
# If public key is necessary for construction of (unsigned)
# transaction, use the public key provided, or find it from the
# blockchain.
if source:
script.validate(source)
source_is_p2sh = script.is_p2sh(source)
# Sanity checks.
if exact_fee and not isinstance(exact_fee, int):
raise exceptions.TransactionError('Exact fees must be in satoshis.')
if not isinstance(fee_provided, int):
raise exceptions.TransactionError('Fee provided must be in satoshis.')
if UTXO_LOCKS is None and config.UTXO_LOCKS_MAX_ADDRESSES > 0: # initialize if configured
UTXO_LOCKS = util.DictCache(size=config.UTXO_LOCKS_MAX_ADDRESSES)
'''Destinations'''
# Destination outputs.
# Replace multi‐sig addresses with multi‐sig pubkeys. Check that the
# destination output isn’t a dust output. Set null values to dust size.
destination_outputs_new = []
for (address, value) in destination_outputs:
# Value.
if script.is_multisig(address):
dust_size = multisig_dust_size
else:
dust_size = regular_dust_size
if value == None:
value = dust_size
elif value < dust_size:
raise exceptions.TransactionError('Destination output is dust.')
# Address.
script.validate(address)
if script.is_multisig(address):
destination_outputs_new.append(
(backend.multisig_pubkeyhashes_to_pubkeys(
address, provided_pubkeys), value))
else:
destination_outputs_new.append((address, value))
destination_outputs = destination_outputs_new
destination_btc_out = sum(
[value for address, value in destination_outputs])
'''Data'''
if data:
# Data encoding methods (choose and validate).
if encoding == 'auto':
if len(data) + len(config.PREFIX) <= config.OP_RETURN_MAX_SIZE:
encoding = 'opreturn'
else:
encoding = 'multisig'
elif encoding not in ('pubkeyhash', 'multisig', 'opreturn'):
raise exceptions.TransactionError('Unknown encoding‐scheme.')
if encoding == 'multisig':
# dust_return_pubkey should be set or explicitly set to False to use the default configured for the node
# the default for the node is optional so could fail
if (source_is_p2sh and dust_return_pubkey is None) or (
dust_return_pubkey is False
and config.P2SH_DUST_RETURN_PUBKEY is None):
raise exceptions.TransactionError(
"Can't use multisig encoding when source is P2SH and no dust_return_pubkey is provided."
)
elif dust_return_pubkey is False:
dust_return_pubkey = binascii.unhexlify(
config.P2SH_DUST_RETURN_PUBKEY)
# Divide data into chunks.
if encoding == 'pubkeyhash':
# Prefix is also a suffix here.
chunk_size = 20 - 1 - 8
elif encoding == 'multisig':
# Two pubkeys, minus length byte, minus prefix, minus two nonces,
# minus two sign bytes.
chunk_size = (33 * 2) - 1 - 8 - 2 - 2
elif encoding == 'opreturn':
chunk_size = config.OP_RETURN_MAX_SIZE
if len(data) + len(config.PREFIX) > chunk_size:
raise exceptions.TransactionError(
'One `OP_RETURN` output per transaction.')
data_array = list(chunks(data, chunk_size))
# Data outputs.
if encoding == 'multisig':
data_value = multisig_dust_size
elif encoding == 'opreturn':
data_value = op_return_value
else:
# Pay‐to‐PubKeyHash, e.g.
data_value = regular_dust_size
data_output = (data_array, data_value)
if not dust_return_pubkey:
if encoding == 'multisig':
dust_return_pubkey = get_dust_return_pubkey(
source, provided_pubkeys, encoding)
else:
dust_return_pubkey = None
else:
data_array = []
data_output = None
dust_return_pubkey = None
data_btc_out = sum([data_value for data_chunk in data_array])
'''Inputs'''
# Calculate collective size of outputs, for fee calculation.
p2pkhsize = 25 + 9
if encoding == 'multisig':
data_output_size = 81 # 71 for the data
elif encoding == 'opreturn':
data_output_size = 90 # 80 for the data
else:
data_output_size = p2pkhsize # Pay‐to‐PubKeyHash (25 for the data?)
outputs_size = (p2pkhsize * len(destination_outputs)) + (len(data_array) *
data_output_size)
# Get inputs.
multisig_inputs = not data
use_inputs = custom_inputs # Array of UTXOs, as retrieved by listunspent function from bitcoind
if custom_inputs is None:
if unspent_tx_hash is not None:
unspent = backend.get_unspent_txouts(
source,
unconfirmed=allow_unconfirmed_inputs,
unspent_tx_hash=unspent_tx_hash,
multisig_inputs=multisig_inputs)
else:
unspent = backend.get_unspent_txouts(
source,
unconfirmed=allow_unconfirmed_inputs,
multisig_inputs=multisig_inputs)
# filter out any locked UTXOs to prevent creating transactions that spend the same UTXO when they're created at the same time
if UTXO_LOCKS is not None and source in UTXO_LOCKS:
unspentkeys = {make_outkey(output) for output in unspent}
filtered_unspentkeys = unspentkeys - UTXO_LOCKS[source].keys()
unspent = [
output for output in unspent
if make_outkey(output) in filtered_unspentkeys
]
unspent = backend.sort_unspent_txouts(unspent)
logger.debug('Sorted candidate UTXOs: {}'.format(
[print_coin(coin) for coin in unspent]))
use_inputs = unspent
# use backend estimated fee_per_kb
if estimate_fee_per_kb:
estimated_fee_per_kb = backend.fee_per_kb(estimate_fee_per_kb_nblocks)
if estimated_fee_per_kb is not None:
fee_per_kb = max(
estimated_fee_per_kb,
fee_per_kb) # never drop below the default fee_per_kb
logger.debug('Fee/KB {:.8f}'.format(fee_per_kb / config.UNIT))
inputs = []
btc_in = 0
change_quantity = 0
sufficient_funds = False
final_fee = fee_per_kb
desired_input_count = 1
if encoding == 'multisig' and data_array and util.enabled('bytespersigop'):
desired_input_count = len(data_array) * 2
for coin in use_inputs:
logger.debug('New input: {}'.format(print_coin(coin)))
inputs.append(coin)
btc_in += round(coin['amount'] * config.UNIT)
size = 181 * len(inputs) + outputs_size + 10
necessary_fee = int(size / 1000 * fee_per_kb)
# If exact fee is specified, use that. Otherwise, calculate size of tx
# and base fee on that (plus provide a minimum fee for selling BTC).
if exact_fee:
final_fee = exact_fee
else:
final_fee = max(fee_provided, necessary_fee)
# Check if good.
btc_out = destination_btc_out + data_btc_out
change_quantity = btc_in - (btc_out + final_fee)
logger.debug('Size: {} Fee: {:.8f} Change quantity: {:.8f} BTC'.format(
size, final_fee / config.UNIT, change_quantity / config.UNIT))
# If change is necessary, must not be a dust output.
if change_quantity == 0 or change_quantity >= regular_dust_size:
sufficient_funds = True
if len(inputs) >= desired_input_count:
break
if not sufficient_funds:
# Approximate needed change, fee by with most recently calculated
# quantities.
btc_out = destination_btc_out + data_btc_out
total_btc_out = btc_out + max(change_quantity, 0) + final_fee
raise exceptions.BalanceError(
'Insufficient {} at address {}. (Need approximately {} {}.) To spend unconfirmed coins, use the flag `--unconfirmed`. (Unconfirmed coins cannot be spent from multi‐sig addresses.)'
.format(config.BTC, source, total_btc_out / config.UNIT,
config.BTC))
# Lock the source's inputs (UTXOs) chosen for this transaction
if UTXO_LOCKS is not None and not disable_utxo_locks:
if source not in UTXO_LOCKS:
UTXO_LOCKS[source] = cachetools.TTLCache(
UTXO_LOCKS_PER_ADDRESS_MAXSIZE, config.UTXO_LOCKS_MAX_AGE)
for input in inputs:
UTXO_LOCKS[source][make_outkey(input)] = input
logger.debug(
"UTXO locks: Potentials ({}): {}, Used: {}, locked UTXOs: {}".
format(len(unspent), [make_outkey(coin) for coin in unspent],
[make_outkey(input) for input in inputs],
list(UTXO_LOCKS[source].keys())))
'''Finish'''
# Change output.
if change_quantity:
if script.is_multisig(source):
change_address = backend.multisig_pubkeyhashes_to_pubkeys(
source, provided_pubkeys)
else:
change_address = source
change_output = (change_address, change_quantity)
else:
change_output = None
# in bitcoin core v0.12.1 a -bytespersigop was added that messes with bare multisig transactions,
# as a safeguard we fall back to pubkeyhash encoding when unsure
# when len(inputs) > len(data_outputs) there's more bytes:sigops ratio and we can safely continue
if encoding == 'multisig' and inputs and data_output and len(
inputs) < len(data_array) * 2 and util.enabled('bytespersigop'):
# if auto encoding we can do pubkeyhash encoding instead
if desired_encoding == 'auto':
return construct(db,
tx_info,
encoding='pubkeyhash',
fee_per_kb=fee_per_kb,
regular_dust_size=regular_dust_size,
multisig_dust_size=multisig_dust_size,
op_return_value=op_return_value,
exact_fee=exact_fee,
fee_provided=fee_provided,
provided_pubkeys=provided_pubkeys,
allow_unconfirmed_inputs=allow_unconfirmed_inputs,
unspent_tx_hash=unspent_tx_hash,
custom_inputs=custom_inputs)
# otherwise raise exception
else:
raise exceptions.EncodingError(
"multisig will be rejected by Bitcoin Core >= v0.12.1, you should use `encoding=auto` or `encoding=pubkeyhash`"
)
# Serialise inputs and outputs.
unsigned_tx = serialise(encoding,
inputs,
destination_outputs,
data_output,
change_output,
dust_return_pubkey=dust_return_pubkey)
unsigned_tx_hex = binascii.hexlify(unsigned_tx).decode('utf-8')
'''Sanity Check'''
from counterpartylib.lib import blocks
# Desired transaction info.
(desired_source, desired_destination_outputs, desired_data) = tx_info
desired_source = script.make_canonical(desired_source)
desired_destination = script.make_canonical(
desired_destination_outputs[0]
[0]) if desired_destination_outputs else ''
# NOTE: Include change in destinations for BTC transactions.
# if change_output and not desired_data and desired_destination != config.UNSPENDABLE:
# if desired_destination == '':
# desired_destination = desired_source
# else:
# desired_destination += '-{}'.format(desired_source)
# NOTE
if desired_data == None:
desired_data = b''
# Parsed transaction info.
try:
parsed_source, parsed_destination, x, y, parsed_data = blocks._get_tx_info(
unsigned_tx_hex)
except exceptions.BTCOnlyError:
# Skip BTC‐only transactions.
return unsigned_tx_hex
desired_source = script.make_canonical(desired_source)
# Check desired info against parsed info.
desired = (desired_source, desired_destination, desired_data)
parsed = (parsed_source, parsed_destination, parsed_data)
if desired != parsed:
# Unlock (revert) UTXO locks
if UTXO_LOCKS is not None:
for input in inputs:
UTXO_LOCKS[source].pop(make_outkey(input), None)
raise exceptions.TransactionError(
'Constructed transaction does not parse correctly: {} ≠ {}'.format(
desired, parsed))
return unsigned_tx_hex
def construct(
db,
tx_info,
encoding='auto',
fee_per_kb=config.DEFAULT_FEE_PER_KB,
estimate_fee_per_kb=None,
estimate_fee_per_kb_conf_target=config.ESTIMATE_FEE_CONF_TARGET,
estimate_fee_per_kb_mode=config.ESTIMATE_FEE_MODE,
estimate_fee_per_kb_nblocks=config.ESTIMATE_FEE_CONF_TARGET,
regular_dust_size=config.DEFAULT_REGULAR_DUST_SIZE,
multisig_dust_size=config.DEFAULT_MULTISIG_DUST_SIZE,
op_return_value=config.DEFAULT_OP_RETURN_VALUE,
exact_fee=None,
fee_provided=0,
provided_pubkeys=None,
dust_return_pubkey=None,
allow_unconfirmed_inputs=False,
unspent_tx_hash=None,
custom_inputs=None,
disable_utxo_locks=False,
extended_tx_info=False,
old_style_api=None,
segwit=False,
p2sh_source_multisig_pubkeys=None,
p2sh_source_multisig_pubkeys_required=None,
p2sh_pretx_txid=None,
):
if estimate_fee_per_kb is None:
estimate_fee_per_kb = config.ESTIMATE_FEE_PER_KB
global UTXO_LOCKS, UTXO_P2SH_ENCODING_LOCKS
# lazy assign from config, because when set as default it's evaluated before it's configured
if old_style_api is None:
old_style_api = config.OLD_STYLE_API
(source, destination_outputs, data) = tx_info
if dust_return_pubkey:
dust_return_pubkey = binascii.unhexlify(dust_return_pubkey)
if p2sh_source_multisig_pubkeys:
p2sh_source_multisig_pubkeys = [
binascii.unhexlify(p) for p in p2sh_source_multisig_pubkeys
]
# Source.
# If public key is necessary for construction of (unsigned)
# transaction, use the public key provided, or find it from the
# blockchain.
if source:
script.validate(source)
source_is_p2sh = script.is_p2sh(source)
# Normalize source
if script.is_multisig(source):
source_address = backend.multisig_pubkeyhashes_to_pubkeys(
source, provided_pubkeys)
else:
source_address = source
# Sanity checks.
if exact_fee and not isinstance(exact_fee, int):
raise exceptions.TransactionError('Exact fees must be in satoshis.')
if not isinstance(fee_provided, int):
raise exceptions.TransactionError('Fee provided must be in satoshis.')
'''Determine encoding method'''
if data:
desired_encoding = encoding
# Data encoding methods (choose and validate).
if desired_encoding == 'auto':
if len(data) + len(config.PREFIX) <= config.OP_RETURN_MAX_SIZE:
encoding = 'opreturn'
else:
encoding = 'p2sh' if not old_style_api and util.enabled(
'p2sh_encoding'
) else 'multisig' # p2sh is not possible with old_style_api
elif desired_encoding == 'p2sh' and not util.enabled('p2sh_encoding'):
raise exceptions.TransactionError('P2SH encoding not enabled yet')
elif encoding not in ('pubkeyhash', 'multisig', 'opreturn', 'p2sh'):
raise exceptions.TransactionError('Unknown encoding‐scheme.')
else:
# no data
encoding = None
'''Destinations'''
# Destination outputs.
# Replace multi‐sig addresses with multi‐sig pubkeys. Check that the
# destination output isn’t a dust output. Set null values to dust size.
destination_outputs_new = []
if encoding != 'p2sh':
for (address, value) in destination_outputs:
# Value.
if script.is_multisig(address):
dust_size = multisig_dust_size
else:
dust_size = regular_dust_size
if value == None:
value = dust_size
elif value < dust_size:
raise exceptions.TransactionError(
'Destination output is dust.')
# Address.
script.validate(address)
if script.is_multisig(address):
destination_outputs_new.append(
(backend.multisig_pubkeyhashes_to_pubkeys(
address, provided_pubkeys), value))
else:
destination_outputs_new.append((address, value))
destination_outputs = destination_outputs_new
destination_btc_out = sum(
[value for address, value in destination_outputs])
'''Data'''
if data:
# @TODO: p2sh encoding require signable dust key
if encoding == 'multisig':
# dust_return_pubkey should be set or explicitly set to False to use the default configured for the node
# the default for the node is optional so could fail
if (source_is_p2sh and dust_return_pubkey is None) or (
dust_return_pubkey is False
and config.P2SH_DUST_RETURN_PUBKEY is None):
raise exceptions.TransactionError(
"Can't use multisig encoding when source is P2SH and no dust_return_pubkey is provided."
)
elif dust_return_pubkey is False:
dust_return_pubkey = binascii.unhexlify(
config.P2SH_DUST_RETURN_PUBKEY)
# Divide data into chunks.
if encoding == 'pubkeyhash':
# Prefix is also a suffix here.
chunk_size = 20 - 1 - 8
elif encoding == 'multisig':
# Two pubkeys, minus length byte, minus prefix, minus two nonces,
# minus two sign bytes.
chunk_size = (33 * 2) - 1 - 8 - 2 - 2
elif encoding == 'p2sh':
chunk_size = p2sh_encoding.maximum_data_chunk_size()
elif encoding == 'opreturn':
chunk_size = config.OP_RETURN_MAX_SIZE
if len(data) + len(config.PREFIX) > chunk_size:
raise exceptions.TransactionError(
'One `OP_RETURN` output per transaction.')
data_array = list(chunks(data, chunk_size))
# Data outputs.
if encoding == 'multisig':
data_value = multisig_dust_size
elif encoding == 'p2sh':
data_value = 0 # this will be calculated later
elif encoding == 'opreturn':
data_value = op_return_value
else:
# Pay‐to‐PubKeyHash, e.g.
data_value = regular_dust_size
data_output = (data_array, data_value)
if not dust_return_pubkey:
if encoding == 'multisig' or encoding == 'p2sh' and not source_is_p2sh:
dust_return_pubkey = get_dust_return_pubkey(
source, provided_pubkeys, encoding)
else:
dust_return_pubkey = None
else:
data_value = 0
data_array = []
data_output = None
dust_return_pubkey = None
data_btc_out = data_value * len(data_array)
logger.getChild('p2shdebug').debug(
'data_btc_out=%s (data_value=%d len(data_array)=%d)' %
(data_btc_out, data_value, len(data_array)))
'''Inputs'''
btc_in = 0
final_fee = 0
# Calculate collective size of outputs, for fee calculation.
p2pkhsize = 25 + 9
if encoding == 'multisig':
data_output_size = 81 # 71 for the data
elif encoding == 'opreturn':
# prefix + data + 10 bytes script overhead
data_output_size = len(config.PREFIX) + 10
if data is not None:
data_output_size = data_output_size + len(data)
else:
data_output_size = p2pkhsize # Pay‐to‐PubKeyHash (25 for the data?)
outputs_size = (p2pkhsize * len(destination_outputs)) + (len(data_array) *
data_output_size)
if encoding == 'p2sh':
# calculate all the p2sh outputs
size_for_fee, datatx_necessary_fee, data_value, data_btc_out = p2sh_encoding.calculate_outputs(
destination_outputs, data_array, fee_per_kb)
# replace the data value
data_output = (data_array, data_value)
else:
sum_data_output_size = len(data_array) * data_output_size
size_for_fee = (
(25 + 9) * len(destination_outputs)) + sum_data_output_size
if not (encoding == 'p2sh' and p2sh_pretx_txid):
inputs, change_quantity, n_btc_in, n_final_fee = construct_coin_selection(
encoding, data_array, source, allow_unconfirmed_inputs,
unspent_tx_hash, custom_inputs, fee_per_kb, estimate_fee_per_kb,
estimate_fee_per_kb_nblocks, exact_fee, size_for_fee, fee_provided,
destination_btc_out, data_btc_out, regular_dust_size,
disable_utxo_locks)
btc_in = n_btc_in
final_fee = n_final_fee
else:
# when encoding is P2SH and the pretx txid is passed we can skip coinselection
inputs, change_quantity = None, None
'''Finish'''
if change_quantity:
change_output = (source_address, change_quantity)
else:
change_output = None
unsigned_pretx_hex = None
unsigned_tx_hex = None
pretx_txid = None
if encoding == 'p2sh':
assert not (segwit and p2sh_pretx_txid
) # shouldn't do old style with segwit enabled
if p2sh_pretx_txid:
pretx_txid = p2sh_pretx_txid if isinstance(
p2sh_pretx_txid,
bytes) else binascii.unhexlify(p2sh_pretx_txid)
unsigned_pretx = None
else:
destination_value_sum = sum(
[value for (destination, value) in destination_outputs])
source_value = destination_value_sum
if change_output:
# add the difference between source and destination to the change
change_value = change_output[1] + (destination_value_sum -
source_value)
change_output = (change_output[0], change_value)
unsigned_pretx = serializer.serialise_p2sh_pretx(
inputs,
source=source_address,
source_value=source_value,
data_output=data_output,
change_output=change_output,
pubkey=dust_return_pubkey,
multisig_pubkeys=p2sh_source_multisig_pubkeys,
multisig_pubkeys_required=p2sh_source_multisig_pubkeys_required
)
unsigned_pretx_hex = binascii.hexlify(unsigned_pretx).decode(
'utf-8')
# with segwit we already know the txid and can return both
if segwit:
#pretx_txid = hashlib.sha256(unsigned_pretx).digest() # this should be segwit txid
ptx = CTransaction.stream_deserialize(
io.BytesIO(unsigned_pretx)) # could be a non-segwit tx anyways
txid_ba = bytearray(ptx.GetTxid())
txid_ba.reverse()
pretx_txid = bytes(
txid_ba) # gonna leave the malleability problem to upstream
logger.getChild('p2shdebug').debug('pretx_txid %s' % pretx_txid)
print('pretx txid:', binascii.hexlify(pretx_txid))
if unsigned_pretx:
# we set a long lock on this, don't want other TXs to spend from it
UTXO_P2SH_ENCODING_LOCKS[make_outkey_vin(unsigned_pretx, 0)] = True
# only generate the data TX if we have the pretx txId
if pretx_txid:
source_input = None
if script.is_p2sh(source):
source_input = select_any_coin_from_source(source)
if not source_input:
raise exceptions.TransactionError(
'Unable to select source input for p2sh source address'
)
unsigned_datatx = serializer.serialise_p2sh_datatx(
pretx_txid,
source=source_address,
source_input=source_input,
destination_outputs=destination_outputs,
data_output=data_output,
pubkey=dust_return_pubkey,
multisig_pubkeys=p2sh_source_multisig_pubkeys,
multisig_pubkeys_required=p2sh_source_multisig_pubkeys_required
)
unsigned_datatx_hex = binascii.hexlify(unsigned_datatx).decode(
'utf-8')
# let the rest of the code work it's magic on the data tx
unsigned_tx_hex = unsigned_datatx_hex
else:
# we're just gonna return the pretx, it doesn't require any of the further checks
logger.warn('old_style_api = %s' % old_style_api)
return return_result([unsigned_pretx_hex],
old_style_api=old_style_api)
else:
# Serialise inputs and outputs.
unsigned_tx = serializer.serialise(
encoding,
inputs,
destination_outputs,
data_output,
change_output,
dust_return_pubkey=dust_return_pubkey)
unsigned_tx_hex = binascii.hexlify(unsigned_tx).decode('utf-8')
'''Sanity Check'''
# Desired transaction info.
(desired_source, desired_destination_outputs, desired_data) = tx_info
desired_source = script.make_canonical(desired_source)
desired_destination = script.make_canonical(
desired_destination_outputs[0]
[0]) if desired_destination_outputs else ''
# NOTE: Include change in destinations for BTC transactions.
# if change_output and not desired_data and desired_destination != config.UNSPENDABLE:
# if desired_destination == '':
# desired_destination = desired_source
# else:
# desired_destination += '-{}'.format(desired_source)
# NOTE
if desired_data == None:
desired_data = b''
# Parsed transaction info.
try:
if pretx_txid and unsigned_pretx:
backend.cache_pretx(pretx_txid, unsigned_pretx)
parsed_source, parsed_destination, x, y, parsed_data, extra = blocks._get_tx_info(
unsigned_tx_hex, p2sh_is_segwit=script.is_bech32(desired_source))
if encoding == 'p2sh':
# make_canonical can't determine the address, so we blindly change the desired to the parsed
desired_source = parsed_source
if pretx_txid and unsigned_pretx:
backend.clear_pretx(pretx_txid)
except exceptions.BTCOnlyError:
# Skip BTC‐only transactions.
if extended_tx_info:
return {
'btc_in': btc_in,
'btc_out': destination_btc_out + data_btc_out,
'btc_change': change_quantity,
'btc_fee': final_fee,
'tx_hex': unsigned_tx_hex,
}
logger.getChild('p2shdebug').debug('BTC-ONLY')
return return_result([unsigned_pretx_hex, unsigned_tx_hex],
old_style_api=old_style_api)
desired_source = script.make_canonical(desired_source)
# Check desired info against parsed info.
desired = (desired_source, desired_destination, desired_data)
parsed = (parsed_source, parsed_destination, parsed_data)
if desired != parsed:
# Unlock (revert) UTXO locks
if UTXO_LOCKS is not None and inputs:
for input in inputs:
UTXO_LOCKS[source].pop(make_outkey(input), None)
raise exceptions.TransactionError(
'Constructed transaction does not parse correctly: {} ≠ {}'.format(
desired, parsed))
if extended_tx_info:
return {
'btc_in': btc_in,
'btc_out': destination_btc_out + data_btc_out,
'btc_change': change_quantity,
'btc_fee': final_fee,
'tx_hex': unsigned_tx_hex,
}
return return_result([unsigned_pretx_hex, unsigned_tx_hex],
old_style_api=old_style_api)