lbry-sdk/lbrynet/wallet/transaction.py

346 lines
12 KiB
Python

import io
import six
import logging
from binascii import hexlify
from typing import List
from lbrynet.wallet import get_wallet_manager
from lbrynet.wallet.bcd_data_stream import BCDataStream
from lbrynet.wallet.hash import sha256, hash160_to_address, claim_id_hash
from lbrynet.wallet.script import InputScript, OutputScript
from lbrynet.wallet.wallet import Wallet
log = logging.getLogger()
NULL_HASH = '\x00'*32
class InputOutput(object):
@property
def fee(self):
""" Fee based on size of the input / output. """
return get_wallet_manager().fee_per_byte * self.size
@property
def size(self):
""" Size of this input / output in bytes. """
stream = BCDataStream()
self.serialize_to(stream)
return len(stream.get_bytes())
def serialize_to(self, stream):
raise NotImplemented
class Input(InputOutput):
NULL_SIGNATURE = '0'*72
NULL_PUBLIC_KEY = '0'*33
def __init__(self, output_or_txid_index, script, sequence=0xFFFFFFFF):
if isinstance(output_or_txid_index, Output):
self.output = output_or_txid_index # type: Output
self.output_txid = self.output.transaction.hash
self.output_index = self.output.index
else:
self.output = None # type: Output
self.output_txid, self.output_index = output_or_txid_index
self.sequence = sequence
self.is_coinbase = self.output_txid == NULL_HASH
self.coinbase = script if self.is_coinbase else None
self.script = script if not self.is_coinbase else None # type: InputScript
def link_output(self, output):
assert self.output is None
assert self.output_txid == output.transaction.id
assert self.output_index == output.index
self.output = output
@property
def amount(self):
""" Amount this input adds to the transaction. """
if self.output is None:
raise ValueError('Cannot get input value without referenced output.')
return self.output.amount
@property
def effective_amount(self):
""" Amount minus fee. """
return self.amount - self.fee
def __lt__(self, other):
return self.effective_amount < other.effective_amount
@classmethod
def deserialize_from(cls, stream):
txid = stream.read(32)
index = stream.read_uint32()
script = stream.read_string()
sequence = stream.read_uint32()
return cls(
(txid, index),
InputScript(script) if not txid == NULL_HASH else script,
sequence
)
def serialize_to(self, stream, alternate_script=None):
stream.write(self.output_txid)
stream.write_uint32(self.output_index)
if alternate_script is not None:
stream.write_string(alternate_script)
else:
if self.is_coinbase:
stream.write_string(self.coinbase)
else:
stream.write_string(self.script.source)
stream.write_uint32(self.sequence)
def to_python_source(self):
return (
u"InputScript(\n"
u" (output_txid=unhexlify('{}'), output_index={}),\n"
u" script=unhexlify('{}')\n"
u" # tokens: {}\n"
u")").format(
hexlify(self.output_txid), self.output_index,
hexlify(self.coinbase) if self.is_coinbase else hexlify(self.script.source),
repr(self.script.tokens)
)
class Output(InputOutput):
def __init__(self, transaction, index, amount, script):
self.transaction = transaction # type: Transaction
self.index = index # type: int
self.amount = amount # type: int
self.script = script # type: OutputScript
self._effective_amount = None # type: int
def __lt__(self, other):
return self.effective_amount < other.effective_amount
def _add_and_return(self):
self.transaction.add_outputs([self])
return self
@classmethod
def pay_pubkey_hash(cls, transaction, index, amount, pubkey_hash):
return cls(
transaction, index, amount,
OutputScript.pay_pubkey_hash(pubkey_hash)
)._add_and_return()
@classmethod
def pay_claim_name_pubkey_hash(cls, transaction, index, amount, claim_name, claim, pubkey_hash):
return cls(
transaction, index, amount,
OutputScript.pay_claim_name_pubkey_hash(claim_name, claim, pubkey_hash)
)._add_and_return()
def spend(self, signature=Input.NULL_SIGNATURE, pubkey=Input.NULL_PUBLIC_KEY):
""" Create the input to spend this output."""
assert self.script.is_pay_pubkey_hash, 'Attempting to spend unsupported output.'
script = InputScript.redeem_pubkey_hash(signature, pubkey)
return Input(self, script)
@property
def effective_amount(self):
""" Amount minus fees it would take to spend this output. """
if self._effective_amount is None:
txi = self.spend()
self._effective_amount = txi.effective_amount
return self._effective_amount
@classmethod
def deserialize_from(cls, stream, transaction, index):
return cls(
transaction=transaction,
index=index,
amount=stream.read_uint64(),
script=OutputScript(stream.read_string())
)
def serialize_to(self, stream):
stream.write_uint64(self.amount)
stream.write_string(self.script.source)
def to_python_source(self):
return (
u"OutputScript(tx, index={}, amount={},\n"
u" script=unhexlify('{}')\n"
u" # tokens: {}\n"
u")").format(
self.index, self.amount, hexlify(self.script.source), repr(self.script.tokens))
class Transaction:
def __init__(self, raw=None, version=1, locktime=0, height=None, is_saved=False):
self._raw = raw
self._hash = None
self._id = None
self.version = version # type: int
self.locktime = locktime # type: int
self.height = height # type: int
self.inputs = [] # type: List[Input]
self.outputs = [] # type: List[Output]
self.is_saved = is_saved # type: bool
if raw is not None:
self._deserialize()
@property
def id(self):
if self._id is None:
self._id = self.hash[::-1]
return self._id
@property
def hash(self):
if self._hash is None:
self._hash = sha256(sha256(self.raw))
return self._hash
@property
def raw(self):
if self._raw is None:
self._raw = self._serialize()
return self._raw
def _reset(self):
self._raw = None
self._hash = None
self._id = None
def get_claim_id(self, output_index):
script = self.outputs[output_index]
assert script.script.is_claim_name(), 'Not a name claim.'
return claim_id_hash(self.hash, output_index)
@property
def is_complete(self):
s, r = self.signature_count()
return r == s
@property
def fee(self):
""" Fee that will actually be paid."""
return self.input_sum - self.output_sum
@property
def size(self):
""" Size in bytes of the entire transaction. """
return len(self.raw)
@property
def base_size(self):
""" Size in bytes of transaction meta data and all outputs; without inputs. """
return len(self._serialize(with_inputs=False))
@property
def base_fee(self):
""" Fee for the transaction header and all outputs; without inputs. """
byte_fee = get_wallet_manager().fee_per_byte * self.base_size
return max(byte_fee, self.claim_name_fee)
@property
def claim_name_fee(self):
char_fee = get_wallet_manager().fee_per_name_char
fee = 0
for output in self.outputs:
if output.script.is_claim_name:
fee += len(output.script.values['claim_name']) * char_fee
return fee
def _serialize(self, with_inputs=True):
stream = BCDataStream()
stream.write_uint32(self.version)
if with_inputs:
stream.write_compact_size(len(self.inputs))
for txin in self.inputs:
txin.serialize_to(stream)
stream.write_compact_size(len(self.outputs))
for txout in self.outputs:
txout.serialize_to(stream)
stream.write_uint32(self.locktime)
return stream.get_bytes()
def _serialize_for_signature(self, signing_input):
stream = BCDataStream()
stream.write_uint32(self.version)
stream.write_compact_size(len(self.inputs))
for i, txin in enumerate(self.inputs):
if signing_input == i:
txin.serialize_to(stream, txin.output.script.source)
else:
txin.serialize_to(stream, b'')
stream.write_compact_size(len(self.outputs))
for txout in self.outputs:
txout.serialize_to(stream)
stream.write_uint32(self.locktime)
stream.write_uint32(1) # signature hash type: SIGHASH_ALL
return stream.get_bytes()
def _deserialize(self):
if self._raw is not None:
stream = BCDataStream(self._raw)
self.version = stream.read_uint32()
input_count = stream.read_compact_size()
self.inputs = [Input.deserialize_from(stream) for _ in range(input_count)]
output_count = stream.read_compact_size()
self.outputs = [Output.deserialize_from(stream, self, i) for i in range(output_count)]
self.locktime = stream.read_uint32()
def add_inputs(self, inputs):
self.inputs.extend(inputs)
self._reset()
def add_outputs(self, outputs):
self.outputs.extend(outputs)
self._reset()
def sign(self, wallet): # type: (Wallet) -> bool
for i, txi in enumerate(self.inputs):
txo_script = txi.output.script
if txo_script.is_pay_pubkey_hash:
address = hash160_to_address(txo_script.values['pubkey_hash'], wallet.chain)
private_key = wallet.get_private_key_for_address(address)
tx = self._serialize_for_signature(i)
txi.script.values['signature'] = private_key.sign(tx)+six.int2byte(1)
txi.script.values['pubkey'] = private_key.public_key.pubkey_bytes
txi.script.generate()
self._reset()
return True
def sort(self):
# See https://github.com/kristovatlas/rfc/blob/master/bips/bip-li01.mediawiki
self.inputs.sort(key=lambda i: (i['prevout_hash'], i['prevout_n']))
self.outputs.sort(key=lambda o: (o[2], pay_script(o[0], o[1])))
@property
def input_sum(self):
return sum(i.amount for i in self.inputs)
@property
def output_sum(self):
return sum(o.amount for o in self.outputs)
def to_python_source(self):
s = io.StringIO()
s.write(u'tx = Transaction(version={}, locktime={}, height={})\n'.format(
self.version, self.locktime, self.height
))
for txi in self.inputs:
s.write(u'tx.add_input(')
s.write(txi.to_python_source())
s.write(u')\n')
for txo in self.outputs:
s.write(u'tx.add_output(')
s.write(txo.to_python_source())
s.write(u')\n')
s.write(u'# tx.id: unhexlify("{}")\n'.format(hexlify(self.id)))
s.write(u'# tx.raw: unhexlify("{}")\n'.format(hexlify(self.raw)))
return s.getvalue()