LBRY-Vault/lib/transaction.py
Neil Booth 93bb09230c Track tx size directly; calculate fees from that
This has several advantages.  Fee calculation is now very fast,
as we don't need to keep reserializing the tx.  Another is that
we can reason about the fees after adding a change output without
having to add it, recalculate the tx fee, and remove it again.
2015-11-29 15:40:11 +09:00

847 lines
30 KiB
Python

#!/usr/bin/env python
#
# Electrum - lightweight Bitcoin client
# Copyright (C) 2011 thomasv@gitorious
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# Note: The deserialization code originally comes from ABE.
import bitcoin
from bitcoin import *
from util import print_error, profiler
import time
import sys
import struct
#
# Workalike python implementation of Bitcoin's CDataStream class.
#
import struct
import StringIO
import random
NO_SIGNATURE = 'ff'
class SerializationError(Exception):
""" Thrown when there's a problem deserializing or serializing """
class BCDataStream(object):
def __init__(self):
self.input = None
self.read_cursor = 0
def clear(self):
self.input = None
self.read_cursor = 0
def write(self, bytes): # Initialize with string of bytes
if self.input is None:
self.input = bytes
else:
self.input += bytes
def read_string(self):
# Strings are encoded depending on length:
# 0 to 252 : 1-byte-length followed by bytes (if any)
# 253 to 65,535 : byte'253' 2-byte-length followed by bytes
# 65,536 to 4,294,967,295 : byte '254' 4-byte-length followed by bytes
# ... and the Bitcoin client is coded to understand:
# greater than 4,294,967,295 : byte '255' 8-byte-length followed by bytes of string
# ... but I don't think it actually handles any strings that big.
if self.input is None:
raise SerializationError("call write(bytes) before trying to deserialize")
try:
length = self.read_compact_size()
except IndexError:
raise SerializationError("attempt to read past end of buffer")
return self.read_bytes(length)
def write_string(self, string):
# Length-encoded as with read-string
self.write_compact_size(len(string))
self.write(string)
def read_bytes(self, length):
try:
result = self.input[self.read_cursor:self.read_cursor+length]
self.read_cursor += length
return result
except IndexError:
raise SerializationError("attempt to read past end of buffer")
return ''
def read_boolean(self): return self.read_bytes(1)[0] != chr(0)
def read_int16(self): return self._read_num('<h')
def read_uint16(self): return self._read_num('<H')
def read_int32(self): return self._read_num('<i')
def read_uint32(self): return self._read_num('<I')
def read_int64(self): return self._read_num('<q')
def read_uint64(self): return self._read_num('<Q')
def write_boolean(self, val): return self.write(chr(1) if val else chr(0))
def write_int16(self, val): return self._write_num('<h', val)
def write_uint16(self, val): return self._write_num('<H', val)
def write_int32(self, val): return self._write_num('<i', val)
def write_uint32(self, val): return self._write_num('<I', val)
def write_int64(self, val): return self._write_num('<q', val)
def write_uint64(self, val): return self._write_num('<Q', val)
def read_compact_size(self):
size = ord(self.input[self.read_cursor])
self.read_cursor += 1
if size == 253:
size = self._read_num('<H')
elif size == 254:
size = self._read_num('<I')
elif size == 255:
size = self._read_num('<Q')
return size
def write_compact_size(self, size):
if size < 0:
raise SerializationError("attempt to write size < 0")
elif size < 253:
self.write(chr(size))
elif size < 2**16:
self.write('\xfd')
self._write_num('<H', size)
elif size < 2**32:
self.write('\xfe')
self._write_num('<I', size)
elif size < 2**64:
self.write('\xff')
self._write_num('<Q', size)
def _read_num(self, format):
(i,) = struct.unpack_from(format, self.input, self.read_cursor)
self.read_cursor += struct.calcsize(format)
return i
def _write_num(self, format, num):
s = struct.pack(format, num)
self.write(s)
#
# enum-like type
# From the Python Cookbook, downloaded from http://code.activestate.com/recipes/67107/
#
import types, string, exceptions
class EnumException(exceptions.Exception):
pass
class Enumeration:
def __init__(self, name, enumList):
self.__doc__ = name
lookup = { }
reverseLookup = { }
i = 0
uniqueNames = [ ]
uniqueValues = [ ]
for x in enumList:
if type(x) == types.TupleType:
x, i = x
if type(x) != types.StringType:
raise EnumException, "enum name is not a string: " + x
if type(i) != types.IntType:
raise EnumException, "enum value is not an integer: " + i
if x in uniqueNames:
raise EnumException, "enum name is not unique: " + x
if i in uniqueValues:
raise EnumException, "enum value is not unique for " + x
uniqueNames.append(x)
uniqueValues.append(i)
lookup[x] = i
reverseLookup[i] = x
i = i + 1
self.lookup = lookup
self.reverseLookup = reverseLookup
def __getattr__(self, attr):
if not self.lookup.has_key(attr):
raise AttributeError
return self.lookup[attr]
def whatis(self, value):
return self.reverseLookup[value]
# This function comes from bitcointools, bct-LICENSE.txt.
def long_hex(bytes):
return bytes.encode('hex_codec')
# This function comes from bitcointools, bct-LICENSE.txt.
def short_hex(bytes):
t = bytes.encode('hex_codec')
if len(t) < 11:
return t
return t[0:4]+"..."+t[-4:]
opcodes = Enumeration("Opcodes", [
("OP_0", 0), ("OP_PUSHDATA1",76), "OP_PUSHDATA2", "OP_PUSHDATA4", "OP_1NEGATE", "OP_RESERVED",
"OP_1", "OP_2", "OP_3", "OP_4", "OP_5", "OP_6", "OP_7",
"OP_8", "OP_9", "OP_10", "OP_11", "OP_12", "OP_13", "OP_14", "OP_15", "OP_16",
"OP_NOP", "OP_VER", "OP_IF", "OP_NOTIF", "OP_VERIF", "OP_VERNOTIF", "OP_ELSE", "OP_ENDIF", "OP_VERIFY",
"OP_RETURN", "OP_TOALTSTACK", "OP_FROMALTSTACK", "OP_2DROP", "OP_2DUP", "OP_3DUP", "OP_2OVER", "OP_2ROT", "OP_2SWAP",
"OP_IFDUP", "OP_DEPTH", "OP_DROP", "OP_DUP", "OP_NIP", "OP_OVER", "OP_PICK", "OP_ROLL", "OP_ROT",
"OP_SWAP", "OP_TUCK", "OP_CAT", "OP_SUBSTR", "OP_LEFT", "OP_RIGHT", "OP_SIZE", "OP_INVERT", "OP_AND",
"OP_OR", "OP_XOR", "OP_EQUAL", "OP_EQUALVERIFY", "OP_RESERVED1", "OP_RESERVED2", "OP_1ADD", "OP_1SUB", "OP_2MUL",
"OP_2DIV", "OP_NEGATE", "OP_ABS", "OP_NOT", "OP_0NOTEQUAL", "OP_ADD", "OP_SUB", "OP_MUL", "OP_DIV",
"OP_MOD", "OP_LSHIFT", "OP_RSHIFT", "OP_BOOLAND", "OP_BOOLOR",
"OP_NUMEQUAL", "OP_NUMEQUALVERIFY", "OP_NUMNOTEQUAL", "OP_LESSTHAN",
"OP_GREATERTHAN", "OP_LESSTHANOREQUAL", "OP_GREATERTHANOREQUAL", "OP_MIN", "OP_MAX",
"OP_WITHIN", "OP_RIPEMD160", "OP_SHA1", "OP_SHA256", "OP_HASH160",
"OP_HASH256", "OP_CODESEPARATOR", "OP_CHECKSIG", "OP_CHECKSIGVERIFY", "OP_CHECKMULTISIG",
"OP_CHECKMULTISIGVERIFY",
("OP_SINGLEBYTE_END", 0xF0),
("OP_DOUBLEBYTE_BEGIN", 0xF000),
"OP_PUBKEY", "OP_PUBKEYHASH",
("OP_INVALIDOPCODE", 0xFFFF),
])
def script_GetOp(bytes):
i = 0
while i < len(bytes):
vch = None
opcode = ord(bytes[i])
i += 1
if opcode >= opcodes.OP_SINGLEBYTE_END:
opcode <<= 8
opcode |= ord(bytes[i])
i += 1
if opcode <= opcodes.OP_PUSHDATA4:
nSize = opcode
if opcode == opcodes.OP_PUSHDATA1:
nSize = ord(bytes[i])
i += 1
elif opcode == opcodes.OP_PUSHDATA2:
(nSize,) = struct.unpack_from('<H', bytes, i)
i += 2
elif opcode == opcodes.OP_PUSHDATA4:
(nSize,) = struct.unpack_from('<I', bytes, i)
i += 4
vch = bytes[i:i+nSize]
i += nSize
yield (opcode, vch, i)
def script_GetOpName(opcode):
return (opcodes.whatis(opcode)).replace("OP_", "")
def decode_script(bytes):
result = ''
for (opcode, vch, i) in script_GetOp(bytes):
if len(result) > 0: result += " "
if opcode <= opcodes.OP_PUSHDATA4:
result += "%d:"%(opcode,)
result += short_hex(vch)
else:
result += script_GetOpName(opcode)
return result
def match_decoded(decoded, to_match):
if len(decoded) != len(to_match):
return False;
for i in range(len(decoded)):
if to_match[i] == opcodes.OP_PUSHDATA4 and decoded[i][0] <= opcodes.OP_PUSHDATA4 and decoded[i][0]>0:
continue # Opcodes below OP_PUSHDATA4 all just push data onto stack, and are equivalent.
if to_match[i] != decoded[i][0]:
return False
return True
def parse_sig(x_sig):
s = []
for sig in x_sig:
if sig[-2:] == '01':
s.append(sig[:-2])
else:
assert sig == NO_SIGNATURE
s.append(None)
return s
def is_extended_pubkey(x_pubkey):
return x_pubkey[0:2] in ['fe', 'ff']
def x_to_xpub(x_pubkey):
if x_pubkey[0:2] == 'ff':
from account import BIP32_Account
xpub, s = BIP32_Account.parse_xpubkey(x_pubkey)
return xpub
def parse_xpub(x_pubkey):
if x_pubkey[0:2] in ['02','03','04']:
pubkey = x_pubkey
elif x_pubkey[0:2] == 'ff':
from account import BIP32_Account
xpub, s = BIP32_Account.parse_xpubkey(x_pubkey)
pubkey = BIP32_Account.derive_pubkey_from_xpub(xpub, s[0], s[1])
elif x_pubkey[0:2] == 'fe':
from account import OldAccount
mpk, s = OldAccount.parse_xpubkey(x_pubkey)
pubkey = OldAccount.get_pubkey_from_mpk(mpk.decode('hex'), s[0], s[1])
elif x_pubkey[0:2] == 'fd':
addrtype = ord(x_pubkey[2:4].decode('hex'))
hash160 = x_pubkey[4:].decode('hex')
pubkey = None
address = hash_160_to_bc_address(hash160, addrtype)
else:
raise BaseException("Cannnot parse pubkey")
if pubkey:
address = public_key_to_bc_address(pubkey.decode('hex'))
return pubkey, address
def parse_scriptSig(d, bytes):
try:
decoded = [ x for x in script_GetOp(bytes) ]
except Exception:
# coinbase transactions raise an exception
print_error("cannot find address in input script", bytes.encode('hex'))
return
# payto_pubkey
match = [ opcodes.OP_PUSHDATA4 ]
if match_decoded(decoded, match):
sig = decoded[0][1].encode('hex')
d['address'] = "(pubkey)"
d['signatures'] = [sig]
d['num_sig'] = 1
d['x_pubkeys'] = ["(pubkey)"]
d['pubkeys'] = ["(pubkey)"]
return
# non-generated TxIn transactions push a signature
# (seventy-something bytes) and then their public key
# (65 bytes) onto the stack:
match = [ opcodes.OP_PUSHDATA4, opcodes.OP_PUSHDATA4 ]
if match_decoded(decoded, match):
sig = decoded[0][1].encode('hex')
x_pubkey = decoded[1][1].encode('hex')
try:
signatures = parse_sig([sig])
pubkey, address = parse_xpub(x_pubkey)
except:
import traceback
traceback.print_exc(file=sys.stdout)
print_error("cannot find address in input script", bytes.encode('hex'))
return
d['signatures'] = signatures
d['x_pubkeys'] = [x_pubkey]
d['num_sig'] = 1
d['pubkeys'] = [pubkey]
d['address'] = address
return
# p2sh transaction, m of n
match = [ opcodes.OP_0 ] + [ opcodes.OP_PUSHDATA4 ] * (len(decoded) - 1)
if not match_decoded(decoded, match):
print_error("cannot find address in input script", bytes.encode('hex'))
return
x_sig = [x[1].encode('hex') for x in decoded[1:-1]]
dec2 = [ x for x in script_GetOp(decoded[-1][1]) ]
m = dec2[0][0] - opcodes.OP_1 + 1
n = dec2[-2][0] - opcodes.OP_1 + 1
op_m = opcodes.OP_1 + m - 1
op_n = opcodes.OP_1 + n - 1
match_multisig = [ op_m ] + [opcodes.OP_PUSHDATA4]*n + [ op_n, opcodes.OP_CHECKMULTISIG ]
if not match_decoded(dec2, match_multisig):
print_error("cannot find address in input script", bytes.encode('hex'))
return
x_pubkeys = map(lambda x: x[1].encode('hex'), dec2[1:-2])
pubkeys = [parse_xpub(x)[0] for x in x_pubkeys] # xpub, addr = parse_xpub()
redeemScript = Transaction.multisig_script(pubkeys, m)
# write result in d
d['num_sig'] = m
d['signatures'] = parse_sig(x_sig)
d['x_pubkeys'] = x_pubkeys
d['pubkeys'] = pubkeys
d['redeemScript'] = redeemScript
d['address'] = hash_160_to_bc_address(hash_160(redeemScript.decode('hex')), 5)
def get_address_from_output_script(bytes):
decoded = [ x for x in script_GetOp(bytes) ]
# The Genesis Block, self-payments, and pay-by-IP-address payments look like:
# 65 BYTES:... CHECKSIG
match = [ opcodes.OP_PUSHDATA4, opcodes.OP_CHECKSIG ]
if match_decoded(decoded, match):
return 'pubkey', decoded[0][1].encode('hex')
# Pay-by-Bitcoin-address TxOuts look like:
# DUP HASH160 20 BYTES:... EQUALVERIFY CHECKSIG
match = [ opcodes.OP_DUP, opcodes.OP_HASH160, opcodes.OP_PUSHDATA4, opcodes.OP_EQUALVERIFY, opcodes.OP_CHECKSIG ]
if match_decoded(decoded, match):
return 'address', hash_160_to_bc_address(decoded[2][1])
# p2sh
match = [ opcodes.OP_HASH160, opcodes.OP_PUSHDATA4, opcodes.OP_EQUAL ]
if match_decoded(decoded, match):
return 'address', hash_160_to_bc_address(decoded[1][1],5)
return 'script', bytes
def parse_input(vds):
d = {}
prevout_hash = hash_encode(vds.read_bytes(32))
prevout_n = vds.read_uint32()
scriptSig = vds.read_bytes(vds.read_compact_size())
d['scriptSig'] = scriptSig.encode('hex')
sequence = vds.read_uint32()
if prevout_hash == '00'*32:
d['is_coinbase'] = True
else:
d['is_coinbase'] = False
d['prevout_hash'] = prevout_hash
d['prevout_n'] = prevout_n
d['sequence'] = sequence
d['pubkeys'] = []
d['signatures'] = {}
d['address'] = None
if scriptSig:
parse_scriptSig(d, scriptSig)
return d
def parse_output(vds, i):
d = {}
d['value'] = vds.read_int64()
scriptPubKey = vds.read_bytes(vds.read_compact_size())
d['type'], d['address'] = get_address_from_output_script(scriptPubKey)
d['scriptPubKey'] = scriptPubKey.encode('hex')
d['prevout_n'] = i
return d
def deserialize(raw):
vds = BCDataStream()
vds.write(raw.decode('hex'))
d = {}
start = vds.read_cursor
d['version'] = vds.read_int32()
n_vin = vds.read_compact_size()
d['inputs'] = list(parse_input(vds) for i in xrange(n_vin))
n_vout = vds.read_compact_size()
d['outputs'] = list(parse_output(vds,i) for i in xrange(n_vout))
d['lockTime'] = vds.read_uint32()
return d
def push_script(x):
return op_push(len(x)/2) + x
class Transaction:
def __str__(self):
if self.raw is None:
self.raw = self.serialize()
return self.raw
def __init__(self, raw):
if raw is None:
self.raw = None
elif type(raw) in [str, unicode]:
self.raw = raw.strip() if raw else None
elif type(raw) is dict:
self.raw = raw['hex']
else:
raise BaseException("cannot initialize transaction", raw)
self.inputs = None
def update(self, raw):
self.raw = raw
self.inputs = None
self.deserialize()
def update_signatures(self, raw):
"""Add new signatures to a transaction"""
d = deserialize(raw)
for i, txin in enumerate(self.inputs):
sigs1 = txin.get('signatures')
sigs2 = d['inputs'][i].get('signatures')
for sig in sigs2:
if sig in sigs1:
continue
for_sig = Hash(self.tx_for_sig(i).decode('hex'))
# der to string
order = ecdsa.ecdsa.generator_secp256k1.order()
r, s = ecdsa.util.sigdecode_der(sig.decode('hex'), order)
sig_string = ecdsa.util.sigencode_string(r, s, order)
pubkeys = txin.get('pubkeys')
compressed = True
for recid in range(4):
public_key = MyVerifyingKey.from_signature(sig_string, recid, for_sig, curve = SECP256k1)
pubkey = point_to_ser(public_key.pubkey.point, compressed).encode('hex')
if pubkey in pubkeys:
public_key.verify_digest(sig_string, for_sig, sigdecode = ecdsa.util.sigdecode_string)
j = pubkeys.index(pubkey)
print_error("adding sig", i, j, pubkey, sig)
self.inputs[i]['signatures'][j] = sig
self.inputs[i]['x_pubkeys'][j] = pubkey
break
# redo raw
self.raw = self.serialize()
def deserialize(self):
if self.raw is None:
self.raw = self.serialize()
if self.inputs is not None:
return
d = deserialize(self.raw)
self.inputs = d['inputs']
self.outputs = [(x['type'], x['address'], x['value']) for x in d['outputs']]
self.locktime = d['lockTime']
return d
@classmethod
def from_io(klass, inputs, outputs, locktime=0):
self = klass(None)
self.inputs = inputs
self.outputs = outputs
self.locktime = locktime
return self
@classmethod
def sweep(klass, privkeys, network, to_address, fee):
inputs = []
keypairs = {}
for privkey in privkeys:
pubkey = public_key_from_private_key(privkey)
address = address_from_private_key(privkey)
u = network.synchronous_get(('blockchain.address.listunspent',[address]))
pay_script = klass.pay_script('address', address)
for item in u:
item['scriptPubKey'] = pay_script
item['redeemPubkey'] = pubkey
item['address'] = address
item['prevout_hash'] = item['tx_hash']
item['prevout_n'] = item['tx_pos']
item['pubkeys'] = [pubkey]
item['x_pubkeys'] = [pubkey]
item['signatures'] = [None]
item['num_sig'] = 1
inputs += u
keypairs[pubkey] = privkey
if not inputs:
return
total = sum(i.get('value') for i in inputs) - fee
outputs = [('address', to_address, total)]
self = klass.from_io(inputs, outputs)
self.sign(keypairs)
return self
@classmethod
def multisig_script(klass, public_keys, m):
n = len(public_keys)
assert n <= 15
assert m <= n
op_m = format(opcodes.OP_1 + m - 1, 'x')
op_n = format(opcodes.OP_1 + n - 1, 'x')
keylist = [op_push(len(k)/2) + k for k in public_keys]
return op_m + ''.join(keylist) + op_n + 'ae'
@classmethod
def pay_script(self, output_type, addr):
if output_type == 'script':
return addr.encode('hex')
elif output_type == 'address':
addrtype, hash_160 = bc_address_to_hash_160(addr)
if addrtype == 0:
script = '76a9' # op_dup, op_hash_160
script += push_script(hash_160.encode('hex'))
script += '88ac' # op_equalverify, op_checksig
elif addrtype == 5:
script = 'a9' # op_hash_160
script += push_script(hash_160.encode('hex'))
script += '87' # op_equal
else:
raise
else:
raise
return script
@classmethod
def input_script(self, txin, i, for_sig):
# for_sig:
# -1 : do not sign, estimate length
# i>=0 : serialized tx for signing input i
# None : add all known signatures
p2sh = txin.get('redeemScript') is not None
num_sig = txin['num_sig'] if p2sh else 1
address = txin['address']
x_signatures = txin['signatures']
signatures = filter(None, x_signatures)
is_complete = len(signatures) == num_sig
if for_sig in [-1, None]:
# if we have enough signatures, we use the actual pubkeys
# use extended pubkeys (with bip32 derivation)
if for_sig == -1:
# we assume that signature will be 0x48 bytes long
pubkeys = txin['pubkeys']
sig_list = [ "00" * 0x48 ] * num_sig
elif is_complete:
pubkeys = txin['pubkeys']
sig_list = ((sig + '01') for sig in signatures)
else:
pubkeys = txin['x_pubkeys']
sig_list = ((sig + '01') if sig else NO_SIGNATURE for sig in x_signatures)
script = ''.join(push_script(x) for x in sig_list)
if not p2sh:
x_pubkey = pubkeys[0]
if x_pubkey is None:
addrtype, h160 = bc_address_to_hash_160(txin['address'])
x_pubkey = 'fd' + (chr(addrtype) + h160).encode('hex')
script += push_script(x_pubkey)
else:
script = '00' + script # put op_0 in front of script
redeem_script = self.multisig_script(pubkeys, num_sig)
script += push_script(redeem_script)
elif for_sig==i:
script = txin['redeemScript'] if p2sh else self.pay_script('address', address)
else:
script = ''
return script
@classmethod
def serialize_input(self, txin, i, for_sig):
# Prev hash and index
s = txin['prevout_hash'].decode('hex')[::-1].encode('hex')
s = int_to_hex(txin['prevout_n'], 4)
# Script length, script, sequence
script = self.input_script(txin, i, for_sig)
s += var_int(len(script) / 2)
s += script
s += "ffffffff"
return s
def BIP_LI01_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], self.pay_script(o[0], o[1])))
def serialize(self, for_sig=None):
inputs = self.inputs
outputs = self.outputs
s = int_to_hex(1,4) # version
s += var_int( len(inputs) ) # number of inputs
for i, txin in enumerate(inputs):
s += self.serialize_input(txin, i, for_sig)
s += var_int( len(outputs) ) # number of outputs
for output in outputs:
output_type, addr, amount = output
s += int_to_hex( amount, 8) # amount
script = self.pay_script(output_type, addr)
s += var_int( len(script)/2 ) # script length
s += script # script
s += int_to_hex(0,4) # lock time
if for_sig is not None and for_sig != -1:
s += int_to_hex(1, 4) # hash type
return s
def tx_for_sig(self,i):
return self.serialize(for_sig = i)
def hash(self):
return Hash(self.raw.decode('hex') )[::-1].encode('hex')
def add_input(self, input):
self.inputs.append(input)
self.raw = None
def input_value(self):
return sum(x['value'] for x in self.inputs)
def output_value(self):
return sum( val for tp,addr,val in self.outputs)
def get_fee(self):
return self.input_value() - self.output_value()
@classmethod
def fee_for_size(self, fee_per_kb, size):
'''Given a fee per kB in satoshis, and a tx size in bytes,
returns the transaction fee.'''
fee = int(fee_per_kb * size / 1000.)
if fee < MIN_RELAY_TX_FEE:
fee = MIN_RELAY_TX_FEE
return fee
@profiler
def estimated_size(self):
'''Return an estimated tx size in bytes.'''
return len(self.serialize(-1)) / 2 # ASCII hex string
@classmethod
def estimated_input_size(self, txin):
'''Return an estimated of serialized input size in bytes.'''
return len(self.serialize_input(txin, -1, -1)) / 2
def estimated_fee(self, fee_per_kb):
'''Return an estimated fee given a fee per kB in satoshis.'''
return self.fee_for_size(fee_per_kb, self.estimated_size())
def signature_count(self):
r = 0
s = 0
for txin in self.inputs:
if txin.get('is_coinbase'):
continue
signatures = filter(None, txin.get('signatures',[]))
s += len(signatures)
r += txin.get('num_sig',-1)
return s, r
def is_complete(self):
s, r = self.signature_count()
return r == s
def inputs_without_script(self):
out = set()
for i, txin in enumerate(self.inputs):
if txin.get('scriptSig') == '':
out.add(i)
return out
def inputs_to_sign(self):
out = set()
for txin in self.inputs:
num_sig = txin.get('num_sig')
if num_sig is None:
continue
x_signatures = txin['signatures']
signatures = filter(None, x_signatures)
if len(signatures) == num_sig:
# input is complete
continue
for k, x_pubkey in enumerate(txin['x_pubkeys']):
if x_signatures[k] is not None:
# this pubkey already signed
continue
out.add(x_pubkey)
return out
def sign(self, keypairs):
for i, txin in enumerate(self.inputs):
num = txin['num_sig']
for x_pubkey in txin['x_pubkeys']:
signatures = filter(None, txin['signatures'])
if len(signatures) == num:
# txin is complete
break
if x_pubkey in keypairs.keys():
print_error("adding signature for", x_pubkey)
# add pubkey to txin
txin = self.inputs[i]
x_pubkeys = txin['x_pubkeys']
ii = x_pubkeys.index(x_pubkey)
sec = keypairs[x_pubkey]
pubkey = public_key_from_private_key(sec)
txin['x_pubkeys'][ii] = pubkey
txin['pubkeys'][ii] = pubkey
self.inputs[i] = txin
# add signature
for_sig = Hash(self.tx_for_sig(i).decode('hex'))
pkey = regenerate_key(sec)
secexp = pkey.secret
private_key = bitcoin.MySigningKey.from_secret_exponent( secexp, curve = SECP256k1 )
public_key = private_key.get_verifying_key()
sig = private_key.sign_digest_deterministic( for_sig, hashfunc=hashlib.sha256, sigencode = ecdsa.util.sigencode_der )
assert public_key.verify_digest( sig, for_sig, sigdecode = ecdsa.util.sigdecode_der)
txin['signatures'][ii] = sig.encode('hex')
self.inputs[i] = txin
print_error("is_complete", self.is_complete())
self.raw = self.serialize()
def get_outputs(self):
"""convert pubkeys to addresses"""
o = []
for type, x, v in self.outputs:
if type == 'address':
addr = x
elif type == 'pubkey':
addr = public_key_to_bc_address(x.decode('hex'))
else:
addr = 'SCRIPT ' + x.encode('hex')
o.append((addr,v)) # consider using yield (addr, v)
return o
def get_output_addresses(self):
return [addr for addr, val in self.get_outputs()]
def has_address(self, addr):
return (addr in self.get_output_addresses()) or (addr in (tx.get("address") for tx in self.inputs))
def as_dict(self):
if self.raw is None:
self.raw = self.serialize()
self.deserialize()
out = {
'hex': self.raw,
'complete': self.is_complete()
}
return out
def requires_fee(self, wallet):
# see https://en.bitcoin.it/wiki/Transaction_fees
#
# size must be smaller than 1 kbyte for free tx
size = len(self.serialize(-1))/2
if size >= 10000:
return True
# all outputs must be 0.01 BTC or larger for free tx
for addr, value in self.get_outputs():
if value < 1000000:
return True
# priority must be large enough for free tx
threshold = 57600000
weight = 0
for txin in self.inputs:
age = wallet.get_confirmations(txin["prevout_hash"])[0]
weight += txin["value"] * age
priority = weight / size
print_error(priority, threshold)
return priority < threshold