URI: 
       tbitcoin.py: SCRIPT-related clean-up. transaction.py: construct_witness - electrum - Electrum Bitcoin wallet
  HTML git clone https://git.parazyd.org/electrum
   DIR Log
   DIR Files
   DIR Refs
   DIR Submodules
       ---
   DIR commit e13183ea7a4d43c861a973f4792980d637005074
   DIR parent 97296432a2bcbdc13979d94f67e283666344c7e9
  HTML Author: SomberNight <somber.night@protonmail.com>
       Date:   Fri, 27 Apr 2018 15:38:44 +0200
       
       bitcoin.py: SCRIPT-related clean-up. transaction.py: construct_witness
       
       Diffstat:
         M lib/bitcoin.py                      |      32 ++++++++++++++-----------------
         M lib/tests/test_bitcoin.py           |      28 ++++++++++++++--------------
         M lib/transaction.py                  |      25 +++++++++++++++++++------
       
       3 files changed, 47 insertions(+), 38 deletions(-)
       ---
   DIR diff --git a/lib/bitcoin.py b/lib/bitcoin.py
       t@@ -152,7 +152,7 @@ def int_to_hex(i, length=1):
            s = "0"*(2*length - len(s)) + s
            return rev_hex(s)
        
       -def script_num_to_hex(i):
       +def script_num_to_hex(i: int) -> str:
            """See CScriptNum in Bitcoin Core.
            Encodes an integer as hex, to be used in script.
        
       t@@ -176,7 +176,7 @@ def script_num_to_hex(i):
            return bh2u(result)
        
        
       -def var_int(i):
       +def var_int(i: int) -> str:
            # https://en.bitcoin.it/wiki/Protocol_specification#Variable_length_integer
            if i<0xfd:
                return int_to_hex(i)
       t@@ -188,14 +188,14 @@ def var_int(i):
                return "ff"+int_to_hex(i,8)
        
        
       -def witness_push(item):
       -    """ Returns data in the form it should be present in the witness.
       +def witness_push(item: str) -> str:
       +    """Returns data in the form it should be present in the witness.
            hex -> hex
            """
            return var_int(len(item) // 2) + item
        
        
       -def op_push(i):
       +def op_push(i: int) -> str:
            if i<0x4c:  # OP_PUSHDATA1
                return int_to_hex(i)
            elif i<=0xff:
       t@@ -206,36 +206,32 @@ def op_push(i):
                return '4e' + int_to_hex(i,4)
        
        
       -def add_data_to_script(data):
       +def push_script(data: str) -> str:
            """Returns pushed data to the script, automatically
            choosing canonical opcodes depending on the length of the data.
       -    bytes -> bytes
       +    hex -> hex
        
            ported from https://github.com/btcsuite/btcd/blob/fdc2bc867bda6b351191b5872d2da8270df00d13/txscript/scriptbuilder.go#L128
            """
       -    assert_bytes(data)
       +    data = bfh(data)
            from .transaction import opcodes
        
            data_len = len(data)
        
            # "small integer" opcodes
            if data_len == 0 or data_len == 1 and data[0] == 0:
       -        return bytes([opcodes.OP_0])
       +        return bh2u(bytes([opcodes.OP_0]))
            elif data_len == 1 and data[0] <= 16:
       -        return bytes([opcodes.OP_1 - 1 + data[0]])
       +        return bh2u(bytes([opcodes.OP_1 - 1 + data[0]]))
            elif data_len == 1 and data[0] == 0x81:
       -        return bytes([opcodes.OP_1NEGATE])
       -
       -    return bfh(push_script(bh2u(data)))
       +        return bh2u(bytes([opcodes.OP_1NEGATE]))
        
       +    return op_push(data_len) + bh2u(data)
        
       -def add_number_to_script(i):
       -    """int -> bytes"""
       -    return add_data_to_script(bfh(script_num_to_hex(i)))
        
       +def add_number_to_script(i: int) -> bytes:
       +    return bfh(push_script(script_num_to_hex(i)))
        
       -def push_script(x):
       -    return op_push(len(x)//2) + x
        
        def sha256(x):
            x = to_bytes(x, 'utf8')
   DIR diff --git a/lib/tests/test_bitcoin.py b/lib/tests/test_bitcoin.py
       t@@ -12,9 +12,9 @@ from lib.bitcoin import (
            verify_message, deserialize_privkey, serialize_privkey, is_segwit_address,
            is_b58_address, address_to_scripthash, is_minikey, is_compressed, is_xpub,
            xpub_type, is_xprv, is_bip32_derivation, seed_type, EncodeBase58Check,
       -    script_num_to_hex, add_data_to_script, add_number_to_script)
       +    script_num_to_hex, push_script, add_number_to_script)
        from lib.transaction import opcodes
       -from lib.util import bfh
       +from lib.util import bfh, bh2u
        from lib import constants
        
        from . import TestCaseForTestnet
       t@@ -167,19 +167,19 @@ class Test_bitcoin(unittest.TestCase):
                self.assertEqual(script_num_to_hex(32768), '008000')
                self.assertEqual(script_num_to_hex(-32768), '008080')
        
       -    def test_add_data_to_script(self):
       +    def test_push_script(self):
                # https://github.com/bitcoin/bips/blob/master/bip-0062.mediawiki#push-operators
       -        self.assertEqual(add_data_to_script(bfh('')), bytes([opcodes.OP_0]))
       -        self.assertEqual(add_data_to_script(bfh('07')), bytes([opcodes.OP_7]))
       -        self.assertEqual(add_data_to_script(bfh('10')), bytes([opcodes.OP_16]))
       -        self.assertEqual(add_data_to_script(bfh('81')), bytes([opcodes.OP_1NEGATE]))
       -        self.assertEqual(add_data_to_script(bfh('11')), bfh('0111'))
       -        self.assertEqual(add_data_to_script(bfh(75 * '42')), bfh('4b' + 75 * '42'))
       -        self.assertEqual(add_data_to_script(bfh(76 * '42')), bytes([opcodes.OP_PUSHDATA1]) + bfh('4c' + 76 * '42'))
       -        self.assertEqual(add_data_to_script(bfh(100 * '42')), bytes([opcodes.OP_PUSHDATA1]) + bfh('64' + 100 * '42'))
       -        self.assertEqual(add_data_to_script(bfh(255 * '42')), bytes([opcodes.OP_PUSHDATA1]) + bfh('ff' + 255 * '42'))
       -        self.assertEqual(add_data_to_script(bfh(256 * '42')), bytes([opcodes.OP_PUSHDATA2]) + bfh('0001' + 256 * '42'))
       -        self.assertEqual(add_data_to_script(bfh(520 * '42')), bytes([opcodes.OP_PUSHDATA2]) + bfh('0802' + 520 * '42'))
       +        self.assertEqual(push_script(''), bh2u(bytes([opcodes.OP_0])))
       +        self.assertEqual(push_script('07'), bh2u(bytes([opcodes.OP_7])))
       +        self.assertEqual(push_script('10'), bh2u(bytes([opcodes.OP_16])))
       +        self.assertEqual(push_script('81'), bh2u(bytes([opcodes.OP_1NEGATE])))
       +        self.assertEqual(push_script('11'), '0111')
       +        self.assertEqual(push_script(75 * '42'), '4b' + 75 * '42')
       +        self.assertEqual(push_script(76 * '42'), bh2u(bytes([opcodes.OP_PUSHDATA1]) + bfh('4c' + 76 * '42')))
       +        self.assertEqual(push_script(100 * '42'), bh2u(bytes([opcodes.OP_PUSHDATA1]) + bfh('64' + 100 * '42')))
       +        self.assertEqual(push_script(255 * '42'), bh2u(bytes([opcodes.OP_PUSHDATA1]) + bfh('ff' + 255 * '42')))
       +        self.assertEqual(push_script(256 * '42'), bh2u(bytes([opcodes.OP_PUSHDATA2]) + bfh('0001' + 256 * '42')))
       +        self.assertEqual(push_script(520 * '42'), bh2u(bytes([opcodes.OP_PUSHDATA2]) + bfh('0802' + 520 * '42')))
        
            def test_add_number_to_script(self):
                # https://github.com/bitcoin/bips/blob/master/bip-0062.mediawiki#numbers
   DIR diff --git a/lib/transaction.py b/lib/transaction.py
       t@@ -27,6 +27,8 @@
        
        # Note: The deserialization code originally comes from ABE.
        
       +from typing import Sequence, Union
       +
        from .util import print_error, profiler
        
        from . import bitcoin
       t@@ -236,7 +238,7 @@ opcodes = Enumeration("Opcodes", [
        ])
        
        
       -def script_GetOp(_bytes):
       +def script_GetOp(_bytes : bytes):
            i = 0
            while i < len(_bytes):
                vch = None
       t@@ -382,7 +384,7 @@ def parse_scriptSig(d, _bytes):
                        bh2u(_bytes))
        
        
       -def parse_redeemScript_multisig(redeem_script):
       +def parse_redeemScript_multisig(redeem_script: bytes):
            dec2 = [ x for x in script_GetOp(redeem_script) ]
            try:
                m = dec2[0][0] - opcodes.OP_1 + 1
       t@@ -464,6 +466,18 @@ def parse_input(vds):
            return d
        
        
       +def construct_witness(items: Sequence[Union[str, int, bytes]]) -> str:
       +    """Constructs a witness from the given stack items."""
       +    witness = var_int(len(items))
       +    for item in items:
       +        if type(item) is int:
       +            item = bitcoin.script_num_to_hex(item)
       +        elif type(item) is bytes:
       +            item = bh2u(item)
       +        witness += bitcoin.witness_push(item)
       +    return witness
       +
       +
        def parse_witness(vds, txin):
            n = vds.read_compact_size()
            if n == 0:
       t@@ -474,7 +488,7 @@ def parse_witness(vds, txin):
            # now 'n' is the number of items in the witness
            w = list(bh2u(vds.read_bytes(vds.read_compact_size())) for i in range(n))
        
       -    txin['witness'] = var_int(n) + ''.join(witness_push(i) for i in w)
       +    txin['witness'] = construct_witness(w)
        
            # FIXME: witness version > 0 will probably fail here.
            # For native segwit, we would need the scriptPubKey of the parent txn
       t@@ -750,11 +764,10 @@ class Transaction:
                if witness is None:
                    pubkeys, sig_list = self.get_siglist(txin, estimate_size)
                    if txin['type'] in ['p2wpkh', 'p2wpkh-p2sh']:
       -                witness = var_int(2) + witness_push(sig_list[0]) + witness_push(pubkeys[0])
       +                witness = construct_witness([sig_list[0], pubkeys[0]])
                    elif txin['type'] in ['p2wsh', 'p2wsh-p2sh']:
       -                n = len(sig_list) + 2
                        witness_script = multisig_script(pubkeys, txin['num_sig'])
       -                witness = var_int(n) + '00' + ''.join(witness_push(x) for x in sig_list) + witness_push(witness_script)
       +                witness = construct_witness([0, *sig_list, witness_script])
                    else:
                        raise Exception('wrong txin type:', txin['type'])
                if self.is_txin_complete(txin) or estimate_size: