Exemplo n.º 1
0
 def get_pubkeyhash(scriptpubkey):
     asm = script.get_asm(scriptpubkey)
     if len(asm
            ) != 5 or asm[0] != 'OP_DUP' or asm[1] != 'OP_HASH160' or asm[
                3] != 'OP_EQUALVERIFY' or asm[4] != 'OP_CHECKSIG':
         return False
     return asm[2]
def test_p2sh_signed_multisig_script_decoding():
    with util_test.ConfigContext(PREFIX=b'CNTRPRTY'):
        txHex = "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"

        ctx = backend.deserialize(txHex)
        vin = ctx.vin[1]
        asm = script.get_asm(vin.scriptSig)
        new_source, new_destination, new_data = p2sh_encoding.decode_p2sh_input(
            asm)

        assert new_data == binascii.unhexlify(
            '1e5a3ae08000000000000000000000000073434950203620737570706f727473207573696e672070327368206164647265737365732061732074686520736f7572636520616464726573732062757420726571756972657320616e206164646974696f6e616c20696e70757420696e207468652064617461207472616e73616374696f6e2e'
        )
Exemplo n.º 3
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def test_p2sh_signed_multisig_script_decoding():
    with util_test.ConfigContext(PREFIX=b'CNTRPRTY'):
        txHex = "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"

        ctx = backend.deserialize(txHex)
        vin = ctx.vin[0]
        asm = script.get_asm(vin.scriptSig)
        new_source, new_destination, new_data = p2sh_encoding.decode_p2sh_input(
            asm)

        assert new_data == binascii.unhexlify(
            '1e5a3ae08000000000000000000000000073434950203620737570706f727473207573696e672070327368206164647265737365732061732074686520736f7572636520616464726573732062757420726571756972657320616e206164646974696f6e616c20696e70757420696e207468652064617461207472616e73616374696f6e2e'
        )
Exemplo n.º 4
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def get_tx_info2(tx_hex, block_parser=None):
    """Get multisig transaction info.
    The destinations, if they exists, always comes before the data output; the
    change, if it exists, always comes after.
    """
    # Decode transaction binary.
    ctx = backend.deserialize(tx_hex)

    def arc4_decrypt(cyphertext):
        '''Un‐obfuscate. Initialise key once per attempt.'''
        key = ARC4.new(ctx.vin[0].prevout.hash[::-1])
        return key.decrypt(cyphertext)

    def get_opreturn(asm):
        if len(asm) == 2 and asm[0] == 'OP_RETURN':
            pubkeyhash = asm[1]
            if type(pubkeyhash) == bytes:
                return pubkeyhash
        raise DecodeError('invalid OP_RETURN')

    def decode_opreturn(asm):
        chunk = get_opreturn(asm)
        chunk = arc4_decrypt(chunk)
        if chunk[:len(config.PREFIX)] == config.PREFIX:             # Data
            destination, data = None, chunk[len(config.PREFIX):]
        else:
            raise DecodeError('unrecognised OP_RETURN output')

        return destination, data

    def decode_checksig(asm):
        pubkeyhash = script.get_checksig(asm)
        chunk = arc4_decrypt(pubkeyhash)
        if chunk[1:len(config.PREFIX) + 1] == config.PREFIX:        # Data
            # Padding byte in each output (instead of just in the last one) so that encoding methods may be mixed. Also, it’s just not very much data.
            chunk_length = chunk[0]
            chunk = chunk[1:chunk_length + 1]
            destination, data = None, chunk[len(config.PREFIX):]
        else:                                                       # Destination
            pubkeyhash = binascii.hexlify(pubkeyhash).decode('utf-8')
            destination, data = script.base58_check_encode(pubkeyhash, config.ADDRESSVERSION), None

        return destination, data

    def decode_checkmultisig(asm):
        pubkeys, signatures_required = script.get_checkmultisig(asm)
        chunk = b''
        for pubkey in pubkeys[:-1]:     # (No data in last pubkey.)
            chunk += pubkey[1:-1]       # Skip sign byte and nonce byte.
        chunk = arc4_decrypt(chunk)
        if chunk[1:len(config.PREFIX) + 1] == config.PREFIX:        # Data
            # Padding byte in each output (instead of just in the last one) so that encoding methods may be mixed. Also, it’s just not very much data.
            chunk_length = chunk[0]
            chunk = chunk[1:chunk_length + 1]
            destination, data = None, chunk[len(config.PREFIX):]
        else:                                                       # Destination
            pubkeyhashes = [script.pubkey_to_pubkeyhash(pubkey) for pubkey in pubkeys]
            destination, data = script.construct_array(signatures_required, pubkeyhashes, len(pubkeyhashes)), None

        return destination, data

    # Ignore coinbase transactions.
    if ctx.is_coinbase():
        raise DecodeError('coinbase transaction')

    # Get destinations and data outputs.
    destinations, btc_amount, fee, data = [], 0, 0, b''
    for vout in ctx.vout:
        # Fee is the input values minus output values.
        output_value = vout.nValue
        fee -= output_value

        # Ignore transactions with invalid script.
        try:
          asm = script.get_asm(vout.scriptPubKey)
        except CScriptInvalidError as e:
          raise DecodeError(e)

        if asm[0] == 'OP_RETURN':
            new_destination, new_data = decode_opreturn(asm)
        elif asm[-1] == 'OP_CHECKSIG':
            new_destination, new_data = decode_checksig(asm)
        elif asm[-1] == 'OP_CHECKMULTISIG':
            new_destination, new_data = decode_checkmultisig(asm)
        else:
            raise DecodeError('unrecognised output type')
        assert not (new_destination and new_data)
        assert new_destination != None or new_data != None  # `decode_*()` should never return `None, None`.

        if util.enabled('null_data_check'):
            if new_data == []:
                raise DecodeError('new destination is `None`')

        # All destinations come before all data.
        if not data and not new_data and destinations != [config.UNSPENDABLE,]:
            destinations.append(new_destination)
            btc_amount += output_value
        else:
            if new_destination:     # Change.
                break
            else:                   # Data.
                data += new_data

    # Only look for source if data were found or destination is `UNSPENDABLE`,
    # for speed.
    if not data and destinations != [config.UNSPENDABLE,]:
        raise BTCOnlyError('no data and not unspendable')

    # Collect all (unique) source addresses.
    sources = []
    for vin in ctx.vin[:]:                   # Loop through inputs.
        # Get the full transaction data for this input transaction.
        if block_parser:
            vin_tx = block_parser.read_raw_transaction(ib2h(vin.prevout.hash))
            vin_ctx = backend.deserialize(vin_tx['__data__'])
        else:
            vin_tx = backend.getrawtransaction(ib2h(vin.prevout.hash))
            vin_ctx = backend.deserialize(vin_tx)
        vout = vin_ctx.vout[vin.prevout.n]
        fee += vout.nValue

        asm = script.get_asm(vout.scriptPubKey)
        if asm[-1] == 'OP_CHECKSIG':
            new_source, new_data = decode_checksig(asm)
            if new_data or not new_source:
                raise DecodeError('data in source')
        elif asm[-1] == 'OP_CHECKMULTISIG':
            new_source, new_data = decode_checkmultisig(asm)
            if new_data or not new_source:
                raise DecodeError('data in source')
        else:
            raise DecodeError('unrecognised source type')

        # Collect unique sources.
        if new_source not in sources:
            sources.append(new_source)

    sources = '-'.join(sources)
    destinations = '-'.join(destinations)
    return sources, destinations, btc_amount, round(fee), data
Exemplo n.º 5
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 def get_pubkeyhash(scriptpubkey):
     asm = script.get_asm(scriptpubkey)
     if len(asm) != 5 or asm[0] != 'OP_DUP' or asm[1] != 'OP_HASH160' or asm[3] != 'OP_EQUALVERIFY' or asm[4] != 'OP_CHECKSIG':
         return False
     return asm[2]
Exemplo n.º 6
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def get_tx_info1(tx_hex, block_index, block_parser=None):
    """Get singlesig transaction info.
    The destination, if it exists, always comes before the data output; the
    change, if it exists, always comes after.
    """
    ctx = backend.deserialize(tx_hex)

    def get_pubkeyhash(scriptpubkey):
        asm = script.get_asm(scriptpubkey)
        if len(asm) != 5 or asm[0] != 'OP_DUP' or asm[1] != 'OP_HASH160' or asm[3] != 'OP_EQUALVERIFY' or asm[4] != 'OP_CHECKSIG':
            return False
        return asm[2]

    def get_address(scriptpubkey):
        pubkeyhash = get_pubkeyhash(scriptpubkey)
        if not pubkeyhash:
            return False
        pubkeyhash = binascii.hexlify(pubkeyhash).decode('utf-8')
        address = script.base58_check_encode(pubkeyhash, config.ADDRESSVERSION)
        # Test decoding of address.
        if address != config.UNSPENDABLE and binascii.unhexlify(bytes(pubkeyhash, 'utf-8')) != script.base58_check_decode(address, config.ADDRESSVERSION):
            return False

        return address

    # Fee is the input values minus output values.
    fee = 0

    # Get destination output and data output.
    destination, btc_amount, data = None, None, b''
    pubkeyhash_encoding = False
    for vout in ctx.vout:
        fee -= vout.nValue

        # Sum data chunks to get data. (Can mix OP_RETURN and multi-sig.)
        asm = script.get_asm(vout.scriptPubKey)
        if len(asm) == 2 and asm[0] == 'OP_RETURN':                                             # OP_RETURN
            if type(asm[1]) != bytes:
                continue
            data_chunk = asm[1]
            data += data_chunk
        elif len(asm) == 5 and asm[0] == 1 and asm[3] == 2 and asm[4] == 'OP_CHECKMULTISIG':    # Multi-sig
            if type(asm[2]) != bytes:
                continue
            data_pubkey = asm[2]
            data_chunk_length = data_pubkey[0]  # No ord() necessary.
            data_chunk = data_pubkey[1:data_chunk_length + 1]
            data += data_chunk
        elif len(asm) == 5 and (block_index >= 293000 or config.TESTNET):    # Protocol change.
            # Be strict.
            pubkeyhash = get_pubkeyhash(vout.scriptPubKey)
            if not pubkeyhash:
                continue

            if ctx.is_coinbase():
                raise DecodeError('coinbase transaction')
            obj1 = ARC4.new(ctx.vin[0].prevout.hash[::-1])
            data_pubkey = obj1.decrypt(pubkeyhash)
            if data_pubkey[1:9] == config.PREFIX or pubkeyhash_encoding:
                pubkeyhash_encoding = True
                data_chunk_length = data_pubkey[0]  # No ord() necessary.
                data_chunk = data_pubkey[1:data_chunk_length + 1]
                if data_chunk[-8:] == config.PREFIX:
                    data += data_chunk[:-8]
                    break
                else:
                    data += data_chunk

        # Destination is the first output before the data.
        if not destination and not btc_amount and not data:
            address = get_address(vout.scriptPubKey)
            if address:
                destination = address
                btc_amount = vout.nValue

    # Check for, and strip away, prefix (except for burns).
    if destination == config.UNSPENDABLE:
        pass
    elif data[:len(config.PREFIX)] == config.PREFIX:
        data = data[len(config.PREFIX):]
    else:
        raise DecodeError('no prefix')

    # Only look for source if data were found or destination is UNSPENDABLE, for speed.
    if not data and destination != config.UNSPENDABLE:
        raise BTCOnlyError('no data and not unspendable')

    # Collect all possible source addresses; ignore coinbase transactions and anything but the simplest Pay‐to‐PubkeyHash inputs.
    source_list = []
    for vin in ctx.vin[:]:                                               # Loop through input transactions.
        if vin.prevout.is_null():
            raise DecodeError('coinbase transaction')
         # Get the full transaction data for this input transaction.
        if block_parser:
            vin_tx = block_parser.read_raw_transaction(ib2h(vin.prevout.hash))
            vin_ctx = backend.deserialize(vin_tx['__data__'])
        else:
            vin_tx = backend.getrawtransaction(ib2h(vin.prevout.hash))
            vin_ctx = backend.deserialize(vin_tx)
        vout = vin_ctx.vout[vin.prevout.n]
        fee += vout.nValue

        address = get_address(vout.scriptPubKey)
        if not address:
            raise DecodeError('invalid scriptpubkey')
        else:
            source_list.append(address)

    # Require that all possible source addresses be the same.
    if all(x == source_list[0] for x in source_list):
        source = source_list[0]
    else:
        source = None

    return source, destination, btc_amount, fee, data
Exemplo n.º 7
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def get_tx_info2(tx_hex, block_parser=None):
    """Get multisig transaction info.
    The destinations, if they exists, always comes before the data output; the
    change, if it exists, always comes after.
    """
    # Decode transaction binary.
    ctx = backend.deserialize(tx_hex)

    def arc4_decrypt(cyphertext):
        '''Un‐obfuscate. Initialise key once per attempt.'''
        key = ARC4.new(ctx.vin[0].prevout.hash[::-1])
        return key.decrypt(cyphertext)

    def get_opreturn(asm):
        if len(asm) == 2 and asm[0] == 'OP_RETURN':
            pubkeyhash = asm[1]
            if type(pubkeyhash) == bytes:
                return pubkeyhash
        raise DecodeError('invalid OP_RETURN')

    def decode_opreturn(asm):
        chunk = get_opreturn(asm)
        chunk = arc4_decrypt(chunk)
        if chunk[:len(config.PREFIX)] == config.PREFIX:  # Data
            destination, data = None, chunk[len(config.PREFIX):]
        else:
            raise DecodeError('unrecognised OP_RETURN output')

        return destination, data

    def decode_checksig(asm):
        pubkeyhash = script.get_checksig(asm)
        chunk = arc4_decrypt(pubkeyhash)
        if chunk[1:len(config.PREFIX) + 1] == config.PREFIX:  # Data
            # Padding byte in each output (instead of just in the last one) so that encoding methods may be mixed. Also, it’s just not very much data.
            chunk_length = chunk[0]
            chunk = chunk[1:chunk_length + 1]
            destination, data = None, chunk[len(config.PREFIX):]
        else:  # Destination
            pubkeyhash = binascii.hexlify(pubkeyhash).decode('utf-8')
            destination, data = script.base58_check_encode(
                pubkeyhash, config.ADDRESSVERSION), None

        return destination, data

    def decode_checkmultisig(asm):
        pubkeys, signatures_required = script.get_checkmultisig(asm)
        chunk = b''
        for pubkey in pubkeys[:-1]:  # (No data in last pubkey.)
            chunk += pubkey[1:-1]  # Skip sign byte and nonce byte.
        chunk = arc4_decrypt(chunk)
        if chunk[1:len(config.PREFIX) + 1] == config.PREFIX:  # Data
            # Padding byte in each output (instead of just in the last one) so that encoding methods may be mixed. Also, it’s just not very much data.
            chunk_length = chunk[0]
            chunk = chunk[1:chunk_length + 1]
            destination, data = None, chunk[len(config.PREFIX):]
        else:  # Destination
            pubkeyhashes = [
                script.pubkey_to_pubkeyhash(pubkey) for pubkey in pubkeys
            ]
            destination, data = script.construct_array(signatures_required,
                                                       pubkeyhashes,
                                                       len(pubkeyhashes)), None

        return destination, data

    # Ignore coinbase transactions.
    if ctx.is_coinbase():
        raise DecodeError('coinbase transaction')

    # Get destinations and data outputs.
    destinations, btc_amount, fee, data = [], 0, 0, b''
    for vout in ctx.vout:
        # Fee is the input values minus output values.
        output_value = vout.nValue
        fee -= output_value

        asm = script.get_asm(vout.scriptPubKey)
        if asm[0] == 'OP_RETURN':
            new_destination, new_data = decode_opreturn(asm)
        elif asm[-1] == 'OP_CHECKSIG':
            new_destination, new_data = decode_checksig(asm)
        elif asm[-1] == 'OP_CHECKMULTISIG':
            new_destination, new_data = decode_checkmultisig(asm)
        else:
            raise DecodeError('unrecognised output type')
        assert not (new_destination and new_data)
        assert new_destination != None or new_data != None

        # All destinations come before all data.
        if not data and not new_data and destinations != [
                config.UNSPENDABLE,
        ]:
            destinations.append(new_destination)
            btc_amount += output_value
        else:
            if new_destination:  # Change.
                break
            else:  # Data.
                data += new_data

    # Only look for source if data were found or destination is `UNSPENDABLE`,
    # for speed.
    if not data and destinations != [
            config.UNSPENDABLE,
    ]:
        raise BTCOnlyError('no data and not unspendable')

    # Collect all (unique) source addresses.
    sources = []
    for vin in ctx.vin[:]:  # Loop through inputs.
        # Get the full transaction data for this input transaction.
        if block_parser:
            vin_tx = block_parser.read_raw_transaction(ib2h(vin.prevout.hash))
            vin_ctx = backend.deserialize(vin_tx['__data__'])
        else:
            vin_tx = backend.getrawtransaction(ib2h(vin.prevout.hash))
            vin_ctx = backend.deserialize(vin_tx)
        vout = vin_ctx.vout[vin.prevout.n]
        fee += vout.nValue

        asm = script.get_asm(vout.scriptPubKey)
        if asm[-1] == 'OP_CHECKSIG':
            new_source, new_data = decode_checksig(asm)
            if new_data or not new_source:
                raise DecodeError('data in source')
        elif asm[-1] == 'OP_CHECKMULTISIG':
            new_source, new_data = decode_checkmultisig(asm)
            if new_data or not new_source:
                raise DecodeError('data in source')
        else:
            raise DecodeError('unrecognised source type')

        # Collect unique sources.
        if new_source not in sources:
            sources.append(new_source)

    sources = '-'.join(sources)
    destinations = '-'.join(destinations)
    return sources, destinations, btc_amount, round(fee), data
Exemplo n.º 8
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def get_tx_info1(tx_hex, block_index, block_parser=None):
    """Get singlesig transaction info.
    The destination, if it exists, always comes before the data output; the
    change, if it exists, always comes after.
    """
    ctx = backend.deserialize(tx_hex)

    def get_pubkeyhash(scriptpubkey):
        asm = script.get_asm(scriptpubkey)
        if len(asm
               ) != 5 or asm[0] != 'OP_DUP' or asm[1] != 'OP_HASH160' or asm[
                   3] != 'OP_EQUALVERIFY' or asm[4] != 'OP_CHECKSIG':
            return False
        return asm[2]

    def get_address(scriptpubkey):
        pubkeyhash = get_pubkeyhash(scriptpubkey)
        if not pubkeyhash:
            return False
        pubkeyhash = binascii.hexlify(pubkeyhash).decode('utf-8')
        address = script.base58_check_encode(pubkeyhash, config.ADDRESSVERSION)
        # Test decoding of address.
        if address != config.UNSPENDABLE and binascii.unhexlify(
                bytes(pubkeyhash, 'utf-8')) != script.base58_check_decode(
                    address, config.ADDRESSVERSION):
            return False

        return address

    # Fee is the input values minus output values.
    fee = 0

    # Get destination output and data output.
    destination, btc_amount, data = None, None, b''
    pubkeyhash_encoding = False
    for vout in ctx.vout:
        fee -= vout.nValue

        # Sum data chunks to get data. (Can mix OP_RETURN and multi-sig.)
        asm = script.get_asm(vout.scriptPubKey)
        if len(asm) == 2 and asm[0] == 'OP_RETURN':  # OP_RETURN
            if type(asm[1]) != bytes:
                continue
            data_chunk = asm[1]
            data += data_chunk
        elif len(asm) == 5 and asm[0] == 1 and asm[3] == 2 and asm[
                4] == 'OP_CHECKMULTISIG':  # Multi-sig
            if type(asm[2]) != bytes:
                continue
            data_pubkey = asm[2]
            data_chunk_length = data_pubkey[0]  # No ord() necessary.
            data_chunk = data_pubkey[1:data_chunk_length + 1]
            data += data_chunk
        elif len(asm) == 5 and (block_index >= 293000
                                or config.TESTNET):  # Protocol change.
            # Be strict.
            pubkeyhash = get_pubkeyhash(vout.scriptPubKey)
            if not pubkeyhash:
                continue

            if ctx.is_coinbase():
                raise DecodeError('coinbase transaction')
            obj1 = ARC4.new(ctx.vin[0].prevout.hash[::-1])
            data_pubkey = obj1.decrypt(pubkeyhash)
            if data_pubkey[1:9] == config.PREFIX or pubkeyhash_encoding:
                pubkeyhash_encoding = True
                data_chunk_length = data_pubkey[0]  # No ord() necessary.
                data_chunk = data_pubkey[1:data_chunk_length + 1]
                if data_chunk[-8:] == config.PREFIX:
                    data += data_chunk[:-8]
                    break
                else:
                    data += data_chunk

        # Destination is the first output before the data.
        if not destination and not btc_amount and not data:
            address = get_address(vout.scriptPubKey)
            if address:
                destination = address
                btc_amount = vout.nValue

    # Check for, and strip away, prefix (except for burns).
    if destination == config.UNSPENDABLE:
        pass
    elif data[:len(config.PREFIX)] == config.PREFIX:
        data = data[len(config.PREFIX):]
    else:
        raise DecodeError('no prefix')

    # Only look for source if data were found or destination is UNSPENDABLE, for speed.
    if not data and destination != config.UNSPENDABLE:
        raise BTCOnlyError('no data and not unspendable')

    # Collect all possible source addresses; ignore coinbase transactions and anything but the simplest Pay‐to‐PubkeyHash inputs.
    source_list = []
    for vin in ctx.vin[:]:  # Loop through input transactions.
        if vin.prevout.is_null():
            raise DecodeError('coinbase transaction')
        # Get the full transaction data for this input transaction.
        if block_parser:
            vin_tx = block_parser.read_raw_transaction(ib2h(vin.prevout.hash))
            vin_ctx = backend.deserialize(vin_tx['__data__'])
        else:
            vin_tx = backend.getrawtransaction(ib2h(vin.prevout.hash))
            vin_ctx = backend.deserialize(vin_tx)
        vout = vin_ctx.vout[vin.prevout.n]
        fee += vout.nValue

        address = get_address(vout.scriptPubKey)
        if not address:
            raise DecodeError('invalid scriptpubkey')
        else:
            source_list.append(address)

    # Require that all possible source addresses be the same.
    if all(x == source_list[0] for x in source_list):
        source = source_list[0]
    else:
        source = None

    return source, destination, btc_amount, fee, data