<filename>bitcoin/bech32.py
# Majority of code taken from reference implementation:
# https://github.com/sipa/bech32/blob/master/ref/python/segwit_addr.py

# Copyright (c) 2017 <NAME>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

"""Reference implementation for Bech32 and segwit addresses."""
import binascii
import re

from bitcoin import encode_pubkey, hash160, SIGHASH_ALL, privkey_to_pubkey, encode, hashlib

from enum import Enum

class Encoding(Enum):
    """Enumeration type to list the various supported encodings."""
    BECH32 = 1
    BECH32M = 2

CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
BECH32M_CONST = 0x2bc830a3

BECH32_BITCOIN_PREFIX = 'bc'
BECH32_BITCOIN_TESTNET_PREFIX = 'tb'
BECH32_BITCOIN_REGTEST_PREFIX = 'bcrt'

BECH32_CUSTOM_SIGNET_PREFIX = 'cbc'
BECH32_CUSTOM_SIGNET_TESTNET_PREFIX = 'cbt'

BECH32_PREFIXES = [
    BECH32_CUSTOM_SIGNET_TESTNET_PREFIX,
    BECH32_CUSTOM_SIGNET_PREFIX,
    BECH32_BITCOIN_PREFIX,
    BECH32_BITCOIN_TESTNET_PREFIX,
    BECH32_BITCOIN_REGTEST_PREFIX
]


def bech32_polymod(values):
    """Internal function that computes the Bech32 checksum."""
    generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
    chk = 1
    for value in values:
        top = chk >> 25
        chk = (chk & 0x1ffffff) << 5 ^ value
        for i in range(5):
            chk ^= generator[i] if ((top >> i) & 1) else 0
    return chk


def bech32_hrp_expand(hrp):
    """Expand the HRP into values for checksum computation."""
    return [ord(x) >> 5 for x in hrp] + [0] + [ord(x) & 31 for x in hrp]

'''
def bech32_verify_checksum(hrp, data):
    """Verify a checksum given HRP and converted data characters."""
    return bech32_polymod(bech32_hrp_expand(hrp) + data) == 1
'''

def bech32_verify_checksum(hrp, data):
    """Verify a checksum given HRP and converted data characters."""
    const = bech32_polymod(bech32_hrp_expand(hrp) + data)
    if const == 1:
        return Encoding.BECH32
    if const == BECH32M_CONST:
        return Encoding.BECH32M
    return None

'''
def bech32_create_checksum(hrp, data):
    """Compute the checksum values given HRP and data."""
    values = bech32_hrp_expand(hrp) + data
    polymod = bech32_polymod(values + [0, 0, 0, 0, 0, 0]) ^ 1
    return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)]
'''

def bech32_create_checksum(hrp, data, spec):
    """Compute the checksum values given HRP and data."""
    values = bech32_hrp_expand(hrp) + data
    const = BECH32M_CONST if spec == Encoding.BECH32M else 1
    polymod = bech32_polymod(values + [0, 0, 0, 0, 0, 0]) ^ const
    return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)]


def bech32_encode(hrp, data, spec):
    """Compute a Bech32 string given HRP and data values."""
    combined = data + bech32_create_checksum(hrp, data, spec)
    return hrp + '1' + ''.join([CHARSET[d] for d in combined])

'''
def bech32_decode(bech):
    """Validate a Bech32 string, and determine HRP and data."""
    if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
            (bech.lower() != bech and bech.upper() != bech)):
        return None, None
    bech = bech.lower()
    pos = bech.rfind('1')
    if pos < 1 or pos + 7 > len(bech) or len(bech) > 90:
        return None, None
    if not all(x in CHARSET for x in bech[pos+1:]):
        return None, None
    hrp = bech[:pos]
    data = [CHARSET.find(x) for x in bech[pos+1:]]
    if not bech32_verify_checksum(hrp, data):
        return None, None
    return hrp, data[:-6]
'''

def _bech32_decode(bech):
    """Validate a Bech32/Bech32m string, and determine HRP and data."""
    if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
            (bech.lower() != bech and bech.upper() != bech)):
        return (None, None, None)
    bech = bech.lower()
    pos = bech.rfind('1')
    if pos < 1 or pos + 7 > len(bech) or len(bech) > 90:
        return (None, None, None)
    if not all(x in CHARSET for x in bech[pos+1:]):
        return (None, None, None)
    hrp = bech[:pos]
    data = [CHARSET.find(x) for x in bech[pos+1:]]
    spec = bech32_verify_checksum(hrp, data)
    if spec is None:
        return (None, None, None)
    return (hrp, data[:-6], spec)


def convertbits(data, frombits, tobits, pad=True):
    """General power-of-2 base conversion."""
    acc = 0
    bits = 0
    ret = []
    maxv = (1 << tobits) - 1
    max_acc = (1 << (frombits + tobits - 1)) - 1
    for value in data:
        if value < 0 or (value >> frombits):
            return None
        acc = ((acc << frombits) | value) & max_acc
        bits += frombits
        while bits >= tobits:
            bits -= tobits
            ret.append((acc >> bits) & maxv)
    if pad:
        if bits:
            ret.append((acc << (tobits - bits)) & maxv)
    elif bits >= frombits or ((acc << (tobits - bits)) & maxv):
        return None
    return ret


def _decode(hrp, addr):
    """Decode a segwit address."""
    hrpgot, data, spec = _bech32_decode(addr)
    if hrpgot != hrp:
        return (None, None)
    decoded = convertbits(data[1:], 5, 8, False)
    if decoded is None or len(decoded) < 2 or len(decoded) > 40:
        return (None, None)
    if data[0] > 16:
        return (None, None)
    if data[0] == 0 and len(decoded) != 20 and len(decoded) != 32:
        return (None, None)
    if data[0] == 0 and spec != Encoding.BECH32 or data[0] != 0 and spec != Encoding.BECH32M:
        return (None, None)
    return (data[0], decoded)


def _bech32_encode(hrp, data, spec):
    """Compute a Bech32 string given HRP and data values."""
    combined = data + bech32_create_checksum(hrp, data, spec)
    return hrp + '1' + ''.join([CHARSET[d] for d in combined])


def _encode(hrp, witver, witprog):
    """Encode a segwit address."""
    spec = Encoding.BECH32 if witver == 0 else Encoding.BECH32M
    ret = _bech32_encode(hrp, [witver] + convertbits(witprog, 8, 5), spec)
    if _decode(hrp, ret) == (None, None):
        return None
    return ret


def bech32encode(script: str, prefix=BECH32_BITCOIN_PREFIX):
    from bitcoin.transaction import deserialize_script
    witnessversion, witnessprogram = deserialize_script(script)
    witnessversion = 0 if witnessversion is None else witnessversion
    assert 0 <= witnessversion <= 16
    if witnessversion == 0:
        assert len(witnessprogram) == 40 or len(witnessprogram) == 64
    return _encode(prefix, witnessversion, bytearray(binascii.unhexlify(witnessprogram))).lower()


def int_to_hex(n: int) -> str:
    return binascii.hexlify(chr(n).encode()).decode()


def segwit_scriptpubkey(witver, witprog):
    """Construct a Segwit scriptPubKey for a given witness program."""
    return bytes([witver + 0x50 if witver else 0, len(witprog)] + witprog)


def bech32decode(text: str):
    assert isinstance(text, str)
    from bitcoin import from_int_to_byte
    if text[:4].lower() == BECH32_BITCOIN_REGTEST_PREFIX:
        human_readable_part_size = 4
    elif text[:2].lower() in (
        BECH32_BITCOIN_PREFIX,
        BECH32_BITCOIN_TESTNET_PREFIX
    ):
        human_readable_part_size = 2
    elif text[:3].lower() in (
        BECH32_CUSTOM_SIGNET_PREFIX,
        BECH32_CUSTOM_SIGNET_TESTNET_PREFIX
    ):
        human_readable_part_size = 3
    else:
        raise ValueError('Invalid readable part')

    if len(set([t.islower() for t in text if t.isalpha()])) > 1:
        raise ValueError('Mixed case')
    text = text.lower().encode("utf-8").decode()

    witnessversion, wit_ordnallist = _decode(text[:human_readable_part_size], text)
    if witnessversion is None and wit_ordnallist is None:
        raise ValueError('Exception with %s (prefix: %s)' % (text, text[:human_readable_part_size]))
    if not witnessversion:
        assert len(wit_ordnallist) == 20 or len(wit_ordnallist) == 32
    o = ""
    for ordinal in wit_ordnallist:
        o += binascii.hexlify(from_int_to_byte(ordinal)).decode()
    return int_to_hex(witnessversion + 0x50 if witnessversion else 0) + int_to_hex(int(len(o) / 2)) + o


def pubkey_to_bech32_address(pubkey, prefix=BECH32_BITCOIN_PREFIX):
    if isinstance(pubkey, (list, tuple)):
        pubkey = encode_pubkey(pubkey, 'bin')
    if len(pubkey) in [66, 130]:
        pubkey = binascii.unhexlify(pubkey)
        pubkey_hash = hash160(pubkey)
        return bech32encode('0014' + pubkey_hash, prefix=prefix)
    if len(pubkey) in [68]:
        return bech32encode(pubkey, prefix=prefix)
    raise ValueError()


def bech32_sign(tx, i, priv, amount, script=None, hashcode=SIGHASH_ALL):
    from bitcoin import deserialize, segwit_signature_form, ecdsa_raw_sign, der_encode_sig, serialize, compress
    i = int(i)
    txobj = tx if isinstance(tx, dict) else deserialize(tx)
    if len(priv) <= 33:
        priv = binascii.hexlify(priv)
    pub = compress(privkey_to_pubkey(priv))
    script = script or ('76a914' + hash160(binascii.unhexlify(pub)) + '88ac')
    signing_tx = segwit_signature_form(tx, i, script, amount, hashcode=hashcode)
    rawsig = ecdsa_raw_sign(hashlib.sha256(hashlib.sha256(binascii.unhexlify(signing_tx)).digest()).hexdigest(), priv)
    sig = der_encode_sig(*rawsig)+encode(hashcode, 16, 2)
    txobj['ins'][i]['txinwitness'] = [sig, pub]
    return serialize(txobj)


def bech32_script_to_address(script, prefix=BECH32_BITCOIN_PREFIX):
    from bitcoin import sha256
    script = binascii.unhexlify(script)
    script_hash = sha256(script)
    return bech32encode('0020' + script_hash, prefix=prefix)


def bech32_scripthash_to_address(scripthash: str, prefix=BECH32_BITCOIN_PREFIX):
    if re.match('^[0-9a-fA-F]*$', scripthash):
        scripthash = bytes.fromhex(scripthash)

    if scripthash[:2] == b'\x00\x20':
        return bech32encode(scripthash.hex(), prefix)
    if scripthash[:2] == b'\x00\x14':
        return bech32encode(scripthash.hex(), prefix)
    raise ValueError

def bech32_multisign(tx, i, priv, amount, script, hashcode=SIGHASH_ALL):
    from bitcoin import segwit_signature_form, ecdsa_raw_sign, der_encode_sig
    i = int(i)
    if len(priv) <= 33:
        priv = binascii.hexlify(priv)
    signing_tx = segwit_signature_form(tx, i, script, amount, hashcode=hashcode)
    rawsig = ecdsa_raw_sign(hashlib.sha256(hashlib.sha256(binascii.unhexlify(signing_tx)).digest()).hexdigest(), priv)
    sig = der_encode_sig(*rawsig)+encode(hashcode, 16, 2)
    return sig


def apply_bech32_multisignatures(tx, i, witness_program, signatures):
    from bitcoin import deserialize, serialize
    o = [""] + signatures + [witness_program]
    txobj = deserialize(tx)
    txobj['ins'][i]['txinwitness'] = o
    return serialize(txobj)

<filename>bitcoin/bech32.py
# Majority of code taken from reference implementation:
# https://github.com/sipa/bech32/blob/master/ref/python/segwit_addr.py

# Copyright (c) 2017 <NAME>
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.

"""Reference implementation for Bech32 and segwit addresses."""
import binascii
import re

from bitcoin import encode_pubkey, hash160, SIGHASH_ALL, privkey_to_pubkey, encode, hashlib

from enum import Enum

class Encoding(Enum):
    """Enumeration type to list the various supported encodings."""
    BECH32 = 1
    BECH32M = 2

CHARSET = "qpzry9x8gf2tvdw0s3jn54khce6mua7l"
BECH32M_CONST = 0x2bc830a3

BECH32_BITCOIN_PREFIX = 'bc'
BECH32_BITCOIN_TESTNET_PREFIX = 'tb'
BECH32_BITCOIN_REGTEST_PREFIX = 'bcrt'

BECH32_CUSTOM_SIGNET_PREFIX = 'cbc'
BECH32_CUSTOM_SIGNET_TESTNET_PREFIX = 'cbt'

BECH32_PREFIXES = [
    BECH32_CUSTOM_SIGNET_TESTNET_PREFIX,
    BECH32_CUSTOM_SIGNET_PREFIX,
    BECH32_BITCOIN_PREFIX,
    BECH32_BITCOIN_TESTNET_PREFIX,
    BECH32_BITCOIN_REGTEST_PREFIX
]


def bech32_polymod(values):
    """Internal function that computes the Bech32 checksum."""
    generator = [0x3b6a57b2, 0x26508e6d, 0x1ea119fa, 0x3d4233dd, 0x2a1462b3]
    chk = 1
    for value in values:
        top = chk >> 25
        chk = (chk & 0x1ffffff) << 5 ^ value
        for i in range(5):
            chk ^= generator[i] if ((top >> i) & 1) else 0
    return chk


def bech32_hrp_expand(hrp):
    """Expand the HRP into values for checksum computation."""
    return [ord(x) >> 5 for x in hrp] + [0] + [ord(x) & 31 for x in hrp]

'''
def bech32_verify_checksum(hrp, data):
    """Verify a checksum given HRP and converted data characters."""
    return bech32_polymod(bech32_hrp_expand(hrp) + data) == 1
'''

def bech32_verify_checksum(hrp, data):
    """Verify a checksum given HRP and converted data characters."""
    const = bech32_polymod(bech32_hrp_expand(hrp) + data)
    if const == 1:
        return Encoding.BECH32
    if const == BECH32M_CONST:
        return Encoding.BECH32M
    return None

'''
def bech32_create_checksum(hrp, data):
    """Compute the checksum values given HRP and data."""
    values = bech32_hrp_expand(hrp) + data
    polymod = bech32_polymod(values + [0, 0, 0, 0, 0, 0]) ^ 1
    return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)]
'''

def bech32_create_checksum(hrp, data, spec):
    """Compute the checksum values given HRP and data."""
    values = bech32_hrp_expand(hrp) + data
    const = BECH32M_CONST if spec == Encoding.BECH32M else 1
    polymod = bech32_polymod(values + [0, 0, 0, 0, 0, 0]) ^ const
    return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)]


def bech32_encode(hrp, data, spec):
    """Compute a Bech32 string given HRP and data values."""
    combined = data + bech32_create_checksum(hrp, data, spec)
    return hrp + '1' + ''.join([CHARSET[d] for d in combined])

'''
def bech32_decode(bech):
    """Validate a Bech32 string, and determine HRP and data."""
    if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
            (bech.lower() != bech and bech.upper() != bech)):
        return None, None
    bech = bech.lower()
    pos = bech.rfind('1')
    if pos < 1 or pos + 7 > len(bech) or len(bech) > 90:
        return None, None
    if not all(x in CHARSET for x in bech[pos+1:]):
        return None, None
    hrp = bech[:pos]
    data = [CHARSET.find(x) for x in bech[pos+1:]]
    if not bech32_verify_checksum(hrp, data):
        return None, None
    return hrp, data[:-6]
'''

def _bech32_decode(bech):
    """Validate a Bech32/Bech32m string, and determine HRP and data."""
    if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or
            (bech.lower() != bech and bech.upper() != bech)):
        return (None, None, None)
    bech = bech.lower()
    pos = bech.rfind('1')
    if pos < 1 or pos + 7 > len(bech) or len(bech) > 90:
        return (None, None, None)
    if not all(x in CHARSET for x in bech[pos+1:]):
        return (None, None, None)
    hrp = bech[:pos]
    data = [CHARSET.find(x) for x in bech[pos+1:]]
    spec = bech32_verify_checksum(hrp, data)
    if spec is None:
        return (None, None, None)
    return (hrp, data[:-6], spec)


def convertbits(data, frombits, tobits, pad=True):
    """General power-of-2 base conversion."""
    acc = 0
    bits = 0
    ret = []
    maxv = (1 << tobits) - 1
    max_acc = (1 << (frombits + tobits - 1)) - 1
    for value in data:
        if value < 0 or (value >> frombits):
            return None
        acc = ((acc << frombits) | value) & max_acc
        bits += frombits
        while bits >= tobits:
            bits -= tobits
            ret.append((acc >> bits) & maxv)
    if pad:
        if bits:
            ret.append((acc << (tobits - bits)) & maxv)
    elif bits >= frombits or ((acc << (tobits - bits)) & maxv):
        return None
    return ret


def _decode(hrp, addr):
    """Decode a segwit address."""
    hrpgot, data, spec = _bech32_decode(addr)
    if hrpgot != hrp:
        return (None, None)
    decoded = convertbits(data[1:], 5, 8, False)
    if decoded is None or len(decoded) < 2 or len(decoded) > 40:
        return (None, None)
    if data[0] > 16:
        return (None, None)
    if data[0] == 0 and len(decoded) != 20 and len(decoded) != 32:
        return (None, None)
    if data[0] == 0 and spec != Encoding.BECH32 or data[0] != 0 and spec != Encoding.BECH32M:
        return (None, None)
    return (data[0], decoded)


def _bech32_encode(hrp, data, spec):
    """Compute a Bech32 string given HRP and data values."""
    combined = data + bech32_create_checksum(hrp, data, spec)
    return hrp + '1' + ''.join([CHARSET[d] for d in combined])


def _encode(hrp, witver, witprog):
    """Encode a segwit address."""
    spec = Encoding.BECH32 if witver == 0 else Encoding.BECH32M
    ret = _bech32_encode(hrp, [witver] + convertbits(witprog, 8, 5), spec)
    if _decode(hrp, ret) == (None, None):
        return None
    return ret


def bech32encode(script: str, prefix=BECH32_BITCOIN_PREFIX):
    from bitcoin.transaction import deserialize_script
    witnessversion, witnessprogram = deserialize_script(script)
    witnessversion = 0 if witnessversion is None else witnessversion
    assert 0 <= witnessversion <= 16
    if witnessversion == 0:
        assert len(witnessprogram) == 40 or len(witnessprogram) == 64
    return _encode(prefix, witnessversion, bytearray(binascii.unhexlify(witnessprogram))).lower()


def int_to_hex(n: int) -> str:
    return binascii.hexlify(chr(n).encode()).decode()


def segwit_scriptpubkey(witver, witprog):
    """Construct a Segwit scriptPubKey for a given witness program."""
    return bytes([witver + 0x50 if witver else 0, len(witprog)] + witprog)


def bech32decode(text: str):
    assert isinstance(text, str)
    from bitcoin import from_int_to_byte
    if text[:4].lower() == BECH32_BITCOIN_REGTEST_PREFIX:
        human_readable_part_size = 4
    elif text[:2].lower() in (
        BECH32_BITCOIN_PREFIX,
        BECH32_BITCOIN_TESTNET_PREFIX
    ):
        human_readable_part_size = 2
    elif text[:3].lower() in (
        BECH32_CUSTOM_SIGNET_PREFIX,
        BECH32_CUSTOM_SIGNET_TESTNET_PREFIX
    ):
        human_readable_part_size = 3
    else:
        raise ValueError('Invalid readable part')

    if len(set([t.islower() for t in text if t.isalpha()])) > 1:
        raise ValueError('Mixed case')
    text = text.lower().encode("utf-8").decode()

    witnessversion, wit_ordnallist = _decode(text[:human_readable_part_size], text)
    if witnessversion is None and wit_ordnallist is None:
        raise ValueError('Exception with %s (prefix: %s)' % (text, text[:human_readable_part_size]))
    if not witnessversion:
        assert len(wit_ordnallist) == 20 or len(wit_ordnallist) == 32
    o = ""
    for ordinal in wit_ordnallist:
        o += binascii.hexlify(from_int_to_byte(ordinal)).decode()
    return int_to_hex(witnessversion + 0x50 if witnessversion else 0) + int_to_hex(int(len(o) / 2)) + o


def pubkey_to_bech32_address(pubkey, prefix=BECH32_BITCOIN_PREFIX):
    if isinstance(pubkey, (list, tuple)):
        pubkey = encode_pubkey(pubkey, 'bin')
    if len(pubkey) in [66, 130]:
        pubkey = binascii.unhexlify(pubkey)
        pubkey_hash = hash160(pubkey)
        return bech32encode('0014' + pubkey_hash, prefix=prefix)
    if len(pubkey) in [68]:
        return bech32encode(pubkey, prefix=prefix)
    raise ValueError()


def bech32_sign(tx, i, priv, amount, script=None, hashcode=SIGHASH_ALL):
    from bitcoin import deserialize, segwit_signature_form, ecdsa_raw_sign, der_encode_sig, serialize, compress
    i = int(i)
    txobj = tx if isinstance(tx, dict) else deserialize(tx)
    if len(priv) <= 33:
        priv = binascii.hexlify(priv)
    pub = compress(privkey_to_pubkey(priv))
    script = script or ('76a914' + hash160(binascii.unhexlify(pub)) + '88ac')
    signing_tx = segwit_signature_form(tx, i, script, amount, hashcode=hashcode)
    rawsig = ecdsa_raw_sign(hashlib.sha256(hashlib.sha256(binascii.unhexlify(signing_tx)).digest()).hexdigest(), priv)
    sig = der_encode_sig(*rawsig)+encode(hashcode, 16, 2)
    txobj['ins'][i]['txinwitness'] = [sig, pub]
    return serialize(txobj)


def bech32_script_to_address(script, prefix=BECH32_BITCOIN_PREFIX):
    from bitcoin import sha256
    script = binascii.unhexlify(script)
    script_hash = sha256(script)
    return bech32encode('0020' + script_hash, prefix=prefix)


def bech32_scripthash_to_address(scripthash: str, prefix=BECH32_BITCOIN_PREFIX):
    if re.match('^[0-9a-fA-F]*$', scripthash):
        scripthash = bytes.fromhex(scripthash)

    if scripthash[:2] == b'\x00\x20':
        return bech32encode(scripthash.hex(), prefix)
    if scripthash[:2] == b'\x00\x14':
        return bech32encode(scripthash.hex(), prefix)
    raise ValueError

def bech32_multisign(tx, i, priv, amount, script, hashcode=SIGHASH_ALL):
    from bitcoin import segwit_signature_form, ecdsa_raw_sign, der_encode_sig
    i = int(i)
    if len(priv) <= 33:
        priv = binascii.hexlify(priv)
    signing_tx = segwit_signature_form(tx, i, script, amount, hashcode=hashcode)
    rawsig = ecdsa_raw_sign(hashlib.sha256(hashlib.sha256(binascii.unhexlify(signing_tx)).digest()).hexdigest(), priv)
    sig = der_encode_sig(*rawsig)+encode(hashcode, 16, 2)
    return sig


def apply_bech32_multisignatures(tx, i, witness_program, signatures):
    from bitcoin import deserialize, serialize
    o = [""] + signatures + [witness_program]
    txobj = deserialize(tx)
    txobj['ins'][i]['txinwitness'] = o
    return serialize(txobj)

# Majority of code taken from reference implementation: # https://github.com/sipa/bech32/blob/master/ref/python/segwit_addr.py # Copyright (c) 2017 <NAME> # # Permission is hereby granted, free of charge, to any person obtaining a copy # of this software and associated documentation files (the "Software"), to deal # in the Software without restriction, including without limitation the rights # to use, copy, modify, merge, publish, distribute, sublicense, and/or sell # copies of the Software, and to permit persons to whom the Software is # furnished to do so, subject to the following conditions: # # The above copyright notice and this permission notice shall be included in # all copies or substantial portions of the Software. # # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR # IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, # FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE # AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER # LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, # OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN # THE SOFTWARE. Reference implementation for Bech32 and segwit addresses. Enumeration type to list the various supported encodings. Internal function that computes the Bech32 checksum. Expand the HRP into values for checksum computation. def bech32_verify_checksum(hrp, data):     """Verify a checksum given HRP and converted data characters."""     return bech32_polymod(bech32_hrp_expand(hrp) + data) == 1 Verify a checksum given HRP and converted data characters. def bech32_create_checksum(hrp, data):     """Compute the checksum values given HRP and data."""     values = bech32_hrp_expand(hrp) + data     polymod = bech32_polymod(values + [0, 0, 0, 0, 0, 0]) ^ 1     return [(polymod >> 5 * (5 - i)) & 31 for i in range(6)] Compute the checksum values given HRP and data. Compute a Bech32 string given HRP and data values. def bech32_decode(bech):     """Validate a Bech32 string, and determine HRP and data."""     if ((any(ord(x) < 33 or ord(x) > 126 for x in bech)) or             (bech.lower() != bech and bech.upper() != bech)):         return None, None     bech = bech.lower()     pos = bech.rfind('1')     if pos < 1 or pos + 7 > len(bech) or len(bech) > 90:         return None, None     if not all(x in CHARSET for x in bech[pos+1:]):         return None, None     hrp = bech[:pos]     data = [CHARSET.find(x) for x in bech[pos+1:]]     if not bech32_verify_checksum(hrp, data):         return None, None     return hrp, data[:-6] Validate a Bech32/Bech32m string, and determine HRP and data. General power-of-2 base conversion. Decode a segwit address. Compute a Bech32 string given HRP and data values. Encode a segwit address. Construct a Segwit scriptPubKey for a given witness program.