Convert Bitcoin WIF to Litecoin WIF format

bitcoin-wif-litecoin-wif.py

'''
Bitcoin WIF to Litecoin WIF converter

=== INFO ===

Idk

=== USAGE (example) ===

% python3 litecoinwif.py
    what is your bitcoin WIF (the key dumped from bitcoin core)?
    L1aW4aubDFB7yfras2S1mN3bqg9nwySY8nkoLmJebSLD5BWv3ENZ
    your private key in litecoin format is: T7QmWLCmcd9ikWVTQfNsyiaynXo724TRwzf4CZwCAQWNb4zrE7RK

=== OWNERSHIP ===

Based on code written by Carlo Cervellin (carlo.cervellin.eu). https://github.com/crcarlo/btcwif/

'''

import hashlib

# base58 alphabet
alphabet = '123456789ABCDEFGHJKLMNPQRSTUVWXYZabcdefghijkmnopqrstuvwxyz'


def sha256(arg):
    ''' Return a sha256 hash of a hex string '''
    byte_array = bytearray.fromhex(arg)
    m = hashlib.sha256()
    m.update(byte_array)
    return m.hexdigest()


def b58encode(hex_string):
    ''' Return a base58 encoded string from hex string '''
    num = int(hex_string, 16)
    encode = ""
    base_count = len(alphabet)
    while (num > 0):
        num, res = divmod(num, base_count)
        encode = alphabet[res] + encode
    return encode


def b58decode(v):
    ''' Decode a Base58 encoded string as an integer and return a hex string '''
    if not isinstance(v, str):
        v = v.decode('ascii')
    decimal = 0
    for char in v:
        decimal = decimal * 58 + alphabet.index(char)
    return hex(decimal)[2:]  # (remove "0x" prefix)


def privToWif(priv, verbose=False):
    ''' Produce a WIF from a private key in the form of an hex string '''
    # 1 - Take a private key
    _priv = priv.lower()  # just for aesthetics
    if verbose:
        print("Private key: "+_priv)
    # 2 - Add a 0xB0 byte in front of it
    # 0xB0 is the Litecoin WIF prefix
    priv_add_x80 = "B0" + _priv
    if verbose:
        print("Private with x80 at beginning: "+priv_add_x80)
    # 3 - Perform SHA-256 hash on the extended key
    first_sha256 = sha256(priv_add_x80)
    if verbose:
        print("sha256: " + first_sha256.upper())
    # 4 - Perform SHA-256 hash on result of SHA-256 hash
    seconf_sha256 = sha256(first_sha256)
    if verbose:
        print("sha256: " + seconf_sha256.upper())
    # 5 - Take the first 4 bytes of the second SHA-256 hash, this is the checksum
    first_4_bytes = seconf_sha256[0:8]
    if verbose:
        print("First 4 bytes: " + first_4_bytes)
    # 6 - Add the 4 checksum bytes from point 5 at the end of the extended key from point 2
    resulting_hex = priv_add_x80 + first_4_bytes
    if verbose:
        print("Resulting WIF in HEX: " + resulting_hex)
    # 7 - Convert the result from a byte string into a base58 string using Base58Check encoding. This is the Wallet Import Format
    result_wif = b58encode(resulting_hex)
    if verbose:
        print("Resulting WIF: " + result_wif)
    return result_wif


def wifToPriv(wif, verbose=False):
    ''' Produce the private ECDSA key in the form of a hex string from a WIF string '''
    if not wifChecksum(wif):
        raise Exception('The WIF is not correct (does not pass checksum)')
    # 1 - Take a Wallet Import Format string
    if verbose:
        print("WIF: " + wif)
    # 2 - Convert it to a byte string using Base58Check encoding
    byte_str = b58decode(wif)
    if verbose:
        print("WIF base58 decoded: " + byte_str)
    # 3 - Drop the last 4 checksum bytes from the byte string
    byte_str_drop_last_4bytes = byte_str[0:-8]
    if verbose:
        print("Decoded WIF drop last 4 bytes: " + byte_str_drop_last_4bytes)
    # 4 - Drop the first byte
    byte_str_drop_first_byte = byte_str_drop_last_4bytes[2:]
    if verbose:
        print("ECDSA private key: " + byte_str_drop_first_byte)
    return byte_str_drop_first_byte


def wifChecksum(wif, verbose=False):
    ''' Returns True if the WIF is positive to the checksum, False otherwise '''
    # 1 - Take the Wallet Import Format string
    if verbose:
        print("WIF: " + wif)
    # 2 - Convert it to a byte string using Base58Check encoding
    byte_str = b58decode(wif)
    if verbose:
        print("WIF base58 decoded: " + byte_str)
    # 3 - Drop the last 4 checksum bytes from the byte string
    byte_str_drop_last_4bytes = byte_str[0:-8]
    if verbose:
        print("Decoded WIF drop last 4 bytes: " + byte_str_drop_last_4bytes)
    # 3 - Perform SHA-256 hash on the shortened string
    sha_256_1 = sha256(byte_str_drop_last_4bytes)
    if verbose:
        print("SHA256 1: " + sha_256_1)
    # 4 - Perform SHA-256 hash on result of SHA-256 hash
    sha_256_2 = sha256(sha_256_1)
    if verbose:
        print("SHA256 2: " + sha_256_2)
    # 5 - Take the first 4 bytes of the second SHA-256 hash, this is the checksum
    first_4_bytes = sha_256_2[0:8]
    if verbose:
        print("First 4 bytes: " + first_4_bytes)
    # 6 - Make sure it is the same, as the last 4 bytes from point 2
    last_4_bytes_WIF = byte_str[-8:]
    if verbose:
        print("Last 4 bytes of WIF: " + last_4_bytes_WIF)
    bytes_check = False
    if first_4_bytes == last_4_bytes_WIF:
        bytes_check = True
    if verbose:
        print("4 bytes check: " + str(bytes_check))
    # 7 - If they are, and the byte string from point 2 starts with 0x80 (0xef for testnet addresses), then there is no error.
    check_sum = False
    if bytes_check and byte_str[0:2] == "80":
        check_sum = True
    if verbose:
        print("Checksum: " + str(check_sum))
    return check_sum


def main():
    user_bitcoin_wif = input(
        'what is your bitcoin WIF (the key dumped from bitcoin core)?\n')
    temp_priv = wifToPriv(user_bitcoin_wif)
    temp_ltiecoin_wif = privToWif(temp_priv)
    print('your private key in litecoin format is: ' + temp_ltiecoin_wif)


main()