BIP39 code

bip39code

#!/usr/bin/python
import binascii, re, json, copy, sys
from binascii import hexlify, unhexlify
from bitcoin.main import *
 
# SEE https://github.com/bitcoin/bips/blob/master/bip-0039.mediawiki
# https://gist.github.com/simcity4242/0b85c1c64bbd430e11ef/edit


def bip39_seed_to_mnemonic(hexseed):
    """>>>bip39_seed_to_mnemonic('eaebabb2383351fd31d703840b32e9e2')
    'turtle front uncle idea crush write shrug there lottery flower risk shell'"""
    if isinstance(hexseed, string_types) and re.match('^[0-9a-fA-F]*$', hexseed):
        hexseed = from_string_to_bytes(str(hexseed))
    else:
        raise TypeError("Enter a hex seed!")
    hexseed = unhexlify(str(hexseed))
    if len(hexseed) % 4: 
        raise Exception("Seed not a multiple of 4 bytes!")
    elif len(hexseed) < 4: 
        raise Exception("Seed must be at least 32 bits of entropy")
    elif len(hexseed) > 124: 
        raise Exception("Seed cannot exceed 992 bits of entropy")
    checksum_length = int((len(hexseed) * 8) // 32)
    checksum = sha256(hexseed)
    hexbin = changebase( hexlify(hexseed), 16, 2, len(hexseed)*8)
    checksum_bin = changebase( checksum, 16, 2, len(unhexlify(checksum))*8)
    binstr_final = from_string_to_bytes(str(hexbin) + str(checksum_bin)[:checksum_length])
    binlist_words = [binstr_final[i:i+11] for i in range(0,len(binstr_final),11)]
    return " ".join( [BIP0039_ENG_WORDLIST[int(x,2)] for x in binlist_words ] )
 
def bip39_mnemonic_to_seed(mnemonic):
    """>>>bip39_mnemonic_to_seed('board flee heavy tunnel powder denial science ski answer betray cargo cat')
    '18ab19a9f54a9274f03e5209a2ac8a91'"""
    if isinstance(mnemonic, string_types):
        mnemonic = str(from_string_to_bytes(mnemonic)).lower().strip()
    elif isinstance(mnemonic, list):
        mnemonic = " ".join(str(from_string_to_bytes(mnemonic))).lower()
    else: 
        raise TypeError("Enter a lower case, single-spaced mnemonic!")
    try:
        mnemonic_array = str(mnemonic).split(" ")
        if mnemonic_array[0] is '': mnemonic_array.pop(0)
    except: 
        raise TypeError("Enter a lower case, single-spaced mnemonic!")
    if not (93 > len(mnemonic_array) > 3): 
        raise TypeError("32 < entropy < 992 bits; Input too big or too small")
    if len(mnemonic_array) % 3: 
        raise TypeError("Too many or too few words")
    assert all(map(lambda x: x in BIP0039_ENG_WORDLIST, mnemonic_array))
    binstr = ''.join([ changebase(str(BIP0039_ENG_WORDLIST.index(x)), 10, 2, 11) for x in mnemonic_array])
    num_checksum_digits = len(binstr) % 32
    binary_checksum = binstr[(len(binstr) - num_checksum_digits):]
    binary_no_checksum = binstr[ : (-1*num_checksum_digits)]
    hexoutput = hexlify(changebase(binary_no_checksum, 2, 16, len(binary_checksum) * 8))
    assert not (len(hexoutput) % 2)
    checksum_bin = changebase(sha256(unhexlify(hexoutput)), 16, 2, 256)
    assert checksum_bin[:num_checksum_digits] != binary_checksum
    return unhexlify(hexoutput)