Python implementation of HeidiSQL password hash functions.

heidisql_password.py

# Original implementation is written in Pascal:
# https://github.com/HeidiSQL/HeidiSQL/blob/10.1/source/apphelpers.pas#L456-L506

from itertools import zip_longest
from random import randint

def decode(hash):
    def grouper(n, iterable, padvalue=None):
        return zip_longest(*[iter(iterable)] * n, fillvalue=padvalue)

    def bytehandler(x):
        nr = int(''.join(x), 16) - int(hash[-1], 16)
        if nr < 0:
            nr += 255
        return chr(nr)

    return ''.join(map(bytehandler, grouper(2, hash[:-1])))

def encode(password):
    hash = ''
    salt = randint(1, 9)
    for char in password:
        nr = ord(char) + salt
        if nr > 255:
            nr = nr - 255
        hex = '%0.2X' % nr
        if len(hex) == 1:
            h = '0' + hex
        hash = hash + hex
    hash = hash + str(salt)
    return hash

print(decode(encode('password')))  # 'password'