Python implementation of Tor's password hashing OpenPGP S2K algorithm

onionporn.py

import os, binascii, hashlib

#supply password
secret = 'foo'

#static 'count' value later referenced as "c"
indicator = chr(96)

#used to generate salt
rng = os.urandom

#generate salt and append indicator value so that it
salt = "%s%s" % (rng(8), indicator)

#That's just the way it is. It's always prefixed with 16
prefix = '16:'

# swap variables just so I can make it look exactly like the RFC example
c = ord(salt[8])

# generate an even number that can be divided in subsequent sections. (Thanks Roman)
EXPBIAS = 6
count = (16+(c&15)) << ((c>>4) + EXPBIAS)  #

d = hashlib.sha1()

#take the salt and append the password
tmp = salt[:8]+secret

#hash the salty password as many times as the length of
# the password divides into the count value
slen = len(tmp)
while count:
  if count > slen:
    d.update(tmp)
    count -= slen
  else:
    d.update(tmp[:count])
    count = 0
hashed = d.digest()
#Convert to hex
salt = binascii.b2a_hex(salt[:8]).upper()
indicator = binascii.b2a_hex(indicator)
torhash = binascii.b2a_hex(hashed).upper()

#Put it all together into the proprietary Tor format.
print(prefix + salt + indicator + torhash)