minicryptlib

import random, os, re

class Pad(object):
  def __init__(self):
    super(Pad, self).__init__()

  def getRandomCypher(self, data):
    """Generates random key and returns dict with key and cyphered data."""
    key = os.urandom(len(data))
    pairs = [[ord(a) for a in i] for i in zip(data, key)]
    retval = [chr(i[0]^i[1]) for i in pairs]
    return {"KEY":key, "CRYPT":str().join(retval)}

  def decypher(self, dict):
    """Decyphers with a dict. Takes dict with keys 'KEY' and 'CRYPT'."""
    if list(sorted(dict.keys())) != ["CRYPT","KEY"]:
      raise SyntaxError, "Invalid argument dict"
    pairs = [[ord(a) for a in i] for i in zip(dict["KEY"], dict["CRYPT"])]
    retval = [chr(i[0]^i[1]) for i in pairs]
    return str().join(retval)

  def cypherFile(self, path):
    kp = self.getRandomCypher(open(path, "rb").read())
    with open("outfile.bin", "wb") as of:
      of.write(kp["CRYPT"])
    with open("cryptkey.KEY", "wb") as ck:
      ckdat = """START?{d}?END\nFILE_NAME:'{fn}'"""\
      .format(d=kp["KEY"].encode("base64"), fn=os.path.split(path)[1])
      ck.write(ckdat)

  def decypherFile(self, keyFile, cypherFile):
    keyDat = open(keyFile, "rb").read()
    cypherDat = open(cypherFile, "rb").read()
    keyRead = re.findall("START\?(.+)\?END", keyDat, re.DOTALL)[0]
    FName   = re.findall("FILE_NAME:'(.+)'", keyDat, re.DOTALL)[0]
    Decyphered = self.decypher({"KEY":keyRead.decode("base64"), "CRYPT":cypherDat})
    with open(FName, "wb") as file:
      file.write(Decyphered)