#!/usr/bin/python
import hashlib, string, sys

ROUNDS = 20000

def xor(a, b):
    l = min(len(a), len(b))
    return ''.join([chr(ord(x) ^ ord(y)) for x, y in zip(a[:l], b[:l])])

def h(x):
    x = hashlib.sha256(x).digest()
    x = xor(x[:16], x[16:])
    return x

def verify(x):
    return all([ord(c) < 127 for c in x])

def crypt(msg, passwd):
    k = h(passwd)

    for i in xrange(ROUNDS):
        k = h(k)

    out = ''
    for i in xrange(0, len(msg), 16):
        out += xor(msg[i:i+16], k)
        k = h(k + str(len(msg)))

    return out

def encrypt(msg, passwd):
    msg = crypt(msg, passwd)

    return msg.encode('base64')

def decrypt(msg, passwd):
    msg = crypt(msg.decode('base64'), passwd)

    if verify(msg):
        return msg
    else:
        sys.stderr.write('Looks like a bad decrypt\n')
        sys.exit(1)

def decrypt2(msg, passwd):
    msg = crypt2(msg.decode('base64'), passwd)

    if verify(msg):
        return msg
    else:
        sys.stderr.write('Looks like a bad decrypt\n')
        sys.exit(1)

def crypt2(msg, k):

    out = ''
    for i in xrange(0, len(msg), 16):
        out += xor(msg[i:i+16], k)
        k = h(k + str(len(msg)))

    return out

def crack(msg):
    plain = "From: Vlugge Japie <vl.japie@yahoo.com>"
    msg = msg.decode('base64')
    key = ""

    for pos in range(16):

        for w in range(256):
    	    passwd = chr(w) * 32

            k = passwd

            out = ''
            for i in xrange(0, len(msg), 16):
                out += xor(msg[i:i+16], k)
            if out[pos] == plain[pos]:
                print "POS " + str(pos) + ": chr(" + str(w) + ")"
                key = key + chr(w)
    return key

def h2(x):
    x = xor(x[:16], x[16:])
    return x

inp = open("msg002.enc").read()

key = crack(inp)

res = decrypt2(inp, key)
print res