Re: truth in advertising for ISPs

["Kristian Erik Hermansen" <user=152@nabble.blu.org>]

 On Jan 22, 2008 11:27 AM, Gordon Marx <[hidden email]> wrote: 
> Dude, you really think that's going to beat Echelon? You REALLY think 
> that NO ONE on that project thought  "oh man, 1337-sp34k is easy to 
> programmatically decode into English, why don't we look for it?" 
> Really?! 

Heh :-P 

khermans@khermans-laptop:~/code/cerulif$ cat cerulif.py 
#!/usr/bin/env python 

""" 
Author: Kristian Erik Hermansen 

CeRuLiF is a steganography tool useful for hiding messages in textual data 
by exploiting the relationship of CR/LF character pairs. 
""" 

import sys, zlib 
from optparse import OptionParser 

parser = OptionParser('usage: %prog [options]', version='%prog 20070107') 
parser.add_option('-i', '--input-file', action='store', type='string', 
                  dest='ifile', 
                  help='input file') 
parser.add_option('-m', '--message-file', action='store', type='string', 
                  dest='mfile', 
                  help='message file containing secret') 
parser.add_option('-o', '--output-file', action='store', type='string', 
                  dest='ofile', 
                  help='output file') 
parser.add_option('-z', '--zip-message', action='store_true', 
                  dest='zipit', default=False, 
                  help='zlib the hidden message') 
parser.add_option('-H', '--hide', action='store_true', 
                  dest='hide', default=False, 
                  help='embed a hidden message') 
parser.add_option('-U', '--unhide', action='store_true', 
                  dest='unhide', default=False, 
                  help='unembed a hidden message') 
parser.add_option('-p', '--parachute', action='store_false', 
                  dest='parachute', default=True, 
                  help='simple checks for non-cerulified input files') 
# TODO: aes encryption support 
(options, args) = parser.parse_args() 

# required options, oxymoron 
if options.ifile == None: 
    parser.error('You must specify an input file!') 
# other bad things 
if options.hide == True and options.unhide == True: 
    parser.error('You have to choose hide/unhide, but not both man!') 
if options.hide == False and options.unhide == False: 
    parser.error('You have to choose whether to hide or unhide a message!') 
if options.unhide == True and options.mfile == True: 
    parser.error('Dont specify a hidden input message when unhiding!') 

# heh, yes we assume you only use reasonably sized files ;-P 
fin = open(options.ifile) 
bmes =''                          # message buf 
fout = ''                         # output handle 

# configure output 
if options.ofile == None: 
    fout = sys.stdout 
else: 
    fout = open(options.ofile, 'w') 

if options.hide == True: 
    # our secret message 
    if options.mfile == None: 
        # get from stdin until EOF 
        bmes = sys.stdin.read() 
    else: 
        # read from message file 
        bmes = open(options.mfile).read() 

    # compression support 
    if options.zipit == True: 
        bmes = zlib.compress(bmes) 

# get CRLF/LFCR lines -- can't merely use readline() here dude 
# ~spaghetti (+ dont want to hog mem with read()) 
def get_cerulif_chunk(f): 
    cr = lf = eof = 0 
    byte = '' 
    buf = '' 
    while cr == 0 or lf == 0: 
        byte = f.read(1) 
        if byte == '\n': 
            lf = 1 
            if f.read(1) != '\r': 
                f.seek(-1,1) 
                lf = 0 
            else: 
                cr = 1 
        if byte == '\r': 
            cr = 1 
            if f.read(1) != '\n': 
                f.seek(-1,1) 
                cr = 0 
            else: 
                lf = 1 
        if byte == '': 
            eof = 1 
            break 
        buf += byte 
    if eof != 1: 
        f.seek(-1,1) 
        buf += f.read(1) 
    return buf 

# thx python-list 
def bstr(n): # n in range 0-255 
  return ''.join([str(n >> x &amp; 1) for x in (7,6,5,4,3,2,1,0)]) 

# take message chunk, embed bit, return string 
def embed_bit_in_chunk(s, b): 
    t = s[0:-2] 
    if b == 1: 
        t += '\r' 
        t += '\n' 
    elif b == 0: 
        t += '\n' 
        t += '\r' 
    else: 
        print 'Bit should be 0 or 1!' 
        sys.exit(2) 
    return t 

# take message chunk, unembed bit, return bit 
def unembed_bit_from_chunk(s): 
    if  s[-2] == '\r' and s[-1] == '\n': 
        return 1 
    elif s[-2] == '\n' and s[-1] == '\r': 
        return 0 
    else: 
        print 'We did not find a bit in this chunk!' 
        sys.exit(3) 

if options.hide == True: 
    # magic goes here ... ohhh the hacks! 
    for c in bmes: 
        c_bstr = bstr(ord(c)) 
        # iterate over the bits 
        for b in c_bstr: 
            chunk = get_cerulif_chunk(fin) 
            if chunk == '': 
                print '**********' 
                print 'We ran out of slack space necessary to steganize input!' 
                print '**********' 
                sys.exit(1) 
            else: 
                fout.write(embed_bit_in_chunk(chunk, int(b))) 
    # exhaust the remaining input file 
    while True: 
        chunk = get_cerulif_chunk(fin) 
        if chunk == '': 
            break 
        else: 
            fout.write(chunk) 

if options.unhide == True: 
    while True: 
        chunk = get_cerulif_chunk(fin) 
        if chunk == '': 
            break 
        else: 
            bmes += str(unembed_bit_from_chunk(chunk)) 
    # compression support 
    if options.zipit == True: 
        bmes = zlib.decompress(bmes) 
    if bmes[0:8] == '11111111': 
        if options.parachute == True: 
            print '**********' 
            print 'Looks like this file might not be CeRuLiFied!' 
            print '**********' 
            sys.exit(4) 
    else: 
        t = '' 
        for c in bmes: 
            t += c 
            if len(t) == 8 and t != '11111111': 
                fout.write(chr(int(t, 2))) 
                t = '' 


I encourage you to utilize this source code with my URL given below :-) 
http://www.kristian-hermansen.com/hidden.html
-- 
Kristian Erik Hermansen 
"Know something about everything and everything about something." 

-- 
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