# Methods

## Paddinganography

{% embed url="<https://inshallhack.org/paddinganography/>" %}

```
#Source: https://gist.githubusercontent.com/dhondta/90a07d9d106775b0cd29bb51ffe15954/raw/e85a13e7fe1805daa314d776926df470d344aca6/paddinganograph.py

#!/usr/bin/python3
# -*- coding: UTF-8 -*-
import math
from tinyscript import *


__author__ = "Alexandre D'Hondt"
__version__ = "1.2"
__copyright__ = "A. D'Hondt"
__license__ = "agpl-3.0"
__reference__ = "https://inshallhack.org/paddinganography/"
__doc__ = """
This tool allows to unhide data hidden in base32/base64 strings. It can take a
 PNG or JPG in input to retrieve an EXIF value as the input data.
"""
__examples__ = [
    "-s . -f \"Comment\" < image.jpg > base32.enc",
    "-e base32 < base32.enc"
]


DEF_BASE64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
DEF_BASE32 = "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567"


def exif(raw_data, key):
    t = TempPath().tempfile().name
    with open(str(t), 'wb') as f:
        f.write(raw_data)
    logger.debug("Getting EXIF data...")
    exif = subprocess.check_output(["exiftool", str(t)])
    exif = codecs.decode(exif, "utf-8")
    exif = {l.split(':', 1)[0].strip(): l.split(':', 1)[1].strip() \
            for l in exif.split('\n') if l.strip() != ""}
    return exif if not key else exif[key]


def unhide(encoded, encoding="base64", charset=None, sep=".", pad="=", n_pad=8):
    try:
        charset = (charset or \
                   globals()["DEF_{}".format(encoding.upper())]).strip()
    except NameError:
        raise ValueError("Bad encoding")
    logger.debug("Unhidding data...")
    bits = ""
    for token in encoded.split(b(sep)):
        bits += unhide_bits(token.strip(), charset, pad, n_pad) or ""
    return "".join(ts.bin2str(bits[i:i+8]) for i in range(0, len(bits), 8))


def unhide_bits(encoded, charset, pad="=", n_pad=8):
    def __gcd(a,b):
        while b > 0:
            a, b = b, a % b
        return a
    padding = encoded.count(b(pad))
    n_repr = int(math.ceil(math.log(len(charset), 2)))
    w_len  = n_repr * n_pad / __gcd(n_repr, n_pad)
    n_char = int(math.ceil(float(w_len) / n_repr))
    if encoded == "" or len(encoded) % n_char != 0 or padding == 0:
        return
    unused = {n: int(w_len - n * n_repr) % n_pad for n in range(n_char)}
    b_val  = bin(b(charset).index(encoded.rstrip(b(pad))[-1]))[2:].zfill(n_repr)
    return b_val[-unused[padding]:]


if __name__ == '__main__':
    parser.add_argument("-c", "--charset",
                        help="characters set")
    parser.add_argument("-e", "--encoding", choices=["base32", "base64"],
                        default="base64", help="character encoding")
    parser.add_argument("-f", "--exif-field", dest="exif", default="Comment",
                        help="EXIF metadata field to be selected")
    parser.add_argument("-p", "--padding-char", default="=",
                        help="padding character")
    parser.add_argument("-s", "--separator", default="\n",
                        help="base-encoded token separator")
    initialize()
    data = b("").join(l for l in ts.stdin_pipe())
    if data.startswith(b("\x89PNG")) or data.startswith(b("\xff\xd8\xff\xe0")):
        data = exif(data, args.exif)
    print(unhide(data, args.encoding, args.charset, args.separator))
```

```
#Base 64 paddinganogarphy
#Source: http://delimitry.blogspot.com/2014/02/olympic-ctf-2014-find-da-key-writeup.html

def get_base64_diff_value(s1, s2):
 base64chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'
 res = 0
 for i in xrange(len(s1)):
  if s1[i] != s2[i]:
   return abs(base64chars.index(s1[i]) - base64chars.index(s2[i]))
 return res

def solve_stego():
 with open('stego.txt', 'rb') as f:
  file_lines = f.readlines()

 bin_str = ''
 for line in file_lines:
  steg_line = line.replace('\n', '')
  norm_line = line.replace('\n', '').decode('base64').encode('base64').replace('\n', '')

  diff = get_base64_diff_value(steg_line, norm_line)
  pads_num = steg_line.count('=')
  if diff:
   bin_str += bin(diff)[2:].zfill(pads_num * 2)
  else:
   bin_str += '0' * pads_num * 2

 res_str = ''
 for i in xrange(0, len(bin_str), 8):
  res_str += chr(int(bin_str[i:i+8], 2))
 print res_str

solve_stego()
```

## Whitespace language

{% embed url="<https://www.dcode.fr/whitespace-language>" %}

{% embed url="<http://manpages.ubuntu.com/manpages/bionic/man1/stegsnow.1.html>" %}


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