source: trunk/bin/bletchley-decode

#!/usr/bin/env python3
#-*- mode: Python;-*-
#
# Requires Python 3+

'''
Simple decoder script; useful in shell scripts

Copyright (C) 2011-2012 Virtual Security Research, LLC
Author: Timothy D. Morgan

 This program is free software: you can redistribute it and/or modify
 it under the terms of the GNU Lesser General Public License, version 3,
 as published by the Free Software Foundation.

 This program is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with this program.  If not, see <http://www.gnu.org/licenses/>.
'''


import sys
import argparse
from bletchley import blobtools


parser = argparse.ArgumentParser(
    description='A simple decoder script that is useful in shell scripts.'
    ' For more information, see:  http://code.google.com/p/bletchley/wiki/Overview')
parser.add_argument(
    'input_file', nargs='?', default=None,
    help='File containing encrypted blobs to analyze, one per line.'
    ' Omit to read from stdin.')
parser.add_argument(
    '-e', dest='encoding_chain', type=str, required=True,
    help='Comma-separated sequence of encoding formats used to encode the token.'
    ' (Use "?" for a listing of supported encodings.)')
options = parser.parse_args()

if options.encoding_chain == '?':
    print('\n\t'.join(['Supported encodings:']+blobtools.supportedEncodings()))
    sys.exit(0)

input_file = sys.stdin.buffer
if options.input_file is not None:
    input_file = open(options.input_file, 'rb')

blob = input_file.read().rstrip(b'\r\n')

specified_encodings = options.encoding_chain.split(',')
sys.stdout.buffer.write(blobtools.decodeChain(specified_encodings, blob))