git.zerfleddert.de Git - proxmark3-svn/blob - tools/findbits.py

   1 #!/usr/bin/python
   2
   3 #  findbits.py - find Binary, Octal, Decimal or Hex number in bitstream
   4 #
   5 #  Adam Laurie <adam@algroup.co.uk>
   6 #  http://rfidiot.org/
   7 #
   8 #  This code is copyright (c) Adam Laurie, 2009, All rights reserved.
   9 #  For non-commercial use only, the following terms apply - for all other
  10 #  uses, please contact the author:
  11 #
  12 #    This code is free software; you can redistribute it and/or modify
  13 #    it under the terms of the GNU General Public License as published by
  14 #    the Free Software Foundation; either version 2 of the License, or
  15 #    (at your option) any later version.
  16 #
  17 #    This code is distributed in the hope that it will be useful,
  18 #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 #    GNU General Public License for more details.
  21 #
  22
  23 import sys
  24 import os
  25
  26 # invert binary string
  27 def invert(data):
  28         return ''.join('0' if c == '1' else '1' for c in data)
  29
  30 # do the actual search
  31 def search(target,data):
  32         location = data.find(target)
  33         if location >= 0:
  34                 print '*** Match at bit %d:' % location,
  35                 print '%s<%s>%s' % (data[:location],target,data[location+len(target):])
  36         else:
  37                 print 'Not found'
  38
  39 # convert integer to binary string
  40 def binstring(number):
  41         return bin(number)[2:] if number > 0 else ''
  42
  43 # reverse string order
  44 def stringreverse(data):
  45         return data[::-1]
  46
  47 # match forward, backward and inverted
  48 def domatch(binary,number):
  49         reversed= stringreverse(number)
  50         inverted= invert(binary)
  51
  52         print '  Forward: (%s)' % number,
  53         search(binary,number)
  54         print '  Reverse: (%s)' % reversed,
  55         search(binary,reversed)
  56         print '  Inverse: (%s)' % inverted
  57         print '    Forward: (%s)' % number,
  58         search(inverted,number)
  59         print '    Reverse: (%s)' % reversed,
  60         search(inverted,reversed)
  61
  62 def main():
  63         if(len(sys.argv) < 3):
  64                 print
  65                 print '\t'+sys.argv[0] + ' - Search bitstream for a known number'
  66                 print
  67                 print 'Usage: ' + sys.argv[0] + ' <NUMBER> <BITSTREAM>'
  68                 print
  69                 print '\tNUMBER will be converted to it\'s BINARY equivalent for all valid'
  70                 print '\tinstances of BINARY, OCTAL, DECIMAL and HEX, and the bitstream'
  71                 print '\tand it\'s inverse will be searched for a pattern match. Note that'
  72                 print '\tNUMBER must be specified in BINARY to match leading zeros.'
  73                 print
  74                 print 'Example:'
  75                 print
  76                 print '\tfindbits.py 73 0110010101110011'
  77                 print
  78                 os._exit(True)
  79
  80         bases=  {
  81                 2:'BINARY',
  82                 8:'OCTAL',
  83                 10:'DECIMAL',
  84                 16:'HEX',
  85                         }
  86
  87         for base, base_name in sorted(bases.iteritems()):
  88                 try:
  89                         number= int(sys.argv[1],base)
  90                         print
  91                         print 'Trying', base_name
  92                         # do BINARY as specified to preserve leading zeros
  93                         if base == 2:
  94                                 domatch(sys.argv[1],sys.argv[2])
  95                         else:
  96                                 domatch(binstring(number),sys.argv[2])
  97                 except:
  98                         continue
  99
 100 if __name__ == '__main__':
 101         main()