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 import string
  26
  27 # invert binary string
  28 def invert(data):
  29         return ''.join('0' if c == '1' else '1' for c in data)
  30
  31 # do the actual search
  32 def search(target,data):
  33         location= string.find(data,target)
  34         if location >= 0:
  35                 print '*** Match at bit %d:' % location,
  36                 print '%s<%s>%s' % (data[:location],target,data[location+len(target):])
  37         else:
  38                 print 'Not found'
  39
  40 # convert integer to binary string
  41 def binstring(number):
  42         out= ''
  43         while number > 0:
  44                 out += chr(0x30 + (number & 0x01))
  45                 number= number >> 1
  46         return stringreverse(out)
  47
  48 # reverse string order
  49 def stringreverse(data):
  50         out= ''
  51         for x in range(len(data) -1,-1,-1):
  52                 out += data[x]
  53         return out
  54
  55 # match forward, backward and inverted
  56 def domatch(number,binary):
  57         reversed= stringreverse(number)
  58         inverted= invert(binary)
  59
  60         print '  Forward: (%s)' % number,
  61         search(binary,number)
  62         print '  Reverse: (%s)' % reversed,
  63         search(binary,reversed)
  64         print '  Inverse: (%s)' % inverted
  65         print '    Forward: (%s)' % number,
  66         search(inverted,number)
  67         print '    Reverse: (%s)' % reversed,
  68         search(inverted,reversed)
  69
  70 def main():
  71         if(len(sys.argv) < 3):
  72                 print
  73                 print '\t'+sys.argv[0] + ' - Search bitstream for a known number'
  74                 print
  75                 print 'Usage: ' + sys.argv[0] + ' <NUMBER> <BITSTREAM>'
  76                 print
  77                 print '\tNUMBER will be converted to it\'s BINARY equivalent for all valid'
  78                 print '\tinstances of BINARY, OCTAL, DECIMAL and HEX, and the bitstream'
  79                 print '\tand it\'s inverse will be searched for a pattern match. Note that'
  80                 print '\tNUMBER must be specified in BINARY to match leading zeros.'
  81                 print
  82                 print 'Example:'
  83                 print
  84                 print '\tfindbits.py 73 0110010101110011'
  85                 print
  86                 os._exit(True)
  87
  88         bases=  {
  89                 2:'BINARY',
  90                 8:'OCTAL',
  91                 10:'DECIMAL',
  92                 16:'HEX',
  93                         }
  94
  95         for base in 2,8,10,16:
  96                 try:
  97                         number= int(sys.argv[1],base)
  98                         print
  99                         print 'Trying', bases[base]
 100                         # do BINARY as specified to preserve leading zeros
 101                         if base == 2:
 102                                 domatch(sys.argv[1],sys.argv[2])
 103                         else:
 104                                 domatch(binstring(number),sys.argv[2])
 105                 except:
 106                         continue
 107
 108 if __name__ == '__main__':
 109         main()