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