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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 | ||
65 | print '\t'+sys.argv[0] + ' - Search bitstream for a known number' | |
66 | ||
67 | print 'Usage: ' + sys.argv[0] + ' <NUMBER> <BITSTREAM>' | |
68 | ||
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 | ||
74 | print 'Example:' | |
75 | ||
76 | print '\tfindbits.py 73 0110010101110011' | |
77 | ||
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 | ||
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() |