]> cvs.zerfleddert.de Git - proxmark3-svn/blame - client/loclass/cipherutils.c
implemented 'hf iclass dump xxxx',
[proxmark3-svn] / client / loclass / cipherutils.c
CommitLineData
a66fca86
AD
1/*****************************************************************************
2 * This file is part of iClassCipher. It is a reconstructon of the cipher engine
3 * used in iClass, and RFID techology.
4 *
5 * The implementation is based on the work performed by
6 * Flavio D. Garcia, Gerhard de Koning Gans, Roel Verdult and
7 * Milosch Meriac in the paper "Dismantling IClass".
8 *
9 * Copyright (C) 2014 Martin Holst Swende
10 *
11 * This is free software: you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as published
13 * by the Free Software Foundation.
14 *
15 * This file is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with IClassCipher. If not, see <http://www.gnu.org/licenses/>.
22 ****************************************************************************/
23
24#include "cipherutils.h"
25#include "../util.h"
26#include <stdint.h>
27#include <stdio.h>
28#include <string.h>
29
30/**
31 *
32 * @brief Return and remove the first bit (x0) in the stream : <x0 x1 x2 x3 ... xn >
33 * @param stream
34 * @return
35 */
36bool headBit( BitstreamIn *stream)
37{
38 int bytepos = stream->position >> 3; // divide by 8
39 int bitpos = (stream->position++) & 7; // mask out 00000111
40 return (*(stream->buffer + bytepos) >> (7-bitpos)) & 1;
41}
42/**
43 * @brief Return and remove the last bit (xn) in the stream: <x0 x1 x2 ... xn>
44 * @param stream
45 * @return
46 */
47bool tailBit( BitstreamIn *stream)
48{
49 int bitpos = stream->numbits -1 - (stream->position++);
50
51 int bytepos= bitpos >> 3;
52 bitpos &= 7;
53 return (*(stream->buffer + bytepos) >> (7-bitpos)) & 1;
54}
55/**
56 * @brief Pushes bit onto the stream
57 * @param stream
58 * @param bit
59 */
60void pushBit( BitstreamOut* stream, bool bit)
61{
62 int bytepos = stream->position >> 3; // divide by 8
63 int bitpos = stream->position & 7;
64 *(stream->buffer+bytepos) |= (bit & 1) << (7 - bitpos);
65 stream->position++;
66 stream->numbits++;
67}
68
69/**
70 * @brief Pushes the lower six bits onto the stream
71 * as b0 b1 b2 b3 b4 b5 b6
72 * @param stream
73 * @param bits
74 */
75void push6bits( BitstreamOut* stream, uint8_t bits)
76{
77 pushBit(stream, bits & 0x20);
78 pushBit(stream, bits & 0x10);
79 pushBit(stream, bits & 0x08);
80 pushBit(stream, bits & 0x04);
81 pushBit(stream, bits & 0x02);
82 pushBit(stream, bits & 0x01);
83}
84
85/**
86 * @brief bitsLeft
87 * @param stream
88 * @return number of bits left in stream
89 */
90int bitsLeft( BitstreamIn *stream)
91{
92 return stream->numbits - stream->position;
93}
94/**
95 * @brief numBits
96 * @param stream
97 * @return Number of bits stored in stream
98 */
99int numBits(BitstreamOut *stream)
100{
101 return stream->numbits;
102}
103
104uint8_t reversebytes(uint8_t b) {
105 b = (b & 0xF0) >> 4 | (b & 0x0F) << 4;
106 b = (b & 0xCC) >> 2 | (b & 0x33) << 2;
107 b = (b & 0xAA) >> 1 | (b & 0x55) << 1;
108 return b;
109}
110void reverse_arraybytes(uint8_t* arr, size_t len)
111{
112 uint8_t i;
113 for( i =0; i< len ; i++)
114 {
115 arr[i] = reversebytes(arr[i]);
116 }
117}
118
119
120//-----------------------------
121// Code for testing below
122//-----------------------------
123
124
125int testBitStream()
126{
127 uint8_t input [] = {0xDE,0xAD,0xBE,0xEF,0xDE,0xAD,0xBE,0xEF};
128 uint8_t output [] = {0,0,0,0,0,0,0,0};
129 BitstreamIn in = { input, sizeof(input) * 8,0};
130 BitstreamOut out ={ output, 0,0}
131 ;
132 while(bitsLeft(&in) > 0)
133 {
134 pushBit(&out, headBit(&in));
135 //printf("Bits left: %d\n", bitsLeft(&in));
136 //printf("Bits out: %d\n", numBits(&out));
137 }
138 if(memcmp(input, output, sizeof(input)) == 0)
139 {
140 printf("Bitstream test 1 ok\n");
141 }else
142 {
143 printf("Bitstream test 1 failed\n");
144 uint8_t i;
145 for(i = 0 ; i < sizeof(input) ; i++)
146 {
147 printf("IN %02x, OUT %02x\n", input[i], output[i]);
148 }
149 return 1;
150 }
151 return 0;
152}
153
154int testReversedBitstream()
155{
156 uint8_t input [] = {0xDE,0xAD,0xBE,0xEF,0xDE,0xAD,0xBE,0xEF};
157 uint8_t reverse [] = {0,0,0,0,0,0,0,0};
158 uint8_t output [] = {0,0,0,0,0,0,0,0};
159 BitstreamIn in = { input, sizeof(input) * 8,0};
160 BitstreamOut out ={ output, 0,0};
161 BitstreamIn reversed_in ={ reverse, sizeof(input)*8,0};
162 BitstreamOut reversed_out ={ reverse,0 ,0};
163
164 while(bitsLeft(&in) > 0)
165 {
166 pushBit(&reversed_out, tailBit(&in));
167 }
168 while(bitsLeft(&reversed_in) > 0)
169 {
170 pushBit(&out, tailBit(&reversed_in));
171 }
172 if(memcmp(input, output, sizeof(input)) == 0)
173 {
174 printf("Bitstream test 2 ok\n");
175 }else
176 {
177 printf("Bitstream test 2 failed\n");
178 uint8_t i;
179 for(i = 0 ; i < sizeof(input) ; i++)
180 {
181 printf("IN %02x, MIDDLE: %02x, OUT %02x\n", input[i],reverse[i], output[i]);
182 }
183 return 1;
184 }
185 return 0;
186}
187
188
189int testCipherUtils(void)
190{
191 int retval = 0;
192 retval |= testBitStream();
193 retval |= testReversedBitstream();
194 return retval;
195}
Impressum, Datenschutz