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fixed bug in CmdFdxDemod
[proxmark3-svn] / common / mbedtls / arc4.c
1 /*
2 * An implementation of the ARCFOUR algorithm
3 *
4 * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
5 * SPDX-License-Identifier: GPL-2.0
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License along
18 * with this program; if not, write to the Free Software Foundation, Inc.,
19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * This file is part of mbed TLS (https://tls.mbed.org)
22 */
23 /*
24 * The ARCFOUR algorithm was publicly disclosed on 94/09.
25 *
26 * http://groups.google.com/group/sci.crypt/msg/10a300c9d21afca0
27 */
28
29 #if !defined(MBEDTLS_CONFIG_FILE)
30 #include "mbedtls/config.h"
31 #else
32 #include MBEDTLS_CONFIG_FILE
33 #endif
34
35 #if defined(MBEDTLS_ARC4_C)
36
37 #include "mbedtls/arc4.h"
38 #include "mbedtls/platform_util.h"
39
40 #include <string.h>
41
42 #if defined(MBEDTLS_SELF_TEST)
43 #if defined(MBEDTLS_PLATFORM_C)
44 #include "mbedtls/platform.h"
45 #else
46 #include <stdio.h>
47 #define mbedtls_printf printf
48 #endif /* MBEDTLS_PLATFORM_C */
49 #endif /* MBEDTLS_SELF_TEST */
50
51 #if !defined(MBEDTLS_ARC4_ALT)
52
53 void mbedtls_arc4_init( mbedtls_arc4_context *ctx )
54 {
55 memset( ctx, 0, sizeof( mbedtls_arc4_context ) );
56 }
57
58 void mbedtls_arc4_free( mbedtls_arc4_context *ctx )
59 {
60 if( ctx == NULL )
61 return;
62
63 mbedtls_platform_zeroize( ctx, sizeof( mbedtls_arc4_context ) );
64 }
65
66 /*
67 * ARC4 key schedule
68 */
69 void mbedtls_arc4_setup( mbedtls_arc4_context *ctx, const unsigned char *key,
70 unsigned int keylen )
71 {
72 int i, j, a;
73 unsigned int k;
74 unsigned char *m;
75
76 ctx->x = 0;
77 ctx->y = 0;
78 m = ctx->m;
79
80 for( i = 0; i < 256; i++ )
81 m[i] = (unsigned char) i;
82
83 j = k = 0;
84
85 for( i = 0; i < 256; i++, k++ )
86 {
87 if( k >= keylen ) k = 0;
88
89 a = m[i];
90 j = ( j + a + key[k] ) & 0xFF;
91 m[i] = m[j];
92 m[j] = (unsigned char) a;
93 }
94 }
95
96 /*
97 * ARC4 cipher function
98 */
99 int mbedtls_arc4_crypt( mbedtls_arc4_context *ctx, size_t length, const unsigned char *input,
100 unsigned char *output )
101 {
102 int x, y, a, b;
103 size_t i;
104 unsigned char *m;
105
106 x = ctx->x;
107 y = ctx->y;
108 m = ctx->m;
109
110 for( i = 0; i < length; i++ )
111 {
112 x = ( x + 1 ) & 0xFF; a = m[x];
113 y = ( y + a ) & 0xFF; b = m[y];
114
115 m[x] = (unsigned char) b;
116 m[y] = (unsigned char) a;
117
118 output[i] = (unsigned char)
119 ( input[i] ^ m[(unsigned char)( a + b )] );
120 }
121
122 ctx->x = x;
123 ctx->y = y;
124
125 return( 0 );
126 }
127
128 #endif /* !MBEDTLS_ARC4_ALT */
129
130 #if defined(MBEDTLS_SELF_TEST)
131 /*
132 * ARC4 tests vectors as posted by Eric Rescorla in sep. 1994:
133 *
134 * http://groups.google.com/group/comp.security.misc/msg/10a300c9d21afca0
135 */
136 static const unsigned char arc4_test_key[3][8] =
137 {
138 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
139 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
140 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
141 };
142
143 static const unsigned char arc4_test_pt[3][8] =
144 {
145 { 0x01, 0x23, 0x45, 0x67, 0x89, 0xAB, 0xCD, 0xEF },
146 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 },
147 { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 }
148 };
149
150 static const unsigned char arc4_test_ct[3][8] =
151 {
152 { 0x75, 0xB7, 0x87, 0x80, 0x99, 0xE0, 0xC5, 0x96 },
153 { 0x74, 0x94, 0xC2, 0xE7, 0x10, 0x4B, 0x08, 0x79 },
154 { 0xDE, 0x18, 0x89, 0x41, 0xA3, 0x37, 0x5D, 0x3A }
155 };
156
157 /*
158 * Checkup routine
159 */
160 int mbedtls_arc4_self_test( int verbose )
161 {
162 int i, ret = 0;
163 unsigned char ibuf[8];
164 unsigned char obuf[8];
165 mbedtls_arc4_context ctx;
166
167 mbedtls_arc4_init( &ctx );
168
169 for( i = 0; i < 3; i++ )
170 {
171 if( verbose != 0 )
172 mbedtls_printf( " ARC4 test #%d: ", i + 1 );
173
174 memcpy( ibuf, arc4_test_pt[i], 8 );
175
176 mbedtls_arc4_setup( &ctx, arc4_test_key[i], 8 );
177 mbedtls_arc4_crypt( &ctx, 8, ibuf, obuf );
178
179 if( memcmp( obuf, arc4_test_ct[i], 8 ) != 0 )
180 {
181 if( verbose != 0 )
182 mbedtls_printf( "failed\n" );
183
184 ret = 1;
185 goto exit;
186 }
187
188 if( verbose != 0 )
189 mbedtls_printf( "passed\n" );
190 }
191
192 if( verbose != 0 )
193 mbedtls_printf( "\n" );
194
195 exit:
196 mbedtls_arc4_free( &ctx );
197
198 return( ret );
199 }
200
201 #endif /* MBEDTLS_SELF_TEST */
202
203 #endif /* MBEDTLS_ARC4_C */
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