md5.c
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1 /*
2  * Copyright (C) 2006 Michael Niedermayer (michaelni@gmx.at)
3  * Copyright (C) 2003-2005 by Christopher R. Hertel (crh@ubiqx.mn.org)
4  *
5  * References:
6  * IETF RFC 1321: The MD5 Message-Digest Algorithm
7  * Ron Rivest. IETF, April, 1992
8  *
9  * based on http://ubiqx.org/libcifs/source/Auth/MD5.c
10  * from Christopher R. Hertel (crh@ubiqx.mn.org)
11  * Simplified, cleaned and IMO redundant comments removed by michael.
12  *
13  * If you use gcc, then version 4.1 or later and -fomit-frame-pointer is
14  * strongly recommended.
15  *
16  * This file is part of Libav.
17  *
18  * Libav is free software; you can redistribute it and/or
19  * modify it under the terms of the GNU Lesser General Public
20  * License as published by the Free Software Foundation; either
21  * version 2.1 of the License, or (at your option) any later version.
22  *
23  * Libav is distributed in the hope that it will be useful,
24  * but WITHOUT ANY WARRANTY; without even the implied warranty of
25  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
26  * Lesser General Public License for more details.
27  *
28  * You should have received a copy of the GNU Lesser General Public
29  * License along with Libav; if not, write to the Free Software
30  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
31  */
32 
33 #include <stdint.h>
34 #include "bswap.h"
35 #include "intreadwrite.h"
36 #include "md5.h"
37 
38 typedef struct AVMD5{
39  uint64_t len;
40  uint8_t block[64];
41  uint32_t ABCD[4];
42 } AVMD5;
43 
44 const int av_md5_size = sizeof(AVMD5);
45 
46 static const uint8_t S[4][4] = {
47  { 7, 12, 17, 22 }, /* round 1 */
48  { 5, 9, 14, 20 }, /* round 2 */
49  { 4, 11, 16, 23 }, /* round 3 */
50  { 6, 10, 15, 21 } /* round 4 */
51 };
52 
53 static const uint32_t T[64] = { // T[i]= fabs(sin(i+1)<<32)
54  0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, /* round 1 */
55  0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
56  0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
57  0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
58 
59  0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa, /* round 2 */
60  0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
61  0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
62  0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
63 
64  0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c, /* round 3 */
65  0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
66  0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
67  0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
68 
69  0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, /* round 4 */
70  0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
71  0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
72  0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
73 };
74 
75 #define CORE(i, a, b, c, d) do { \
76  t = S[i >> 4][i & 3]; \
77  a += T[i]; \
78  \
79  if (i < 32) { \
80  if (i < 16) a += (d ^ (b & (c ^ d))) + X[ i & 15]; \
81  else a += (c ^ (d & (c ^ b))) + X[(1 + 5*i) & 15]; \
82  } else { \
83  if (i < 48) a += (b ^ c ^ d) + X[(5 + 3*i) & 15]; \
84  else a += (c ^ (b | ~d)) + X[( 7*i) & 15]; \
85  } \
86  a = b + (a << t | a >> (32 - t)); \
87  } while (0)
88 
89 static void body(uint32_t ABCD[4], uint32_t X[16])
90 {
91  int t;
92  int i av_unused;
93  unsigned int a = ABCD[3];
94  unsigned int b = ABCD[2];
95  unsigned int c = ABCD[1];
96  unsigned int d = ABCD[0];
97 
98 #if HAVE_BIGENDIAN
99  for (i = 0; i < 16; i++)
100  X[i] = av_bswap32(X[i]);
101 #endif
102 
103 #if CONFIG_SMALL
104  for (i = 0; i < 64; i++) {
105  CORE(i, a, b, c, d);
106  t = d;
107  d = c;
108  c = b;
109  b = a;
110  a = t;
111  }
112 #else
113 #define CORE2(i) \
114  CORE( i, a,b,c,d); CORE((i+1),d,a,b,c); \
115  CORE((i+2),c,d,a,b); CORE((i+3),b,c,d,a)
116 #define CORE4(i) CORE2(i); CORE2((i+4)); CORE2((i+8)); CORE2((i+12))
117  CORE4(0); CORE4(16); CORE4(32); CORE4(48);
118 #endif
119 
120  ABCD[0] += d;
121  ABCD[1] += c;
122  ABCD[2] += b;
123  ABCD[3] += a;
124 }
125 
126 void av_md5_init(AVMD5 *ctx)
127 {
128  ctx->len = 0;
129 
130  ctx->ABCD[0] = 0x10325476;
131  ctx->ABCD[1] = 0x98badcfe;
132  ctx->ABCD[2] = 0xefcdab89;
133  ctx->ABCD[3] = 0x67452301;
134 }
135 
136 void av_md5_update(AVMD5 *ctx, const uint8_t *src, const int len)
137 {
138  int i, j;
139 
140  j = ctx->len & 63;
141  ctx->len += len;
142 
143  for (i = 0; i < len; i++) {
144  ctx->block[j++] = src[i];
145  if (j == 64) {
146  body(ctx->ABCD, (uint32_t *) ctx->block);
147  j = 0;
148  }
149  }
150 }
151 
152 void av_md5_final(AVMD5 *ctx, uint8_t *dst)
153 {
154  int i;
155  uint64_t finalcount = av_le2ne64(ctx->len << 3);
156 
157  av_md5_update(ctx, "\200", 1);
158  while ((ctx->len & 63) != 56)
159  av_md5_update(ctx, "", 1);
160 
161  av_md5_update(ctx, (uint8_t *)&finalcount, 8);
162 
163  for (i = 0; i < 4; i++)
164  AV_WL32(dst + 4*i, ctx->ABCD[3 - i]);
165 }
166 
167 void av_md5_sum(uint8_t *dst, const uint8_t *src, const int len)
168 {
169  AVMD5 ctx;
170 
171  av_md5_init(&ctx);
172  av_md5_update(&ctx, src, len);
173  av_md5_final(&ctx, dst);
174 }
175 
176 #ifdef TEST
177 #undef printf
178 #include <stdio.h>
179 
180 static void print_md5(uint8_t *md5)
181 {
182  int i;
183  for (i = 0; i < 16; i++)
184  printf("%02x", md5[i]);
185  printf("\n");
186 }
187 
188 int main(void){
189  uint8_t md5val[16];
190  int i;
191  uint8_t in[1000];
192 
193  for (i = 0; i < 1000; i++)
194  in[i] = i * i;
195  av_md5_sum(md5val, in, 1000); print_md5(md5val);
196  av_md5_sum(md5val, in, 63); print_md5(md5val);
197  av_md5_sum(md5val, in, 64); print_md5(md5val);
198  av_md5_sum(md5val, in, 65); print_md5(md5val);
199  for (i = 0; i < 1000; i++)
200  in[i] = i % 127;
201  av_md5_sum(md5val, in, 999); print_md5(md5val);
202 
203  return 0;
204 }
205 #endif