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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 FFmpeg.
17  *
18  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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 #include "mem.h"
38 
39 typedef struct AVMD5{
40  uint64_t len;
42  uint32_t ABCD[4];
43 } AVMD5;
44 
45 const int av_md5_size = sizeof(AVMD5);
46 
47 struct AVMD5 *av_md5_alloc(void)
48 {
49  return av_mallocz(sizeof(struct AVMD5));
50 }
51 
52 static const uint8_t S[4][4] = {
53  { 7, 12, 17, 22 }, /* round 1 */
54  { 5, 9, 14, 20 }, /* round 2 */
55  { 4, 11, 16, 23 }, /* round 3 */
56  { 6, 10, 15, 21 } /* round 4 */
57 };
58 
59 static const uint32_t T[64] = { // T[i]= fabs(sin(i+1)<<32)
60  0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee, /* round 1 */
61  0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
62  0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
63  0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
64 
65  0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa, /* round 2 */
66  0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
67  0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
68  0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
69 
70  0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c, /* round 3 */
71  0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
72  0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
73  0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
74 
75  0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039, /* round 4 */
76  0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
77  0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
78  0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
79 };
80 
81 #define CORE(i, a, b, c, d) do { \
82  t = S[i >> 4][i & 3]; \
83  a += T[i]; \
84  \
85  if (i < 32) { \
86  if (i < 16) a += (d ^ (b & (c ^ d))) + X[ i & 15]; \
87  else a += ((d & b) | (~d & c)) + X[(1 + 5*i) & 15]; \
88  } else { \
89  if (i < 48) a += (b ^ c ^ d) + X[(5 + 3*i) & 15]; \
90  else a += (c ^ (b | ~d)) + X[( 7*i) & 15]; \
91  } \
92  a = b + (a << t | a >> (32 - t)); \
93  } while (0)
94 
95 static void body(uint32_t ABCD[4], uint32_t *src, int nblocks)
96 {
97  int i av_unused;
98  int n;
99  uint32_t a, b, c, d, t, *X;
100 
101  for (n = 0; n < nblocks; n++) {
102  a = ABCD[3];
103  b = ABCD[2];
104  c = ABCD[1];
105  d = ABCD[0];
106 
107  X = src + n * 16;
108 
109 #if HAVE_BIGENDIAN
110  for (i = 0; i < 16; i++)
111  X[i] = av_bswap32(X[i]);
112 #endif
113 
114 #if CONFIG_SMALL
115  for (i = 0; i < 64; i++) {
116  CORE(i, a, b, c, d);
117  t = d;
118  d = c;
119  c = b;
120  b = a;
121  a = t;
122  }
123 #else
124 #define CORE2(i) \
125  CORE( i, a,b,c,d); CORE((i+1),d,a,b,c); \
126  CORE((i+2),c,d,a,b); CORE((i+3),b,c,d,a)
127 #define CORE4(i) CORE2(i); CORE2((i+4)); CORE2((i+8)); CORE2((i+12))
128  CORE4(0); CORE4(16); CORE4(32); CORE4(48);
129 #endif
130 
131  ABCD[0] += d;
132  ABCD[1] += c;
133  ABCD[2] += b;
134  ABCD[3] += a;
135  }
136 }
137 
138 void av_md5_init(AVMD5 *ctx)
139 {
140  ctx->len = 0;
141 
142  ctx->ABCD[0] = 0x10325476;
143  ctx->ABCD[1] = 0x98badcfe;
144  ctx->ABCD[2] = 0xefcdab89;
145  ctx->ABCD[3] = 0x67452301;
146 }
147 
148 void av_md5_update(AVMD5 *ctx, const uint8_t *src, int len)
149 {
150  const uint8_t *end;
151  int j;
152 
153  j = ctx->len & 63;
154  ctx->len += len;
155 
156  if (j) {
157  int cnt = FFMIN(len, 64 - j);
158  memcpy(ctx->block + j, src, cnt);
159  src += cnt;
160  len -= cnt;
161  if (j + cnt < 64)
162  return;
163  body(ctx->ABCD, (uint32_t *)ctx->block, 1);
164  }
165 
166  end = src + (len & ~63);
167  if (HAVE_BIGENDIAN || (!HAVE_FAST_UNALIGNED && ((intptr_t)src & 3))) {
168  while (src < end) {
169  memcpy(ctx->block, src, 64);
170  body(ctx->ABCD, (uint32_t *) ctx->block, 1);
171  src += 64;
172  }
173  } else {
174  int nblocks = len / 64;
175  body(ctx->ABCD, (uint32_t *)src, nblocks);
176  src = end;
177  }
178  len &= 63;
179  if (len > 0)
180  memcpy(ctx->block, src, len);
181 }
182 
183 void av_md5_final(AVMD5 *ctx, uint8_t *dst)
184 {
185  int i;
186  uint64_t finalcount = av_le2ne64(ctx->len << 3);
187 
188  av_md5_update(ctx, "\200", 1);
189  while ((ctx->len & 63) != 56)
190  av_md5_update(ctx, "", 1);
191 
192  av_md5_update(ctx, (uint8_t *)&finalcount, 8);
193 
194  for (i = 0; i < 4; i++)
195  AV_WL32(dst + 4*i, ctx->ABCD[3 - i]);
196 }
197 
198 void av_md5_sum(uint8_t *dst, const uint8_t *src, const int len)
199 {
200  AVMD5 ctx;
201 
202  av_md5_init(&ctx);
203  av_md5_update(&ctx, src, len);
204  av_md5_final(&ctx, dst);
205 }
206 
207 #ifdef TEST
208 #include <stdio.h>
209 
210 static void print_md5(uint8_t *md5)
211 {
212  int i;
213  for (i = 0; i < 16; i++)
214  printf("%02x", md5[i]);
215  printf("\n");
216 }
217 
218 int main(void){
219  uint8_t md5val[16];
220  int i;
221  uint8_t in[1000];
222 
223  for (i = 0; i < 1000; i++)
224  in[i] = i * i;
225  av_md5_sum(md5val, in, 1000); print_md5(md5val);
226  av_md5_sum(md5val, in, 63); print_md5(md5val);
227  av_md5_sum(md5val, in, 64); print_md5(md5val);
228  av_md5_sum(md5val, in, 65); print_md5(md5val);
229  for (i = 0; i < 1000; i++)
230  in[i] = i % 127;
231  av_md5_sum(md5val, in, 999); print_md5(md5val);
232 
233  return 0;
234 }
235 #endif