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 
35 #include "bswap.h"
36 #include "intreadwrite.h"
37 #include "mem.h"
38 #include "md5.h"
39 
40 typedef struct AVMD5 {
41     uint64_t len;
42     uint8_t  block[64];
43     uint32_t ABCD[4];
44 } AVMD5;
45 
46 const int av_md5_size = sizeof(AVMD5);
47 
av_md5_alloc(void)48 struct AVMD5 *av_md5_alloc(void)
49 {
50     return av_mallocz(sizeof(struct AVMD5));
51 }
52 
53 static const uint8_t S[4][4] = {
54     { 7, 12, 17, 22 },  /* round 1 */
55     { 5,  9, 14, 20 },  /* round 2 */
56     { 4, 11, 16, 23 },  /* round 3 */
57     { 6, 10, 15, 21 }   /* round 4 */
58 };
59 
60 static const uint32_t T[64] = { // T[i]= fabs(sin(i+1)<<32)
61     0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,   /* round 1 */
62     0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
63     0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
64     0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
65 
66     0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,   /* round 2 */
67     0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
68     0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
69     0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
70 
71     0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,   /* round 3 */
72     0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
73     0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
74     0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
75 
76     0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,   /* round 4 */
77     0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
78     0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
79     0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
80 };
81 
82 #define CORE(i, a, b, c, d)                                             \
83     do {                                                                \
84         t  = S[i >> 4][i & 3];                                          \
85         a += T[i];                                                      \
86                                                                         \
87         if (i < 32) {                                                   \
88             if (i < 16)                                                 \
89                 a += (d ^ (b & (c ^ d)))  + AV_RL32(X+(       i  & 15));\
90             else                                                        \
91                 a += ((d & b) | (~d & c)) + AV_RL32(X+((1 + 5*i) & 15));\
92         } else {                                                        \
93             if (i < 48)                                                 \
94                 a += (b ^ c ^ d)          + AV_RL32(X+((5 + 3*i) & 15));\
95             else                                                        \
96                 a += (c ^ (b | ~d))       + AV_RL32(X+((    7*i) & 15));\
97         }                                                               \
98         a = b + (a << t | a >> (32 - t));                               \
99     } while (0)
100 
body(uint32_t ABCD[4],const uint8_t * src,int nblocks)101 static void body(uint32_t ABCD[4], const uint8_t *src, int nblocks)
102 {
103     int i av_unused;
104     int n;
105     const uint32_t *X;
106     uint32_t a, b, c, d, t;
107 
108     for (n = 0; n < nblocks; n++) {
109         a = ABCD[3];
110         b = ABCD[2];
111         c = ABCD[1];
112         d = ABCD[0];
113 
114         X = (const uint32_t *)src + n * 16;
115 
116 #if CONFIG_SMALL
117         for (i = 0; i < 64; i++) {
118             CORE(i, a, b, c, d);
119             t = d;
120             d = c;
121             c = b;
122             b = a;
123             a = t;
124         }
125 #else
126 #define CORE2(i)                                                        \
127         CORE(i, a, b, c, d); CORE((i + 1), d, a, b, c);                 \
128         CORE((i + 2), c, d, a, b); CORE((i + 3), b, c, d, a)
129 #define CORE4(i) CORE2(i); CORE2((i + 4)); CORE2((i + 8)); CORE2((i + 12))
130         CORE4(0);
131         CORE4(16);
132         CORE4(32);
133         CORE4(48);
134 #endif
135 
136         ABCD[0] += d;
137         ABCD[1] += c;
138         ABCD[2] += b;
139         ABCD[3] += a;
140     }
141 }
142 
av_md5_init(AVMD5 * ctx)143 void av_md5_init(AVMD5 *ctx)
144 {
145     ctx->len     = 0;
146 
147     ctx->ABCD[0] = 0x10325476;
148     ctx->ABCD[1] = 0x98badcfe;
149     ctx->ABCD[2] = 0xefcdab89;
150     ctx->ABCD[3] = 0x67452301;
151 }
152 
153 #if FF_API_CRYPTO_SIZE_T
av_md5_update(AVMD5 * ctx,const uint8_t * src,int len)154 void av_md5_update(AVMD5 *ctx, const uint8_t *src, int len)
155 #else
156 void av_md5_update(AVMD5 *ctx, const uint8_t *src, size_t len)
157 #endif
158 {
159     const uint8_t *end;
160     int j;
161 
162     j         = ctx->len & 63;
163     ctx->len += len;
164 
165     if (j) {
166         int cnt = FFMIN(len, 64 - j);
167         memcpy(ctx->block + j, src, cnt);
168         src += cnt;
169         len -= cnt;
170         if (j + cnt < 64)
171             return;
172         body(ctx->ABCD, ctx->block, 1);
173     }
174 
175     end = src + (len & ~63);
176     if (!HAVE_FAST_UNALIGNED && ((intptr_t)src & 3)) {
177        while (src < end) {
178            memcpy(ctx->block, src, 64);
179            body(ctx->ABCD, ctx->block, 1);
180            src += 64;
181         }
182     } else {
183         int nblocks = len / 64;
184         body(ctx->ABCD, src, nblocks);
185         src = end;
186     }
187     len &= 63;
188     if (len > 0)
189         memcpy(ctx->block, src, len);
190 }
191 
av_md5_final(AVMD5 * ctx,uint8_t * dst)192 void av_md5_final(AVMD5 *ctx, uint8_t *dst)
193 {
194     int i;
195     uint64_t finalcount = av_le2ne64(ctx->len << 3);
196 
197     av_md5_update(ctx, "\200", 1);
198     while ((ctx->len & 63) != 56)
199         av_md5_update(ctx, "", 1);
200 
201     av_md5_update(ctx, (uint8_t *) &finalcount, 8);
202 
203     for (i = 0; i < 4; i++)
204         AV_WL32(dst + 4 * i, ctx->ABCD[3 - i]);
205 }
206 
207 #if FF_API_CRYPTO_SIZE_T
av_md5_sum(uint8_t * dst,const uint8_t * src,const int len)208 void av_md5_sum(uint8_t *dst, const uint8_t *src, const int len)
209 #else
210 void av_md5_sum(uint8_t *dst, const uint8_t *src, size_t len)
211 #endif
212 {
213     AVMD5 ctx;
214 
215     av_md5_init(&ctx);
216     av_md5_update(&ctx, src, len);
217     av_md5_final(&ctx, dst);
218 }
219