xref: /third_party/ffmpeg/libavutil/md5.c (revision cabdff1a)
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
40typedef struct AVMD5 {
41    uint64_t len;
42    uint8_t  block[64];
43    uint32_t ABCD[4];
44} AVMD5;
45
46const int av_md5_size = sizeof(AVMD5);
47
48struct AVMD5 *av_md5_alloc(void)
49{
50    return av_mallocz(sizeof(struct AVMD5));
51}
52
53static 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
60static 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
101static void body(uint32_t ABCD[4], const uint8_t *src, size_t nblocks)
102{
103    const uint32_t *X;
104    uint32_t a, b, c, d, t;
105
106    for (size_t n = 0; n < nblocks; n++) {
107        a = ABCD[3];
108        b = ABCD[2];
109        c = ABCD[1];
110        d = ABCD[0];
111
112        X = (const uint32_t *)src + n * 16;
113
114#if CONFIG_SMALL
115        for (int 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);
129        CORE4(16);
130        CORE4(32);
131        CORE4(48);
132#endif
133
134        ABCD[0] += d;
135        ABCD[1] += c;
136        ABCD[2] += b;
137        ABCD[3] += a;
138    }
139}
140
141void av_md5_init(AVMD5 *ctx)
142{
143    ctx->len     = 0;
144
145    ctx->ABCD[0] = 0x10325476;
146    ctx->ABCD[1] = 0x98badcfe;
147    ctx->ABCD[2] = 0xefcdab89;
148    ctx->ABCD[3] = 0x67452301;
149}
150
151void av_md5_update(AVMD5 *ctx, const uint8_t *src, size_t len)
152{
153    const uint8_t *end;
154    int j;
155
156    j         = ctx->len & 63;
157    ctx->len += len;
158
159    if (j) {
160        int cnt = FFMIN(len, 64 - j);
161        memcpy(ctx->block + j, src, cnt);
162        src += cnt;
163        len -= cnt;
164        if (j + cnt < 64)
165            return;
166        body(ctx->ABCD, ctx->block, 1);
167    }
168
169    end = src + (len & ~63);
170    if (!HAVE_FAST_UNALIGNED && ((intptr_t)src & 3)) {
171       while (src < end) {
172           memcpy(ctx->block, src, 64);
173           body(ctx->ABCD, ctx->block, 1);
174           src += 64;
175        }
176    } else {
177        size_t nblocks = len / 64;
178        body(ctx->ABCD, src, nblocks);
179        src = end;
180    }
181    len &= 63;
182    if (len > 0)
183        memcpy(ctx->block, src, len);
184}
185
186void av_md5_final(AVMD5 *ctx, uint8_t *dst)
187{
188    int i;
189    uint64_t finalcount = av_le2ne64(ctx->len << 3);
190
191    av_md5_update(ctx, "\200", 1);
192    while ((ctx->len & 63) != 56)
193        av_md5_update(ctx, "", 1);
194
195    av_md5_update(ctx, (uint8_t *) &finalcount, 8);
196
197    for (i = 0; i < 4; i++)
198        AV_WL32(dst + 4 * i, ctx->ABCD[3 - i]);
199}
200
201void av_md5_sum(uint8_t *dst, const uint8_t *src, size_t len)
202{
203    AVMD5 ctx;
204
205    av_md5_init(&ctx);
206    av_md5_update(&ctx, src, len);
207    av_md5_final(&ctx, dst);
208}
209