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
39typedef struct AVMD5{
40    uint64_t len;
41    uint8_t  block[64];
42    uint32_t ABCD[4];
43} AVMD5;
44
45const int av_md5_size = sizeof(AVMD5);
46
47struct AVMD5 *av_md5_alloc(void)
48{
49    return av_mallocz(sizeof(struct AVMD5));
50}
51
52static 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
59static 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
95static 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
138void 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
148void 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
183void 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
198void 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
210static 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
218int 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
236