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;
41     uint8_t  block[64];
42     uint32_t ABCD[4];
43 } AVMD5;
44 
45 const int av_md5_size = sizeof(AVMD5);
46 
av_md5_alloc(void)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 
body(uint32_t ABCD[4],uint32_t * src,int nblocks)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 
av_md5_init(AVMD5 * ctx)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 
av_md5_update(AVMD5 * ctx,const uint8_t * src,int len)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 
av_md5_final(AVMD5 * ctx,uint8_t * dst)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 
av_md5_sum(uint8_t * dst,const uint8_t * src,const int len)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 
print_md5(uint8_t * md5)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 
main(void)218 int main(void){
219     uint8_t md5val[16];
220     int i;
221     volatile uint8_t in[1000]; // volatile to workaround http://llvm.org/bugs/show_bug.cgi?id=20849
222     // FIXME remove volatile once it has been fixed and all fate clients are updated
223 
224     for (i = 0; i < 1000; i++)
225         in[i] = i * i;
226     av_md5_sum(md5val, in, 1000); print_md5(md5val);
227     av_md5_sum(md5val, in,   63); print_md5(md5val);
228     av_md5_sum(md5val, in,   64); print_md5(md5val);
229     av_md5_sum(md5val, in,   65); print_md5(md5val);
230     for (i = 0; i < 1000; i++)
231         in[i] = i % 127;
232     av_md5_sum(md5val, in,  999); print_md5(md5val);
233 
234     return 0;
235 }
236 #endif
237