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libavutil/md5.c

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00001 /*
00002  * Copyright (C) 2006 Michael Niedermayer (michaelni@gmx.at)
00003  * Copyright (C) 2003-2005 by Christopher R. Hertel (crh@ubiqx.mn.org)
00004  *
00005  * References:
00006  *  IETF RFC 1321: The MD5 Message-Digest Algorithm
00007  *       Ron Rivest. IETF, April, 1992
00008  *
00009  * based on http://ubiqx.org/libcifs/source/Auth/MD5.c
00010  *          from Christopher R. Hertel (crh@ubiqx.mn.org)
00011  * Simplified, cleaned and IMO redundant comments removed by michael.
00012  *
00013  * If you use gcc, then version 4.1 or later and -fomit-frame-pointer is
00014  * strongly recommended.
00015  *
00016  * This file is part of Libav.
00017  *
00018  * Libav is free software; you can redistribute it and/or
00019  * modify it under the terms of the GNU Lesser General Public
00020  * License as published by the Free Software Foundation; either
00021  * version 2.1 of the License, or (at your option) any later version.
00022  *
00023  * Libav is distributed in the hope that it will be useful,
00024  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00025  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00026  * Lesser General Public License for more details.
00027  *
00028  * You should have received a copy of the GNU Lesser General Public
00029  * License along with Libav; if not, write to the Free Software
00030  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00031  */
00032 
00033 #include <stdint.h>
00034 #include "bswap.h"
00035 #include "intreadwrite.h"
00036 #include "md5.h"
00037 
00038 typedef struct AVMD5{
00039     uint64_t len;
00040     uint8_t  block[64];
00041     uint32_t ABCD[4];
00042 } AVMD5;
00043 
00044 const int av_md5_size = sizeof(AVMD5);
00045 
00046 static const uint8_t S[4][4] = {
00047     { 7, 12, 17, 22 },  /* round 1 */
00048     { 5,  9, 14, 20 },  /* round 2 */
00049     { 4, 11, 16, 23 },  /* round 3 */
00050     { 6, 10, 15, 21 }   /* round 4 */
00051 };
00052 
00053 static const uint32_t T[64] = { // T[i]= fabs(sin(i+1)<<32)
00054     0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,   /* round 1 */
00055     0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
00056     0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
00057     0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
00058 
00059     0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,   /* round 2 */
00060     0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
00061     0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
00062     0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
00063 
00064     0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,   /* round 3 */
00065     0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
00066     0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
00067     0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
00068 
00069     0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,   /* round 4 */
00070     0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
00071     0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
00072     0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
00073 };
00074 
00075 #define CORE(i, a, b, c, d) do {                                        \
00076         t = S[i >> 4][i & 3];                                           \
00077         a += T[i];                                                      \
00078                                                                         \
00079         if (i < 32) {                                                   \
00080             if (i < 16) a += (d ^ (b & (c ^ d))) + X[       i  & 15];   \
00081             else        a += (c ^ (d & (c ^ b))) + X[(1 + 5*i) & 15];   \
00082         } else {                                                        \
00083             if (i < 48) a += (b ^ c ^ d)         + X[(5 + 3*i) & 15];   \
00084             else        a += (c ^ (b | ~d))      + X[(    7*i) & 15];   \
00085         }                                                               \
00086         a = b + (a << t | a >> (32 - t));                               \
00087     } while (0)
00088 
00089 static void body(uint32_t ABCD[4], uint32_t X[16])
00090 {
00091     int t;
00092     int i av_unused;
00093     unsigned int a = ABCD[3];
00094     unsigned int b = ABCD[2];
00095     unsigned int c = ABCD[1];
00096     unsigned int d = ABCD[0];
00097 
00098 #if HAVE_BIGENDIAN
00099     for (i = 0; i < 16; i++)
00100         X[i] = av_bswap32(X[i]);
00101 #endif
00102 
00103 #if CONFIG_SMALL
00104     for (i = 0; i < 64; i++) {
00105         CORE(i, a, b, c, d);
00106         t = d;
00107         d = c;
00108         c = b;
00109         b = a;
00110         a = t;
00111     }
00112 #else
00113 #define CORE2(i)                                                        \
00114     CORE( i,   a,b,c,d); CORE((i+1),d,a,b,c);                           \
00115     CORE((i+2),c,d,a,b); CORE((i+3),b,c,d,a)
00116 #define CORE4(i) CORE2(i); CORE2((i+4)); CORE2((i+8)); CORE2((i+12))
00117     CORE4(0); CORE4(16); CORE4(32); CORE4(48);
00118 #endif
00119 
00120     ABCD[0] += d;
00121     ABCD[1] += c;
00122     ABCD[2] += b;
00123     ABCD[3] += a;
00124 }
00125 
00126 void av_md5_init(AVMD5 *ctx)
00127 {
00128     ctx->len     = 0;
00129 
00130     ctx->ABCD[0] = 0x10325476;
00131     ctx->ABCD[1] = 0x98badcfe;
00132     ctx->ABCD[2] = 0xefcdab89;
00133     ctx->ABCD[3] = 0x67452301;
00134 }
00135 
00136 void av_md5_update(AVMD5 *ctx, const uint8_t *src, const int len)
00137 {
00138     int i, j;
00139 
00140     j = ctx->len & 63;
00141     ctx->len += len;
00142 
00143     for (i = 0; i < len; i++) {
00144         ctx->block[j++] = src[i];
00145         if (j == 64) {
00146             body(ctx->ABCD, (uint32_t *) ctx->block);
00147             j = 0;
00148         }
00149     }
00150 }
00151 
00152 void av_md5_final(AVMD5 *ctx, uint8_t *dst)
00153 {
00154     int i;
00155     uint64_t finalcount = av_le2ne64(ctx->len << 3);
00156 
00157     av_md5_update(ctx, "\200", 1);
00158     while ((ctx->len & 63) != 56)
00159         av_md5_update(ctx, "", 1);
00160 
00161     av_md5_update(ctx, (uint8_t *)&finalcount, 8);
00162 
00163     for (i = 0; i < 4; i++)
00164         AV_WL32(dst + 4*i, ctx->ABCD[3 - i]);
00165 }
00166 
00167 void av_md5_sum(uint8_t *dst, const uint8_t *src, const int len)
00168 {
00169     AVMD5 ctx;
00170 
00171     av_md5_init(&ctx);
00172     av_md5_update(&ctx, src, len);
00173     av_md5_final(&ctx, dst);
00174 }
00175 
00176 #ifdef TEST
00177 #undef printf
00178 #include <stdio.h>
00179 
00180 static void print_md5(uint8_t *md5)
00181 {
00182     int i;
00183     for (i = 0; i < 16; i++)
00184         printf("%02x", md5[i]);
00185     printf("\n");
00186 }
00187 
00188 int main(void){
00189     uint8_t md5val[16];
00190     int i;
00191     uint8_t in[1000];
00192 
00193     for (i = 0; i < 1000; i++)
00194         in[i] = i * i;
00195     av_md5_sum(md5val, in, 1000); print_md5(md5val);
00196     av_md5_sum(md5val, in,   63); print_md5(md5val);
00197     av_md5_sum(md5val, in,   64); print_md5(md5val);
00198     av_md5_sum(md5val, in,   65); print_md5(md5val);
00199     for (i = 0; i < 1000; i++)
00200         in[i] = i % 127;
00201     av_md5_sum(md5val, in,  999); print_md5(md5val);
00202 
00203     return 0;
00204 }
00205 #endif
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