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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 FFmpeg.
00017  *
00018  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
00030  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00031  */
00032 
00033 #include <string.h>
00034 #include "bswap.h"
00035 #include "md5.h"
00036 
00037 typedef struct AVMD5{
00038     uint64_t len;
00039     uint8_t  block[64];
00040     uint32_t ABCD[4];
00041 } AVMD5;
00042 
00043 const int av_md5_size= sizeof(AVMD5);
00044 
00045 static const uint8_t S[4][4] = {
00046     { 7, 12, 17, 22 },  /* round 1 */
00047     { 5,  9, 14, 20 },  /* round 2 */
00048     { 4, 11, 16, 23 },  /* round 3 */
00049     { 6, 10, 15, 21 }   /* round 4 */
00050 };
00051 
00052 static const uint32_t T[64] = { // T[i]= fabs(sin(i+1)<<32)
00053     0xd76aa478, 0xe8c7b756, 0x242070db, 0xc1bdceee,   /* round 1 */
00054     0xf57c0faf, 0x4787c62a, 0xa8304613, 0xfd469501,
00055     0x698098d8, 0x8b44f7af, 0xffff5bb1, 0x895cd7be,
00056     0x6b901122, 0xfd987193, 0xa679438e, 0x49b40821,
00057 
00058     0xf61e2562, 0xc040b340, 0x265e5a51, 0xe9b6c7aa,   /* round 2 */
00059     0xd62f105d, 0x02441453, 0xd8a1e681, 0xe7d3fbc8,
00060     0x21e1cde6, 0xc33707d6, 0xf4d50d87, 0x455a14ed,
00061     0xa9e3e905, 0xfcefa3f8, 0x676f02d9, 0x8d2a4c8a,
00062 
00063     0xfffa3942, 0x8771f681, 0x6d9d6122, 0xfde5380c,   /* round 3 */
00064     0xa4beea44, 0x4bdecfa9, 0xf6bb4b60, 0xbebfbc70,
00065     0x289b7ec6, 0xeaa127fa, 0xd4ef3085, 0x04881d05,
00066     0xd9d4d039, 0xe6db99e5, 0x1fa27cf8, 0xc4ac5665,
00067 
00068     0xf4292244, 0x432aff97, 0xab9423a7, 0xfc93a039,   /* round 4 */
00069     0x655b59c3, 0x8f0ccc92, 0xffeff47d, 0x85845dd1,
00070     0x6fa87e4f, 0xfe2ce6e0, 0xa3014314, 0x4e0811a1,
00071     0xf7537e82, 0xbd3af235, 0x2ad7d2bb, 0xeb86d391,
00072 };
00073 
00074 #define CORE(i, a, b, c, d) \
00075         t = S[i>>4][i&3];\
00076         a += T[i];\
00077 \
00078         if(i<32){\
00079             if(i<16) a += (d ^ (b&(c^d))) + X[      i &15 ];\
00080             else     a += (c ^ (d&(c^b))) + X[ (1+5*i)&15 ];\
00081         }else{\
00082             if(i<48) a += (b^c^d)         + X[ (5+3*i)&15 ];\
00083             else     a += (c^(b|~d))      + X[ (  7*i)&15 ];\
00084         }\
00085         a = b + (( a << t ) | ( a >> (32 - t) ));
00086 
00087 static void body(uint32_t ABCD[4], uint32_t X[16]){
00088 
00089     int t;
00090     int i av_unused;
00091     unsigned int a= ABCD[3];
00092     unsigned int b= ABCD[2];
00093     unsigned int c= ABCD[1];
00094     unsigned int d= ABCD[0];
00095 
00096 #if HAVE_BIGENDIAN
00097     for(i=0; i<16; i++)
00098         X[i]= bswap_32(X[i]);
00099 #endif
00100 
00101 #if CONFIG_SMALL
00102     for( i = 0; i < 64; i++ ){
00103         CORE(i,a,b,c,d)
00104         t=d; d=c; c=b; b=a; a=t;
00105     }
00106 #else
00107 #define CORE2(i) CORE(i,a,b,c,d) CORE((i+1),d,a,b,c) CORE((i+2),c,d,a,b) CORE((i+3),b,c,d,a)
00108 #define CORE4(i) CORE2(i) CORE2((i+4)) CORE2((i+8)) CORE2((i+12))
00109 CORE4(0) CORE4(16) CORE4(32) CORE4(48)
00110 #endif
00111 
00112     ABCD[0] += d;
00113     ABCD[1] += c;
00114     ABCD[2] += b;
00115     ABCD[3] += a;
00116 }
00117 
00118 void av_md5_init(AVMD5 *ctx){
00119     ctx->len    = 0;
00120 
00121     ctx->ABCD[0] = 0x10325476;
00122     ctx->ABCD[1] = 0x98badcfe;
00123     ctx->ABCD[2] = 0xefcdab89;
00124     ctx->ABCD[3] = 0x67452301;
00125 }
00126 
00127 void av_md5_update(AVMD5 *ctx, const uint8_t *src, const int len){
00128     int i, j;
00129 
00130     j= ctx->len & 63;
00131     ctx->len += len;
00132 
00133     for( i = 0; i < len; i++ ){
00134         ctx->block[j++] = src[i];
00135         if( 64 == j ){
00136             body(ctx->ABCD, (uint32_t*) ctx->block);
00137             j = 0;
00138         }
00139     }
00140 }
00141 
00142 void av_md5_final(AVMD5 *ctx, uint8_t *dst){
00143     int i;
00144     uint64_t finalcount= le2me_64(ctx->len<<3);
00145 
00146     av_md5_update(ctx, "\200", 1);
00147     while((ctx->len & 63)!=56)
00148         av_md5_update(ctx, "", 1);
00149 
00150     av_md5_update(ctx, (uint8_t*)&finalcount, 8);
00151 
00152     for(i=0; i<4; i++)
00153         ((uint32_t*)dst)[i]= le2me_32(ctx->ABCD[3-i]);
00154 }
00155 
00156 void av_md5_sum(uint8_t *dst, const uint8_t *src, const int len){
00157     AVMD5 ctx[1];
00158 
00159     av_md5_init(ctx);
00160     av_md5_update(ctx, src, len);
00161     av_md5_final(ctx, dst);
00162 }
00163 
00164 #ifdef TEST
00165 #include <stdio.h>
00166 #include <inttypes.h>
00167 #undef printf
00168 int main(void){
00169     uint64_t md5val;
00170     int i;
00171     uint8_t in[1000];
00172 
00173     for(i=0; i<1000; i++) in[i]= i*i;
00174     av_md5_sum( (uint8_t*)&md5val, in,  1000); printf("%"PRId64"\n", md5val);
00175     av_md5_sum( (uint8_t*)&md5val, in,  63); printf("%"PRId64"\n", md5val);
00176     av_md5_sum( (uint8_t*)&md5val, in,  64); printf("%"PRId64"\n", md5val);
00177     av_md5_sum( (uint8_t*)&md5val, in,  65); printf("%"PRId64"\n", md5val);
00178     for(i=0; i<1000; i++) in[i]= i % 127;
00179     av_md5_sum( (uint8_t*)&md5val, in,  999); printf("%"PRId64"\n", md5val);
00180 
00181     return 0;
00182 }
00183 #endif

Generated on Fri Sep 16 2011 17:17:51 for FFmpeg by  doxygen 1.7.1