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libavutil/sha1.c

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00001 /*
00002  * Copyright (C) 2007 Michael Niedermayer <michaelni@gmx.at>
00003  * based on public domain SHA-1 code by Steve Reid <steve@edmweb.com>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "common.h"
00023 #include "bswap.h"
00024 #include "sha1.h"
00025 
00026 typedef struct AVSHA1 {
00027     uint64_t count;
00028     uint8_t buffer[64];
00029     uint32_t state[5];
00030 } AVSHA1;
00031 
00032 const int av_sha1_size = sizeof(AVSHA1);
00033 
00034 #define rol(value, bits) (((value) << (bits)) | ((value) >> (32 - (bits))))
00035 
00036 /* (R0+R1), R2, R3, R4 are the different operations used in SHA1 */
00037 #define blk0(i) (block[i] = be2me_32(((const uint32_t*)buffer)[i]))
00038 #define blk(i) (block[i] = rol(block[i-3]^block[i-8]^block[i-14]^block[i-16],1))
00039 
00040 #define R0(v,w,x,y,z,i) z+=((w&(x^y))^y)    +blk0(i)+0x5A827999+rol(v,5);w=rol(w,30);
00041 #define R1(v,w,x,y,z,i) z+=((w&(x^y))^y)    +blk (i)+0x5A827999+rol(v,5);w=rol(w,30);
00042 #define R2(v,w,x,y,z,i) z+=( w^x     ^y)    +blk (i)+0x6ED9EBA1+rol(v,5);w=rol(w,30);
00043 #define R3(v,w,x,y,z,i) z+=(((w|x)&y)|(w&x))+blk (i)+0x8F1BBCDC+rol(v,5);w=rol(w,30);
00044 #define R4(v,w,x,y,z,i) z+=( w^x     ^y)    +blk (i)+0xCA62C1D6+rol(v,5);w=rol(w,30);
00045 
00046 /* Hash a single 512-bit block. This is the core of the algorithm. */
00047 
00048 static void transform(uint32_t state[5], const uint8_t buffer[64]){
00049     uint32_t block[80];
00050     unsigned int i, a, b, c, d, e;
00051 
00052     a = state[0];
00053     b = state[1];
00054     c = state[2];
00055     d = state[3];
00056     e = state[4];
00057 #if CONFIG_SMALL
00058     for(i=0; i<80; i++){
00059         int t;
00060         if(i<16) t= be2me_32(((uint32_t*)buffer)[i]);
00061         else     t= rol(block[i-3]^block[i-8]^block[i-14]^block[i-16],1);
00062         block[i]= t;
00063         t+= e+rol(a,5);
00064         if(i<40){
00065             if(i<20)    t+= ((b&(c^d))^d)    +0x5A827999;
00066             else        t+= ( b^c     ^d)    +0x6ED9EBA1;
00067         }else{
00068             if(i<60)    t+= (((b|c)&d)|(b&c))+0x8F1BBCDC;
00069             else        t+= ( b^c     ^d)    +0xCA62C1D6;
00070         }
00071         e= d;
00072         d= c;
00073         c= rol(b,30);
00074         b= a;
00075         a= t;
00076     }
00077 #else
00078     for(i=0; i<15; i+=5){
00079         R0(a,b,c,d,e,0+i); R0(e,a,b,c,d,1+i); R0(d,e,a,b,c,2+i); R0(c,d,e,a,b,3+i); R0(b,c,d,e,a,4+i);
00080     }
00081     R0(a,b,c,d,e,15); R1(e,a,b,c,d,16); R1(d,e,a,b,c,17); R1(c,d,e,a,b,18); R1(b,c,d,e,a,19);
00082     for(i=20; i<40; i+=5){
00083         R2(a,b,c,d,e,0+i); R2(e,a,b,c,d,1+i); R2(d,e,a,b,c,2+i); R2(c,d,e,a,b,3+i); R2(b,c,d,e,a,4+i);
00084     }
00085     for(; i<60; i+=5){
00086         R3(a,b,c,d,e,0+i); R3(e,a,b,c,d,1+i); R3(d,e,a,b,c,2+i); R3(c,d,e,a,b,3+i); R3(b,c,d,e,a,4+i);
00087     }
00088     for(; i<80; i+=5){
00089         R4(a,b,c,d,e,0+i); R4(e,a,b,c,d,1+i); R4(d,e,a,b,c,2+i); R4(c,d,e,a,b,3+i); R4(b,c,d,e,a,4+i);
00090     }
00091 #endif
00092     state[0] += a;
00093     state[1] += b;
00094     state[2] += c;
00095     state[3] += d;
00096     state[4] += e;
00097 }
00098 
00099 void av_sha1_init(AVSHA1* ctx){
00100     ctx->state[0] = 0x67452301;
00101     ctx->state[1] = 0xEFCDAB89;
00102     ctx->state[2] = 0x98BADCFE;
00103     ctx->state[3] = 0x10325476;
00104     ctx->state[4] = 0xC3D2E1F0;
00105     ctx->count    = 0;
00106 }
00107 
00108 void av_sha1_update(AVSHA1* ctx, const uint8_t* data, unsigned int len){
00109     unsigned int i, j;
00110 
00111     j = ctx->count & 63;
00112     ctx->count += len;
00113 #if CONFIG_SMALL
00114     for( i = 0; i < len; i++ ){
00115         ctx->buffer[ j++ ] = data[i];
00116         if( 64 == j ){
00117             transform(ctx->state, ctx->buffer);
00118             j = 0;
00119         }
00120     }
00121 #else
00122     if ((j + len) > 63) {
00123         memcpy(&ctx->buffer[j], data, (i = 64-j));
00124         transform(ctx->state, ctx->buffer);
00125         for ( ; i + 63 < len; i += 64) {
00126             transform(ctx->state, &data[i]);
00127         }
00128         j=0;
00129     }
00130     else i = 0;
00131     memcpy(&ctx->buffer[j], &data[i], len - i);
00132 #endif
00133 }
00134 
00135 void av_sha1_final(AVSHA1* ctx, uint8_t digest[20]){
00136     int i;
00137     uint64_t finalcount= be2me_64(ctx->count<<3);
00138 
00139     av_sha1_update(ctx, "\200", 1);
00140     while ((ctx->count & 63) != 56) {
00141         av_sha1_update(ctx, "", 1);
00142     }
00143     av_sha1_update(ctx, (uint8_t *)&finalcount, 8); /* Should cause a transform() */
00144     for(i=0; i<5; i++)
00145         ((uint32_t*)digest)[i]= be2me_32(ctx->state[i]);
00146 }
00147 
00148 #ifdef TEST
00149 #include <stdio.h>
00150 #undef printf
00151 
00152 int main(void){
00153     int i, k;
00154     AVSHA1 ctx;
00155     unsigned char digest[20];
00156 
00157     for(k=0; k<3; k++){
00158         av_sha1_init(&ctx);
00159         if(k==0)
00160             av_sha1_update(&ctx, "abc", 3);
00161         else if(k==1)
00162             av_sha1_update(&ctx, "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq", 56);
00163         else
00164             for(i=0; i<1000*1000; i++)
00165                 av_sha1_update(&ctx, "a", 1);
00166         av_sha1_final(&ctx, digest);
00167         for (i = 0; i < 20; i++)
00168             printf("%02X", digest[i]);
00169         putchar('\n');
00170     }
00171     //test vectors (from FIPS PUB 180-1)
00172     printf("A9993E36 4706816A BA3E2571 7850C26C 9CD0D89D\n"
00173            "84983E44 1C3BD26E BAAE4AA1 F95129E5 E54670F1\n"
00174            "34AA973C D4C4DAA4 F61EEB2B DBAD2731 6534016F\n");
00175 
00176     return 0;
00177 }
00178 #endif

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