sha1算法

falcon_13

/* sha1sum.c - print SHA-1 Message-Digest Algorithm
* Copyright (C) 1998, 1999, 2000, 2001 Free Software Foundation, Inc.
* Copyright (C) 2004 g10 Code GmbH
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License as published by the
* Free Software Foundation; either version 2, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/* SHA-1 coden take from gnupg 1.3.92.
  Note, that this is a simple tool to be used for MS Windows.
*/
#include
#include
#include
#include
#include
#undef BIG_ENDIAN_HOST
typedef unsigned int u32;
/****************
* Rotate a 32 bit integer by n bytes
****************/
#if defined(__GNUC__) && defined(__i386__)
static inline u32 rol( u32 x, int n)
{
        __asm__("roll %%cl,%0"
            :"=r" (x)
            :"0" (x),"c" (n));
        return x;
}
#else
#define rol(x,n) ( ((x) > (32-(n))) )
#endif
typedef struct {
    u32  h0,h1,h2,h3,h4;
    u32  nblocks;
    unsigned char buf[64];
    int  count;
} SHA1_CONTEXT;
void sha1_init( SHA1_CONTEXT *hd )
{
    hd->h0 = 0x67452301;
    hd->h1 = 0xefcdab89;
    hd->h2 = 0x98badcfe;
    hd->h3 = 0x10325476;
    hd->h4 = 0xc3d2e1f0;
    hd->nblocks = 0;
    hd->count = 0;
}
/*
* Transform the message X which consists of 16 32-bit-words
*/
static void
transform( SHA1_CONTEXT *hd, unsigned char *data )
{
    u32 a,b,c,d,e,tm;
    u32 x[16];
    /* get values from the chaining vars */
    a = hd->h0;
    b = hd->h1;
    c = hd->h2;
    d = hd->h3;
    e = hd->h4;
#ifdef BIG_ENDIAN_HOST
    memcpy( x, data, 64 );
#else
    { int i;
        unsigned char *p2;
        for(i=0, p2=(unsigned char*)x; i h0 += a;
    hd->h1 += b;
    hd->h2 += c;
    hd->h3 += d;
    hd->h4 += e;
}
/* Update the message digest with the contents
* of INBUF with length INLEN.
*/
static void sha1_write( SHA1_CONTEXT *hd, unsigned char *inbuf, size_t inlen)
{
    if( hd->count == 64 ) { /* flush the buffer */
        transform( hd, hd->buf );
        hd->count = 0;
        hd->nblocks++;
    }
    if( !inbuf )
        return;
    if( hd->count ) {
        for( ; inlen && hd->count buf[hd->count++] = *inbuf++;
        sha1_write( hd, NULL, 0 );
        if( !inlen )
            return;
    }
    while( inlen >= 64 ) {
        transform( hd, inbuf );
        hd->count = 0;
        hd->nblocks++;
        inlen -= 64;
        inbuf += 64;
    }
    for( ; inlen && hd->count buf[hd->count++] = *inbuf++;
}
/* The routine final terminates the computation and
* returns the digest.
* The handle is prepared for a new cycle, but adding bytes to the
* handle will the destroy the returned buffer.
* Returns: 20 bytes representing the digest.
*/
static void sha1_final(SHA1_CONTEXT *hd)
{
    u32 t, msb, lsb;
    unsigned char *p;
    sha1_write(hd, NULL, 0); /* flush */;
    t = hd->nblocks;
    /* multiply by 64 to make a byte count */
    lsb = t > 26;
    /* add the count */
    t = lsb;
    if( (lsb += hd->count) > 29;
    if( hd->count buf[hd->count++] = 0x80; /* pad */
        while( hd->count buf[hd->count++] = 0;  /* pad */
    }
    else { /* need one extra block */
        hd->buf[hd->count++] = 0x80; /* pad character */
        while( hd->count buf[hd->count++] = 0;
        sha1_write(hd, NULL, 0);  /* flush */;
        memset(hd->buf, 0, 56 ); /* fill next block with zeroes */
    }
    /* append the 64 bit count */
    hd->buf[56] = msb >> 24;
    hd->buf[57] = msb >> 16;
    hd->buf[58] = msb >>  8;
    hd->buf[59] = msb          ;
    hd->buf[60] = lsb >> 24;
    hd->buf[61] = lsb >> 16;
    hd->buf[62] = lsb >>  8;
    hd->buf[63] = lsb          ;
    transform( hd, hd->buf );
    p = hd->buf;
#ifdef BIG_ENDIAN_HOST
#define X(a) do { *(u32*)p = hd->h##a ; p += 4; } while(0)
#else /* little endian */
#define X(a) do { *p++ = hd->h##a >> 24; *p++ = hd->h##a >> 16; \
        *p++ = hd->h##a >> 8; *p++ = hd->h##a; } while(0)
#endif
    X(0);
    X(1);
    X(2);
    X(3);
    X(4);
#undef X
}
int main (int argc, char **argv)
{
    assert (sizeof (u32) == 4);
    FILE *fp,*fp1;
    char buffer[262144];
    size_t n;
    SHA1_CONTEXT ctx;
    int i;
    int sum=0,all=0;
    fp = fopen ("/home/falcon/test/Around.mp3", "rb");
    fp1=fopen("t","wb+");
    while ( (n = fread (buffer, 1, sizeof buffer, fp)))
    {
        sha1_init (&ctx);
        sha1_write (&ctx, buffer, n);
        sha1_final (&ctx);
         all=all+n;
        for (i=0; i

本文来自ChinaUnix博客，如果查看原文请点：http://blog.chinaunix.net/u1/57427/showart_488186.html