sha1.c 8.67 KB
/* sha1.c ****************************************************

                        Anubis Web Server
                      SHA1 digest algorithm

*************************************************************/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include "cipher.h"

/****************
 * 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) << (n)) | ((x) >> (32-(n))) )
#endif



typedef struct {
    u32  h0,h1,h2,h3,h4;
    u32  nblocks;
    byte 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, byte *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;
      byte *p2;
      for(i=0, p2=(byte*)x; i < 16; i++, p2 += 4 ) {
	p2[3] = *data++;
	p2[2] = *data++;
	p2[1] = *data++;
	p2[0] = *data++;
      }
    }
  #endif


#define K1  0x5A827999L
#define K2  0x6ED9EBA1L
#define K3  0x8F1BBCDCL
#define K4  0xCA62C1D6L
#define F1(x,y,z)   ( z ^ ( x & ( y ^ z ) ) )
#define F2(x,y,z)   ( x ^ y ^ z )
#define F3(x,y,z)   ( ( x & y ) | ( z & ( x | y ) ) )
#define F4(x,y,z)   ( x ^ y ^ z )


#define M(i) ( tm =   x[i&0x0f] ^ x[(i-14)&0x0f] \
		    ^ x[(i-8)&0x0f] ^ x[(i-3)&0x0f] \
	       , (x[i&0x0f] = (tm << 1) | (tm >> 31)) )

#define R(a,b,c,d,e,f,k,m)  do { e += rol( a, 5 )     \
				      + f( b, c, d )  \
				      + k	      \
				      + m;	      \
				 b = rol( b, 30 );    \
			       } while(0)
    R( a, b, c, d, e, F1, K1, x[ 0] );
    R( e, a, b, c, d, F1, K1, x[ 1] );
    R( d, e, a, b, c, F1, K1, x[ 2] );
    R( c, d, e, a, b, F1, K1, x[ 3] );
    R( b, c, d, e, a, F1, K1, x[ 4] );
    R( a, b, c, d, e, F1, K1, x[ 5] );
    R( e, a, b, c, d, F1, K1, x[ 6] );
    R( d, e, a, b, c, F1, K1, x[ 7] );
    R( c, d, e, a, b, F1, K1, x[ 8] );
    R( b, c, d, e, a, F1, K1, x[ 9] );
    R( a, b, c, d, e, F1, K1, x[10] );
    R( e, a, b, c, d, F1, K1, x[11] );
    R( d, e, a, b, c, F1, K1, x[12] );
    R( c, d, e, a, b, F1, K1, x[13] );
    R( b, c, d, e, a, F1, K1, x[14] );
    R( a, b, c, d, e, F1, K1, x[15] );
    R( e, a, b, c, d, F1, K1, M(16) );
    R( d, e, a, b, c, F1, K1, M(17) );
    R( c, d, e, a, b, F1, K1, M(18) );
    R( b, c, d, e, a, F1, K1, M(19) );
    R( a, b, c, d, e, F2, K2, M(20) );
    R( e, a, b, c, d, F2, K2, M(21) );
    R( d, e, a, b, c, F2, K2, M(22) );
    R( c, d, e, a, b, F2, K2, M(23) );
    R( b, c, d, e, a, F2, K2, M(24) );
    R( a, b, c, d, e, F2, K2, M(25) );
    R( e, a, b, c, d, F2, K2, M(26) );
    R( d, e, a, b, c, F2, K2, M(27) );
    R( c, d, e, a, b, F2, K2, M(28) );
    R( b, c, d, e, a, F2, K2, M(29) );
    R( a, b, c, d, e, F2, K2, M(30) );
    R( e, a, b, c, d, F2, K2, M(31) );
    R( d, e, a, b, c, F2, K2, M(32) );
    R( c, d, e, a, b, F2, K2, M(33) );
    R( b, c, d, e, a, F2, K2, M(34) );
    R( a, b, c, d, e, F2, K2, M(35) );
    R( e, a, b, c, d, F2, K2, M(36) );
    R( d, e, a, b, c, F2, K2, M(37) );
    R( c, d, e, a, b, F2, K2, M(38) );
    R( b, c, d, e, a, F2, K2, M(39) );
    R( a, b, c, d, e, F3, K3, M(40) );
    R( e, a, b, c, d, F3, K3, M(41) );
    R( d, e, a, b, c, F3, K3, M(42) );
    R( c, d, e, a, b, F3, K3, M(43) );
    R( b, c, d, e, a, F3, K3, M(44) );
    R( a, b, c, d, e, F3, K3, M(45) );
    R( e, a, b, c, d, F3, K3, M(46) );
    R( d, e, a, b, c, F3, K3, M(47) );
    R( c, d, e, a, b, F3, K3, M(48) );
    R( b, c, d, e, a, F3, K3, M(49) );
    R( a, b, c, d, e, F3, K3, M(50) );
    R( e, a, b, c, d, F3, K3, M(51) );
    R( d, e, a, b, c, F3, K3, M(52) );
    R( c, d, e, a, b, F3, K3, M(53) );
    R( b, c, d, e, a, F3, K3, M(54) );
    R( a, b, c, d, e, F3, K3, M(55) );
    R( e, a, b, c, d, F3, K3, M(56) );
    R( d, e, a, b, c, F3, K3, M(57) );
    R( c, d, e, a, b, F3, K3, M(58) );
    R( b, c, d, e, a, F3, K3, M(59) );
    R( a, b, c, d, e, F4, K4, M(60) );
    R( e, a, b, c, d, F4, K4, M(61) );
    R( d, e, a, b, c, F4, K4, M(62) );
    R( c, d, e, a, b, F4, K4, M(63) );
    R( b, c, d, e, a, F4, K4, M(64) );
    R( a, b, c, d, e, F4, K4, M(65) );
    R( e, a, b, c, d, F4, K4, M(66) );
    R( d, e, a, b, c, F4, K4, M(67) );
    R( c, d, e, a, b, F4, K4, M(68) );
    R( b, c, d, e, a, F4, K4, M(69) );
    R( a, b, c, d, e, F4, K4, M(70) );
    R( e, a, b, c, d, F4, K4, M(71) );
    R( d, e, a, b, c, F4, K4, M(72) );
    R( c, d, e, a, b, F4, K4, M(73) );
    R( b, c, d, e, a, F4, K4, M(74) );
    R( a, b, c, d, e, F4, K4, M(75) );
    R( e, a, b, c, d, F4, K4, M(76) );
    R( d, e, a, b, c, F4, K4, M(77) );
    R( c, d, e, a, b, F4, K4, M(78) );
    R( b, c, d, e, a, F4, K4, M(79) );

    /* update chaining vars */
    hd->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, byte *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 < 64; inlen-- )
	    hd->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 < 64; inlen-- )
	hd->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;
    byte *p;

    sha1_write(hd, NULL, 0); /* flush */;

    msb = 0;
    t = hd->nblocks;
    if( (lsb = t << 6) < t ) /* multiply by 64 to make a byte count */
	msb++;
    msb += t >> 26;
    t = lsb;
    if( (lsb = t + hd->count) < t ) /* add the count */
	msb++;
    t = lsb;
    if( (lsb = t << 3) < t ) /* multiply by 8 to make a bit count */
	msb++;
    msb += t >> 29;

    if( hd->count < 56 ) { /* enough room */
	hd->buf[hd->count++] = 0x80; /* pad */
	while( hd->count < 56 )
	    hd->buf[hd->count++] = 0;  /* pad */
    }
    else { /* need one extra block */
	hd->buf[hd->count++] = 0x80; /* pad character */
	while( hd->count < 64 )
	    hd->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

}

static char result[41]; 

static SHA1_CONTEXT sha1_ctxt; 

#define hex_digit(n) (((unsigned char)(n)) < 10 ? ('0'+(n)) : ('a'+(n)-10))

/* compute the sha1 digest as a sequence of 40 ascii hex digits */ 
char *ascii_sha1(char *source, int n)
{
  int i; 
  sha1_init(&sha1_ctxt); 
  sha1_write(&sha1_ctxt,(byte *)source,n);
  sha1_final(&sha1_ctxt);
  for (i = 0; i < 20; i++)
    {
      result[i<<1] = hex_digit(((sha1_ctxt.buf)[i])&0xF); 
      result[(i<<1)|1] = hex_digit(((sha1_ctxt.buf)[i])>>4); 
    }
  result[40] = 0; 
  return result; 
}


/* compute the sha1 digest as an array of 20 bytes */ 
byte *sha1(char *source, int n)
{
  sha1_init(&sha1_ctxt); 
  sha1_write(&sha1_ctxt,(byte *)source,n); 
  sha1_final(&sha1_ctxt);
  return (byte *)(&(sha1_ctxt.buf)); 
}


/* compare two sha1 digests */ 
int same_sha1(byte *s1, byte *s2)
{
  int i; 
  for (i = 0; i < 20; i++)
    if (s1[i] != s2[i])
      return 0; 
  return 1; 
}


char sha1asciibuf[41];
char *sha1_to_ascii(byte *sha)
{
  int i; 
  for (i = 0; i < 20 ; i++)
    {
      sha1asciibuf[i<<1] = hex_digit(((sha[i])>>4)&0xf);
      sha1asciibuf[(i<<1)+1] = hex_digit((sha[i])&0xf);
    }
  sha1asciibuf[40] = 0; 
  return sha1asciibuf;
}