/*
 * $Log: sha.c,v $
 * Revision 1.3  2003/01/16 18:18:56  josh
 * directory structure shifting
 *
 * Revision 1.2  2001/11/06 22:15:53  tneale
 * Fixed for newest file layout
 *
 * Revision 1.1.1.1  2001/11/05 17:48:39  tneale
 * Tornado shuffle
 *
 * Revision 1.4  2001/01/19 22:21:31  paul
 * Update copyright.
 *
 * Revision 1.3  2000/03/17 00:16:56  meister
 * Update copyright message
 *
 * Revision 1.2  1998/06/16 05:12:26  sar
 * Clean up some type questions
 *
 * Revision 1.1  1998/05/22 18:03:35  sar
 * SHA digest functions
 *
 */

/* [clearcase]
modification history
-------------------
01b,20apr05,job  update copyright notices
01a,11dec03,job  fix copyright statements
*/


/* NIST Secure Hash Algorithm */
/* heavily modified by Uwe Hollerbach <uh@alumni.caltech edu> */
/* from Peter C. Gutmann's implementation as found in */
/* Applied Cryptography by Bruce Schneier */
/* Further modifications to include the "UNRAVEL" stuff, below */

/* This code is in the public domain */

#include <wrn/wm/common/install.h>
#include <wrn/wm/common/types.h>
#include <wrn/wm/common/config.h>
#include <wrn/wm/common/glue.h>

#include <wrn/wm/common/sha.h>


/* Always use version 1, but leave the code around in case
   somebody wants to know that the difference is */
#define SHA_VERSION 1

/* SHA f()-functions */

#define f1(x,y,z)	((x & y) | (~x & z))
#define f2(x,y,z)	(x ^ y ^ z)
#define f3(x,y,z)	((x & y) | (x & z) | (y & z))
#define f4(x,y,z)	(x ^ y ^ z)

/* SHA constants */

#define CONST1		0x5a827999L
#define CONST2		0x6ed9eba1L
#define CONST3		0x8f1bbcdcL
#define CONST4		0xca62c1d6L

/* 32-bit rotate */

#define R32(x,n)	((x << n) | (x >> (32 - n)))

#define FG(n)	\
    T = R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n;	\
    E = D; D = C; C = R32(B,30); B = A; A = T

/* do SHA transformation */

static void sha_transform (SHA_CTX *sha_info)
{
    int i;
    bits8_t *dp;
    bits32_t T, A, B, C, D, E, W[80], *WP;

    dp = sha_info->data;

#if (INSTALL_ON_LITTLE_ENDIAN)
    for (i = 0; i < 16; ++i) 
    {
	T = *((bits32_t *) dp);
	dp += 4;
	W[i] =  ((T << 24) & 0xff000000L) | ((T <<  8) & 0x00ff0000L) |
		((T >>  8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);
    }
#endif /* #if (INSTALL_ON_LITTLE_ENDIAN) */

#if (INSTALL_ON_BIG_ENDIAN)
    for (i = 0; i < 16; ++i) 
    {
	T = *((bits32_t *) dp);
	dp += 4;
	W[i] = T;
    }
#endif /* #if (INSTALL_ON_BIG_ENDIAN) **/

    for (i = 16; i < 80; ++i) 
    {
	W[i] = W[i-3] ^ W[i-8] ^ W[i-14] ^ W[i-16];
#if (SHA_VERSION == 1)
	W[i] = R32(W[i], 1);
#endif /* SHA_VERSION */
    }

    A = sha_info->buf[0];
    B = sha_info->buf[1];
    C = sha_info->buf[2];
    D = sha_info->buf[3];
    E = sha_info->buf[4];
    WP = W;

    for (i =  0; i < 20; ++i) { FG(1); }
    for (i = 20; i < 40; ++i) { FG(2); }
    for (i = 40; i < 60; ++i) { FG(3); }
    for (i = 60; i < 80; ++i) { FG(4); }

    sha_info->buf[0] += A;
    sha_info->buf[1] += B;
    sha_info->buf[2] += C;
    sha_info->buf[3] += D;
    sha_info->buf[4] += E;

}

/* initialize the SHA digest */

void sha_init(SHA_CTX *sha_info)
{
    sha_info->buf[0] = 0x67452301L;
    sha_info->buf[1] = 0xefcdab89L;
    sha_info->buf[2] = 0x98badcfeL;
    sha_info->buf[3] = 0x10325476L;
    sha_info->buf[4] = 0xc3d2e1f0L;
    sha_info->count_lo = 0L;
    sha_info->count_hi = 0L;
    sha_info->local = 0;
}

/* update the SHA digest */

void sha_update(SHA_CTX  *sha_info,
		bits8_t  *buffer,
		bits32_t  count)
{
    bits32_t clo;
    size_t i;

    clo = sha_info->count_lo + ((bits32_t) count << 3);
    if (clo < sha_info->count_lo) {
	++sha_info->count_hi;
    }
    sha_info->count_lo = clo;
    sha_info->count_hi += (bits32_t) count >> 29;
    if (sha_info->local) 
    {
	i = SHA_BLOCKSIZE - sha_info->local;
	if (i > count) 
            i = (size_t)count;
	
	MEMCPY(sha_info->data + sha_info->local, buffer, i);
	count -= i;
	buffer += i;
	sha_info->local += i;
	if (sha_info->local == SHA_BLOCKSIZE) 
	    sha_transform(sha_info);
        else 
	    return;
    }
    while (count >= SHA_BLOCKSIZE) 
    {      MEMCPY (sha_info->data, buffer, SHA_BLOCKSIZE);
           buffer += SHA_BLOCKSIZE;
           count -= SHA_BLOCKSIZE;
           sha_transform (sha_info);
    }
    if (count) {
        MEMCPY (sha_info->data, buffer, (size_t)count);
        }
    sha_info->local = (size_t)count;

}

/* finish computing the SHA digest */

void sha_final (SHA_CTX *sha_info)
{
    int count, i, ii;
    bits32_t lo_bit_count, hi_bit_count;

    lo_bit_count = sha_info->count_lo;
    hi_bit_count = sha_info->count_hi;
    count = (int) ((lo_bit_count >> 3) & 0x3f);
    ((bits8_t *) sha_info->data)[count++] = 0x80;
    if (count > SHA_BLOCKSIZE - 8) {
	MEMSET(sha_info->data + count, 0, SHA_BLOCKSIZE - count);
	sha_transform(sha_info);
	MEMSET(sha_info->data, 0, SHA_BLOCKSIZE - 8);
    } else {
	MEMSET(sha_info->data + count, 0, SHA_BLOCKSIZE - 8 - count);
    }
    sha_info->data[56] = (bits8_t) ((hi_bit_count >> 24) & 0xffL);
    sha_info->data[57] = (bits8_t) ((hi_bit_count >> 16) & 0xffL);
    sha_info->data[58] = (bits8_t) ((hi_bit_count >>  8) & 0xffL);
    sha_info->data[59] = (bits8_t) ((hi_bit_count      ) & 0xffL);
    sha_info->data[60] = (bits8_t) ((lo_bit_count >> 24) & 0xffL);
    sha_info->data[61] = (bits8_t) ((lo_bit_count >> 16) & 0xffL);
    sha_info->data[62] = (bits8_t) ((lo_bit_count >>  8) & 0xffL);
    sha_info->data[63] = (bits8_t) ((lo_bit_count      ) & 0xffL);

    sha_transform(sha_info);

    /* store buffer in digest */
    for(i = 0, ii = 0; i < 5; i++, ii += 4) {
        sha_info->digest[ii]   = (bits8_t)((sha_info->buf[i] >> 24) & 0xFF);
        sha_info->digest[ii+1] = (bits8_t)((sha_info->buf[i] >> 16) & 0xFF);
        sha_info->digest[ii+2] = (bits8_t)((sha_info->buf[i] >>  8) & 0xFF);
        sha_info->digest[ii+3] = (bits8_t)((sha_info->buf[i]) & 0xFF);
        }
}