/* (PD) 2001 The Bitzi Corporation

 * Please see file COPYING or http://bitzi.com/publicdomain 

 * for more info.

 *

 * 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 

 *

 * $Id: sha1.c,v 1.2 2008-02-27 10:42:08 slomo Exp $

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include <glib.h>

#define SHA_BYTE_ORDER G_BYTE_ORDER

#include <string.h>

#include "sha1.h"

/* UNRAVEL should be fastest & biggest */

/* UNROLL_LOOPS should be just as big, but slightly slower */

/* both undefined should be smallest and slowest */

#define UNRAVEL

/* #define UNROLL_LOOPS */

/* 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

/* truncate to 32 bits -- should be a null op on 32-bit machines */

#define T32(x)	((x) & 0xffffffffL)

/* 32-bit rotate */

#define R32(x,n)	T32(((x << n) | (x >> (32 - n))))

/* the generic case, for when the overall rotation is not unraveled */

#define FG(n)	\

    T = T32(R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n);	\

    E = D; D = C; C = R32(B,30); B = A; A = T

/* specific cases, for when the overall rotation is unraveled */

#define FA(n)	\

    T = T32(R32(A,5) + f##n(B,C,D) + E + *WP++ + CONST##n); B = R32(B,30)

#define FB(n)	\

    E = T32(R32(T,5) + f##n(A,B,C) + D + *WP++ + CONST##n); A = R32(A,30)

#define FC(n)	\

    D = T32(R32(E,5) + f##n(T,A,B) + C + *WP++ + CONST##n); T = R32(T,30)

#define FD(n)	\

    C = T32(R32(D,5) + f##n(E,T,A) + B + *WP++ + CONST##n); E = R32(E,30)

#define FE(n)	\

    B = T32(R32(C,5) + f##n(D,E,T) + A + *WP++ + CONST##n); D = R32(D,30)

#define FT(n)	\

    A = T32(R32(B,5) + f##n(C,D,E) + T + *WP++ + CONST##n); C = R32(C,30)

/* do SHA transformation */

static void

sha_transform (SHA_INFO * sha_info)

{

  int i;

  SHA_BYTE *dp;

  SHA_LONG T, A, B, C, D, E, W[80], *WP;

  dp = sha_info->data;

/*

the following makes sure that at least one code block below is

traversed or an error is reported, without the necessity for nested

preprocessor if/else/endif blocks, which are a great pain in the

nether regions of the anatomy...

*/

#undef SWAP_DONE

#if (SHA_BYTE_ORDER == 1234)

#define SWAP_DONE

  for (i = 0; i < 16; ++i) {

    memcpy (&T, dp, sizeof (SHA_LONG));

    dp += 4;

    W[i] = ((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |

        ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);

  }

#endif /* SHA_BYTE_ORDER == 1234 */

#if (SHA_BYTE_ORDER == 4321)

#define SWAP_DONE

  for (i = 0; i < 16; ++i) {

    memcpy (&T, dp, sizeof (SHA_LONG));

    dp += 4;

    W[i] = T32 (T);

  }

#endif /* SHA_BYTE_ORDER == 4321 */

#if (SHA_BYTE_ORDER == 12345678)

#define SWAP_DONE

  for (i = 0; i < 16; i += 2) {

    memcpy (&T, dp, sizeof (SHA_LONG));

    dp += 8;

    W[i] = ((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |

        ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);

    T >>= 32;

    W[i + 1] = ((T << 24) & 0xff000000) | ((T << 8) & 0x00ff0000) |

        ((T >> 8) & 0x0000ff00) | ((T >> 24) & 0x000000ff);

  }

#endif /* SHA_BYTE_ORDER == 12345678 */

#if (SHA_BYTE_ORDER == 87654321)

#define SWAP_DONE

  for (i = 0; i < 16; i += 2) {

    memcpy (&T, dp, sizeof (SHA_LONG));

    dp += 8;

    W[i] = T32 (T >> 32);

    W[i + 1] = T32 (T);

  }

#endif /* SHA_BYTE_ORDER == 87654321 */

#ifndef SWAP_DONE

#error Unknown byte order -- you need to add code here

#endif /* SWAP_DONE */

  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->digest[0];

  B = sha_info->digest[1];

  C = sha_info->digest[2];

  D = sha_info->digest[3];

  E = sha_info->digest[4];

  WP = W;

#ifdef UNRAVEL

  FA (1);

  FB (1);

  FC (1);

  FD (1);

  FE (1);

  FT (1);

  FA (1);

  FB (1);

  FC (1);

  FD (1);

  FE (1);

  FT (1);

  FA (1);

  FB (1);

  FC (1);

  FD (1);

  FE (1);

  FT (1);

  FA (1);

  FB (1);

  FC (2);

  FD (2);

  FE (2);

  FT (2);

  FA (2);

  FB (2);

  FC (2);

  FD (2);

  FE (2);

  FT (2);

  FA (2);

  FB (2);

  FC (2);

  FD (2);

  FE (2);

  FT (2);

  FA (2);

  FB (2);

  FC (2);

  FD (2);

  FE (3);

  FT (3);

  FA (3);

  FB (3);

  FC (3);

  FD (3);

  FE (3);

  FT (3);

  FA (3);

  FB (3);

  FC (3);

  FD (3);

  FE (3);

  FT (3);

  FA (3);

  FB (3);

  FC (3);

  FD (3);

  FE (3);

  FT (3);

  FA (4);

  FB (4);

  FC (4);

  FD (4);

  FE (4);

  FT (4);

  FA (4);

  FB (4);

  FC (4);

  FD (4);

  FE (4);

  FT (4);

  FA (4);

  FB (4);

  FC (4);

  FD (4);

  FE (4);

  FT (4);

  FA (4);

  FB (4);

  sha_info->digest[0] = T32 (sha_info->digest[0] + E);

  sha_info->digest[1] = T32 (sha_info->digest[1] + T);

  sha_info->digest[2] = T32 (sha_info->digest[2] + A);

  sha_info->digest[3] = T32 (sha_info->digest[3] + B);

  sha_info->digest[4] = T32 (sha_info->digest[4] + C);

#else /* !UNRAVEL */

#ifdef UNROLL_LOOPS

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (1);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (2);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (3);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

  FG (4);

#else /* !UNROLL_LOOPS */

  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);

  }

#endif /* !UNROLL_LOOPS */

  sha_info->digest[0] = T32 (sha_info->digest[0] + A);

  sha_info->digest[1] = T32 (sha_info->digest[1] + B);

  sha_info->digest[2] = T32 (sha_info->digest[2] + C);

  sha_info->digest[3] = T32 (sha_info->digest[3] + D);

  sha_info->digest[4] = T32 (sha_info->digest[4] + E);

#endif /* !UNRAVEL */

}

/* initialize the SHA digest */

void

sha_init (SHA_INFO * sha_info)

{

  sha_info->digest[0] = 0x67452301L;

  sha_info->digest[1] = 0xefcdab89L;

  sha_info->digest[2] = 0x98badcfeL;

  sha_info->digest[3] = 0x10325476L;

  sha_info->digest[4] = 0xc3d2e1f0L;

  sha_info->count_lo = 0L;

  sha_info->count_hi = 0L;

  sha_info->local = 0;

}

/* update the SHA digest */

void

sha_update (SHA_INFO * sha_info, SHA_BYTE * buffer, int count)

{

  int i;

  SHA_LONG clo;

  clo = T32 (sha_info->count_lo + ((SHA_LONG) count << 3));

  if (clo < sha_info->count_lo) {

    ++sha_info->count_hi;

  }

  sha_info->count_lo = clo;

  sha_info->count_hi += (SHA_LONG) count >> 29;

  if (sha_info->local) {

    i = SHA_BLOCKSIZE - sha_info->local;

    if (i > count) {

      i = count;

    }

    memcpy (((SHA_BYTE *) 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);

  }

  memcpy (sha_info->data, buffer, count);

  sha_info->local = count;

}

/* finish computing the SHA digest */

void

sha_final (unsigned char digest[20], SHA_INFO * sha_info)

{

  int count;

  SHA_LONG 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);

  ((SHA_BYTE *) sha_info->data)[count++] = 0x80;

  if (count > SHA_BLOCKSIZE - 8) {

    memset (((SHA_BYTE *) sha_info->data) + count, 0, SHA_BLOCKSIZE - count);

    sha_transform (sha_info);

    memset ((SHA_BYTE *) sha_info->data, 0, SHA_BLOCKSIZE - 8);

  } else {

    memset (((SHA_BYTE *) sha_info->data) + count, 0,

        SHA_BLOCKSIZE - 8 - count);

  }

  sha_info->data[56] = (unsigned char) ((hi_bit_count >> 24) & 0xff);

  sha_info->data[57] = (unsigned char) ((hi_bit_count >> 16) & 0xff);

  sha_info->data[58] = (unsigned char) ((hi_bit_count >> 8) & 0xff);

  sha_info->data[59] = (unsigned char) ((hi_bit_count >> 0) & 0xff);

  sha_info->data[60] = (unsigned char) ((lo_bit_count >> 24) & 0xff);

  sha_info->data[61] = (unsigned char) ((lo_bit_count >> 16) & 0xff);

  sha_info->data[62] = (unsigned char) ((lo_bit_count >> 8) & 0xff);

  sha_info->data[63] = (unsigned char) ((lo_bit_count >> 0) & 0xff);

  sha_transform (sha_info);

  digest[0] = (unsigned char) ((sha_info->digest[0] >> 24) & 0xff);

  digest[1] = (unsigned char) ((sha_info->digest[0] >> 16) & 0xff);

  digest[2] = (unsigned char) ((sha_info->digest[0] >> 8) & 0xff);

  digest[3] = (unsigned char) ((sha_info->digest[0]) & 0xff);

  digest[4] = (unsigned char) ((sha_info->digest[1] >> 24) & 0xff);

  digest[5] = (unsigned char) ((sha_info->digest[1] >> 16) & 0xff);

  digest[6] = (unsigned char) ((sha_info->digest[1] >> 8) & 0xff);

  digest[7] = (unsigned char) ((sha_info->digest[1]) & 0xff);

  digest[8] = (unsigned char) ((sha_info->digest[2] >> 24) & 0xff);

  digest[9] = (unsigned char) ((sha_info->digest[2] >> 16) & 0xff);

  digest[10] = (unsigned char) ((sha_info->digest[2] >> 8) & 0xff);

  digest[11] = (unsigned char) ((sha_info->digest[2]) & 0xff);

  digest[12] = (unsigned char) ((sha_info->digest[3] >> 24) & 0xff);

  digest[13] = (unsigned char) ((sha_info->digest[3] >> 16) & 0xff);

  digest[14] = (unsigned char) ((sha_info->digest[3] >> 8) & 0xff);

  digest[15] = (unsigned char) ((sha_info->digest[3]) & 0xff);

  digest[16] = (unsigned char) ((sha_info->digest[4] >> 24) & 0xff);

  digest[17] = (unsigned char) ((sha_info->digest[4] >> 16) & 0xff);

  digest[18] = (unsigned char) ((sha_info->digest[4] >> 8) & 0xff);

  digest[19] = (unsigned char) ((sha_info->digest[4]) & 0xff);

}