/*

 * Copyright (C) 1995, 1996, 1997, and 1998 WIDE Project.

 * All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 * 1. Redistributions of source code must retain the above copyright

 *    notice, this list of conditions and the following disclaimer.

 * 2. Redistributions in binary form must reproduce the above copyright

 *    notice, this list of conditions and the following disclaimer in the

 *    documentation and/or other materials provided with the distribution.

 * 3. Neither the name of the project nor the names of its contributors

 *    may be used to endorse or promote products derived from this software

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE PROJECT AND CONTRIBUTORS ``AS IS'' AND

 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE

 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE

 * ARE DISCLAIMED.  IN NO EVENT SHALL THE PROJECT OR CONTRIBUTORS BE LIABLE

 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL

 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS

 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)

 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT

 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY

 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF

 * SUCH DAMAGE.

 */

/*

 * FIPS pub 180-1: Secure Hash Algorithm (SHA-1)

 * based on: http://www.itl.nist.gov/fipspubs/fip180-1.htm

 * implemented by Jun-ichiro itojun Itoh <itojun@itojun.org>

 */

#include "sha1.h"

#include <string.h>

/* constant table */

static uint32_t _K[] = {0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6};

#define K(t)  _K[(t) / 20]

#define F0(b, c, d) (((b) & (c)) | ((~(b)) & (d)))

#define F1(b, c, d) (((b) ^ (c)) ^ (d))

#define F2(b, c, d) (((b) & (c)) | ((b) & (d)) | ((c) & (d)))

#define F3(b, c, d) (((b) ^ (c)) ^ (d))

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

#define H(n)  (ctxt->h.b32[(n)])

#define COUNT (ctxt->count)

#define BCOUNT  (ctxt->c.b64[0] / 8)

#define W(n)  (ctxt->m.b32[(n)])

#define PUTBYTE(x) \

do { \

  ctxt->m.b8[(COUNT % 64)] = (x);   \

  COUNT++;        \

  COUNT %= 64;        \

  ctxt->c.b64[0] += 8;      \

  if (COUNT % 64 == 0)      \

    sha1_step(ctxt);    \

} while (0)

#define PUTPAD(x) \

do { \

  ctxt->m.b8[(COUNT % 64)] = (x);    \

  COUNT++;       \

  COUNT %= 64;       \

  if (COUNT % 64 == 0)     \

    sha1_step(ctxt);   \

} while (0)

static void sha1_step(struct sha1_ctxt *);

static void

sha1_step(struct sha1_ctxt * ctxt)

{

  uint32_t    a,

        b,

        c,

        d,

        e;

  size_t    t,

        s;

  uint32_t    tmp;

#ifndef WORDS_BIGENDIAN

  struct sha1_ctxt tctxt;

  memmove(&tctxt.m.b8[0], &ctxt->m.b8[0], 64);

  ctxt->m.b8[0] = tctxt.m.b8[3];

  ctxt->m.b8[1] = tctxt.m.b8[2];

  ctxt->m.b8[2] = tctxt.m.b8[1];

  ctxt->m.b8[3] = tctxt.m.b8[0];

  ctxt->m.b8[4] = tctxt.m.b8[7];

  ctxt->m.b8[5] = tctxt.m.b8[6];

  ctxt->m.b8[6] = tctxt.m.b8[5];

  ctxt->m.b8[7] = tctxt.m.b8[4];

  ctxt->m.b8[8] = tctxt.m.b8[11];

  ctxt->m.b8[9] = tctxt.m.b8[10];

  ctxt->m.b8[10] = tctxt.m.b8[9];

  ctxt->m.b8[11] = tctxt.m.b8[8];

  ctxt->m.b8[12] = tctxt.m.b8[15];

  ctxt->m.b8[13] = tctxt.m.b8[14];

  ctxt->m.b8[14] = tctxt.m.b8[13];

  ctxt->m.b8[15] = tctxt.m.b8[12];

  ctxt->m.b8[16] = tctxt.m.b8[19];

  ctxt->m.b8[17] = tctxt.m.b8[18];

  ctxt->m.b8[18] = tctxt.m.b8[17];

  ctxt->m.b8[19] = tctxt.m.b8[16];

  ctxt->m.b8[20] = tctxt.m.b8[23];

  ctxt->m.b8[21] = tctxt.m.b8[22];

  ctxt->m.b8[22] = tctxt.m.b8[21];

  ctxt->m.b8[23] = tctxt.m.b8[20];

  ctxt->m.b8[24] = tctxt.m.b8[27];

  ctxt->m.b8[25] = tctxt.m.b8[26];

  ctxt->m.b8[26] = tctxt.m.b8[25];

  ctxt->m.b8[27] = tctxt.m.b8[24];

  ctxt->m.b8[28] = tctxt.m.b8[31];

  ctxt->m.b8[29] = tctxt.m.b8[30];

  ctxt->m.b8[30] = tctxt.m.b8[29];

  ctxt->m.b8[31] = tctxt.m.b8[28];

  ctxt->m.b8[32] = tctxt.m.b8[35];

  ctxt->m.b8[33] = tctxt.m.b8[34];

  ctxt->m.b8[34] = tctxt.m.b8[33];

  ctxt->m.b8[35] = tctxt.m.b8[32];

  ctxt->m.b8[36] = tctxt.m.b8[39];

  ctxt->m.b8[37] = tctxt.m.b8[38];

  ctxt->m.b8[38] = tctxt.m.b8[37];

  ctxt->m.b8[39] = tctxt.m.b8[36];

  ctxt->m.b8[40] = tctxt.m.b8[43];

  ctxt->m.b8[41] = tctxt.m.b8[42];

  ctxt->m.b8[42] = tctxt.m.b8[41];

  ctxt->m.b8[43] = tctxt.m.b8[40];

  ctxt->m.b8[44] = tctxt.m.b8[47];

  ctxt->m.b8[45] = tctxt.m.b8[46];

  ctxt->m.b8[46] = tctxt.m.b8[45];

  ctxt->m.b8[47] = tctxt.m.b8[44];

  ctxt->m.b8[48] = tctxt.m.b8[51];

  ctxt->m.b8[49] = tctxt.m.b8[50];

  ctxt->m.b8[50] = tctxt.m.b8[49];

  ctxt->m.b8[51] = tctxt.m.b8[48];

  ctxt->m.b8[52] = tctxt.m.b8[55];

  ctxt->m.b8[53] = tctxt.m.b8[54];

  ctxt->m.b8[54] = tctxt.m.b8[53];

  ctxt->m.b8[55] = tctxt.m.b8[52];

  ctxt->m.b8[56] = tctxt.m.b8[59];

  ctxt->m.b8[57] = tctxt.m.b8[58];

  ctxt->m.b8[58] = tctxt.m.b8[57];

  ctxt->m.b8[59] = tctxt.m.b8[56];

  ctxt->m.b8[60] = tctxt.m.b8[63];

  ctxt->m.b8[61] = tctxt.m.b8[62];

  ctxt->m.b8[62] = tctxt.m.b8[61];

  ctxt->m.b8[63] = tctxt.m.b8[60];

#endif

  a = H(0);

  b = H(1);

  c = H(2);

  d = H(3);

  e = H(4);

  for (t = 0; t < 20; t++)

  {

    s = t & 0x0f;

    if (t >= 16)

      W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));

    tmp = S(5, a) + F0(b, c, d) + e + W(s) + K(t);

    e = d;

    d = c;

    c = S(30, b);

    b = a;

    a = tmp;

  }

  for (t = 20; t < 40; t++)

  {

    s = t & 0x0f;

    W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));

    tmp = S(5, a) + F1(b, c, d) + e + W(s) + K(t);

    e = d;

    d = c;

    c = S(30, b);

    b = a;

    a = tmp;

  }

  for (t = 40; t < 60; t++)

  {

    s = t & 0x0f;

    W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));

    tmp = S(5, a) + F2(b, c, d) + e + W(s) + K(t);

    e = d;

    d = c;

    c = S(30, b);

    b = a;

    a = tmp;

  }

  for (t = 60; t < 80; t++)

  {

    s = t & 0x0f;

    W(s) = S(1, W((s + 13) & 0x0f) ^ W((s + 8) & 0x0f) ^ W((s + 2) & 0x0f) ^ W(s));

    tmp = S(5, a) + F3(b, c, d) + e + W(s) + K(t);

    e = d;

    d = c;

    c = S(30, b);

    b = a;

    a = tmp;

  }

  H(0) = H(0) + a;

  H(1) = H(1) + b;

  H(2) = H(2) + c;

  H(3) = H(3) + d;

  H(4) = H(4) + e;

  memset(&ctxt->m.b8[0], 0, 64);

}

/*------------------------------------------------------------*/

void

sha1_init(struct sha1_ctxt * ctxt)

{

  memset(ctxt, 0, sizeof(struct sha1_ctxt));

  H(0) = 0x67452301;

  H(1) = 0xefcdab89;

  H(2) = 0x98badcfe;

  H(3) = 0x10325476;

  H(4) = 0xc3d2e1f0;

}

void

sha1_pad(struct sha1_ctxt * ctxt)

{

  size_t    padlen;     /* pad length in bytes */

  size_t    padstart;

  PUTPAD(0x80);

  padstart = COUNT % 64;

  padlen = 64 - padstart;

  if (padlen < 8)

  {

    memset(&ctxt->m.b8[padstart], 0, padlen);

    COUNT += (uint8_t) padlen;

    COUNT %= 64;

    sha1_step(ctxt);

    padstart = COUNT % 64;  /* should be 0 */

    padlen = 64 - padstart; /* should be 64 */

  }

  memset(&ctxt->m.b8[padstart], 0, padlen - 8);

    COUNT += ((uint8_t) padlen - 8);

  COUNT %= 64;

#ifdef WORDS_BIGENDIAN

  PUTPAD(ctxt->c.b8[0]);

  PUTPAD(ctxt->c.b8[1]);

  PUTPAD(ctxt->c.b8[2]);

  PUTPAD(ctxt->c.b8[3]);

  PUTPAD(ctxt->c.b8[4]);

  PUTPAD(ctxt->c.b8[5]);

  PUTPAD(ctxt->c.b8[6]);

  PUTPAD(ctxt->c.b8[7]);

#else

  PUTPAD(ctxt->c.b8[7]);

  PUTPAD(ctxt->c.b8[6]);

  PUTPAD(ctxt->c.b8[5]);

  PUTPAD(ctxt->c.b8[4]);

  PUTPAD(ctxt->c.b8[3]);

  PUTPAD(ctxt->c.b8[2]);

  PUTPAD(ctxt->c.b8[1]);

  PUTPAD(ctxt->c.b8[0]);

#endif

}

void

sha1_loop(struct sha1_ctxt * ctxt, const uint8_t *input0, size_t len)

{

  const uint8_t *input;

  size_t    gaplen;

  size_t    gapstart;

  size_t    off;

  size_t    copysiz;

  input = (const uint8_t *) input0;

  off = 0;

  while (off < len)

  {

    gapstart = COUNT % 64;

    gaplen = 64 - gapstart;

    copysiz = (gaplen < len - off) ? gaplen : len - off;

    memmove(&ctxt->m.b8[gapstart], &input[off], copysiz);

    COUNT += (uint8_t) copysiz;

    COUNT %= 64;

    ctxt->c.b64[0] += copysiz * 8;

    if (COUNT % 64 == 0)

      sha1_step(ctxt);

    off += copysiz;

  }

}

void

sha1_result(struct sha1_ctxt * ctxt, uint8_t *digest0)

{

  uint8_t    *digest;

  digest = (uint8_t *) digest0;

  sha1_pad(ctxt);

#ifdef WORDS_BIGENDIAN

  memmove(digest, &ctxt->h.b8[0], 20);

#else

  digest[0] = ctxt->h.b8[3];

  digest[1] = ctxt->h.b8[2];

  digest[2] = ctxt->h.b8[1];

  digest[3] = ctxt->h.b8[0];

  digest[4] = ctxt->h.b8[7];

  digest[5] = ctxt->h.b8[6];

  digest[6] = ctxt->h.b8[5];

  digest[7] = ctxt->h.b8[4];

  digest[8] = ctxt->h.b8[11];

  digest[9] = ctxt->h.b8[10];

  digest[10] = ctxt->h.b8[9];

  digest[11] = ctxt->h.b8[8];

  digest[12] = ctxt->h.b8[15];

  digest[13] = ctxt->h.b8[14];

  digest[14] = ctxt->h.b8[13];

  digest[15] = ctxt->h.b8[12];

  digest[16] = ctxt->h.b8[19];

  digest[17] = ctxt->h.b8[18];

  digest[18] = ctxt->h.b8[17];

  digest[19] = ctxt->h.b8[16];

#endif

}