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

 *

 *  sha1.c

 *    Implements the SHA1 Secure Hash Algorithm

 *

 * Fallback implementation of SHA1, as specified in RFC 3174.

 *

 * Portions Copyright (c) 1996-2026, PostgreSQL Global Development Group

 * Portions Copyright (c) 1994, Regents of the University of California

 *

 * IDENTIFICATION

 *    src/common/sha1.c

 *

 *-------------------------------------------------------------------------

 */

/*     $KAME: sha1.c,v 1.3 2000/02/22 14:01:18 itojun Exp $    */

/*

 * 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>

 */

#ifndef FRONTEND

#include "postgres.h"

#else

#include "postgres_fe.h"

#endif

#include <sys/param.h>

#include "sha1_int.h"

/* constant table */

static const uint32 _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)  (ctx->h.b32[(n)])

#define COUNT (ctx->count)

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

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

#define PUTPAD(x) \

do { \

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

  COUNT++;       \

  COUNT %= 64;       \

  if (COUNT % 64 == 0)     \

    sha1_step(ctx);   \

} while (0)

static void

sha1_step(pg_sha1_ctx *ctx)

{

  uint32    a,

        b,

        c,

        d,

        e;

  size_t    t,

        s;

  uint32    tmp;

#ifndef WORDS_BIGENDIAN

  pg_sha1_ctx tctx;

  memmove(&tctx.m.b8[0], &ctx->m.b8[0], 64);

  ctx->m.b8[0] = tctx.m.b8[3];

  ctx->m.b8[1] = tctx.m.b8[2];

  ctx->m.b8[2] = tctx.m.b8[1];

  ctx->m.b8[3] = tctx.m.b8[0];

  ctx->m.b8[4] = tctx.m.b8[7];

  ctx->m.b8[5] = tctx.m.b8[6];

  ctx->m.b8[6] = tctx.m.b8[5];

  ctx->m.b8[7] = tctx.m.b8[4];

  ctx->m.b8[8] = tctx.m.b8[11];

  ctx->m.b8[9] = tctx.m.b8[10];

  ctx->m.b8[10] = tctx.m.b8[9];

  ctx->m.b8[11] = tctx.m.b8[8];

  ctx->m.b8[12] = tctx.m.b8[15];

  ctx->m.b8[13] = tctx.m.b8[14];

  ctx->m.b8[14] = tctx.m.b8[13];

  ctx->m.b8[15] = tctx.m.b8[12];

  ctx->m.b8[16] = tctx.m.b8[19];

  ctx->m.b8[17] = tctx.m.b8[18];

  ctx->m.b8[18] = tctx.m.b8[17];

  ctx->m.b8[19] = tctx.m.b8[16];

  ctx->m.b8[20] = tctx.m.b8[23];

  ctx->m.b8[21] = tctx.m.b8[22];

  ctx->m.b8[22] = tctx.m.b8[21];

  ctx->m.b8[23] = tctx.m.b8[20];

  ctx->m.b8[24] = tctx.m.b8[27];

  ctx->m.b8[25] = tctx.m.b8[26];

  ctx->m.b8[26] = tctx.m.b8[25];

  ctx->m.b8[27] = tctx.m.b8[24];

  ctx->m.b8[28] = tctx.m.b8[31];

  ctx->m.b8[29] = tctx.m.b8[30];

  ctx->m.b8[30] = tctx.m.b8[29];

  ctx->m.b8[31] = tctx.m.b8[28];

  ctx->m.b8[32] = tctx.m.b8[35];

  ctx->m.b8[33] = tctx.m.b8[34];

  ctx->m.b8[34] = tctx.m.b8[33];

  ctx->m.b8[35] = tctx.m.b8[32];

  ctx->m.b8[36] = tctx.m.b8[39];

  ctx->m.b8[37] = tctx.m.b8[38];

  ctx->m.b8[38] = tctx.m.b8[37];

  ctx->m.b8[39] = tctx.m.b8[36];

  ctx->m.b8[40] = tctx.m.b8[43];

  ctx->m.b8[41] = tctx.m.b8[42];

  ctx->m.b8[42] = tctx.m.b8[41];

  ctx->m.b8[43] = tctx.m.b8[40];

  ctx->m.b8[44] = tctx.m.b8[47];

  ctx->m.b8[45] = tctx.m.b8[46];

  ctx->m.b8[46] = tctx.m.b8[45];

  ctx->m.b8[47] = tctx.m.b8[44];

  ctx->m.b8[48] = tctx.m.b8[51];

  ctx->m.b8[49] = tctx.m.b8[50];

  ctx->m.b8[50] = tctx.m.b8[49];

  ctx->m.b8[51] = tctx.m.b8[48];

  ctx->m.b8[52] = tctx.m.b8[55];

  ctx->m.b8[53] = tctx.m.b8[54];

  ctx->m.b8[54] = tctx.m.b8[53];

  ctx->m.b8[55] = tctx.m.b8[52];

  ctx->m.b8[56] = tctx.m.b8[59];

  ctx->m.b8[57] = tctx.m.b8[58];

  ctx->m.b8[58] = tctx.m.b8[57];

  ctx->m.b8[59] = tctx.m.b8[56];

  ctx->m.b8[60] = tctx.m.b8[63];

  ctx->m.b8[61] = tctx.m.b8[62];

  ctx->m.b8[62] = tctx.m.b8[61];

  ctx->m.b8[63] = tctx.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(&ctx->m.b8[0], 0, 64);

}

static void

sha1_pad(pg_sha1_ctx *ctx)

{

  size_t    padlen;     /* pad length in bytes */

  size_t    padstart;

  PUTPAD(0x80);

  padstart = COUNT % 64;

  padlen = 64 - padstart;

  if (padlen < 8)

  {

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

    COUNT += padlen;

    COUNT %= 64;

    sha1_step(ctx);

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

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

  }

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

  COUNT += (padlen - 8);

  COUNT %= 64;

#ifdef WORDS_BIGENDIAN

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

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

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

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

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

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

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

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

#else

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

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

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

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

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

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

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

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

#endif

}

static void

sha1_result(uint8 *digest0, pg_sha1_ctx *ctx)

{

  uint8    *digest;

  digest = digest0;

#ifdef WORDS_BIGENDIAN

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

#else

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

#endif

}

/* External routines for this SHA1 implementation */

/*

 * pg_sha1_init

 *

 * Initialize a SHA1 context.

 */

void

pg_sha1_init(pg_sha1_ctx *ctx)

{

  memset(ctx, 0, sizeof(pg_sha1_ctx));

  H(0) = 0x67452301;

  H(1) = 0xefcdab89;

  H(2) = 0x98badcfe;

  H(3) = 0x10325476;

  H(4) = 0xc3d2e1f0;

}

/*

 * pg_sha1_update

 *

 * Update a SHA1 context.

 */

void

pg_sha1_update(pg_sha1_ctx *ctx, const uint8 *data, size_t len)

{

  const uint8 *input;

  size_t    gaplen;

  size_t    gapstart;

  size_t    off;

  size_t    copysiz;

  input = data;

  off = 0;

  while (off < len)

  {

    gapstart = COUNT % 64;

    gaplen = 64 - gapstart;

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

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

    COUNT += copysiz;

    COUNT %= 64;

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

    if (COUNT % 64 == 0)

      sha1_step(ctx);

    off += copysiz;

  }

}

/*

 * pg_sha1_final

 *

 * Finalize a SHA1 context.

 */

void

pg_sha1_final(pg_sha1_ctx *ctx, uint8 *dest)

{

  sha1_pad(ctx);

  sha1_result(dest, ctx);

}