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

 *

 * sha2.c

 *     SHA functions for SHA-224, SHA-256, SHA-384 and SHA-512.

 *

 * This includes the fallback implementation for SHA2 cryptographic

 * hashes.

 *

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

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

 *

 * IDENTIFICATION

 *    src/common/sha2.c

 *

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

 */

/*  $OpenBSD: sha2.c,v 1.6 2004/05/03 02:57:36 millert Exp $  */

/*

 * FILE:  sha2.c

 * AUTHOR:  Aaron D. Gifford <me@aarongifford.com>

 *

 * Copyright (c) 2000-2001, Aaron D. Gifford

 * 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 copyright holder nor the names of contributors

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

 *    without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTOR(S) ``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 AUTHOR OR CONTRIBUTOR(S) 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.

 *

 * $From: sha2.c,v 1.1 2001/11/08 00:01:51 adg Exp adg $

 */

#ifndef FRONTEND

#include "postgres.h"

#else

#include "postgres_fe.h"

#endif

#include "sha2_int.h"

/*

 * In backend, use palloc/pfree to ease the error handling.  In frontend,

 * use malloc to be able to return a failure status back to the caller.

 */

#ifndef FRONTEND

#define ALLOC(size) palloc(size)

#define FREE(ptr) pfree(ptr)

#else

#define ALLOC(size) malloc(size)

#define FREE(ptr) free(ptr)

#endif

/*

 * UNROLLED TRANSFORM LOOP NOTE:

 * You can define SHA2_UNROLL_TRANSFORM to use the unrolled transform

 * loop version for the hash transform rounds (defined using macros

 * later in this file).  Either define on the command line, for example:

 *

 *   cc -DSHA2_UNROLL_TRANSFORM -o sha2 sha2.c sha2prog.c

 *

 * or define below:

 *

 *   #define SHA2_UNROLL_TRANSFORM

 *

 */

/*** SHA-256/384/512 Various Length Definitions ***********************/

#define PG_SHA256_SHORT_BLOCK_LENGTH  (PG_SHA256_BLOCK_LENGTH - 8)

#define PG_SHA384_SHORT_BLOCK_LENGTH  (PG_SHA384_BLOCK_LENGTH - 16)

#define PG_SHA512_SHORT_BLOCK_LENGTH  (PG_SHA512_BLOCK_LENGTH - 16)

/*** ENDIAN REVERSAL MACROS *******************************************/

#ifndef WORDS_BIGENDIAN

#define REVERSE32(w,x)  { \

  uint32 tmp = (w); \

  tmp = (tmp >> 16) | (tmp << 16); \

  (x) = ((tmp & 0xff00ff00UL) >> 8) | ((tmp & 0x00ff00ffUL) << 8); \

}

#define REVERSE64(w,x)  { \

  uint64 tmp = (w); \

  tmp = (tmp >> 32) | (tmp << 32); \

  tmp = ((tmp & 0xff00ff00ff00ff00ULL) >> 8) | \

      ((tmp & 0x00ff00ff00ff00ffULL) << 8); \

  (x) = ((tmp & 0xffff0000ffff0000ULL) >> 16) | \

      ((tmp & 0x0000ffff0000ffffULL) << 16); \

}

#endif              /* not bigendian */

/*

 * Macro for incrementally adding the unsigned 64-bit integer n to the

 * unsigned 128-bit integer (represented using a two-element array of

 * 64-bit words):

 */

#define ADDINC128(w,n)  { \

  (w)[0] += (uint64)(n); \

  if ((w)[0] < (n)) { \

    (w)[1]++; \

  } \

}

/*** THE SIX LOGICAL FUNCTIONS ****************************************/

/*

 * Bit shifting and rotation (used by the six SHA-XYZ logical functions:

 *

 *   NOTE:  The naming of R and S appears backwards here (R is a SHIFT and

 *   S is a ROTATION) because the SHA-256/384/512 description document

 *   (see http://www.iwar.org.uk/comsec/resources/cipher/sha256-384-512.pdf)

 *   uses this same "backwards" definition.

 */

/* Shift-right (used in SHA-256, SHA-384, and SHA-512): */

#define R(b,x)    ((x) >> (b))

/* 32-bit Rotate-right (used in SHA-256): */

#define S32(b,x)  (((x) >> (b)) | ((x) << (32 - (b))))

/* 64-bit Rotate-right (used in SHA-384 and SHA-512): */

#define S64(b,x)  (((x) >> (b)) | ((x) << (64 - (b))))

/* Two of six logical functions used in SHA-256, SHA-384, and SHA-512: */

#define Ch(x,y,z) (((x) & (y)) ^ ((~(x)) & (z)))

#define Maj(x,y,z)  (((x) & (y)) ^ ((x) & (z)) ^ ((y) & (z)))

/* Four of six logical functions used in SHA-256: */

#define Sigma0_256(x) (S32(2,  (x)) ^ S32(13, (x)) ^ S32(22, (x)))

#define Sigma1_256(x) (S32(6,  (x)) ^ S32(11, (x)) ^ S32(25, (x)))

#define sigma0_256(x) (S32(7,  (x)) ^ S32(18, (x)) ^ R(3 ,   (x)))

#define sigma1_256(x) (S32(17, (x)) ^ S32(19, (x)) ^ R(10,   (x)))

/* Four of six logical functions used in SHA-384 and SHA-512: */

#define Sigma0_512(x) (S64(28, (x)) ^ S64(34, (x)) ^ S64(39, (x)))

#define Sigma1_512(x) (S64(14, (x)) ^ S64(18, (x)) ^ S64(41, (x)))

#define sigma0_512(x) (S64( 1, (x)) ^ S64( 8, (x)) ^ R( 7,   (x)))

#define sigma1_512(x) (S64(19, (x)) ^ S64(61, (x)) ^ R( 6,   (x)))

/*** INTERNAL FUNCTION PROTOTYPES *************************************/

/*

 * NOTE: These should not be accessed directly from outside this

 * library -- they are intended for private internal visibility/use

 * only.

 */

static void SHA512_Last(pg_sha512_ctx *context);

static void SHA256_Transform(pg_sha256_ctx *context, const uint8 *data);

static void SHA512_Transform(pg_sha512_ctx *context, const uint8 *data);

/*** SHA-XYZ INITIAL HASH VALUES AND CONSTANTS ************************/

/* Hash constant words K for SHA-256: */

static const uint32 K256[64] = {

  0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL,

  0x3956c25bUL, 0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL,

  0xd807aa98UL, 0x12835b01UL, 0x243185beUL, 0x550c7dc3UL,

  0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL, 0xc19bf174UL,

  0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,

  0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL,

  0x983e5152UL, 0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL,

  0xc6e00bf3UL, 0xd5a79147UL, 0x06ca6351UL, 0x14292967UL,

  0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL, 0x53380d13UL,

  0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,

  0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL,

  0xd192e819UL, 0xd6990624UL, 0xf40e3585UL, 0x106aa070UL,

  0x19a4c116UL, 0x1e376c08UL, 0x2748774cUL, 0x34b0bcb5UL,

  0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL, 0x682e6ff3UL,

  0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,

  0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL

};

/* Initial hash value H for SHA-224: */

static const uint32 sha224_initial_hash_value[8] = {

  0xc1059ed8UL,

  0x367cd507UL,

  0x3070dd17UL,

  0xf70e5939UL,

  0xffc00b31UL,

  0x68581511UL,

  0x64f98fa7UL,

  0xbefa4fa4UL

};

/* Initial hash value H for SHA-256: */

static const uint32 sha256_initial_hash_value[8] = {

  0x6a09e667UL,

  0xbb67ae85UL,

  0x3c6ef372UL,

  0xa54ff53aUL,

  0x510e527fUL,

  0x9b05688cUL,

  0x1f83d9abUL,

  0x5be0cd19UL

};

/* Hash constant words K for SHA-384 and SHA-512: */

static const uint64 K512[80] = {

  0x428a2f98d728ae22ULL, 0x7137449123ef65cdULL,

  0xb5c0fbcfec4d3b2fULL, 0xe9b5dba58189dbbcULL,

  0x3956c25bf348b538ULL, 0x59f111f1b605d019ULL,

  0x923f82a4af194f9bULL, 0xab1c5ed5da6d8118ULL,

  0xd807aa98a3030242ULL, 0x12835b0145706fbeULL,

  0x243185be4ee4b28cULL, 0x550c7dc3d5ffb4e2ULL,

  0x72be5d74f27b896fULL, 0x80deb1fe3b1696b1ULL,

  0x9bdc06a725c71235ULL, 0xc19bf174cf692694ULL,

  0xe49b69c19ef14ad2ULL, 0xefbe4786384f25e3ULL,

  0x0fc19dc68b8cd5b5ULL, 0x240ca1cc77ac9c65ULL,

  0x2de92c6f592b0275ULL, 0x4a7484aa6ea6e483ULL,

  0x5cb0a9dcbd41fbd4ULL, 0x76f988da831153b5ULL,

  0x983e5152ee66dfabULL, 0xa831c66d2db43210ULL,

  0xb00327c898fb213fULL, 0xbf597fc7beef0ee4ULL,

  0xc6e00bf33da88fc2ULL, 0xd5a79147930aa725ULL,

  0x06ca6351e003826fULL, 0x142929670a0e6e70ULL,

  0x27b70a8546d22ffcULL, 0x2e1b21385c26c926ULL,

  0x4d2c6dfc5ac42aedULL, 0x53380d139d95b3dfULL,

  0x650a73548baf63deULL, 0x766a0abb3c77b2a8ULL,

  0x81c2c92e47edaee6ULL, 0x92722c851482353bULL,

  0xa2bfe8a14cf10364ULL, 0xa81a664bbc423001ULL,

  0xc24b8b70d0f89791ULL, 0xc76c51a30654be30ULL,

  0xd192e819d6ef5218ULL, 0xd69906245565a910ULL,

  0xf40e35855771202aULL, 0x106aa07032bbd1b8ULL,

  0x19a4c116b8d2d0c8ULL, 0x1e376c085141ab53ULL,

  0x2748774cdf8eeb99ULL, 0x34b0bcb5e19b48a8ULL,

  0x391c0cb3c5c95a63ULL, 0x4ed8aa4ae3418acbULL,

  0x5b9cca4f7763e373ULL, 0x682e6ff3d6b2b8a3ULL,

  0x748f82ee5defb2fcULL, 0x78a5636f43172f60ULL,

  0x84c87814a1f0ab72ULL, 0x8cc702081a6439ecULL,

  0x90befffa23631e28ULL, 0xa4506cebde82bde9ULL,

  0xbef9a3f7b2c67915ULL, 0xc67178f2e372532bULL,

  0xca273eceea26619cULL, 0xd186b8c721c0c207ULL,

  0xeada7dd6cde0eb1eULL, 0xf57d4f7fee6ed178ULL,

  0x06f067aa72176fbaULL, 0x0a637dc5a2c898a6ULL,

  0x113f9804bef90daeULL, 0x1b710b35131c471bULL,

  0x28db77f523047d84ULL, 0x32caab7b40c72493ULL,

  0x3c9ebe0a15c9bebcULL, 0x431d67c49c100d4cULL,

  0x4cc5d4becb3e42b6ULL, 0x597f299cfc657e2aULL,

  0x5fcb6fab3ad6faecULL, 0x6c44198c4a475817ULL

};

/* Initial hash value H for SHA-384 */

static const uint64 sha384_initial_hash_value[8] = {

  0xcbbb9d5dc1059ed8ULL,

  0x629a292a367cd507ULL,

  0x9159015a3070dd17ULL,

  0x152fecd8f70e5939ULL,

  0x67332667ffc00b31ULL,

  0x8eb44a8768581511ULL,

  0xdb0c2e0d64f98fa7ULL,

  0x47b5481dbefa4fa4ULL

};

/* Initial hash value H for SHA-512 */

static const uint64 sha512_initial_hash_value[8] = {

  0x6a09e667f3bcc908ULL,

  0xbb67ae8584caa73bULL,

  0x3c6ef372fe94f82bULL,

  0xa54ff53a5f1d36f1ULL,

  0x510e527fade682d1ULL,

  0x9b05688c2b3e6c1fULL,

  0x1f83d9abfb41bd6bULL,

  0x5be0cd19137e2179ULL

};

/*** SHA-256: *********************************************************/

void

pg_sha256_init(pg_sha256_ctx *context)

{

  if (context == NULL)

    return;

  memcpy(context->state, sha256_initial_hash_value, PG_SHA256_DIGEST_LENGTH);

  memset(context->buffer, 0, PG_SHA256_BLOCK_LENGTH);

  context->bitcount = 0;

}

#ifdef SHA2_UNROLL_TRANSFORM

/* Unrolled SHA-256 round macros: */

#define ROUND256_0_TO_15(a,b,c,d,e,f,g,h) do {          \

  W256[j] = (uint32)data[3] | ((uint32)data[2] << 8) |    \

    ((uint32)data[1] << 16) | ((uint32)data[0] << 24);    \

  data += 4;                \

  T1 = (h) + Sigma1_256((e)) + Ch((e), (f), (g)) + K256[j] + W256[j]; \

  (d) += T1;                \

  (h) = T1 + Sigma0_256((a)) + Maj((a), (b), (c));      \

  j++;                  \

} while(0)

#define ROUND256(a,b,c,d,e,f,g,h) do {            \

  s0 = W256[(j+1)&0x0f];              \

  s0 = sigma0_256(s0);              \

  s1 = W256[(j+14)&0x0f];             \

  s1 = sigma1_256(s1);              \

  T1 = (h) + Sigma1_256((e)) + Ch((e), (f), (g)) + K256[j] +    \

     (W256[j&0x0f] += s1 + W256[(j+9)&0x0f] + s0);      \

  (d) += T1;                \

  (h) = T1 + Sigma0_256((a)) + Maj((a), (b), (c));      \

  j++;                  \

} while(0)

static void

SHA256_Transform(pg_sha256_ctx *context, const uint8 *data)

{

  uint32    a,

        b,

        c,

        d,

        e,

        f,

        g,

        h,

        s0,

        s1;

  uint32    T1,

         *W256;

  int     j;

  W256 = (uint32 *) context->buffer;

  /* Initialize registers with the prev. intermediate value */

  a = context->state[0];

  b = context->state[1];

  c = context->state[2];

  d = context->state[3];

  e = context->state[4];

  f = context->state[5];

  g = context->state[6];

  h = context->state[7];

  j = 0;

  do

  {

    /* Rounds 0 to 15 (unrolled): */

    ROUND256_0_TO_15(a, b, c, d, e, f, g, h);

    ROUND256_0_TO_15(h, a, b, c, d, e, f, g);

    ROUND256_0_TO_15(g, h, a, b, c, d, e, f);

    ROUND256_0_TO_15(f, g, h, a, b, c, d, e);

    ROUND256_0_TO_15(e, f, g, h, a, b, c, d);

    ROUND256_0_TO_15(d, e, f, g, h, a, b, c);

    ROUND256_0_TO_15(c, d, e, f, g, h, a, b);

    ROUND256_0_TO_15(b, c, d, e, f, g, h, a);

  } while (j < 16);

  /* Now for the remaining rounds to 64: */

  do

  {

    ROUND256(a, b, c, d, e, f, g, h);

    ROUND256(h, a, b, c, d, e, f, g);

    ROUND256(g, h, a, b, c, d, e, f);

    ROUND256(f, g, h, a, b, c, d, e);

    ROUND256(e, f, g, h, a, b, c, d);

    ROUND256(d, e, f, g, h, a, b, c);

    ROUND256(c, d, e, f, g, h, a, b);

    ROUND256(b, c, d, e, f, g, h, a);

  } while (j < 64);

  /* Compute the current intermediate hash value */

  context->state[0] += a;

  context->state[1] += b;

  context->state[2] += c;

  context->state[3] += d;

  context->state[4] += e;

  context->state[5] += f;

  context->state[6] += g;

  context->state[7] += h;

  /* Clean up */

  a = b = c = d = e = f = g = h = T1 = 0;

}

#else             /* SHA2_UNROLL_TRANSFORM */

static void

SHA256_Transform(pg_sha256_ctx *context, const uint8 *data)

{

  uint32    a,

        b,

        c,

        d,

        e,

        f,

        g,

        h,

        s0,

        s1;

  uint32    T1,

        T2,

         *W256;

  int     j;

  W256 = (uint32 *) context->buffer;

  /* Initialize registers with the prev. intermediate value */

  a = context->state[0];

  b = context->state[1];

  c = context->state[2];

  d = context->state[3];

  e = context->state[4];

  f = context->state[5];

  g = context->state[6];

  h = context->state[7];

  j = 0;

  do

  {

    W256[j] = (uint32) data[3] | ((uint32) data[2] << 8) |

      ((uint32) data[1] << 16) | ((uint32) data[0] << 24);

    data += 4;

    /* Apply the SHA-256 compression function to update a..h */

    T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j] + W256[j];

    T2 = Sigma0_256(a) + Maj(a, b, c);

    h = g;

    g = f;

    f = e;

    e = d + T1;

    d = c;

    c = b;

    b = a;

    a = T1 + T2;

    j++;

  } while (j < 16);

  do

  {

    /* Part of the message block expansion: */

    s0 = W256[(j + 1) & 0x0f];

    s0 = sigma0_256(s0);

    s1 = W256[(j + 14) & 0x0f];

    s1 = sigma1_256(s1);

    /* Apply the SHA-256 compression function to update a..h */

    T1 = h + Sigma1_256(e) + Ch(e, f, g) + K256[j] +

      (W256[j & 0x0f] += s1 + W256[(j + 9) & 0x0f] + s0);

    T2 = Sigma0_256(a) + Maj(a, b, c);

    h = g;

    g = f;

    f = e;

    e = d + T1;

    d = c;

    c = b;

    b = a;

    a = T1 + T2;

    j++;

  } while (j < 64);

  /* Compute the current intermediate hash value */

  context->state[0] += a;

  context->state[1] += b;

  context->state[2] += c;

  context->state[3] += d;

  context->state[4] += e;

  context->state[5] += f;

  context->state[6] += g;

  context->state[7] += h;

  /* Clean up */

  a = b = c = d = e = f = g = h = T1 = T2 = 0;

}

#endif              /* SHA2_UNROLL_TRANSFORM */

void

pg_sha256_update(pg_sha256_ctx *context, const uint8 *data, size_t len)

{

  size_t    freespace,

        usedspace;

  /* Calling with no data is valid (we do nothing) */

  if (len == 0)

    return;

  usedspace = (context->bitcount >> 3) % PG_SHA256_BLOCK_LENGTH;

  if (usedspace > 0)

  {

    /* Calculate how much free space is available in the buffer */

    freespace = PG_SHA256_BLOCK_LENGTH - usedspace;

    if (len >= freespace)

    {

      /* Fill the buffer completely and process it */

      memcpy(&context->buffer[usedspace], data, freespace);

      context->bitcount += freespace << 3;

      len -= freespace;

      data += freespace;

      SHA256_Transform(context, context->buffer);

    }

    else

    {

      /* The buffer is not yet full */

      memcpy(&context->buffer[usedspace], data, len);

      context->bitcount += len << 3;

      /* Clean up: */

      usedspace = freespace = 0;

      return;

    }

  }

  while (len >= PG_SHA256_BLOCK_LENGTH)

  {

    /* Process as many complete blocks as we can */

    SHA256_Transform(context, data);

    context->bitcount += PG_SHA256_BLOCK_LENGTH << 3;

    len -= PG_SHA256_BLOCK_LENGTH;

    data += PG_SHA256_BLOCK_LENGTH;

  }

  if (len > 0)

  {

    /* There's left-overs, so save 'em */

    memcpy(context->buffer, data, len);

    context->bitcount += len << 3;

  }

  /* Clean up: */

  usedspace = freespace = 0;

}

static void

SHA256_Last(pg_sha256_ctx *context)

{

  unsigned int usedspace;

  usedspace = (context->bitcount >> 3) % PG_SHA256_BLOCK_LENGTH;

#ifndef WORDS_BIGENDIAN

  /* Convert FROM host byte order */

  REVERSE64(context->bitcount, context->bitcount);

#endif

  if (usedspace > 0)

  {

    /* Begin padding with a 1 bit: */

    context->buffer[usedspace++] = 0x80;

    if (usedspace <= PG_SHA256_SHORT_BLOCK_LENGTH)

    {

      /* Set-up for the last transform: */

      memset(&context->buffer[usedspace], 0, PG_SHA256_SHORT_BLOCK_LENGTH - usedspace);

    }

    else

    {

      if (usedspace < PG_SHA256_BLOCK_LENGTH)

      {

        memset(&context->buffer[usedspace], 0, PG_SHA256_BLOCK_LENGTH - usedspace);

      }

      /* Do second-to-last transform: */

      SHA256_Transform(context, context->buffer);

      /* And set-up for the last transform: */

      memset(context->buffer, 0, PG_SHA256_SHORT_BLOCK_LENGTH);

    }

  }

  else

  {

    /* Set-up for the last transform: */

    memset(context->buffer, 0, PG_SHA256_SHORT_BLOCK_LENGTH);

    /* Begin padding with a 1 bit: */

    *context->buffer = 0x80;

  }

  /* Set the bit count: */

  *(uint64 *) &context->buffer[PG_SHA256_SHORT_BLOCK_LENGTH] = context->bitcount;

  /* Final transform: */

  SHA256_Transform(context, context->buffer);

}

void

pg_sha256_final(pg_sha256_ctx *context, uint8 *digest)

{

  /* If no digest buffer is passed, we don't bother doing this: */

  if (digest != NULL)

  {

    SHA256_Last(context);

#ifndef WORDS_BIGENDIAN

    {

      /* Convert TO host byte order */

      int     j;

      for (j = 0; j < 8; j++)

      {

        REVERSE32(context->state[j], context->state[j]);

      }

    }

#endif

    memcpy(digest, context->state, PG_SHA256_DIGEST_LENGTH);

  }

  /* Clean up state data: */

  memset(context, 0, sizeof(pg_sha256_ctx));

}

/*** SHA-512: *********************************************************/

void

pg_sha512_init(pg_sha512_ctx *context)

{

  if (context == NULL)

    return;

  memcpy(context->state, sha512_initial_hash_value, PG_SHA512_DIGEST_LENGTH);

  memset(context->buffer, 0, PG_SHA512_BLOCK_LENGTH);

  context->bitcount[0] = context->bitcount[1] = 0;

}

#ifdef SHA2_UNROLL_TRANSFORM

/* Unrolled SHA-512 round macros: */

#define ROUND512_0_TO_15(a,b,c,d,e,f,g,h) do {          \

  W512[j] = (uint64)data[7] | ((uint64)data[6] << 8) |    \

    ((uint64)data[5] << 16) | ((uint64)data[4] << 24) |   \

    ((uint64)data[3] << 32) | ((uint64)data[2] << 40) |   \

    ((uint64)data[1] << 48) | ((uint64)data[0] << 56);    \

  data += 8;                \

  T1 = (h) + Sigma1_512((e)) + Ch((e), (f), (g)) + K512[j] + W512[j]; \

  (d) += T1;                \

  (h) = T1 + Sigma0_512((a)) + Maj((a), (b), (c));      \

  j++;                  \

} while(0)

#define ROUND512(a,b,c,d,e,f,g,h) do {            \

  s0 = W512[(j+1)&0x0f];              \

  s0 = sigma0_512(s0);              \

  s1 = W512[(j+14)&0x0f];             \

  s1 = sigma1_512(s1);              \

  T1 = (h) + Sigma1_512((e)) + Ch((e), (f), (g)) + K512[j] +    \

       (W512[j&0x0f] += s1 + W512[(j+9)&0x0f] + s0);      \

  (d) += T1;                \

  (h) = T1 + Sigma0_512((a)) + Maj((a), (b), (c));      \

  j++;                  \

} while(0)

static void

SHA512_Transform(pg_sha512_ctx *context, const uint8 *data)

{

  uint64    a,

        b,

        c,

        d,

        e,

        f,

        g,

        h,

        s0,

        s1;

  uint64    T1,

         *W512 = (uint64 *) context->buffer;

  int     j;

  /* Initialize registers with the prev. intermediate value */

  a = context->state[0];

  b = context->state[1];

  c = context->state[2];

  d = context->state[3];

  e = context->state[4];

  f = context->state[5];

  g = context->state[6];

  h = context->state[7];

  j = 0;

  do

  {

    ROUND512_0_TO_15(a, b, c, d, e, f, g, h);

    ROUND512_0_TO_15(h, a, b, c, d, e, f, g);

    ROUND512_0_TO_15(g, h, a, b, c, d, e, f);

    ROUND512_0_TO_15(f, g, h, a, b, c, d, e);

    ROUND512_0_TO_15(e, f, g, h, a, b, c, d);

    ROUND512_0_TO_15(d, e, f, g, h, a, b, c);

    ROUND512_0_TO_15(c, d, e, f, g, h, a, b);

    ROUND512_0_TO_15(b, c, d, e, f, g, h, a);

  } while (j < 16);

  /* Now for the remaining rounds up to 79: */

  do

  {

    ROUND512(a, b, c, d, e, f, g, h);

    ROUND512(h, a, b, c, d, e, f, g);

    ROUND512(g, h, a, b, c, d, e, f);

    ROUND512(f, g, h, a, b, c, d, e);

    ROUND512(e, f, g, h, a, b, c, d);

    ROUND512(d, e, f, g, h, a, b, c);

    ROUND512(c, d, e, f, g, h, a, b);

    ROUND512(b, c, d, e, f, g, h, a);

  } while (j < 80);

  /* Compute the current intermediate hash value */

  context->state[0] += a;

  context->state[1] += b;

  context->state[2] += c;

  context->state[3] += d;

  context->state[4] += e;

  context->state[5] += f;

  context->state[6] += g;

  context->state[7] += h;

  /* Clean up */

  a = b = c = d = e = f = g = h = T1 = 0;

}

#else             /* SHA2_UNROLL_TRANSFORM */

static void

SHA512_Transform(pg_sha512_ctx *context, const uint8 *data)

{

  uint64    a,

        b,

        c,

        d,

        e,

        f,

        g,

        h,

        s0,

        s1;

  uint64    T1,

        T2,

         *W512 = (uint64 *) context->buffer;

  int     j;

  /* Initialize registers with the prev. intermediate value */

  a = context->state[0];

  b = context->state[1];

  c = context->state[2];

  d = context->state[3];

  e = context->state[4];

  f = context->state[5];

  g = context->state[6];

  h = context->state[7];

  j = 0;

  do

  {

    W512[j] = (uint64) data[7] | ((uint64) data[6] << 8) |

      ((uint64) data[5] << 16) | ((uint64) data[4] << 24) |

      ((uint64) data[3] << 32) | ((uint64) data[2] << 40) |

      ((uint64) data[1] << 48) | ((uint64) data[0] << 56);

    data += 8;

    /* Apply the SHA-512 compression function to update a..h */

    T1 = h + Sigma1_512(e) + Ch(e, f, g) + K512[j] + W512[j];

    T2 = Sigma0_512(a) + Maj(a, b, c);

    h = g;

    g = f;

    f = e;

    e = d + T1;

    d = c;

    c = b;

    b = a;

    a = T1 + T2;

    j++;

  } while (j < 16);

  do

  {

    /* Part of the message block expansion: */

    s0 = W512[(j + 1) & 0x0f];

    s0 = sigma0_512(s0);

    s1 = W512[(j + 14) & 0x0f];

    s1 = sigma1_512(s1);

    /* Apply the SHA-512 compression function to update a..h */

    T1 = h + Sigma1_512(e) + Ch(e, f, g) + K512[j] +

      (W512[j & 0x0f] += s1 + W512[(j + 9) & 0x0f] + s0);

    T2 = Sigma0_512(a) + Maj(a, b, c);

    h = g;

    g = f;

    f = e;

    e = d + T1;

    d = c;

    c = b;

    b = a;

    a = T1 + T2;

    j++;

  } while (j < 80);

  /* Compute the current intermediate hash value */

  context->state[0] += a;

  context->state[1] += b;

  context->state[2] += c;

  context->state[3] += d;

  context->state[4] += e;

  context->state[5] += f;

  context->state[6] += g;

  context->state[7] += h;

  /* Clean up */

  a = b = c = d = e = f = g = h = T1 = T2 = 0;

}

#endif              /* SHA2_UNROLL_TRANSFORM */

void

pg_sha512_update(pg_sha512_ctx *context, const uint8 *data, size_t len)

{

  size_t    freespace,

        usedspace;

  /* Calling with no data is valid (we do nothing) */

  if (len == 0)

    return;

  usedspace = (context->bitcount[0] >> 3) % PG_SHA512_BLOCK_LENGTH;

  if (usedspace > 0)

  {

    /* Calculate how much free space is available in the buffer */

    freespace = PG_SHA512_BLOCK_LENGTH - usedspace;

    if (len >= freespace)

    {

      /* Fill the buffer completely and process it */

      memcpy(&context->buffer[usedspace], data, freespace);

      ADDINC128(context->bitcount, freespace << 3);

      len -= freespace;

      data += freespace;

      SHA512_Transform(context, context->buffer);

    }

    else

    {

      /* The buffer is not yet full */

      memcpy(&context->buffer[usedspace], data, len);

      ADDINC128(context->bitcount, len << 3);

      /* Clean up: */

      usedspace = freespace = 0;

      return;

    }

  }

  while (len >= PG_SHA512_BLOCK_LENGTH)

  {

    /* Process as many complete blocks as we can */

    SHA512_Transform(context, data);

    ADDINC128(context->bitcount, PG_SHA512_BLOCK_LENGTH << 3);

    len -= PG_SHA512_BLOCK_LENGTH;

    data += PG_SHA512_BLOCK_LENGTH;

  }

  if (len > 0)

  {

    /* There's left-overs, so save 'em */

    memcpy(context->buffer, data, len);

    ADDINC128(context->bitcount, len << 3);

  }

  /* Clean up: */

  usedspace = freespace = 0;

}

static void

SHA512_Last(pg_sha512_ctx *context)

{

  unsigned int usedspace;

  usedspace = (context->bitcount[0] >> 3) % PG_SHA512_BLOCK_LENGTH;

#ifndef WORDS_BIGENDIAN

  /* Convert FROM host byte order */

  REVERSE64(context->bitcount[0], context->bitcount[0]);

  REVERSE64(context->bitcount[1], context->bitcount[1]);

#endif

  if (usedspace > 0)

  {

    /* Begin padding with a 1 bit: */

    context->buffer[usedspace++] = 0x80;

    if (usedspace <= PG_SHA512_SHORT_BLOCK_LENGTH)

    {

      /* Set-up for the last transform: */

      memset(&context->buffer[usedspace], 0, PG_SHA512_SHORT_BLOCK_LENGTH - usedspace);

    }

    else

    {

      if (usedspace < PG_SHA512_BLOCK_LENGTH)

      {

        memset(&context->buffer[usedspace], 0, PG_SHA512_BLOCK_LENGTH - usedspace);

      }

      /* Do second-to-last transform: */

      SHA512_Transform(context, context->buffer);

      /* And set-up for the last transform: */

      memset(context->buffer, 0, PG_SHA512_BLOCK_LENGTH - 2);

    }

  }

  else

  {

    /* Prepare for final transform: */

    memset(context->buffer, 0, PG_SHA512_SHORT_BLOCK_LENGTH);

    /* Begin padding with a 1 bit: */

    *context->buffer = 0x80;

  }

  /* Store the length of input data (in bits): */

  *(uint64 *) &context->buffer[PG_SHA512_SHORT_BLOCK_LENGTH] = context->bitcount[1];

  *(uint64 *) &context->buffer[PG_SHA512_SHORT_BLOCK_LENGTH + 8] = context->bitcount[0];

  /* Final transform: */

  SHA512_Transform(context, context->buffer);

}

void

pg_sha512_final(pg_sha512_ctx *context, uint8 *digest)

{

  /* If no digest buffer is passed, we don't bother doing this: */

  if (digest != NULL)

  {

    SHA512_Last(context);

    /* Save the hash data for output: */

#ifndef WORDS_BIGENDIAN

    {

      /* Convert TO host byte order */

      int     j;

      for (j = 0; j < 8; j++)

      {

        REVERSE64(context->state[j], context->state[j]);

      }

    }

#endif

    memcpy(digest, context->state, PG_SHA512_DIGEST_LENGTH);

  }

  /* Zero out state data */

  memset(context, 0, sizeof(pg_sha512_ctx));

}

/*** SHA-384: *********************************************************/

void

pg_sha384_init(pg_sha384_ctx *context)

{

  if (context == NULL)

    return;

  memcpy(context->state, sha384_initial_hash_value, PG_SHA512_DIGEST_LENGTH);

  memset(context->buffer, 0, PG_SHA384_BLOCK_LENGTH);

  context->bitcount[0] = context->bitcount[1] = 0;

}

void

pg_sha384_update(pg_sha384_ctx *context, const uint8 *data, size_t len)

{

  pg_sha512_update((pg_sha512_ctx *) context, data, len);

}

void

pg_sha384_final(pg_sha384_ctx *context, uint8 *digest)

{

  /* If no digest buffer is passed, we don't bother doing this: */

  if (digest != NULL)

  {

    SHA512_Last((pg_sha512_ctx *) context);

    /* Save the hash data for output: */

#ifndef WORDS_BIGENDIAN

    {

      /* Convert TO host byte order */

      int     j;

      for (j = 0; j < 6; j++)

      {

        REVERSE64(context->state[j], context->state[j]);

      }

    }

#endif

    memcpy(digest, context->state, PG_SHA384_DIGEST_LENGTH);

  }

  /* Zero out state data */

  memset(context, 0, sizeof(pg_sha384_ctx));