/*  $OpenBSD: sha2.c,v 1.28 2019/07/23 12:35:22 dtucker 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 $

 */

/* OPENBSD ORIGINAL: lib/libc/hash/sha2.c */

#include "includes.h"

#if !defined(HAVE_SHA256UPDATE) || !defined(HAVE_SHA384UPDATE) || \

    !defined(HAVE_SHA512UPDATE)

/* no-op out, similar to DEF_WEAK but only needed here */

#define MAKE_CLONE(x, y)  void __ssh_compat_make_clone_##x_##y(void)

#include <string.h>

#include "openbsd-compat/sha2.h"

/*

 * 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

 *

 */

#ifndef SHA2_SMALL

#if defined(__amd64__) || defined(__i386__)

#define SHA2_UNROLL_TRANSFORM

#endif

#endif

/*** SHA-224/256/384/512 Machine Architecture Definitions *****************/

/*

 * BYTE_ORDER NOTE:

 *

 * Please make sure that your system defines BYTE_ORDER.  If your

 * architecture is little-endian, make sure it also defines

 * LITTLE_ENDIAN and that the two (BYTE_ORDER and LITTLE_ENDIAN) are

 * equivalent.

 *

 * If your system does not define the above, then you can do so by

 * hand like this:

 *

 *   #define LITTLE_ENDIAN 1234

 *   #define BIG_ENDIAN    4321

 *

 * And for little-endian machines, add:

 *

 *   #define BYTE_ORDER LITTLE_ENDIAN 

 *

 * Or for big-endian machines:

 *

 *   #define BYTE_ORDER BIG_ENDIAN

 *

 * The FreeBSD machine this was written on defines BYTE_ORDER

 * appropriately by including <sys/types.h> (which in turn includes

 * <machine/endian.h> where the appropriate definitions are actually

 * made).

 */

#if !defined(BYTE_ORDER) || (BYTE_ORDER != LITTLE_ENDIAN && BYTE_ORDER != BIG_ENDIAN)

#error Define BYTE_ORDER to be equal to either LITTLE_ENDIAN or BIG_ENDIAN

#endif

/*** SHA-224/256/384/512 Various Length Definitions ***********************/

/* NOTE: Most of these are in sha2.h */

#define SHA224_SHORT_BLOCK_LENGTH (SHA224_BLOCK_LENGTH - 8)

#define SHA256_SHORT_BLOCK_LENGTH (SHA256_BLOCK_LENGTH - 8)

#define SHA384_SHORT_BLOCK_LENGTH (SHA384_BLOCK_LENGTH - 16)

#define SHA512_SHORT_BLOCK_LENGTH (SHA512_BLOCK_LENGTH - 16)

/*** ENDIAN SPECIFIC COPY MACROS **************************************/

#define BE_8_TO_32(dst, cp) do {         \

  (dst) = (u_int32_t)(cp)[3] | ((u_int32_t)(cp)[2] << 8) |  \

      ((u_int32_t)(cp)[1] << 16) | ((u_int32_t)(cp)[0] << 24);  \

} while(0)

#define BE_8_TO_64(dst, cp) do {         \

  (dst) = (u_int64_t)(cp)[7] | ((u_int64_t)(cp)[6] << 8) |  \

      ((u_int64_t)(cp)[5] << 16) | ((u_int64_t)(cp)[4] << 24) | \

      ((u_int64_t)(cp)[3] << 32) | ((u_int64_t)(cp)[2] << 40) | \

      ((u_int64_t)(cp)[1] << 48) | ((u_int64_t)(cp)[0] << 56);  \

} while (0)

#define BE_64_TO_8(cp, src) do {         \

  (cp)[0] = (src) >> 56;            \

        (cp)[1] = (src) >> 48;            \

  (cp)[2] = (src) >> 40;            \

  (cp)[3] = (src) >> 32;            \

  (cp)[4] = (src) >> 24;            \

  (cp)[5] = (src) >> 16;            \

  (cp)[6] = (src) >> 8;           \

  (cp)[7] = (src);            \

} while (0)

#define BE_32_TO_8(cp, src) do {         \

  (cp)[0] = (src) >> 24;            \

  (cp)[1] = (src) >> 16;            \

  (cp)[2] = (src) >> 8;           \

  (cp)[3] = (src);            \

} while (0)

/*

 * 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) do {           \

  (w)[0] += (u_int64_t)(n);         \

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

    (w)[1]++;           \

  }                \

} while (0)

/*** 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-224/256/384/512 description document

 *   (see http://csrc.nist.gov/cryptval/shs/sha256-384-512.pdf) uses this

 *   same "backwards" definition.

 */

/* Shift-right (used in SHA-224, SHA-256, SHA-384, and SHA-512): */

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

/* 32-bit Rotate-right (used in SHA-224 and 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-224, 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-224 and 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)))

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

/* Hash constant words K for SHA-224 and SHA-256: */

static const u_int32_t 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-256: */

static const u_int32_t 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 u_int64_t 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-512 */

static const u_int64_t sha512_initial_hash_value[8] = {

  0x6a09e667f3bcc908ULL,

  0xbb67ae8584caa73bULL,

  0x3c6ef372fe94f82bULL,

  0xa54ff53a5f1d36f1ULL,

  0x510e527fade682d1ULL,

  0x9b05688c2b3e6c1fULL,

  0x1f83d9abfb41bd6bULL,

  0x5be0cd19137e2179ULL

};

#if !defined(SHA2_SMALL)

#if 0

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

static const u_int32_t sha224_initial_hash_value[8] = {

  0xc1059ed8UL,

  0x367cd507UL,

  0x3070dd17UL,

  0xf70e5939UL,

  0xffc00b31UL,

  0x68581511UL,

  0x64f98fa7UL,

  0xbefa4fa4UL

};

#endif /* 0 */

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

static const u_int64_t sha384_initial_hash_value[8] = {

  0xcbbb9d5dc1059ed8ULL,

  0x629a292a367cd507ULL,

  0x9159015a3070dd17ULL,

  0x152fecd8f70e5939ULL,

  0x67332667ffc00b31ULL,

  0x8eb44a8768581511ULL,

  0xdb0c2e0d64f98fa7ULL,

  0x47b5481dbefa4fa4ULL

};

#if 0

/* Initial hash value H for SHA-512-256 */

static const u_int64_t sha512_256_initial_hash_value[8] = {

  0x22312194fc2bf72cULL,

  0x9f555fa3c84c64c2ULL,

  0x2393b86b6f53b151ULL,

  0x963877195940eabdULL,

  0x96283ee2a88effe3ULL,

  0xbe5e1e2553863992ULL,

  0x2b0199fc2c85b8aaULL,

  0x0eb72ddc81c52ca2ULL

};

/*** SHA-224: *********************************************************/

void

SHA224Init(SHA2_CTX *context)

{

  memcpy(context->state.st32, sha224_initial_hash_value,

      sizeof(sha224_initial_hash_value));

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

  context->bitcount[0] = 0;

}

DEF_WEAK(SHA224Init);

MAKE_CLONE(SHA224Transform, SHA256Transform);

MAKE_CLONE(SHA224Update, SHA256Update);

MAKE_CLONE(SHA224Pad, SHA256Pad);

DEF_WEAK(SHA224Transform);

DEF_WEAK(SHA224Update);

DEF_WEAK(SHA224Pad);

void

SHA224Final(u_int8_t digest[SHA224_DIGEST_LENGTH], SHA2_CTX *context)

{

  SHA224Pad(context);

#if BYTE_ORDER == LITTLE_ENDIAN

  int i;

  /* Convert TO host byte order */

  for (i = 0; i < 7; i++)

    BE_32_TO_8(digest + i * 4, context->state.st32[i]);

#else

  memcpy(digest, context->state.st32, SHA224_DIGEST_LENGTH);

#endif

  explicit_bzero(context, sizeof(*context));

}

DEF_WEAK(SHA224Final);

#endif /* !defined(SHA2_SMALL) */

#endif /* 0 */

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

void

SHA256Init(SHA2_CTX *context)

{

  memcpy(context->state.st32, sha256_initial_hash_value,

      sizeof(sha256_initial_hash_value));

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

  context->bitcount[0] = 0;

}

DEF_WEAK(SHA256Init);

#ifdef SHA2_UNROLL_TRANSFORM

/* Unrolled SHA-256 round macros: */

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

  BE_8_TO_32(W256[j], data);              \

  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)

void

SHA256Transform(u_int32_t state[8], const u_int8_t data[SHA256_BLOCK_LENGTH])

{

  u_int32_t a, b, c, d, e, f, g, h, s0, s1;

  u_int32_t T1, W256[16];

  int   j;

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

  a = state[0];

  b = state[1];

  c = state[2];

  d = state[3];

  e = state[4];

  f = state[5];

  g = state[6];

  h = 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 up to 63: */

  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 */

  state[0] += a;

  state[1] += b;

  state[2] += c;

  state[3] += d;

  state[4] += e;

  state[5] += f;

  state[6] += g;

  state[7] += h;

  /* Clean up */

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

}

#else /* SHA2_UNROLL_TRANSFORM */

void

SHA256Transform(u_int32_t state[8], const u_int8_t data[SHA256_BLOCK_LENGTH])

{

  u_int32_t a, b, c, d, e, f, g, h, s0, s1;

  u_int32_t T1, T2, W256[16];

  int   j;

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

  a = state[0];

  b = state[1];

  c = state[2];

  d = state[3];

  e = state[4];

  f = state[5];

  g = state[6];

  h = state[7];

  j = 0;

  do {

    BE_8_TO_32(W256[j], data);

    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 */

  state[0] += a;

  state[1] += b;

  state[2] += c;

  state[3] += d;

  state[4] += e;

  state[5] += f;

  state[6] += g;

  state[7] += h;

  /* Clean up */

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

}

#endif /* SHA2_UNROLL_TRANSFORM */

DEF_WEAK(SHA256Transform);

void

SHA256Update(SHA2_CTX *context, const u_int8_t *data, size_t len)

{

  u_int64_t freespace, usedspace;

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

  if (len == 0)

    return;

  usedspace = (context->bitcount[0] >> 3) % SHA256_BLOCK_LENGTH;

  if (usedspace > 0) {

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

    freespace = SHA256_BLOCK_LENGTH - usedspace;

    if (len >= freespace) {

      /* Fill the buffer completely and process it */

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

      context->bitcount[0] += freespace << 3;

      len -= freespace;

      data += freespace;

      SHA256Transform(context->state.st32, context->buffer);

    } else {

      /* The buffer is not yet full */

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

      context->bitcount[0] += (u_int64_t)len << 3;

      /* Clean up: */

      usedspace = freespace = 0;

      return;

    }

  }

  while (len >= SHA256_BLOCK_LENGTH) {

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

    SHA256Transform(context->state.st32, data);

    context->bitcount[0] += SHA256_BLOCK_LENGTH << 3;

    len -= SHA256_BLOCK_LENGTH;

    data += SHA256_BLOCK_LENGTH;

  }

  if (len > 0) {

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

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

    context->bitcount[0] += len << 3;

  }

  /* Clean up: */

  usedspace = freespace = 0;

}

DEF_WEAK(SHA256Update);

void

SHA256Pad(SHA2_CTX *context)

{

  unsigned int  usedspace;

  usedspace = (context->bitcount[0] >> 3) % SHA256_BLOCK_LENGTH;

  if (usedspace > 0) {

    /* Begin padding with a 1 bit: */

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

    if (usedspace <= SHA256_SHORT_BLOCK_LENGTH) {

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

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

          SHA256_SHORT_BLOCK_LENGTH - usedspace);

    } else {

      if (usedspace < SHA256_BLOCK_LENGTH) {

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

            SHA256_BLOCK_LENGTH - usedspace);

      }

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

      SHA256Transform(context->state.st32, context->buffer);

      /* Prepare for last transform: */

      memset(context->buffer, 0, SHA256_SHORT_BLOCK_LENGTH);

    }

  } else {

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

    memset(context->buffer, 0, SHA256_SHORT_BLOCK_LENGTH);

    /* Begin padding with a 1 bit: */

    *context->buffer = 0x80;

  }

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

  BE_64_TO_8(&context->buffer[SHA256_SHORT_BLOCK_LENGTH],

      context->bitcount[0]);

  /* Final transform: */

  SHA256Transform(context->state.st32, context->buffer);

  /* Clean up: */

  usedspace = 0;

}

DEF_WEAK(SHA256Pad);

void

SHA256Final(u_int8_t digest[SHA256_DIGEST_LENGTH], SHA2_CTX *context)

{

  SHA256Pad(context);

#if BYTE_ORDER == LITTLE_ENDIAN

  int i;

  /* Convert TO host byte order */

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

    BE_32_TO_8(digest + i * 4, context->state.st32[i]);

#else

  memcpy(digest, context->state.st32, SHA256_DIGEST_LENGTH);

#endif

  explicit_bzero(context, sizeof(*context));

}

DEF_WEAK(SHA256Final);

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

void

SHA512Init(SHA2_CTX *context)

{

  memcpy(context->state.st64, sha512_initial_hash_value,

      sizeof(sha512_initial_hash_value));

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

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

}

DEF_WEAK(SHA512Init);

#ifdef SHA2_UNROLL_TRANSFORM

/* Unrolled SHA-512 round macros: */

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

  BE_8_TO_64(W512[j], data);              \

  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)

void

SHA512Transform(u_int64_t state[8], const u_int8_t data[SHA512_BLOCK_LENGTH])

{

  u_int64_t a, b, c, d, e, f, g, h, s0, s1;

  u_int64_t T1, W512[16];

  int   j;

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

  a = state[0];

  b = state[1];

  c = state[2];

  d = state[3];

  e = state[4];

  f = state[5];

  g = state[6];

  h = state[7];

  j = 0;

  do {

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

    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 */

  state[0] += a;

  state[1] += b;

  state[2] += c;

  state[3] += d;

  state[4] += e;

  state[5] += f;

  state[6] += g;

  state[7] += h;

  /* Clean up */

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

}

#else /* SHA2_UNROLL_TRANSFORM */

void

SHA512Transform(u_int64_t state[8], const u_int8_t data[SHA512_BLOCK_LENGTH])

{

  u_int64_t a, b, c, d, e, f, g, h, s0, s1;

  u_int64_t T1, T2, W512[16];

  int   j;

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

  a = state[0];

  b = state[1];

  c = state[2];

  d = state[3];

  e = state[4];

  f = state[5];

  g = state[6];

  h = state[7];

  j = 0;

  do {

    BE_8_TO_64(W512[j], data);

    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 */

  state[0] += a;

  state[1] += b;

  state[2] += c;

  state[3] += d;

  state[4] += e;

  state[5] += f;

  state[6] += g;

  state[7] += h;

  /* Clean up */

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

}

#endif /* SHA2_UNROLL_TRANSFORM */

DEF_WEAK(SHA512Transform);

void

SHA512Update(SHA2_CTX *context, const u_int8_t *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) % SHA512_BLOCK_LENGTH;

  if (usedspace > 0) {

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

    freespace = 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;

      SHA512Transform(context->state.st64, 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 >= SHA512_BLOCK_LENGTH) {

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

    SHA512Transform(context->state.st64, data);

    ADDINC128(context->bitcount, SHA512_BLOCK_LENGTH << 3);

    len -= SHA512_BLOCK_LENGTH;

    data += 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;

}

DEF_WEAK(SHA512Update);

void

SHA512Pad(SHA2_CTX *context)

{

  unsigned int  usedspace;

  usedspace = (context->bitcount[0] >> 3) % SHA512_BLOCK_LENGTH;

  if (usedspace > 0) {

    /* Begin padding with a 1 bit: */

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

    if (usedspace <= SHA512_SHORT_BLOCK_LENGTH) {

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

      memset(&context->buffer[usedspace], 0, SHA512_SHORT_BLOCK_LENGTH - usedspace);

    } else {

      if (usedspace < SHA512_BLOCK_LENGTH) {

        memset(&context->buffer[usedspace], 0, SHA512_BLOCK_LENGTH - usedspace);

      }

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

      SHA512Transform(context->state.st64, context->buffer);

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

      memset(context->buffer, 0, SHA512_BLOCK_LENGTH - 2);

    }

  } else {

    /* Prepare for final transform: */

    memset(context->buffer, 0, SHA512_SHORT_BLOCK_LENGTH);

    /* Begin padding with a 1 bit: */

    *context->buffer = 0x80;

  }

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

  BE_64_TO_8(&context->buffer[SHA512_SHORT_BLOCK_LENGTH],

      context->bitcount[1]);

  BE_64_TO_8(&context->buffer[SHA512_SHORT_BLOCK_LENGTH + 8],

      context->bitcount[0]);

  /* Final transform: */

  SHA512Transform(context->state.st64, context->buffer);

  /* Clean up: */

  usedspace = 0;

}

DEF_WEAK(SHA512Pad);

void

SHA512Final(u_int8_t digest[SHA512_DIGEST_LENGTH], SHA2_CTX *context)

{

  SHA512Pad(context);

#if BYTE_ORDER == LITTLE_ENDIAN

  int i;

  /* Convert TO host byte order */

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

    BE_64_TO_8(digest + i * 8, context->state.st64[i]);

#else

  memcpy(digest, context->state.st64, SHA512_DIGEST_LENGTH);

#endif

  explicit_bzero(context, sizeof(*context));

}

DEF_WEAK(SHA512Final);

#if !defined(SHA2_SMALL)

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

void

SHA384Init(SHA2_CTX *context)

{

  memcpy(context->state.st64, sha384_initial_hash_value,

      sizeof(sha384_initial_hash_value));

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

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

}

DEF_WEAK(SHA384Init);

MAKE_CLONE(SHA384Transform, SHA512Transform);

MAKE_CLONE(SHA384Update, SHA512Update);

MAKE_CLONE(SHA384Pad, SHA512Pad);

DEF_WEAK(SHA384Transform);

DEF_WEAK(SHA384Update);

DEF_WEAK(SHA384Pad);

/* Equivalent of MAKE_CLONE (which is a no-op) for SHA384 funcs */

void

SHA384Transform(u_int64_t state[8], const u_int8_t data[SHA512_BLOCK_LENGTH])

{

  SHA512Transform(state, data);

}

void

SHA384Update(SHA2_CTX *context, const u_int8_t *data, size_t len)

{

  SHA512Update(context, data, len);

}

void

SHA384Pad(SHA2_CTX *context)

{

  SHA512Pad(context);

}

void

SHA384Final(u_int8_t digest[SHA384_DIGEST_LENGTH], SHA2_CTX *context)

{

  SHA384Pad(context);

#if BYTE_ORDER == LITTLE_ENDIAN

  int i;

  /* Convert TO host byte order */

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

    BE_64_TO_8(digest + i * 8, context->state.st64[i]);

#else

  memcpy(digest, context->state.st64, SHA384_DIGEST_LENGTH);

#endif

  /* Zero out state data */

  explicit_bzero(context, sizeof(*context));

}

DEF_WEAK(SHA384Final);

#if 0

/*** SHA-512/256: *********************************************************/

void

SHA512_256Init(SHA2_CTX *context)

{

  memcpy(context->state.st64, sha512_256_initial_hash_value,

      sizeof(sha512_256_initial_hash_value));

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

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

}

DEF_WEAK(SHA512_256Init);

MAKE_CLONE(SHA512_256Transform, SHA512Transform);

MAKE_CLONE(SHA512_256Update, SHA512Update);

MAKE_CLONE(SHA512_256Pad, SHA512Pad);

DEF_WEAK(SHA512_256Transform);

DEF_WEAK(SHA512_256Update);

DEF_WEAK(SHA512_256Pad);