/*

 * FILE:  sha256.c

 * AUTHOR:  Aaron D. Gifford - http://www.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 w627ith 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.

 *

 */

#include <string.h> /* memcpy()/memset() or bcopy()/bzero() */

#include <assert.h> /* assert() */

#include "sha256.h"

/* discover byte order on solaris */

#if defined(__SVR4) || defined(__sun)

#include <sys/isa_defs.h>

#define BYTE_ORDER _BYTE_ORDER

#endif

/*

 * ASSERT NOTE:

 * Some sanity checking code is included using assert().  On my FreeBSD

 * system, this additional code can be removed by compiling with NDEBUG

 * defined.  Check your own systems manpage on assert() to see how to

 * compile WITHOUT the sanity checking code on your system.

 *

 * 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 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

 * equivilent.

 *

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

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

#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 REVERSAL MACROS *******************************************/

#if BYTE_ORDER == LITTLE_ENDIAN

#define REVERSE32(w, x)                                                  \

  {                                                                    \

    sha2_word32 tmp = (w);                                           \

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

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

  }

#define REVERSE64(w, x)                                \

  {                                                  \

    sha2_word64 tmp = (w);                         \

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

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

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

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

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

  }

#endif /* BYTE_ORDER == LITTLE_ENDIAN */

/*

 * 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] += (sha2_word64)(n); \

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

      (w)[1]++;               \

    }                           \

  }

/*

 * Macros for copying blocks of memory and for zeroing out ranges

 * of memory.  Using these macros makes it easy to switch from

 * using memset()/memcpy() and using bzero()/bcopy().

 *

 * Please define either SHA2_USE_MEMSET_MEMCPY or define

 * SHA2_USE_BZERO_BCOPY depending on which function set you

 * choose to use:

 */

#if !defined(SHA2_USE_MEMSET_MEMCPY) && !defined(SHA2_USE_BZERO_BCOPY)

/* Default to memset()/memcpy() if no option is specified */

#define SHA2_USE_MEMSET_MEMCPY 1

#endif

#if defined(SHA2_USE_MEMSET_MEMCPY) && defined(SHA2_USE_BZERO_BCOPY)

/* Abort with an error if BOTH options are defined */

#error Define either SHA2_USE_MEMSET_MEMCPY or SHA2_USE_BZERO_BCOPY, not both!

#endif

#ifdef SHA2_USE_MEMSET_MEMCPY

#define MEMSET_BZERO(p, l) memset((p), 0, (l))

#define MEMCPY_BCOPY(d, s, l) memcpy((d), (s), (l))

#endif

#ifdef SHA2_USE_BZERO_BCOPY

#define MEMSET_BZERO(p, l) bzero((p), (l))

#define MEMCPY_BCOPY(d, s, l) bcopy((s), (d), (l))

#endif

/*** 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://csrc.nist.gov/cryptval/shs/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.

 */

void SHA512_Last(SHA512_CTX *);

void SHA256_Transform(SHA256_CTX *, const sha2_word32 *);

void SHA512_Transform(SHA512_CTX *, const sha2_word64 *);

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

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

const static sha2_word32 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: */

const static sha2_word32 sha256_initial_hash_value[8] = {0x6a09e667UL,

    0xbb67ae85UL, 0x3c6ef372UL, 0xa54ff53aUL, 0x510e527fUL, 0x9b05688cUL,

    0x1f83d9abUL, 0x5be0cd19UL};

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

const static sha2_word64 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 */

const static sha2_word64 sha384_initial_hash_value[8] = {0xcbbb9d5dc1059ed8ULL,

    0x629a292a367cd507ULL, 0x9159015a3070dd17ULL, 0x152fecd8f70e5939ULL,

    0x67332667ffc00b31ULL, 0x8eb44a8768581511ULL, 0xdb0c2e0d64f98fa7ULL,

    0x47b5481dbefa4fa4ULL};

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

const static sha2_word64 sha512_initial_hash_value[8] = {0x6a09e667f3bcc908ULL,

    0xbb67ae8584caa73bULL, 0x3c6ef372fe94f82bULL, 0xa54ff53a5f1d36f1ULL,

    0x510e527fade682d1ULL, 0x9b05688c2b3e6c1fULL, 0x1f83d9abfb41bd6bULL,

    0x5be0cd19137e2179ULL};

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

const static sha2_word64 sha512_256_initial_hash_value[8] = {

    0x22312194FC2BF72CULL, 0x9F555FA3C84C64C2ULL, 0x2393B86B6F53B151ULL,

    0x963877195940EABDULL, 0x96283EE2A88EFFE3ULL, 0xBE5E1E2553863992ULL,

    0x2B0199FC2C85B8AAULL, 0x0EB72DDC81C52CA2ULL};

/*

 * Constant used by SHA256/384/512_End() functions for converting the

 * digest to a readable hexadecimal character string:

 */

static const char *sha2_hex_digits = "0123456789abcdef";

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

void sr_SHA256_Init(SHA256_CTX *context)

{

  if(context == (SHA256_CTX *)0) {

    return;

  }

  MEMCPY_BCOPY(

      context->state, sha256_initial_hash_value, SHA256_DIGEST_LENGTH);

  MEMSET_BZERO(context->buffer, SHA256_BLOCK_LENGTH);

  context->bitcount = 0;

}

#ifdef SHA2_UNROLL_TRANSFORM

/* Unrolled SHA-256 round macros: */

#if BYTE_ORDER == LITTLE_ENDIAN

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

  REVERSE32(*data++, W256[j]);                                      \

  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++

#else /* BYTE_ORDER == LITTLE_ENDIAN */

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

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

     + (W256[j] = *data++);                            \

  (d) += T1;                                             \

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

  j++

#endif /* BYTE_ORDER == LITTLE_ENDIAN */

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

  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++

void SHA256_Transform(SHA256_CTX *context, const sha2_word32 *data)

{

  sha2_word32 a, b, c, d, e, f, g, h, s0, s1;

  sha2_word32 T1, *W256;

  int j;

  W256 = (sha2_word32 *)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 */

void SHA256_Transform(SHA256_CTX *context, const sha2_word32 *data)

{

  sha2_word32 a, b, c, d, e, f, g, h, s0, s1;

  sha2_word32 T1, T2, *W256;

  int j;

  W256 = (sha2_word32 *)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 {

#if BYTE_ORDER == LITTLE_ENDIAN

    /* Copy data while converting to host byte order */

    REVERSE32(*data++, W256[j]);

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

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

#else  /* BYTE_ORDER == LITTLE_ENDIAN */

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

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

#endif /* BYTE_ORDER == LITTLE_ENDIAN */

    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 sr_SHA256_Update(SHA256_CTX *context, const sha2_byte *data, size_t len)

{

  unsigned int freespace, usedspace;

  if(len == 0) {

    /* Calling with no data is valid - we do nothing */

    return;

  }

  /* Sanity check: */

  assert(context != (SHA256_CTX *)0 && data != (sha2_byte *)0);

  usedspace = (context->bitcount >> 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_BCOPY(&context->buffer[usedspace], data, freespace);

      context->bitcount += freespace << 3;

      len -= freespace;

      data += freespace;

      SHA256_Transform(context, (sha2_word32 *)context->buffer);

    } else {

      /* The buffer is not yet full */

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

      context->bitcount += len << 3;

      /* Clean up: */

      usedspace = freespace = 0;

      return;

    }

  }

  while(len >= SHA256_BLOCK_LENGTH) {

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

    SHA256_Transform(context, (sha2_word32 *)data);

    context->bitcount += SHA256_BLOCK_LENGTH << 3;

    len -= SHA256_BLOCK_LENGTH;

    data += SHA256_BLOCK_LENGTH;

  }

  if(len > 0) {

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

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

    context->bitcount += len << 3;

  }

  /* Clean up: */

  usedspace = freespace = 0;

}

void sr_SHA256_Final(

    sha2_byte digest[SHA256_DIGEST_LENGTH], SHA256_CTX *context)

{

  sha2_word32 *d = (sha2_word32 *)digest;

  unsigned int usedspace;

  /* Sanity check: */

  assert(context != (SHA256_CTX *)0);

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

  if(digest != (sha2_byte *)0) {

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

#if BYTE_ORDER == LITTLE_ENDIAN

    /* 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 <= SHA256_SHORT_BLOCK_LENGTH) {

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

        MEMSET_BZERO(&context->buffer[usedspace],

            SHA256_SHORT_BLOCK_LENGTH - usedspace);

      } else {

        if(usedspace < SHA256_BLOCK_LENGTH) {

          MEMSET_BZERO(&context->buffer[usedspace],

              SHA256_BLOCK_LENGTH - usedspace);

        }

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

        SHA256_Transform(context, (sha2_word32 *)context->buffer);

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

        MEMSET_BZERO(context->buffer, SHA256_SHORT_BLOCK_LENGTH);

      }

    } else {

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

      MEMSET_BZERO(context->buffer, SHA256_SHORT_BLOCK_LENGTH);

      /* Begin padding with a 1 bit: */

      *context->buffer = 0x80;

    }

    /* Set the bit count: */

    MEMCPY_BCOPY(&(context->buffer[SHA256_SHORT_BLOCK_LENGTH]),

        &(context->bitcount), sizeof(sha2_word64));

    /* Final transform: */

    SHA256_Transform(context, (sha2_word32 *)context->buffer);

#if BYTE_ORDER == LITTLE_ENDIAN

    {

      /* Convert TO host byte order */

      int j;

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

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

        *d++ = context->state[j];

      }

    }

#else

    MEMCPY_BCOPY(d, context->state, SHA256_DIGEST_LENGTH);

#endif

  }

  /* Clean up state data: */

  MEMSET_BZERO(context, sizeof(*context));

  usedspace = 0;

}

char *sr_SHA256_End(

    SHA256_CTX *context, char buffer[SHA256_DIGEST_STRING_LENGTH])

{

  sha2_byte digest[SHA256_DIGEST_LENGTH], *d = digest;

  int i;

  /* Sanity check: */

  assert(context != (SHA256_CTX *)0);

  if(buffer != (char *)0) {

    sr_SHA256_Final(digest, context);

    for(i = 0; i < SHA256_DIGEST_LENGTH; i++) {

      *buffer++ = sha2_hex_digits[(*d & 0xf0) >> 4];

      *buffer++ = sha2_hex_digits[*d & 0x0f];

      d++;

    }

    *buffer = (char)0;

  } else {

    MEMSET_BZERO(context, sizeof(*context));

  }

  MEMSET_BZERO(digest, SHA256_DIGEST_LENGTH);

  return buffer;

}

char *sr_SHA256_Data(const sha2_byte *data, size_t len,

    char digest[SHA256_DIGEST_STRING_LENGTH])

{

  SHA256_CTX context;

  sr_SHA256_Init(&context);

  sr_SHA256_Update(&context, data, len);

  return sr_SHA256_End(&context, digest);

}

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

void sr_SHA512_Init(SHA512_CTX *context)

{

  if(context == (SHA512_CTX *)0) {

    return;

  }

  MEMCPY_BCOPY(

      context->state, sha512_initial_hash_value, SHA512_DIGEST_LENGTH);

  MEMSET_BZERO(context->buffer, SHA512_BLOCK_LENGTH);

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

}

void sr_SHA512_256_Init(SHA512_CTX *context)

{

  if(context == (SHA512_CTX *)0) {

    return;

  }

  MEMCPY_BCOPY(context->state, sha512_256_initial_hash_value,

      SHA512_DIGEST_LENGTH);

  MEMSET_BZERO(context->buffer, SHA512_BLOCK_LENGTH);

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

}

#ifdef SHA2_UNROLL_TRANSFORM

/* Unrolled SHA-512 round macros: */

#if BYTE_ORDER == LITTLE_ENDIAN

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

  REVERSE64(*data++, W512[j]);                                      \

  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++

#else /* BYTE_ORDER == LITTLE_ENDIAN */

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

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

     + (W512[j] = *data++);                            \

  (d) += T1;                                             \

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

  j++

#endif /* BYTE_ORDER == LITTLE_ENDIAN */

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

  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++

void SHA512_Transform(SHA512_CTX *context, const sha2_word64 *data)

{

  sha2_word64 a, b, c, d, e, f, g, h, s0, s1;

  sha2_word64 T1, *W512 = (sha2_word64 *)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 */

void SHA512_Transform(SHA512_CTX *context, const sha2_word64 *data)

{

  sha2_word64 a, b, c, d, e, f, g, h, s0, s1;

  sha2_word64 T1, T2, *W512 = (sha2_word64 *)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 {

#if BYTE_ORDER == LITTLE_ENDIAN

    /* Convert TO host byte order */

    REVERSE64(*data++, W512[j]);

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

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

#else  /* BYTE_ORDER == LITTLE_ENDIAN */

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

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

#endif /* BYTE_ORDER == LITTLE_ENDIAN */

    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 sr_SHA512_Update(SHA512_CTX *context, const sha2_byte *data, size_t len)

{

  unsigned int freespace, usedspace;

  if(len == 0) {

    /* Calling with no data is valid - we do nothing */

    return;

  }

  /* Sanity check: */

  assert(context != (SHA512_CTX *)0 && data != (sha2_byte *)0);

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

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

      len -= freespace;

      data += freespace;

      SHA512_Transform(context, (sha2_word64 *)context->buffer);

    } else {

      /* The buffer is not yet full */

      MEMCPY_BCOPY(&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 */

    SHA512_Transform(context, (sha2_word64 *)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_BCOPY(context->buffer, data, len);

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

  }

  /* Clean up: */

  usedspace = freespace = 0;

}

void SHA512_Last(SHA512_CTX *context)

{

  unsigned int usedspace;

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

#if BYTE_ORDER == LITTLE_ENDIAN

  /* 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 <= SHA512_SHORT_BLOCK_LENGTH) {

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

      MEMSET_BZERO(&context->buffer[usedspace],

          SHA512_SHORT_BLOCK_LENGTH - usedspace);

    } else {

      if(usedspace < SHA512_BLOCK_LENGTH) {

        MEMSET_BZERO(&context->buffer[usedspace],

            SHA512_BLOCK_LENGTH - usedspace);

      }

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

      SHA512_Transform(context, (sha2_word64 *)context->buffer);

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

      MEMSET_BZERO(context->buffer, SHA512_BLOCK_LENGTH - 2);

    }

  } else {

    /* Prepare for final transform: */

    MEMSET_BZERO(context->buffer, SHA512_SHORT_BLOCK_LENGTH);

    /* Begin padding with a 1 bit: */

    *context->buffer = 0x80;

  }

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

  MEMCPY_BCOPY(&(context->buffer[SHA512_SHORT_BLOCK_LENGTH + 0]),

      &(context->bitcount[1]), sizeof(sha2_word64));

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

      &(context->bitcount[0]), sizeof(sha2_word64));

  /* Final transform: */

  SHA512_Transform(context, (sha2_word64 *)context->buffer);

}

void sr_SHA512_Final(

    sha2_byte digest[SHA512_DIGEST_LENGTH], SHA512_CTX *context)

{

  sha2_word64 *d = (sha2_word64 *)digest;

  /* Sanity check: */

  assert(context != (SHA512_CTX *)0);

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

  if(digest != (sha2_byte *)0) {

    SHA512_Last(context);

    /* Save the hash data for output: */

#if BYTE_ORDER == LITTLE_ENDIAN

    {

      /* Convert TO host byte order */

      int j;

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

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

        *d++ = context->state[j];

      }

    }

#else

    MEMCPY_BCOPY(d, context->state, SHA512_DIGEST_LENGTH);

#endif

  }

  /* Zero out state data */

  MEMSET_BZERO(context, sizeof(*context));

}

char *sr_SHA512_End(

    SHA512_CTX *context, char buffer[SHA512_DIGEST_STRING_LENGTH])

{

  sha2_byte digest[SHA512_DIGEST_LENGTH], *d = digest;

  int i;

  /* Sanity check: */

  assert(context != (SHA512_CTX *)0);

  if(buffer != (char *)0) {

    sr_SHA512_Final(digest, context);

    for(i = 0; i < SHA512_DIGEST_LENGTH; i++) {

      *buffer++ = sha2_hex_digits[(*d & 0xf0) >> 4];

      *buffer++ = sha2_hex_digits[*d & 0x0f];

      d++;

    }

    *buffer = (char)0;

  } else {

    MEMSET_BZERO(context, sizeof(*context));

  }

  MEMSET_BZERO(digest, SHA512_DIGEST_LENGTH);

  return buffer;

}

char *sr_SHA512_Data(const sha2_byte *data, size_t len,

    char digest[SHA512_DIGEST_STRING_LENGTH])

{

  SHA512_CTX context;

  sr_SHA512_Init(&context);

  sr_SHA512_Update(&context, data, len);

  return sr_SHA512_End(&context, digest);