/*      $OpenBSD: sha2.c,v 1.18 2015/03/14 03:38:46 jsg 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 $
 */

#if 0 // crypto extpkg mod

#include <sys/time.h>
#include <sys/systm.h>
#include <crypto/sha2.h>

#else // crypto extpkg mod

#ifdef HAVE_PLATFORM_H 
  #include "platform.h" 
#endif
#include "crypto.h"
#include "sha2.h"

#endif // crypto extpkg mod

/*
 * 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 SMALL_KERNEL
#if defined(__amd64__) || defined(__i386__)
#define SHA2_UNROLL_TRANSFORM
#endif
#endif

/*** 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)

/*
 * 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] += (u_int64_t)(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://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)))

#if !defined( CRYPTO_EXTPKG_MOD )

/*** INTERNAL FUNCTION PROTOTYPES *************************************/
/* NOTE: These should not be accessed directly from outside this
 * library -- they are intended for private internal visibility/use
 * only.
 */
void SHA512Last(SHA2_CTX *);
void SHA256Transform(u_int32_t *, const u_int8_t *);
void SHA512Transform(u_int64_t *, const u_int8_t *);

#endif // !defined( CRYPTO_EXTPKG_MOD )


/*** SHA-XYZ INITIAL HASH VALUES AND CONSTANTS ************************/
/* Hash constant words K for SHA-256: */
const static 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: */
const static 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: */
const static 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-384 */
const static u_int64_t sha384_initial_hash_value[8] = {
        0xcbbb9d5dc1059ed8ULL,
        0x629a292a367cd507ULL,
        0x9159015a3070dd17ULL,
        0x152fecd8f70e5939ULL,
        0x67332667ffc00b31ULL,
        0x8eb44a8768581511ULL,
        0xdb0c2e0d64f98fa7ULL,
        0x47b5481dbefa4fa4ULL
};

/* Initial hash value H for SHA-512 */
const static u_int64_t sha512_initial_hash_value[8] = {
        0x6a09e667f3bcc908ULL,
        0xbb67ae8584caa73bULL,
        0x3c6ef372fe94f82bULL,
        0xa54ff53a5f1d36f1ULL,
        0x510e527fade682d1ULL,
        0x9b05688c2b3e6c1fULL,
        0x1f83d9abfb41bd6bULL,
        0x5be0cd19137e2179ULL
};


/*** SHA-256: *********************************************************/
void
SHA256Init(SHA2_CTX *context)
{
        memcpy(context->state.st32, sha256_initial_hash_value,
            SHA256_DIGEST_LENGTH);
        memset(context->buffer, 0, SHA256_BLOCK_LENGTH);
        context->bitcount[0] = 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] = (u_int32_t)data[3] | ((u_int32_t)data[2] << 8) |          \
            ((u_int32_t)data[1] << 16) | ((u_int32_t)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)

void
SHA256Transform(u_int32_t *state, const u_int8_t *data)
{
        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 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 */
        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 */
        explicit_bzero(&a,sizeof(a));
        explicit_bzero(&b,sizeof(b));
        explicit_bzero(&c,sizeof(c));
        explicit_bzero(&d,sizeof(d));
        explicit_bzero(&e,sizeof(e));
        explicit_bzero(&f,sizeof(f));
        explicit_bzero(&g,sizeof(g));
        explicit_bzero(&h,sizeof(h));
        explicit_bzero(&s0,sizeof(s0));
        explicit_bzero(&s1,sizeof(s1));
        explicit_bzero(&T1,sizeof(T1));
        explicit_bzero(W256,sizeof(W256));
}

#else /* SHA2_UNROLL_TRANSFORM */

void
SHA256Transform(u_int32_t *state, const u_int8_t *data)
{
        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 {
                W256[j] = (u_int32_t)data[3] | ((u_int32_t)data[2] << 8) |
                    ((u_int32_t)data[1] << 16) | ((u_int32_t)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 */
        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 */
        explicit_bzero(&a,sizeof(a));
        explicit_bzero(&b,sizeof(b));
        explicit_bzero(&c,sizeof(c));
        explicit_bzero(&d,sizeof(d));
        explicit_bzero(&e,sizeof(e));
        explicit_bzero(&f,sizeof(f));
        explicit_bzero(&g,sizeof(g));
        explicit_bzero(&h,sizeof(h));
        explicit_bzero(&s0,sizeof(s0));
        explicit_bzero(&s1,sizeof(s1));
        explicit_bzero(&T1,sizeof(T1));
        explicit_bzero(&T2,sizeof(T2));
        explicit_bzero(W256,sizeof(W256));
}

#endif /* SHA2_UNROLL_TRANSFORM */

void
SHA256Update(SHA2_CTX *context, const void *dataptr, size_t len)
{
        const uint8_t *data = dataptr;
        size_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] += 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;
}

void
SHA256Final(u_int8_t digest[], SHA2_CTX *context)
{
        unsigned int    usedspace;

        usedspace = (context->bitcount[0] >> 3) % SHA256_BLOCK_LENGTH;
#if BYTE_ORDER == LITTLE_ENDIAN
        /* Convert FROM host byte order */
        context->bitcount[0] = swap64(context->bitcount[0]);
#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(&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);

                        /* And set-up for the 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;
        }
        /* Set the bit count: */
        *(u_int64_t *)&context->buffer[SHA256_SHORT_BLOCK_LENGTH] = context->bitcount[0];

        /* Final transform: */
        SHA256Transform(context->state.st32, context->buffer);

#if BYTE_ORDER == LITTLE_ENDIAN
        {
                /* Convert TO host byte order */
                int     j;
                for (j = 0; j < 8; j++) {
                        context->state.st32[j] = swap32(context->state.st32[j]);
                }
        }
#endif
        memcpy(digest, context->state.st32, SHA256_DIGEST_LENGTH);
        /* Clean up state data: */
        explicit_bzero(context, sizeof(*context));
        explicit_bzero(&usedspace,sizeof(usedspace));
}


/*** SHA-512: *********************************************************/
void
SHA512Init(SHA2_CTX *context)
{
        memcpy(context->state.st64, sha512_initial_hash_value,
            SHA512_DIGEST_LENGTH);
        memset(context->buffer, 0, 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] = (u_int64_t)data[7] | ((u_int64_t)data[6] << 8) |          \
            ((u_int64_t)data[5] << 16) | ((u_int64_t)data[4] << 24) |       \
            ((u_int64_t)data[3] << 32) | ((u_int64_t)data[2] << 40) |       \
            ((u_int64_t)data[1] << 48) | ((u_int64_t)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)

void
SHA512Transform(u_int64_t *state, const u_int8_t *data)
{
        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 {
                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 */
        explicit_bzero(&a,sizeof(a));
        explicit_bzero(&b,sizeof(b));
        explicit_bzero(&c,sizeof(c));
        explicit_bzero(&d,sizeof(d));
        explicit_bzero(&e,sizeof(e));
        explicit_bzero(&f,sizeof(f));
        explicit_bzero(&g,sizeof(g));
        explicit_bzero(&h,sizeof(h));
        explicit_bzero(&T1,sizeof(T1));
        explicit_bzero(W512,sizeof(W512));
}

#else /* SHA2_UNROLL_TRANSFORM */

void
SHA512Transform(u_int64_t *state, const u_int8_t *data)
{
        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 {
                W512[j] = (u_int64_t)data[7] | ((u_int64_t)data[6] << 8) |
                    ((u_int64_t)data[5] << 16) | ((u_int64_t)data[4] << 24) |
                    ((u_int64_t)data[3] << 32) | ((u_int64_t)data[2] << 40) |
                    ((u_int64_t)data[1] << 48) | ((u_int64_t)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 */
        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 */
        explicit_bzero(&a,sizeof(a));
        explicit_bzero(&b,sizeof(b));
        explicit_bzero(&c,sizeof(c));
        explicit_bzero(&d,sizeof(d));
        explicit_bzero(&e,sizeof(e));
        explicit_bzero(&f,sizeof(f));
        explicit_bzero(&g,sizeof(g));
        explicit_bzero(&s0,sizeof(s0));
        explicit_bzero(&s1,sizeof(s1));
        explicit_bzero(&h,sizeof(h));
        explicit_bzero(&T1,sizeof(T1));
        explicit_bzero(&T2,sizeof(T2));
        explicit_bzero(W512,sizeof(W512));
}

#endif /* SHA2_UNROLL_TRANSFORM */

void
SHA512Update(SHA2_CTX *context, const void *dataptr, size_t len)
{
        const uint8_t *data = dataptr;
        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;
}

void
SHA512Last(SHA2_CTX *context)
{
        unsigned int    usedspace;

        usedspace = (context->bitcount[0] >> 3) % SHA512_BLOCK_LENGTH;
#if BYTE_ORDER == LITTLE_ENDIAN
        /* Convert FROM host byte order */
        context->bitcount[0] = swap64(context->bitcount[0]);
        context->bitcount[1] = swap64(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(&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): */
        *(u_int64_t *)&context->buffer[SHA512_SHORT_BLOCK_LENGTH] = context->bitcount[1];
        *(u_int64_t *)&context->buffer[SHA512_SHORT_BLOCK_LENGTH+8] = context->bitcount[0];

        /* Final transform: */
        SHA512Transform(context->state.st64, context->buffer);
}

void
SHA512Final(u_int8_t digest[], SHA2_CTX *context)
{

        SHA512Last(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++) {
                        context->state.st64[j] = swap64(context->state.st64[j]);
                }
        }
#endif
        memcpy(digest, context->state.st64, SHA512_DIGEST_LENGTH);

        /* Zero out state data */
        explicit_bzero(context, sizeof(*context));
}


/*** SHA-384: *********************************************************/
void
SHA384Init(SHA2_CTX *context)
{
        memcpy(context->state.st64, sha384_initial_hash_value,
            SHA512_DIGEST_LENGTH);
        memset(context->buffer, 0, SHA384_BLOCK_LENGTH);
        context->bitcount[0] = context->bitcount[1] = 0;
}

void
SHA384Update(SHA2_CTX *context, const void *data, size_t len)
{
        SHA512Update(context, data, len);
}

void
SHA384Final(u_int8_t digest[], SHA2_CTX *context)
{

        SHA512Last(context);

        /* Save the hash data for output: */
#if BYTE_ORDER == LITTLE_ENDIAN
        {
                /* Convert TO host byte order */
                int     j;
                for (j = 0; j < 6; j++) {
                        context->state.st64[j] = swap64(context->state.st64[j]);
                }
        }
#endif
        memcpy(digest, context->state.st64, SHA384_DIGEST_LENGTH);
        /* Zero out state data */
        explicit_bzero(context, sizeof(*context));
}
