/*-
 * Copyright (c) 2014-2015 Carsten Larsen
 * Copyright (c) 2001-2003 Allan Saddi <allan@saddi.com>
 * 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.
 *
 * THIS SOFTWARE IS PROVIDED BY ALLAN SADDI AND HIS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL ALLAN SADDI OR HIS CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 */

/*
 * Define WORDS_BIGENDIAN if compiling on a big-endian architecture.
 *
 * Define SHA384_TEST to test the implementation using the NIST's
 * sample messages. The output should be:
 *
 *   cb00753f45a35e8b b5a03d699ac65007 272c32ab0eded163 1a8b605a43ff5bed
 *   8086072ba1e7cc23 58baeca134c825a7
 *   09330c33f71147e8 3d192fc782cd1b47 53111b173b3b05d2 2fa08086e3b0f712
 *   fcc7c71a557e2db9 66c3e9fa91746039
 *   9d0e1809716474cb 086e834e310a4a1c ed149e9c00f24852 7972cec5704c2a5b
 *   07b8b3dc38ecc4eb ae97ddd87f3d8985
 */

#include "compiler.h"
#include "sha384.h"

#define ROTL(x, n) (((x) << (n)) | ((x) >> (32 - (n))))
#define ROTR(x, n) (((x) >> (n)) | ((x) << (32 - (n))))
#define ROTL64(x, n) (((x) << (n)) | ((x) >> (64 - (n))))
#define ROTR64(x, n) (((x) >> (n)) | ((x) << (64 - (n))))

#define Ch(x, y, z) ((z) ^ ((x) & ((y) ^ (z))))
#define Maj(x, y, z) (((x) & ((y) | (z))) | ((y) & (z)))
#define SIGMA0(x) (ROTR64((x), 28) ^ ROTR64((x), 34) ^ ROTR64((x), 39))
#define SIGMA1(x) (ROTR64((x), 14) ^ ROTR64((x), 18) ^ ROTR64((x), 41))
#define sigma0(x) (ROTR64((x), 1) ^ ROTR64((x), 8) ^ ((x) >> 7))
#define sigma1(x) (ROTR64((x), 19) ^ ROTR64((x), 61) ^ ((x) >> 6))

#define DO_ROUND() { \
  t1 = h + SIGMA1(e) + Ch(e, f, g) + *(Kp++) + *(W++); \
  t2 = SIGMA0(a) + Maj(a, b, c); \
  h = g; \
  g = f; \
  f = e; \
  e = d + t1; \
  d = c; \
  c = b; \
  b = a; \
  a = t1 + t2; \
}

static const uint64_t K[80] = {
    0x428a2f98d728ae22LL, 0x7137449123ef65cdLL,
    0xb5c0fbcfec4d3b2fLL, 0xe9b5dba58189dbbcLL,
    0x3956c25bf348b538LL, 0x59f111f1b605d019LL,
    0x923f82a4af194f9bLL, 0xab1c5ed5da6d8118LL,
    0xd807aa98a3030242LL, 0x12835b0145706fbeLL,
    0x243185be4ee4b28cLL, 0x550c7dc3d5ffb4e2LL,
    0x72be5d74f27b896fLL, 0x80deb1fe3b1696b1LL,
    0x9bdc06a725c71235LL, 0xc19bf174cf692694LL,
    0xe49b69c19ef14ad2LL, 0xefbe4786384f25e3LL,
    0x0fc19dc68b8cd5b5LL, 0x240ca1cc77ac9c65LL,
    0x2de92c6f592b0275LL, 0x4a7484aa6ea6e483LL,
    0x5cb0a9dcbd41fbd4LL, 0x76f988da831153b5LL,
    0x983e5152ee66dfabLL, 0xa831c66d2db43210LL,
    0xb00327c898fb213fLL, 0xbf597fc7beef0ee4LL,
    0xc6e00bf33da88fc2LL, 0xd5a79147930aa725LL,
    0x06ca6351e003826fLL, 0x142929670a0e6e70LL,
    0x27b70a8546d22ffcLL, 0x2e1b21385c26c926LL,
    0x4d2c6dfc5ac42aedLL, 0x53380d139d95b3dfLL,
    0x650a73548baf63deLL, 0x766a0abb3c77b2a8LL,
    0x81c2c92e47edaee6LL, 0x92722c851482353bLL,
    0xa2bfe8a14cf10364LL, 0xa81a664bbc423001LL,
    0xc24b8b70d0f89791LL, 0xc76c51a30654be30LL,
    0xd192e819d6ef5218LL, 0xd69906245565a910LL,
    0xf40e35855771202aLL, 0x106aa07032bbd1b8LL,
    0x19a4c116b8d2d0c8LL, 0x1e376c085141ab53LL,
    0x2748774cdf8eeb99LL, 0x34b0bcb5e19b48a8LL,
    0x391c0cb3c5c95a63LL, 0x4ed8aa4ae3418acbLL,
    0x5b9cca4f7763e373LL, 0x682e6ff3d6b2b8a3LL,
    0x748f82ee5defb2fcLL, 0x78a5636f43172f60LL,
    0x84c87814a1f0ab72LL, 0x8cc702081a6439ecLL,
    0x90befffa23631e28LL, 0xa4506cebde82bde9LL,
    0xbef9a3f7b2c67915LL, 0xc67178f2e372532bLL,
    0xca273eceea26619cLL, 0xd186b8c721c0c207LL,
    0xeada7dd6cde0eb1eLL, 0xf57d4f7fee6ed178LL,
    0x06f067aa72176fbaLL, 0x0a637dc5a2c898a6LL,
    0x113f9804bef90daeLL, 0x1b710b35131c471bLL,
    0x28db77f523047d84LL, 0x32caab7b40c72493LL,
    0x3c9ebe0a15c9bebcLL, 0x431d67c49c100d4cLL,
    0x4cc5d4becb3e42b6LL, 0x597f299cfc657e2aLL,
    0x5fcb6fab3ad6faecLL, 0x6c44198c4a475817LL
};

#ifndef RUNTIME_ENDIAN

#ifdef WORDS_BIGENDIAN

#define BYTESWAP(x) (x)
#define BYTESWAP64(x) (x)

#else /* WORDS_BIGENDIAN */

#define BYTESWAP(x) ((ROTR((x), 8) & 0xff00ff00L) | \
		     (ROTL((x), 8) & 0x00ff00ffL))
#define BYTESWAP64(x) _byteswap64(x)

static inline uint64_t _byteswap64(uint64_t x)
{
    uint32_t a = x >> 32;
    uint32_t b = (uint32_t) x;
    return ((uint64_t) BYTESWAP(b) << 32) | (uint64_t) BYTESWAP(a);
}

#endif /* WORDS_BIGENDIAN */

#else /* !RUNTIME_ENDIAN */

#define BYTESWAP(x) _byteswap(sc->littleEndian, x)
#define BYTESWAP64(x) _byteswap64(sc->littleEndian, x)

#define _BYTESWAP(x) ((ROTR((x), 8) & 0xff00ff00L) | \
		      (ROTL((x), 8) & 0x00ff00ffL))
#define _BYTESWAP64(x) __byteswap64(x)

static inline uint64_t __byteswap64(uint64_t x)
{
    uint32_t a = x >> 32;
    uint32_t b = (uint32_t) x;
    return ((uint64_t) _BYTESWAP(b) << 32) | (uint64_t) _BYTESWAP(a);
}

static inline uint32_t _byteswap(int littleEndian, uint32_t x)
{
    if (!littleEndian)
        return x;
    else
        return _BYTESWAP(x);
}

static inline uint64_t _byteswap64(int littleEndian, uint64_t x)
{
    if (!littleEndian)
        return x;
    else
        return _BYTESWAP64(x);
}

static inline void setEndian(int *littleEndianp)
{
    union {
        uint32_t w;
        uint8_t b[4];
    } endian;

    endian.w = 1L;
    *littleEndianp = endian.b[0] != 0;
}

#endif /* !RUNTIME_ENDIAN */

static const uint8_t padding[128] = {
    0x80, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
    0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
};

void
SHA384Init (SHA384Context *sc)
{
#ifdef RUNTIME_ENDIAN
    setEndian (&sc->littleEndian);
#endif /* RUNTIME_ENDIAN */

    sc->totalLength[0] = 0LL;
    sc->totalLength[1] = 0LL;
    sc->hash[0] = 0xcbbb9d5dc1059ed8LL;
    sc->hash[1] = 0x629a292a367cd507LL;
    sc->hash[2] = 0x9159015a3070dd17LL;
    sc->hash[3] = 0x152fecd8f70e5939LL;
    sc->hash[4] = 0x67332667ffc00b31LL;
    sc->hash[5] = 0x8eb44a8768581511LL;
    sc->hash[6] = 0xdb0c2e0d64f98fa7LL;
    sc->hash[7] = 0x47b5481dbefa4fa4LL;
    sc->bufferLength = 0L;
}

static void
burnStack (int size)
{
    char buf[128];

    memset (buf, 0, sizeof (buf));
    size -= sizeof (buf);
    if (size > 0)
        burnStack (size);
}

static void
SHA384Guts (SHA384Context *sc, const uint64_t *cbuf)
{
    uint64_t buf[80];
    uint64_t *W, *W2, *W7, *W15, *W16;
    uint64_t a, b, c, d, e, f, g, h;
    uint64_t t1, t2;
    const uint64_t *Kp;
    int i;

    W = buf;

    for (i = 15; i >= 0; i--) {
        *(W++) = BYTESWAP64(*cbuf);
        cbuf++;
    }

    W16 = &buf[0];
    W15 = &buf[1];
    W7 = &buf[9];
    W2 = &buf[14];

    for (i = 63; i >= 0; i--) {
        *(W++) = sigma1(*W2) + *(W7++) + sigma0(*W15) + *(W16++);
        W2++;
        W15++;
    }

    a = sc->hash[0];
    b = sc->hash[1];
    c = sc->hash[2];
    d = sc->hash[3];
    e = sc->hash[4];
    f = sc->hash[5];
    g = sc->hash[6];
    h = sc->hash[7];

    Kp = K;
    W = buf;

    for (i = 79; i >= 0; i--)
        DO_ROUND();

    sc->hash[0] += a;
    sc->hash[1] += b;
    sc->hash[2] += c;
    sc->hash[3] += d;
    sc->hash[4] += e;
    sc->hash[5] += f;
    sc->hash[6] += g;
    sc->hash[7] += h;
}

void
SHA384Update (SHA384Context *sc, const void *vdata, uint32_t len)
{
    const uint8_t *data = vdata;
    uint32_t bufferBytesLeft;
    uint32_t bytesToCopy;
    uint64_t carryCheck;
    int needBurn = 0;

#ifdef SHA384_FAST_COPY
    if (sc->bufferLength) {
        bufferBytesLeft = 128L - sc->bufferLength;

        bytesToCopy = bufferBytesLeft;
        if (bytesToCopy > len)
            bytesToCopy = len;

        memcpy (&sc->buffer.bytes[sc->bufferLength], data, bytesToCopy);

        carryCheck = sc->totalLength[1];
        sc->totalLength[1] += bytesToCopy * 8L;
        if (sc->totalLength[1] < carryCheck)
            sc->totalLength[0]++;

        sc->bufferLength += bytesToCopy;
        data += bytesToCopy;
        len -= bytesToCopy;

        if (sc->bufferLength == 128L) {
            SHA384Guts (sc, sc->buffer.words);
            needBurn = 1;
            sc->bufferLength = 0L;
        }
    }

    while (len > 127) {
        carryCheck = sc->totalLength[1];
        sc->totalLength[1] += 1024L;
        if (sc->totalLength[1] < carryCheck)
            sc->totalLength[0]++;

        SHA384Guts (sc, data);
        needBurn = 1;

        data += 128L;
        len -= 128L;
    }

    if (len) {
        memcpy (&sc->buffer.bytes[sc->bufferLength], data, len);

        carryCheck = sc->totalLength[1];
        sc->totalLength[1] += len * 8L;
        if (sc->totalLength[1] < carryCheck)
            sc->totalLength[0]++;

        sc->bufferLength += len;
    }
#else /* SHA384_FAST_COPY */
    while (len) {
        bufferBytesLeft = 128L - sc->bufferLength;

        bytesToCopy = bufferBytesLeft;
        if (bytesToCopy > len)
            bytesToCopy = len;

        memcpy (&sc->buffer.bytes[sc->bufferLength], data, bytesToCopy);

        carryCheck = sc->totalLength[1];
        sc->totalLength[1] += bytesToCopy * 8L;
        if (sc->totalLength[1] < carryCheck)
            sc->totalLength[0]++;

        sc->bufferLength += bytesToCopy;
        data += bytesToCopy;
        len -= bytesToCopy;

        if (sc->bufferLength == 128L) {
            SHA384Guts (sc, sc->buffer.words);
            needBurn = 1;
            sc->bufferLength = 0L;
        }
    }
#endif /* SHA384_FAST_COPY */

    if (needBurn)
        burnStack (sizeof (uint64_t[90]) + sizeof (uint64_t *[6]) + sizeof (int));
}

void
SHA384Final (SHA384Context *sc, uint8_t hash[SHA384_HASH_SIZE])
{
    uint32_t bytesToPad;
    uint64_t lengthPad[2];
    int i;

    bytesToPad = 240L - sc->bufferLength;
    if (bytesToPad > 128L)
        bytesToPad -= 128L;

    lengthPad[0] = BYTESWAP64(sc->totalLength[0]);
    lengthPad[1] = BYTESWAP64(sc->totalLength[1]);

    SHA384Update (sc, padding, bytesToPad);
    SHA384Update (sc, lengthPad, 16L);

    if (hash) {
        for (i = 0; i < SHA384_HASH_WORDS; i++) {
#ifdef SHA384_FAST_COPY
            *((uint64_t *) hash) = BYTESWAP64(sc->hash[i]);
#else /* SHA384_FAST_COPY */
            hash[0] = (uint8_t) (sc->hash[i] >> 56);
            hash[1] = (uint8_t) (sc->hash[i] >> 48);
            hash[2] = (uint8_t) (sc->hash[i] >> 40);
            hash[3] = (uint8_t) (sc->hash[i] >> 32);
            hash[4] = (uint8_t) (sc->hash[i] >> 24);
            hash[5] = (uint8_t) (sc->hash[i] >> 16);
            hash[6] = (uint8_t) (sc->hash[i] >> 8);
            hash[7] = (uint8_t) sc->hash[i];
#endif /* SHA384_FAST_COPY */
            hash += 8;
        }
    }
}

#ifdef SHA384_TEST

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

int
main (int argc, char *argv[])
{
    SHA384Context foo;
    uint8_t hash[SHA384_HASH_SIZE];
    char buf[1000];
    int i;

    SHA384Init (&foo);
    SHA384Update (&foo, "abc", 3);
    SHA384Final (&foo, hash);

    for (i = 0; i < SHA384_HASH_SIZE;) {
        printf ("%02x", hash[i++]);
        if (!(i % 8))
            printf (" ");
        if (!(i % 32))
            printf ("\n");
    }
    printf ("\n");

    SHA384Init (&foo);
    SHA384Update (&foo,
                  "abcdefghbcdefghicdefghijdefghijkefghijklfghijklmghijklmn"
                  "hijklmnoijklmnopjklmnopqklmnopqrlmnopqrsmnopqrstnopqrstu",
                  112);
    SHA384Final (&foo, hash);

    for (i = 0; i < SHA384_HASH_SIZE;) {
        printf ("%02x", hash[i++]);
        if (!(i % 8))
            printf (" ");
        if (!(i % 32))
            printf ("\n");
    }
    printf ("\n");

    SHA384Init (&foo);
    memset (buf, 'a', sizeof (buf));
    for (i = 0; i < 1000; i++)
        SHA384Update (&foo, buf, sizeof (buf));
    SHA384Final (&foo, hash);

    for (i = 0; i < SHA384_HASH_SIZE;) {
        printf ("%02x", hash[i++]);
        if (!(i % 8))
            printf (" ");
        if (!(i % 32))
            printf ("\n");
    }
    printf ("\n");

    exit (0);
}

#endif /* SHA384_TEST */