/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * 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 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 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.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.] */

#include <openssl/sha.h>

#include <string.h>

#include <openssl/mem.h>


#if !defined(OPENSSL_NO_ASM) &&                         \
    (defined(OPENSSL_X86) || defined(OPENSSL_X86_64) || \
     defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64))
#define SHA256_ASM
#endif

int SHA224_Init(SHA256_CTX *sha) {
  memset(sha, 0, sizeof(SHA256_CTX));
  sha->h[0] = 0xc1059ed8UL;
  sha->h[1] = 0x367cd507UL;
  sha->h[2] = 0x3070dd17UL;
  sha->h[3] = 0xf70e5939UL;
  sha->h[4] = 0xffc00b31UL;
  sha->h[5] = 0x68581511UL;
  sha->h[6] = 0x64f98fa7UL;
  sha->h[7] = 0xbefa4fa4UL;
  sha->md_len = SHA224_DIGEST_LENGTH;
  return 1;
}

int SHA256_Init(SHA256_CTX *sha) {
  memset(sha, 0, sizeof(SHA256_CTX));
  sha->h[0] = 0x6a09e667UL;
  sha->h[1] = 0xbb67ae85UL;
  sha->h[2] = 0x3c6ef372UL;
  sha->h[3] = 0xa54ff53aUL;
  sha->h[4] = 0x510e527fUL;
  sha->h[5] = 0x9b05688cUL;
  sha->h[6] = 0x1f83d9abUL;
  sha->h[7] = 0x5be0cd19UL;
  sha->md_len = SHA256_DIGEST_LENGTH;
  return 1;
}

uint8_t *SHA224(const uint8_t *data, size_t len, uint8_t *out) {
  SHA256_CTX ctx;
  static uint8_t buf[SHA224_DIGEST_LENGTH];

  /* TODO(fork): remove this static buffer. */
  if (out == NULL) {
    out = buf;
  }
  SHA224_Init(&ctx);
  SHA256_Update(&ctx, data, len);
  SHA256_Final(out, &ctx);
  OPENSSL_cleanse(&ctx, sizeof(ctx));
  return out;
}

uint8_t *SHA256(const uint8_t *data, size_t len, uint8_t *out) {
  SHA256_CTX ctx;
  static uint8_t buf[SHA256_DIGEST_LENGTH];

  /* TODO(fork): remove this static buffer. */
  if (out == NULL) {
    out = buf;
  }
  SHA256_Init(&ctx);
  SHA256_Update(&ctx, data, len);
  SHA256_Final(out, &ctx);
  OPENSSL_cleanse(&ctx, sizeof(ctx));
  return out;
}

int SHA224_Update(SHA256_CTX *ctx, const void *data, size_t len) {
  return SHA256_Update(ctx, data, len);
}

int SHA224_Final(uint8_t *md, SHA256_CTX *ctx) {
  return SHA256_Final(md, ctx);
}

#define DATA_ORDER_IS_BIG_ENDIAN

#define HASH_CTX SHA256_CTX
#define HASH_CBLOCK 64

/* Note that FIPS180-2 discusses "Truncation of the Hash Function Output."
 * default: case below covers for it. It's not clear however if it's permitted
 * to truncate to amount of bytes not divisible by 4. I bet not, but if it is,
 * then default: case shall be extended. For reference. Idea behind separate
 * cases for pre-defined lenghts is to let the compiler decide if it's
 * appropriate to unroll small loops.
 *
 * TODO(davidben): The small |md_len| case is one of the few places a low-level
 * hash 'final' function can fail. This should never happen. */
#define HASH_MAKE_STRING(c, s)                              \
  do {                                                      \
    uint32_t ll;                                            \
    unsigned int nn;                                        \
    switch ((c)->md_len) {                                  \
      case SHA224_DIGEST_LENGTH:                            \
        for (nn = 0; nn < SHA224_DIGEST_LENGTH / 4; nn++) { \
          ll = (c)->h[nn];                                  \
          (void) HOST_l2c(ll, (s));                         \
        }                                                   \
        break;                                              \
      case SHA256_DIGEST_LENGTH:                            \
        for (nn = 0; nn < SHA256_DIGEST_LENGTH / 4; nn++) { \
          ll = (c)->h[nn];                                  \
          (void) HOST_l2c(ll, (s));                         \
        }                                                   \
        break;                                              \
      default:                                              \
        if ((c)->md_len > SHA256_DIGEST_LENGTH) {           \
          return 0;                                         \
        }                                                   \
        for (nn = 0; nn < (c)->md_len / 4; nn++) {          \
          ll = (c)->h[nn];                                  \
          (void) HOST_l2c(ll, (s));                         \
        }                                                   \
        break;                                              \
    }                                                       \
  } while (0)


#define HASH_UPDATE SHA256_Update
#define HASH_TRANSFORM SHA256_Transform
#define HASH_FINAL SHA256_Final
#define HASH_BLOCK_DATA_ORDER sha256_block_data_order
#ifndef SHA256_ASM
static
#endif
void sha256_block_data_order(uint32_t *state, const uint8_t *in, size_t num);

#include "../digest/md32_common.h"

#ifndef SHA256_ASM
static const uint32_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};

/* FIPS specification refers to right rotations, while our ROTATE macro
 * is left one. This is why you might notice that rotation coefficients
 * differ from those observed in FIPS document by 32-N... */
#define Sigma0(x) (ROTATE((x), 30) ^ ROTATE((x), 19) ^ ROTATE((x), 10))
#define Sigma1(x) (ROTATE((x), 26) ^ ROTATE((x), 21) ^ ROTATE((x), 7))
#define sigma0(x) (ROTATE((x), 25) ^ ROTATE((x), 14) ^ ((x) >> 3))
#define sigma1(x) (ROTATE((x), 15) ^ ROTATE((x), 13) ^ ((x) >> 10))

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

#define ROUND_00_15(i, a, b, c, d, e, f, g, h)   \
  do {                                           \
    T1 += h + Sigma1(e) + Ch(e, f, g) + K256[i]; \
    h = Sigma0(a) + Maj(a, b, c);                \
    d += T1;                                     \
    h += T1;                                     \
  } while (0)

#define ROUND_16_63(i, a, b, c, d, e, f, g, h, X)      \
  do {                                                 \
    s0 = X[(i + 1) & 0x0f];                            \
    s0 = sigma0(s0);                                   \
    s1 = X[(i + 14) & 0x0f];                           \
    s1 = sigma1(s1);                                   \
    T1 = X[(i) & 0x0f] += s0 + s1 + X[(i + 9) & 0x0f]; \
    ROUND_00_15(i, a, b, c, d, e, f, g, h);            \
  } while (0)

static void sha256_block_data_order(uint32_t *state, const uint8_t *data,
                                    size_t num) {
  uint32_t a, b, c, d, e, f, g, h, s0, s1, T1;
  uint32_t X[16];
  int i;

  while (num--) {
    a = state[0];
    b = state[1];
    c = state[2];
    d = state[3];
    e = state[4];
    f = state[5];
    g = state[6];
    h = state[7];

    uint32_t l;

    HOST_c2l(data, l);
    T1 = X[0] = l;
    ROUND_00_15(0, a, b, c, d, e, f, g, h);
    HOST_c2l(data, l);
    T1 = X[1] = l;
    ROUND_00_15(1, h, a, b, c, d, e, f, g);
    HOST_c2l(data, l);
    T1 = X[2] = l;
    ROUND_00_15(2, g, h, a, b, c, d, e, f);
    HOST_c2l(data, l);
    T1 = X[3] = l;
    ROUND_00_15(3, f, g, h, a, b, c, d, e);
    HOST_c2l(data, l);
    T1 = X[4] = l;
    ROUND_00_15(4, e, f, g, h, a, b, c, d);
    HOST_c2l(data, l);
    T1 = X[5] = l;
    ROUND_00_15(5, d, e, f, g, h, a, b, c);
    HOST_c2l(data, l);
    T1 = X[6] = l;
    ROUND_00_15(6, c, d, e, f, g, h, a, b);
    HOST_c2l(data, l);
    T1 = X[7] = l;
    ROUND_00_15(7, b, c, d, e, f, g, h, a);
    HOST_c2l(data, l);
    T1 = X[8] = l;
    ROUND_00_15(8, a, b, c, d, e, f, g, h);
    HOST_c2l(data, l);
    T1 = X[9] = l;
    ROUND_00_15(9, h, a, b, c, d, e, f, g);
    HOST_c2l(data, l);
    T1 = X[10] = l;
    ROUND_00_15(10, g, h, a, b, c, d, e, f);
    HOST_c2l(data, l);
    T1 = X[11] = l;
    ROUND_00_15(11, f, g, h, a, b, c, d, e);
    HOST_c2l(data, l);
    T1 = X[12] = l;
    ROUND_00_15(12, e, f, g, h, a, b, c, d);
    HOST_c2l(data, l);
    T1 = X[13] = l;
    ROUND_00_15(13, d, e, f, g, h, a, b, c);
    HOST_c2l(data, l);
    T1 = X[14] = l;
    ROUND_00_15(14, c, d, e, f, g, h, a, b);
    HOST_c2l(data, l);
    T1 = X[15] = l;
    ROUND_00_15(15, b, c, d, e, f, g, h, a);

    for (i = 16; i < 64; i += 8) {
      ROUND_16_63(i + 0, a, b, c, d, e, f, g, h, X);
      ROUND_16_63(i + 1, h, a, b, c, d, e, f, g, X);
      ROUND_16_63(i + 2, g, h, a, b, c, d, e, f, X);
      ROUND_16_63(i + 3, f, g, h, a, b, c, d, e, X);
      ROUND_16_63(i + 4, e, f, g, h, a, b, c, d, X);
      ROUND_16_63(i + 5, d, e, f, g, h, a, b, c, X);
      ROUND_16_63(i + 6, c, d, e, f, g, h, a, b, X);
      ROUND_16_63(i + 7, b, c, d, e, f, g, h, a, X);
    }

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

#endif /* SHA256_ASM */