// SPDX-License-Identifier: BSD-2-Clause
/*
 * Copyright (c) 2015, Linaro Limited
 * All rights reserved.
 * Copyright (c) 2001-2007, Tom St Denis
 * 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 THE COPYRIGHT HOLDERS AND 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 THE COPYRIGHT HOLDER 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.
 */

/* LibTomCrypt, modular cryptographic library -- Tom St Denis
 *
 * LibTomCrypt is a library that provides various cryptographic
 * algorithms in a highly modular and flexible manner.
 *
 * The library is free for all purposes without any express
 * guarantee it works.
 *
 * Tom St Denis, tomstdenis@gmail.com, http://libtom.org
 */
#include <crypto/crypto_accel.h>
#include <tomcrypt_private.h>

#ifdef LTC_SHA256

const struct ltc_hash_descriptor sha256_desc =
{
    "sha256",
    0,
    32,
    64,

    /* OID */
   { 2, 16, 840, 1, 101, 3, 4, 2, 1,  },
   9,

    &sha256_init,
    &sha256_process,
    &sha256_done,
    &sha256_test,
    NULL
};


/* Implemented in assembly */
int sha256_ce_transform(ulong32 *state, const unsigned char *buf, int blocks);

static int sha256_compress_nblocks(hash_state *md, const unsigned char *buf,
				   int blocks)
{
   void *state = md->sha256.state;

   COMPILE_TIME_ASSERT(sizeof(md->sha256.state[0]) == sizeof(uint32_t));

    crypto_accel_sha256_compress(state, buf, blocks);
    return CRYPT_OK;
}

static int sha256_compress(hash_state *md, const unsigned char *buf)
{
   return sha256_compress_nblocks(md, buf, 1);
}

/**
   Initialize the hash state
   @param md   The hash state you wish to initialize
   @return CRYPT_OK if successful
*/
int sha256_init(hash_state * md)
{
    LTC_ARGCHK(md != NULL);

    md->sha256.curlen = 0;
    md->sha256.length = 0;
    md->sha256.state[0] = 0x6A09E667UL;
    md->sha256.state[1] = 0xBB67AE85UL;
    md->sha256.state[2] = 0x3C6EF372UL;
    md->sha256.state[3] = 0xA54FF53AUL;
    md->sha256.state[4] = 0x510E527FUL;
    md->sha256.state[5] = 0x9B05688CUL;
    md->sha256.state[6] = 0x1F83D9ABUL;
    md->sha256.state[7] = 0x5BE0CD19UL;
    return CRYPT_OK;
}

/**
   Process a block of memory though the hash
   @param md     The hash state
   @param in     The data to hash
   @param inlen  The length of the data (octets)
   @return CRYPT_OK if successful
*/
HASH_PROCESS_NBLOCKS(sha256_process, sha256_compress_nblocks, sha256, 64)

/**
   Terminate the hash to get the digest
   @param md  The hash state
   @param out [out] The destination of the hash (32 bytes)
   @return CRYPT_OK if successful
*/
int sha256_done(hash_state * md, unsigned char *out)
{
    int i;

    LTC_ARGCHK(md  != NULL);
    LTC_ARGCHK(out != NULL);

    if (md->sha256.curlen >= sizeof(md->sha256.buf)) {
       return CRYPT_INVALID_ARG;
    }


    /* increase the length of the message */
    md->sha256.length += md->sha256.curlen * 8;

    /* append the '1' bit */
    md->sha256.buf[md->sha256.curlen++] = (unsigned char)0x80;

    /* if the length is currently above 56 bytes we append zeros
     * then compress.  Then we can fall back to padding zeros and length
     * encoding like normal.
     */
    if (md->sha256.curlen > 56) {
        while (md->sha256.curlen < 64) {
            md->sha256.buf[md->sha256.curlen++] = (unsigned char)0;
        }
        sha256_compress(md, md->sha256.buf);
        md->sha256.curlen = 0;
    }

    /* pad upto 56 bytes of zeroes */
    while (md->sha256.curlen < 56) {
        md->sha256.buf[md->sha256.curlen++] = (unsigned char)0;
    }

    /* store length */
    STORE64H(md->sha256.length, md->sha256.buf+56);
    sha256_compress(md, md->sha256.buf);

    /* copy output */
    for (i = 0; i < 8; i++) {
        STORE32H(md->sha256.state[i], out+(4*i));
    }
#ifdef LTC_CLEAN_STACK
    zeromem(md, sizeof(hash_state));
#endif
    return CRYPT_OK;
}

/**
  Self-test the hash
  @return CRYPT_OK if successful, CRYPT_NOP if self-tests have been disabled
*/
int  sha256_test(void)
{
 #ifndef LTC_TEST
    return CRYPT_NOP;
 #else
  static const struct {
      const char *msg;
      unsigned char hash[32];
  } tests[] = {
    { "abc",
      { 0xba, 0x78, 0x16, 0xbf, 0x8f, 0x01, 0xcf, 0xea,
        0x41, 0x41, 0x40, 0xde, 0x5d, 0xae, 0x22, 0x23,
        0xb0, 0x03, 0x61, 0xa3, 0x96, 0x17, 0x7a, 0x9c,
        0xb4, 0x10, 0xff, 0x61, 0xf2, 0x00, 0x15, 0xad }
    },
    { "abcdbcdecdefdefgefghfghighijhijkijkljklmklmnlmnomnopnopq",
      { 0x24, 0x8d, 0x6a, 0x61, 0xd2, 0x06, 0x38, 0xb8,
        0xe5, 0xc0, 0x26, 0x93, 0x0c, 0x3e, 0x60, 0x39,
        0xa3, 0x3c, 0xe4, 0x59, 0x64, 0xff, 0x21, 0x67,
        0xf6, 0xec, 0xed, 0xd4, 0x19, 0xdb, 0x06, 0xc1 }
    },
  };

  int i;
  unsigned char tmp[32];
  hash_state md;

  for (i = 0; i < (int)(sizeof(tests) / sizeof(tests[0])); i++) {
      sha256_init(&md);
      sha256_process(&md, (unsigned char*)tests[i].msg, (unsigned long)strlen(tests[i].msg));
      sha256_done(&md, tmp);
      if (XMEMCMP(tmp, tests[i].hash, 32) != 0) {
         return CRYPT_FAIL_TESTVECTOR;
      }
  }
  return CRYPT_OK;
 #endif
}

#endif /*LTC_SHA256*/