/* GOST 28147-89 (Magma) implementation

 *

 * Copyright: 2015, 2016 Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

 * Copyright: 2009-2012 Aleksey Kravchenko <rhash.admin@gmail.com>

 *

 * Permission is hereby granted, free of charge, to any person obtaining a

 * copy of this software and associated documentation files (the

 * "Software"), to deal in the Software without restriction, including

 * without limitation the rights to use, copy, modify, merge, publish,

 * distribute, sublicense, and/or sell copies of the Software, and to

 * permit persons to whom the Software is furnished to do so, subject to

 * the following conditions:

 *

 * The above copyright notice and this permission notice shall be included

 * in all copies or substantial portions of the Software.

 *

 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS

 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF

 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.

 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY

 * CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,

 * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE

 * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

 */

#if HAVE_CONFIG_H

#include "config.h"

#endif

#include "gnutls_int.h"

#include <string.h>

#include <nettle/macros.h>

#include "gost28147.h"

#include <nettle/cfb.h>

#include <nettle/memops.h>

void gost28147_kdf_cryptopro(const struct gost28147_param *param,

           const uint8_t *in, const uint8_t *ukm,

           uint8_t *out)

{

  struct gost28147_ctx ctx;

  int i;

  memcpy(out, in, GOST28147_KEY_SIZE);

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

    uint8_t mask;

    uint8_t *p;

    uint8_t iv[GOST28147_BLOCK_SIZE];

    uint32_t block[2] = { 0, 0 };

    uint32_t t;

    for (p = out, mask = 1; mask; mask <<= 1) {

      t = LE_READ_UINT32(p);

      p += 4;

      if (mask & ukm[i])

        block[0] += t;

      else

        block[1] += t;

    }

    LE_WRITE_UINT32(iv + 0, block[0]);

    LE_WRITE_UINT32(iv + 4, block[1]);

    gost28147_set_key(&ctx, out);

    gost28147_set_param(&ctx, param);

    cfb_encrypt(&ctx,

          (nettle_cipher_func *)gost28147_encrypt_for_cfb,

          GOST28147_BLOCK_SIZE, iv, GOST28147_KEY_SIZE, out,

          out);

  }

}

void gost28147_key_wrap_cryptopro(const struct gost28147_param *param,

          const uint8_t *kek, const uint8_t *ukm,

          size_t ukm_size, const uint8_t *cek,

          uint8_t *enc, uint8_t *imit)

{

  uint8_t kd[GOST28147_KEY_SIZE];

  struct gost28147_ctx ctx;

  struct gost28147_imit_ctx ictx;

  assert(ukm_size >= GOST28147_IMIT_BLOCK_SIZE);

  gost28147_kdf_cryptopro(param, kek, ukm, kd);

  gost28147_set_key(&ctx, kd);

  gost28147_set_param(&ctx, param);

  gost28147_encrypt(&ctx, GOST28147_KEY_SIZE, enc, cek);

  gost28147_imit_set_key(&ictx, GOST28147_KEY_SIZE, kd);

  gost28147_imit_set_param(&ictx, param);

  gost28147_imit_set_nonce(&ictx, ukm);

  gost28147_imit_update(&ictx, GOST28147_KEY_SIZE, cek);

  gost28147_imit_digest(&ictx, GOST28147_IMIT_DIGEST_SIZE, imit);

}

int gost28147_key_unwrap_cryptopro(const struct gost28147_param *param,

           const uint8_t *kek, const uint8_t *ukm,

           size_t ukm_size, const uint8_t *enc,

           const uint8_t *imit, uint8_t *cek)

{

  uint8_t kd[GOST28147_KEY_SIZE];

  uint8_t mac[GOST28147_IMIT_DIGEST_SIZE];

  struct gost28147_ctx ctx;

  struct gost28147_imit_ctx ictx;

  assert(ukm_size >= GOST28147_IMIT_BLOCK_SIZE);

  gost28147_kdf_cryptopro(param, kek, ukm, kd);

  gost28147_set_key(&ctx, kd);

  gost28147_set_param(&ctx, param);

  gost28147_decrypt(&ctx, GOST28147_KEY_SIZE, cek, enc);

  gost28147_imit_set_key(&ictx, GOST28147_KEY_SIZE, kd);

  gost28147_imit_set_param(&ictx, param);

  gost28147_imit_set_nonce(&ictx, ukm);

  gost28147_imit_update(&ictx, GOST28147_KEY_SIZE, cek);

  gost28147_imit_digest(&ictx, GOST28147_IMIT_DIGEST_SIZE, mac);

  return memeql_sec(mac, imit, GOST28147_IMIT_DIGEST_SIZE);

}