/*

 * Copyright (C) 2019 Frank Morgner <frankmorgner@gmail.com>

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Lesser General Public

 * License as published by the Free Software Foundation; either

 * version 2.1 of the License, or (at your option) any later version.

 *

 * This library is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

 * Lesser General Public License for more details.

 *

 * You should have received a copy of the GNU Lesser General Public

 * License along with this library; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "fuzzer_reader.h"

#include "libopensc/pkcs15.h"

#include "libopensc/internal.h"

uint16_t fuzz_get_buffer(const uint8_t **buf, size_t buf_len, const uint8_t **out, size_t *out_len)

{

  uint16_t len = 0;

  if (!buf || !(*buf) || buf_len < 2)

    return 0;

  /* Get length of the result buffer*/

  len = *((uint16_t *) *buf);

  if (buf_len - 2 <= len)

    return 0;

  (*buf) += 2;

  buf_len -= 2;

  /* Set out buffer to new reader data*/

  *out = *buf + len;

  *out_len = buf_len - len;

  return len;

}

int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size)

{

  size_t i = 0;

  struct sc_reader *reader = NULL;

  const uint8_t *buf = Data, *reader_data = NULL;

  uint16_t buf_len = 0;

  size_t reader_data_len = 0;

  struct sc_context *ctx = NULL;

  struct sc_pkcs15_card *p15card = NULL;

  sc_card_t *card = NULL;

  struct sc_pkcs15_tokeninfo *tokeninfo = NULL;

  int (* decode_entries[])(struct sc_pkcs15_card *, struct sc_pkcs15_object *,

      const u8 **nbuf, size_t *nbufsize) = {

    sc_pkcs15_decode_prkdf_entry, sc_pkcs15_decode_pukdf_entry,

    sc_pkcs15_decode_skdf_entry, sc_pkcs15_decode_cdf_entry,

    sc_pkcs15_decode_dodf_entry, sc_pkcs15_decode_aodf_entry

  };

  int algorithms[] = { SC_ALGORITHM_RSA, SC_ALGORITHM_EC, SC_ALGORITHM_GOSTR3410, SC_ALGORITHM_EDDSA };

  /* Split data into testing buffer and APDU for connecting */

  if ((buf_len = fuzz_get_buffer(&buf, Size, &reader_data, &reader_data_len)) == 0)

    return 0;

  /* Establish context for fuzz app*/

  sc_establish_context(&ctx, "fuzz");

  if (!ctx)

    return 0;

  if (fuzz_connect_card(ctx, &card, &reader, reader_data, reader_data_len) != SC_SUCCESS)

    goto err;

  sc_pkcs15_bind(card, NULL, &p15card);

  if (!p15card)

    goto err;

  for (i = 0; i < sizeof decode_entries/sizeof *decode_entries; i++) {

    struct sc_pkcs15_object *obj;

    const u8 *p = buf;

    size_t len = (size_t) buf_len;

    if (!(obj = calloc(1, sizeof *obj)))

      goto err;

    while (SC_SUCCESS == decode_entries[i](p15card, obj, &p, &len)) {

      sc_pkcs15_free_object(obj);

      if (!(obj = calloc(1, sizeof *obj)))

        goto err;

    }

    sc_pkcs15_free_object(obj);

  }

  for (i = 0; i < 4; i++) {

    struct sc_pkcs15_pubkey *pubkey = calloc(1, sizeof *pubkey);

    if (!pubkey)

      goto err;

    pubkey->algorithm = algorithms[i];

    sc_pkcs15_decode_pubkey(ctx, pubkey, buf, buf_len);

    sc_pkcs15_free_pubkey(pubkey);

  }

  tokeninfo = sc_pkcs15_tokeninfo_new();

  sc_pkcs15_parse_tokeninfo(ctx, tokeninfo, buf, buf_len);

  sc_pkcs15_free_tokeninfo(tokeninfo);

  sc_pkcs15_parse_unusedspace(buf, buf_len, p15card);

err:

  sc_pkcs15_card_free(p15card);

  sc_disconnect_card(card);

  sc_release_context(ctx);

  return 0;

}