/*

 * Copyright © 2014 Nikos Mavrogiannopoulos

 *

 * Author: Nikos Mavrogiannopoulos

 *

 * GnuTLS 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 program.  If not, see <https://www.gnu.org/licenses/>

 *

 */

#include "gnutls_int.h"

#include "errors.h"

#include "str.h"

#include "urls.h"

#include "system-keys.h"

#include <c-strcase.h>

#define MAX_CUSTOM_URLS 8

gnutls_custom_url_st _gnutls_custom_urls[MAX_CUSTOM_URLS];

unsigned _gnutls_custom_urls_size = 0;

/**

 * gnutls_url_is_supported:

 * @url: A URI to be tested

 *

 * Check whether the provided @url is supported.  Depending on the system libraries

 * GnuTLS may support pkcs11, tpmkey or other URLs.

 *

 * Returns: return non-zero if the given URL is supported, and zero if

 * it is not known.

 *

 * Since: 3.1.0

 **/

unsigned gnutls_url_is_supported(const char *url)

{

  unsigned i;

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

    if (c_strncasecmp(url, _gnutls_custom_urls[i].name,

          _gnutls_custom_urls[i].name_size) == 0)

      return 1;

  }

#ifdef ENABLE_PKCS11

  if (c_strncasecmp(url, PKCS11_URL, sizeof(PKCS11_URL) - 1) == 0)

    return 1;

#endif

#ifdef HAVE_TROUSERS

  if (c_strncasecmp(url, TPMKEY_URL, sizeof(TPMKEY_URL) - 1) == 0)

    return 1;

#endif

  if (c_strncasecmp(url, SYSTEM_URL, sizeof(SYSTEM_URL) - 1) == 0)

    return _gnutls_system_url_is_supported(url);

  return 0;

}

int _gnutls_url_is_known(const char *url)

{

  unsigned i;

  if (c_strncasecmp(url, PKCS11_URL, sizeof(PKCS11_URL) - 1) == 0)

    return 1;

  else if (c_strncasecmp(url, TPMKEY_URL, sizeof(TPMKEY_URL) - 1) == 0)

    return 1;

  else if (c_strncasecmp(url, SYSTEM_URL, sizeof(SYSTEM_URL) - 1) == 0)

    return 1;

  else {

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

      if (c_strncasecmp(url, _gnutls_custom_urls[i].name,

            _gnutls_custom_urls[i].name_size) ==

          0)

        return 1;

    }

    return 0;

  }

}

/**

 * gnutls_register_custom_url:

 * @st: A %gnutls_custom_url_st structure

 *

 * Register a custom URL. This will affect the following functions:

 * gnutls_url_is_supported(), gnutls_privkey_import_url(),

 * gnutls_pubkey_import_url, gnutls_x509_crt_import_url() 

 * and all functions that depend on

 * them, e.g., gnutls_certificate_set_x509_key_file2().

 *

 * The provided structure and callback functions must be valid throughout

 * the lifetime of the process. The registration of an existing URL type

 * will fail with %GNUTLS_E_INVALID_REQUEST. Since GnuTLS 3.5.0 this function

 * can be used to override the builtin URLs.

 *

 * This function is not thread safe.

 *

 * Returns: returns zero if the given structure was imported or a negative value otherwise.

 *

 * Since: 3.4.0

 **/

int gnutls_register_custom_url(const gnutls_custom_url_st *st)

{

  unsigned i;

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

    if (_gnutls_custom_urls[i].name_size == st->name_size &&

        strcmp(_gnutls_custom_urls[i].name, st->name) == 0) {

      return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);

    }

  }

  if (_gnutls_custom_urls_size < MAX_CUSTOM_URLS - 1) {

    memcpy(&_gnutls_custom_urls[_gnutls_custom_urls_size], st,

           sizeof(*st));

    _gnutls_custom_urls_size++;

    return 0;

  } else {

    return gnutls_assert_val(GNUTLS_E_UNIMPLEMENTED_FEATURE);

  }

}

/*-

 * _gnutls_get_raw_issuer:

 * @url: A PKCS 11 url identifying a token

 * @cert: is the certificate to find issuer for

 * @issuer: Will hold the issuer if any in an allocated buffer.

 * @flags: Use zero or flags from %GNUTLS_PKCS11_OBJ_FLAG.

 *

 * This function will return the issuer of a given certificate in

 * DER format.

 *

 * Returns: On success, %GNUTLS_E_SUCCESS (0) is returned, otherwise a

 *   negative error value.

 *

 * Since: 3.4.0

 -*/

int _gnutls_get_raw_issuer(const char *url, gnutls_x509_crt_t cert,

         gnutls_datum_t *issuer, unsigned int flags)

{

  unsigned i;

#ifdef ENABLE_PKCS11

  if (c_strncasecmp(url, PKCS11_URL, PKCS11_URL_SIZE) == 0) {

    return gnutls_pkcs11_get_raw_issuer(url, cert, issuer,

                GNUTLS_X509_FMT_DER, flags);

  }

#endif

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

    if (c_strncasecmp(url, _gnutls_custom_urls[i].name,

          _gnutls_custom_urls[i].name_size) == 0) {

      if (_gnutls_custom_urls[i].get_issuer) {

        return _gnutls_custom_urls[i].get_issuer(

          url, cert, issuer, flags);

      }

      break;

    }

  }

  return GNUTLS_E_REQUESTED_DATA_NOT_AVAILABLE;

}