curl / libcurl / API / Examples / https.c

https.c

/***************************************************************************
 *                                  _   _ ____  _
 *  Project                     ___| | | |  _ \| |
 *                             / __| | | | |_) | |
 *                            | (__| |_| |  _ <| |___
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
 *
 * This software is licensed as described in the file COPYING, which
 * you should have received as part of this distribution. The terms
 * are also available at https://curl.se/docs/copyright.html.
 *
 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
 * copies of the Software, and permit persons to whom the Software is
 * furnished to do so, under the terms of the COPYING file.
 *
 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
 * KIND, either express or implied.
 *
 * SPDX-License-Identifier: curl
 *
 ***************************************************************************/
/* <DESC>
 * Simple HTTPS GET
 * </DESC>
 */
#include <stdio.h>
 
#include <curl/curl.h>
 
int main(void)
{
  CURL *curl;
 
  CURLcode result = curl_global_init(CURL_GLOBAL_ALL);
  if(result != CURLE_OK)
    return (int)result;
 
  curl = curl_easy_init();
  if(curl) {
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
 
#ifdef SKIP_PEER_VERIFICATION
    /*
     * If you want to connect to a site who is not using a certificate that is
     * signed by one of the certs in the CA bundle you have, you can skip the
     * verification of the server's certificate. This makes the connection
     * A LOT LESS SECURE.
     *
     * If you have a CA cert for the server stored someplace else than in the
     * default bundle, then the CURLOPT_CAPATH option might come handy for
     * you.
     */
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
#endif
 
#ifdef SKIP_HOSTNAME_VERIFICATION
    /*
     * If the site you are connecting to uses a different hostname than what
     * they have mentioned in their server certificate's commonName (or
     * subjectAltName) fields, libcurl refuses to connect. You can skip this
     * check, but it makes the connection insecure.
     */
    curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
#endif
 
    /* cache the CA cert bundle in memory for a week */
    curl_easy_setopt(curl, CURLOPT_CA_CACHE_TIMEOUT, 604800L);
 
    /* Perform the request, result gets the return code */
    result = curl_easy_perform(curl);
    /* Check for errors */
    if(result != CURLE_OK)
      fprintf(stderr, "curl_easy_perform() failed: %s\n",
              curl_easy_strerror(result));
 
    /* always cleanup */
    curl_easy_cleanup(curl);
  }
 
  curl_global_cleanup();
 
  return (int)result;
}

Notice

This source code example is simplified and may ignore return codes and error checks. We do this to highlight the libcurl function calls and related options and reduce unrelated code.

A real-world application does of course properly check every return value and exit correctly at the first serious error.