text: /***************************************************************************
   *                                  _   _ ____  _
   *  Project                     ___| | | |  _ \| |
   *                             / __| | | | |_) | |
   *                            | (__| |_| |  _ <| |___
   *                             \___|\___/|_| \_\_____|
   *
   * Copyright (C) 1998 - 2015, 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.haxx.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.
   *
   ***************************************************************************/
  
  /* <DESC>
   * POP3 example using SSL
   * </DESC>
   */
  
  #include <stdio.h>
  #include <curl/curl.h>
  
  /* This is a simple example showing how to retrieve mail using libcurl's POP3
   * capabilities. It builds on the pop3-retr.c example adding transport
   * security to protect the authentication details from being snooped.
   *
   * Note that this example requires libcurl 7.20.0 or above.
   */
  
  int main(void) {
      CURL *curl;
      CURLcode res = CURLE_OK;
  
      curl = curl_easy_init();
      if (curl) {
          /* Set username and password */
          curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
          curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
  
          /* This will retrieve message 1 from the user's mailbox. Note the use of
           * pop3s:// rather than pop3:// to request a SSL based connection. */
          curl_easy_setopt(curl, CURLOPT_URL, "pop3s://pop.example.com/1");
  
          /* If you want to connect to a site who isn't 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. */
  #ifdef SKIP_PEER_VERIFICATION
          curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
  #endif
  
          /* If the site you're connecting to uses a different host name that what
           * they have mentioned in their server certificate's commonName (or
           * subjectAltName) fields, libcurl will refuse to connect. You can skip
           * this check, but this will make the connection less secure. */
  #ifdef SKIP_HOSTNAME_VERIFICATION
          curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
  #endif
  
          /* Since the traffic will be encrypted, it is very useful to turn on debug
           * information within libcurl to see what is happening during the
           * transfer */
          curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
  
          /* Perform the retr */
          res = curl_easy_perform(curl);
  
          /* Check for errors */
          if (res != CURLE_OK)
              fprintf(stderr, "curl_easy_perform() failed: %s\n",
                      curl_easy_strerror(res));
  
          /* Always cleanup */
          curl_easy_cleanup(curl);
      }
  
      return (int) res;
  }
  