1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at https://curl.haxx.se/docs/copyright.html.
13 *
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 ***************************************************************************/
22
23 /* <DESC>
24 * POP3 example using TLS
25 * </DESC>
26 */
27
28 #include <stdio.h>
29 #include <curl/curl.h>
30
31 /* This is a simple example showing how to retrieve mail using libcurl's POP3
32 * capabilities. It builds on the pop3-retr.c example adding transport
33 * security to protect the authentication details from being snooped.
34 *
35 * Note that this example requires libcurl 7.20.0 or above.
36 */
37
main(void)38 int main(void)
39 {
40 CURL *curl;
41 CURLcode res = CURLE_OK;
42
43 curl = curl_easy_init();
44 if(curl) {
45 /* Set username and password */
46 curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
47 curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
48
49 /* This will retrieve message 1 from the user's mailbox */
50 curl_easy_setopt(curl, CURLOPT_URL, "pop3://pop.example.com/1");
51
52 /* In this example, we'll start with a plain text connection, and upgrade
53 * to Transport Layer Security (TLS) using the STLS command. Be careful of
54 * using CURLUSESSL_TRY here, because if TLS upgrade fails, the transfer
55 * will continue anyway - see the security discussion in the libcurl
56 * tutorial for more details. */
57 curl_easy_setopt(curl, CURLOPT_USE_SSL, (long)CURLUSESSL_ALL);
58
59 /* If your server doesn't have a valid certificate, then you can disable
60 * part of the Transport Layer Security protection by setting the
61 * CURLOPT_SSL_VERIFYPEER and CURLOPT_SSL_VERIFYHOST options to 0 (false).
62 * curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
63 * curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
64 *
65 * That is, in general, a bad idea. It is still better than sending your
66 * authentication details in plain text though. Instead, you should get
67 * the issuer certificate (or the host certificate if the certificate is
68 * self-signed) and add it to the set of certificates that are known to
69 * libcurl using CURLOPT_CAINFO and/or CURLOPT_CAPATH. See docs/SSLCERTS
70 * for more information. */
71 curl_easy_setopt(curl, CURLOPT_CAINFO, "/path/to/certificate.pem");
72
73 /* Since the traffic will be encrypted, it is very useful to turn on debug
74 * information within libcurl to see what is happening during the
75 * transfer */
76 curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
77
78 /* Perform the retr */
79 res = curl_easy_perform(curl);
80
81 /* Check for errors */
82 if(res != CURLE_OK)
83 fprintf(stderr, "curl_easy_perform() failed: %s\n",
84 curl_easy_strerror(res));
85
86 /* Always cleanup */
87 curl_easy_cleanup(curl);
88 }
89
90 return (int)res;
91 }
92