xref: /curl/docs/examples/pop3-ssl.c (revision f540e43b)
1 /***************************************************************************
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7  *
8  * Copyright (C) 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.se/docs/copyright.html.
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19  * KIND, either express or implied.
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21  * SPDX-License-Identifier: curl
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23  ***************************************************************************/
24 
25 /* <DESC>
26  * Get POP3 email using implicit SSL
27  * </DESC>
28  */
29 
30 #include <stdio.h>
31 #include <curl/curl.h>
32 
33 /* This is a simple example showing how to retrieve mail using libcurl's POP3
34  * capabilities. It builds on the pop3-retr.c example adding transport
35  * security to protect the authentication details from being snooped.
36  *
37  * Note that this example requires libcurl 7.20.0 or above.
38  */
39 
main(void)40 int main(void)
41 {
42   CURL *curl;
43   CURLcode res = CURLE_OK;
44 
45   curl = curl_easy_init();
46   if(curl) {
47     /* Set username and password */
48     curl_easy_setopt(curl, CURLOPT_USERNAME, "user");
49     curl_easy_setopt(curl, CURLOPT_PASSWORD, "secret");
50 
51     /* This retrieves message 1 from the user's mailbox. Note the use of
52      * pop3s:// rather than pop3:// to request a SSL based connection. */
53     curl_easy_setopt(curl, CURLOPT_URL, "pop3s://pop.example.com/1");
54 
55     /* If you want to connect to a site who is not using a certificate that is
56      * signed by one of the certs in the CA bundle you have, you can skip the
57      * verification of the server's certificate. This makes the connection
58      * A LOT LESS SECURE.
59      *
60      * If you have a CA cert for the server stored someplace else than in the
61      * default bundle, then the CURLOPT_CAPATH option might come handy for
62      * you. */
63 #ifdef SKIP_PEER_VERIFICATION
64     curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
65 #endif
66 
67     /* If the site you are connecting to uses a different host name that what
68      * they have mentioned in their server certificate's commonName (or
69      * subjectAltName) fields, libcurl refuses to connect. You can skip this
70      * check, but it makes the connection insecure. */
71 #ifdef SKIP_HOSTNAME_VERIFICATION
72     curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
73 #endif
74 
75     /* Since the traffic is encrypted, it is useful to turn on debug
76      * information within libcurl to see what is happening during the
77      * transfer */
78     curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
79 
80     /* Perform the retr */
81     res = curl_easy_perform(curl);
82 
83     /* Check for errors */
84     if(res != CURLE_OK)
85       fprintf(stderr, "curl_easy_perform() failed: %s\n",
86               curl_easy_strerror(res));
87 
88     /* Always cleanup */
89     curl_easy_cleanup(curl);
90   }
91 
92   return (int)res;
93 }
94