1 /***************************************************************************
2 * _ _ ____ _
3 * Project ___| | | | _ \| |
4 * / __| | | | |_) | |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
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.
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 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24 /* <DESC>
25 * Uses the CURLINFO_TLS_SESSION data.
26 * </DESC>
27 */
28
29 /* Note that this example currently requires curl to be linked against
30 GnuTLS (and this program must also be linked against -lgnutls). */
31
32 #include <stdio.h>
33
34 #include <curl/curl.h>
35 #include <gnutls/gnutls.h>
36 #include <gnutls/x509.h>
37
38 static CURL *curl;
39
wrfu(void * ptr,size_t size,size_t nmemb,void * stream)40 static size_t wrfu(void *ptr, size_t size, size_t nmemb, void *stream)
41 {
42 const struct curl_tlssessioninfo *info;
43 unsigned int cert_list_size;
44 const gnutls_datum_t *chainp;
45 CURLcode res;
46
47 (void)stream;
48 (void)ptr;
49
50 res = curl_easy_getinfo(curl, CURLINFO_TLS_SESSION, &info);
51
52 if(!res) {
53 switch(info->backend) {
54 case CURLSSLBACKEND_GNUTLS:
55 /* info->internals is now the gnutls_session_t */
56 chainp = gnutls_certificate_get_peers(info->internals, &cert_list_size);
57 if((chainp) && (cert_list_size)) {
58 unsigned int i;
59
60 for(i = 0; i < cert_list_size; i++) {
61 gnutls_x509_crt_t cert;
62 gnutls_datum_t dn;
63
64 if(GNUTLS_E_SUCCESS == gnutls_x509_crt_init(&cert)) {
65 if(GNUTLS_E_SUCCESS ==
66 gnutls_x509_crt_import(cert, &chainp[i], GNUTLS_X509_FMT_DER)) {
67 if(GNUTLS_E_SUCCESS ==
68 gnutls_x509_crt_print(cert, GNUTLS_CRT_PRINT_FULL, &dn)) {
69 fprintf(stderr, "Certificate #%u: %.*s", i, dn.size, dn.data);
70
71 gnutls_free(dn.data);
72 }
73 }
74
75 gnutls_x509_crt_deinit(cert);
76 }
77 }
78 }
79 break;
80 case CURLSSLBACKEND_NONE:
81 default:
82 break;
83 }
84 }
85
86 return size * nmemb;
87 }
88
main(void)89 int main(void)
90 {
91 curl_global_init(CURL_GLOBAL_DEFAULT);
92
93 curl = curl_easy_init();
94 if(curl) {
95 curl_easy_setopt(curl, CURLOPT_URL, "https://www.example.com/");
96
97 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, wrfu);
98
99 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
100 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);
101
102 curl_easy_setopt(curl, CURLOPT_VERBOSE, 0L);
103
104 (void) curl_easy_perform(curl);
105
106 curl_easy_cleanup(curl);
107 }
108
109 curl_global_cleanup();
110
111 return 0;
112 }
113
