1 /*************************************************************************** 2 * _ _ ____ _ 3 * Project ___| | | | _ \| | 4 * / __| | | | |_) | | 5 * | (__| |_| | _ <| |___ 6 * \___|\___/|_| \_\_____| 7 * 8 * Copyright (C) 1998 - 2016, Daniel Stenberg, <daniel (at) 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 /* <DESC> 23 * Uses the CURLINFO_TLS_SESSION data. 24 * </DESC> 25 */ 26 27 /* Note that this example currently requires cURL to be linked against 28 GnuTLS (and this program must also be linked against -lgnutls). */ 29 30 #include <stdio.h> 31 32 #include <curl/curl.h> 33 #include <gnutls/gnutls.h> 34 35 static CURL *curl; 36 37 static size_t wrfu(void *ptr, size_t size, size_t nmemb, void *stream) 38 { 39 const struct curl_tlssessioninfo *info; 40 unsigned int cert_list_size; 41 const gnutls_datum_t *chainp; 42 CURLcode res; 43 44 (void)stream; 45 (void)ptr; 46 47 res = curl_easy_getinfo(curl, CURLINFO_TLS_SESSION, &info); 48 49 if(!res) { 50 switch(info->backend) { 51 case CURLSSLBACKEND_GNUTLS: 52 /* info->internals is now the gnutls_session_t */ 53 chainp = gnutls_certificate_get_peers(info->internals, &cert_list_size); 54 if((chainp) && (cert_list_size)) { 55 unsigned int i; 56 57 for(i = 0; i < cert_list_size; i++) { 58 gnutls_x509_crt_t cert; 59 gnutls_datum_t dn; 60 61 if(GNUTLS_E_SUCCESS == gnutls_x509_crt_init(&cert)) { 62 if(GNUTLS_E_SUCCESS == 63 gnutls_x509_crt_import(cert, &chainp[i], GNUTLS_X509_FMT_DER)) { 64 if(GNUTLS_E_SUCCESS == 65 gnutls_x509_crt_print(cert, GNUTLS_CRT_PRINT_FULL, &dn)) { 66 fprintf(stderr, "Certificate #%d: %.*s", i, dn.size, dn.data); 67 68 gnutls_free(dn.data); 69 } 70 } 71 72 gnutls_x509_crt_deinit(cert); 73 } 74 } 75 } 76 break; 77 case CURLSSLBACKEND_NONE: 78 default: 79 break; 80 } 81 } 82 83 return size * nmemb; 84 } 85 86 int main(void) 87 { 88 curl_global_init(CURL_GLOBAL_DEFAULT); 89 90 curl = curl_easy_init(); 91 if(curl) { 92 curl_easy_setopt(curl, CURLOPT_URL, "https://www.example.com/"); 93 94 curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, wrfu); 95 96 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L); 97 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L); 98 99 curl_easy_setopt(curl, CURLOPT_VERBOSE, 0L); 100 101 (void) curl_easy_perform(curl); 102 103 curl_easy_cleanup(curl); 104 } 105 106 curl_global_cleanup(); 107 108 return 0; 109 } 110