1--- 2c: Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. 3SPDX-License-Identifier: curl 4Title: CURLOPT_CERTINFO 5Section: 3 6Source: libcurl 7See-also: 8 - CURLINFO_CAINFO (3) 9 - CURLINFO_CAPATH (3) 10 - CURLINFO_CERTINFO (3) 11 - CURLOPT_CAINFO (3) 12 - CURLOPT_SSL_VERIFYPEER (3) 13Protocol: 14 - TLS 15TLS-backend: 16 - OpenSSL 17 - GnuTLS 18 - Schannel 19 - Secure Transport 20--- 21 22# NAME 23 24CURLOPT_CERTINFO - request SSL certificate information 25 26# SYNOPSIS 27 28~~~c 29#include <curl/curl.h> 30 31CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CERTINFO, long certinfo); 32~~~ 33 34# DESCRIPTION 35 36Pass a long set to 1 to enable libcurl's certificate chain info gatherer. With 37this enabled, libcurl extracts lots of information and data about the 38certificates in the certificate chain used in the SSL connection. This data 39may then be retrieved after a transfer using curl_easy_getinfo(3) and 40its option CURLINFO_CERTINFO(3). 41 42# DEFAULT 43 440 45 46# EXAMPLE 47 48~~~c 49int main(void) 50{ 51 CURL *curl = curl_easy_init(); 52 if(curl) { 53 CURLcode res; 54 curl_easy_setopt(curl, CURLOPT_URL, "https://www.example.com/"); 55 56 /* connect to any HTTPS site, trusted or not */ 57 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L); 58 curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L); 59 60 curl_easy_setopt(curl, CURLOPT_CERTINFO, 1L); 61 62 res = curl_easy_perform(curl); 63 64 if(!res) { 65 struct curl_certinfo *ci; 66 res = curl_easy_getinfo(curl, CURLINFO_CERTINFO, &ci); 67 68 if(!res) { 69 int i; 70 printf("%d certs!\n", ci->num_of_certs); 71 72 for(i = 0; i < ci->num_of_certs; i++) { 73 struct curl_slist *slist; 74 75 for(slist = ci->certinfo[i]; slist; slist = slist->next) 76 printf("%s\n", slist->data); 77 } 78 } 79 } 80 curl_easy_cleanup(curl); 81 } 82} 83~~~ 84 85# AVAILABILITY 86 87Schannel support added in 7.50.0. Secure Transport support added in 7.79.0. 88 89# RETURN VALUE 90 91Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not. 92
