NAME

       CURLOPT_CERTINFO - request SSL certificate information

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_CERTINFO, long certinfo);

DESCRIPTION

       Pass a long set to 1 to enable libcurl's certificate chain info gatherer. With this enabled, libcurl will
       extract  lots  of  information  and  data about the certificates in the certificate chain used in the SSL
       connection. This data may then be retrieved after a transfer using curl_easy_getinfo(3)  and  its  option
       CURLINFO_CERTINFO(3).

DEFAULT

       0

PROTOCOLS

       All TLS-based

EXAMPLE

       curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://www.example.com/");

         /* connect to any HTTPS site, trusted or not */
         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYPEER, 0L);
         curl_easy_setopt(curl, CURLOPT_SSL_VERIFYHOST, 0L);

         curl_easy_setopt(curl, CURLOPT_CERTINFO, 1L);

         res = curl_easy_perform(curl);

         if (!res) {
           struct curl_certinfo *ci;
           res = curl_easy_getinfo(curl, CURLINFO_CERTINFO, &ci);

           if (!res) {
             printf("%d certs!\n", ci->num_of_certs);

             for(i = 0; i < ci->num_of_certs; i++) {
               struct curl_slist *slist;

               for(slist = ci->certinfo[i]; slist; slist = slist->next)
                 printf("%s\n", slist->data);
             }
           }
         }
         curl_easy_cleanup(curl);
       }

AVAILABILITY

       This  option  is  supported  by  the OpenSSL, GnuTLS, Schannel, NSS, GSKit and Secure Transport backends.
       Schannel support added in 7.50.0. Secure Transport support added in 7.79.0.

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_CAINFO(3), CURLOPT_SSL_VERIFYPEER(3),

libcurl 7.81.0                                  November 26, 2021                            CURLOPT_CERTINFO(3)