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 extracts 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

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode res;
           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) {
               int i;
               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 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

       CURLINFO_CAINFO(3),     CURLINFO_CAPATH(3),    CURLINFO_CERTINFO(3),    CURLOPT_CAINFO(3),
       CURLOPT_SSL_VERIFYPEER(3)