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

       This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

       This option works only with the following TLS backends: GnuTLS, OpenSSL, Schannel and Secure Transport

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);
         }
       }

HISTORY

       Schannel support added in 7.50.0. Secure Transport support added in 7.79.0.   mbedTLS  support  added  in
       8.9.0.

AVAILABILITY

       Added in curl 7.19.1

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)