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)