plucky (3) CURLINFO_CERTINFO.3.gz

NAME

       CURLINFO_CERTINFO - get the TLS certificate chain

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_CERTINFO,
                                  struct curl_certinfo **chainp);

DESCRIPTION

       Pass  a  pointer to a struct curl_certinfo * and it is set to point to a struct that holds info about the
       server's certificate chain, assuming you had CURLOPT_CERTINFO(3) enabled when the request was made.

       struct curl_certinfo {
         int num_of_certs;
         struct curl_slist **certinfo;
       };

       The certinfo struct member is an array of linked  lists  of  certificate  information.  The  num_of_certs
       struct  member  is  the  number  of  certificates  which  is  the  number  of elements in the array. Each
       certificate's list has items with textual information in the format "name:content" such as "Subject:Foo",
       "Issuer:Bar", etc. The items in each list varies depending on the SSL backend and the certificate.

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) {
             int i;
             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);
         }
       }

       See also the certinfo.c example.

HISTORY

       GnuTLS  support  added  in  7.42.0.  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

       curl_easy_getinfo(3) returns a CURLcode indicating success or error.

       CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

SEE ALSO

       CURLINFO_CAPATH(3), curl_easy_getinfo(3), curl_easy_setopt(3)