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)