docs/libcurl/opts/CURLINFO_CERTINFO.3

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.TH CURLINFO_CERTINFO 3 "November 04, 2020" "libcurl 7.78.0" "curl_easy_getinfo options"

.SH NAME
CURLINFO_CERTINFO \- get the TLS certificate chain
.SH SYNOPSIS
#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_CERTINFO,
                           struct curl_certinfo **chainp);
.SH DESCRIPTION
Pass a pointer to a 'struct curl_certinfo *' and you'll get it set to point to
a struct that holds a number of linked lists with info about the certificate
chain, assuming you had \fICURLOPT_CERTINFO(3)\fP enabled when the request was
made. The struct reports how many certs it found and then you can extract info
for each of those certs by following the linked lists. The info chain is
provided in a series of data in the format "name:content" where the content is
for the specific named data. See also the certinfo.c example.
.SH PROTOCOLS
All TLS-based
.SH EXAMPLE
.nf
curl = curl_easy_init();
if(curl) {
  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) {
      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);
}
.fi
.SH AVAILABILITY
This option is only working in libcurl built with OpenSSL, NSS, Schannel or
GSKit support. Schannel support added in 7.50.0

Added in 7.19.1
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH "SEE ALSO"
.BR curl_easy_getinfo "(3), " curl_easy_setopt "(3), "