curl/docs/libcurl/opts/CURLINFO_CERTINFO.md
Daniel Stenberg b935fd4a07
docs: make each libcurl man specify protocol(s)
The mandatory header now has a mandatory list of protocols for which the
manpage is relevant.

Most man pages already has a "PROTOCOLS" section, but this introduces a
stricter way to specify the relevant protocols.

cd2nroff verifies that at least one protocol is mentioned (which can be
`*`).

This information is not used just yet, but A) the PROTOCOLS section can
now instead get generated and get a unified wording across all manpages
and B) this allows us to more reliably filter/search for protocol
specific manpages/options.

Closes #13166
2024-03-21 15:27:06 +01:00

2.4 KiB

c SPDX-License-Identifier Title Section Source See-also Protocol
Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al. curl CURLINFO_CERTINFO 3 libcurl
CURLINFO_CAPATH (3)
curl_easy_getinfo (3)
curl_easy_setopt (3)
TLS

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

All TLS-based

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.

AVAILABILITY

This option is only working in libcurl built with OpenSSL, GnuTLS, Schannel or Secure Transport. GnuTLS support added in 7.42.0. Schannel support added in 7.50.0. Secure Transport support added in 7.79.0.

Added in 7.19.1

RETURN VALUE

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.