CURLINFO_SSL_ENGINES - Man Page

#include <curl/curl.h>

CURLcode curl_easy_getinfo(CURL *handle, CURLINFO_SSL_ENGINES,
                           struct curl_slist **engine_list);

Pass the address of a 'struct curl_slist *' to receive a linked-list of OpenSSL crypto-engines supported. Note that engines are normally implemented in separate dynamic libraries. Hence not all the returned engines may be available at runtime. NOTE: you must call curl_slist_free_all(3) on the list pointer once you are done with it, as libcurl will not free the data for you.

All TLS based ones.

CURL *curl = curl_easy_init();
if(curl) {
  CURLcode res;
  struct curl_slist *engines;
  res = curl_easy_getinfo(curl, CURLINFO_SSL_ENGINES, &engines);
  if((res == CURLE_OK) && engines) {
    /* we have a list, free it when done using it */
    curl_slist_free_all(engines);
  }

  curl_easy_cleanup(curl);
}

Added in 7.12.3. Available in OpenSSL builds with "engine" support.

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

curl_easy_getinfo(3), curl_easy_setopt(3),

curl_easy_getinfo(3).