CURLOPT_SSL_SESSIONID_CACHE(3) Library Functions Manual CURLOPT_SSL_SESSIONID_CACHE(3)

CURLOPT_SSL_SESSIONID_CACHE - use the SSL session-ID cache

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_SESSIONID_CACHE,
                         long enabled);

Pass a long set to 0 to disable libcurl's use of SSL session-ID caching. Set this to 1 to enable it. By default all transfers are done using the cache enabled. While nothing ever should get hurt by attempting to reuse SSL session-IDs, there seem to be or have been broken SSL implementations in the wild that may require you to disable this in order for you to succeed.

1

All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

All TLS backends support this option.

int main(void)
{
  CURL *curl = curl_easy_init();
  if(curl) {
    CURLcode res;
    curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
    /* switch off session-id use! */
    curl_easy_setopt(curl, CURLOPT_SSL_SESSIONID_CACHE, 0L);
    res = curl_easy_perform(curl);
    curl_easy_cleanup(curl);
  }
}

Added in 7.16.0

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

CURLOPT_DNS_CACHE_TIMEOUT(3), CURLOPT_MAXAGE_CONN(3), CURLOPT_MAXLIFETIME_CONN(3), CURLOPT_SSLVERSION(3)

April 26 2024 libcurl