---
name: "CURLOPT_SSL_SESSIONID_CACHE"
section: "3"
platform: "linux"
package: "curl"
version: "8.23.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux", "macos"]
url: "https://new.carta.tech/CURLOPT_SSL_SESSIONID_CACHE"
---

# CURLOPT\_SSL\_SESSIONID\_CACHE(3)

use the SSL session-ID cache

## NAME

CURLOPT\_SSL\_SESSIONID\_CACHE - use the SSL session-ID cache

## SYNOPSIS

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

## DESCRIPTION

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.

## DEFAULT

1

## PROTOCOLS

This functionality affects  all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc. only

All TLS backends support this option.

## EXAMPLE

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

## AVAILABILITY

Added in curl 7.16.0

## RETURN VALUE

*[curl\_easy\_setopt(3)](/curl_easy_setopt/3.md)* returns a CURLcode indicating success or error.

CURLE\_OK (0) means everything was OK, non-zero means an error occurred, see *[libcurl-errors(3)](/libcurl-errors/3.md)*.

## SEE ALSO

[**CURLOPT\_DNS\_CACHE\_TIMEOUT**(3)](/CURLOPT_DNS_CACHE_TIMEOUT/3.md), [**CURLOPT\_MAXAGE\_CONN**(3)](/CURLOPT_MAXAGE_CONN/3.md), [**CURLOPT\_MAXLIFETIME\_CONN**(3)](/CURLOPT_MAXLIFETIME_CONN/3.md), [**CURLOPT\_SSLVERSION**(3)](/CURLOPT_SSLVERSION/3.md)