CURLOPT\_SSL\_SESSIONID\_CACHE(3) Library Functions Manual CURLOPT\_SSL\_SESSIONID\_CACHE(3)

# [NAME](#NAME)

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

# [SYNOPSIS](#SYNOPSIS)

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


                         long enabled);
```

# [DESCRIPTION](#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](#DEFAULT)

1

# [PROTOCOLS](#PROTOCOLS)

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

All TLS backends support this option.

# [EXAMPLE](#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](#AVAILABILITY)

Added in curl 7.16.0

# [RETURN VALUE](#RETURN_VALUE)

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

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

# [SEE ALSO](#SEE_ALSO)

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

2026-10-14 libcurl

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Document: CURLOPT_SSL_SESSIONID_CACHE(3) from curl 8.23.0-r0 (Chainguard OS)
Source: https://github.com/curl/curl.git