---
name: "SSL_set_session"
section: "3ssl"
platform: "linux"
package: "openssl"
version: "3.6.5-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/SSL_set_session"
---

# SSL\_set\_session(3ssl)

set a TLS/SSL session to be used during TLS/SSL connect

## NAME

SSL\_set\_session - set a TLS/SSL session to be used during TLS/SSL connect

## SYNOPSIS

```
 #include <openssl/ssl.h>
 int SSL_set_session(SSL *ssl, SSL_SESSION *session);
```

## DESCRIPTION

**SSL\_set\_session()** sets **session** to be used when the TLS/SSL connection is to be established. **SSL\_set\_session()** is only useful for TLS/SSL clients. When the session is set, the reference count of **session** is incremented by 1. If the session is not reused, the reference count is decremented again during **SSL\_connect()**. Whether the session was reused can be queried with the **SSL\_session\_reused**(3) call.

If there is already a session set inside **ssl** (because it was set with **SSL\_set\_session()** before or because the same **ssl** was already used for a connection), **SSL\_SESSION\_free()** will be called for that session. This is also the case when **session** is a NULL pointer. If that old session is still **open**, it is considered bad and will be removed from the session cache (if used). A session is considered open, if **SSL\_shutdown**(3) was not called for the connection (or at least **SSL\_set\_shutdown**(3) was used to set the SSL\_SENT\_SHUTDOWN state).

## NOTES

SSL\_SESSION objects keep internal link information about the session cache list, when being inserted into one SSL\_CTX object's session cache. One SSL\_SESSION object, regardless of its reference count, must therefore only be used with one SSL\_CTX object (and the SSL objects created from this SSL\_CTX object).

## RETURN VALUES

The following return values can occur:

- 0

  The operation failed; check the error stack to find out the reason.

- 1

  The operation succeeded.

## SEE ALSO

[**ssl**(7)](/ssl/7.md), **SSL\_SESSION\_free**(3), **SSL\_get\_session**(3), **SSL\_session\_reused**(3), **SSL\_CTX\_set\_session\_cache\_mode**(3)

## COPYRIGHT

Copyright 2000-2022 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License").  You may not use this file except in compliance with the License.  You can obtain a copy in the file LICENSE in the source distribution or at \<https://www.openssl.org/source/license.html\>.