---
name: "gnutls_session_key_update"
section: "3"
platform: "linux"
package: "gnutls"
version: "3.8.13-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/gnutls_session_key_update"
---

# gnutls\_session\_key\_update(3)

API function

## NAME

gnutls\_session\_key\_update - API function

## SYNOPSIS

**#include \<gnutls/gnutls.h\>**

**int gnutls\_session\_key\_update(gnutls\_session\_t** *session***, unsigned** *flags***);**

## ARGUMENTS

- gnutls\_session\_t session

  is a **gnutls\_session\_t** type.

- unsigned flags

  zero of **GNUTLS\_KU\_PEER**

## DESCRIPTION

This function will update/refresh the session keys when the TLS protocol is 1.3 or better. The peer is notified of the update by sending a message, so this function should be treated similarly to **gnutls\_record\_send()** --i.e., it may return **GNUTLS\_E\_AGAIN** or **GNUTLS\_E\_INTERRUPTED**.

When this flag **GNUTLS\_KU\_PEER** is specified, this function in addition to updating the local keys, will ask the peer to refresh its keys too.

If the negotiated version is not TLS 1.3 or better this function will return **GNUTLS\_E\_INVALID\_REQUEST**.

## RETURNS

**GNUTLS\_E\_SUCCESS** on success, otherwise a negative error code.

## SINCE

3\.6.3

## REPORTING BUGS

Report bugs to \<bugs@gnutls.org\>.\
 Home page: https://www.gnutls.org

## COPYRIGHT

Copyright © 2001-2023 Free Software Foundation, Inc., and others.\
 Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.

## SEE ALSO

The full documentation for **gnutls** is maintained as a Texinfo manual. If the /usr/share/doc/gnutls/ directory does not contain the HTML form visit

- https://www.gnutls.org/manual/