---
name: "gnutls_dtls_cookie_verify"
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_dtls_cookie_verify"
---

# gnutls\_dtls\_cookie\_verify(3)

API function

## NAME

gnutls\_dtls\_cookie\_verify - API function

## SYNOPSIS

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

**int gnutls\_dtls\_cookie\_verify(gnutls\_datum\_t \*** *key***, void \*** *client\_data***, size\_t** *client\_data\_size***, void \*** *\_msg***, size\_t** *msg\_size***, gnutls\_dtls\_prestate\_st \*** *prestate***);**

## ARGUMENTS

- gnutls\_datum\_t \* key

  is a random key to be used at cookie generation

- void \* client\_data

  contains data identifying the client (i.e. address)

- size\_t client\_data\_size

  The size of client's data

- void \* \_msg

  An incoming message that initiates a connection.

- size\_t msg\_size

  The size of the message.

- gnutls\_dtls\_prestate\_st \* prestate

  The cookie of this client.

## DESCRIPTION

This function will verify the received message for a valid cookie. If a valid cookie is returned then it should be associated with the session using **gnutls\_dtls\_prestate\_set()**;

This function must be called after **gnutls\_dtls\_cookie\_send()**.

## RETURNS

**GNUTLS\_E\_SUCCESS** (0) on success, or a negative error code.

## SINCE

3\.0

## 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/