---
name: "gnutls_psk_set_server_credentials_function"
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_psk_set_server_credentials_function"
---

# gnutls\_psk\_set\_server\_credentials\_function(3)

API function

## NAME

gnutls\_psk\_set\_server\_credentials\_function - API function

## SYNOPSIS

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

**void gnutls\_psk\_set\_server\_credentials\_function(gnutls\_psk\_server\_credentials\_t** *cred***, gnutls\_psk\_server\_credentials\_function \*** *func***);**

## ARGUMENTS

- gnutls\_psk\_server\_credentials\_t cred

  is a **gnutls\_psk\_server\_credentials\_t** type.

- gnutls\_psk\_server\_credentials\_function \* func

  is the callback function

## DESCRIPTION

This function can be used to set a callback to retrieve the user's PSK credentials. The callback's function form is: int (\*callback)(gnutls\_session\_t, const char\* username, gnutls\_datum\_t\* key);

 *username* contains the actual username. The  *key* must be filled in using the **gnutls\_malloc()**.

In case the callback returned a negative number then gnutls will assume that the username does not exist.

The callback function will only be called once per handshake.  The callback function should return 0 on success, while -1 indicates an error.

## 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/