---
name: "gnutls_cipher_add_auth"
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_cipher_add_auth"
---

# gnutls\_cipher\_add\_auth(3)

API function

## NAME

gnutls\_cipher\_add\_auth - API function

## SYNOPSIS

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

**int gnutls\_cipher\_add\_auth(gnutls\_cipher\_hd\_t** *handle***, const void \*** *ptext***, size\_t** *ptext\_size***);**

## ARGUMENTS

- gnutls\_cipher\_hd\_t handle

  is a **gnutls\_cipher\_hd\_t** type

- const void \* ptext

  the data to be authenticated

- size\_t ptext\_size

  the length of the data

## DESCRIPTION

This function operates on authenticated encryption with associated data (AEAD) ciphers and authenticate the input data. This function can only be called once and before any encryption operations.

## RETURNS

Zero or a negative error code on error.

## 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/