---
name: "gnutls_crypto_register_cipher"
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_crypto_register_cipher"
---

# gnutls\_crypto\_register\_cipher(3)

API function

## NAME

gnutls\_crypto\_register\_cipher - API function

## SYNOPSIS

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

**int gnutls\_crypto\_register\_cipher(gnutls\_cipher\_algorithm\_t** *algorithm***, int** *priority***, gnutls\_cipher\_init\_func** *init***, gnutls\_cipher\_setkey\_func** *setkey***, gnutls\_cipher\_setiv\_func** *setiv***, gnutls\_cipher\_encrypt\_func** *encrypt***, gnutls\_cipher\_decrypt\_func** *decrypt***, gnutls\_cipher\_deinit\_func** *deinit***);**

## ARGUMENTS

- gnutls\_cipher\_algorithm\_t algorithm

  is the gnutls algorithm identifier

- int priority

  is the priority of the algorithm

- gnutls\_cipher\_init\_func init

  A function which initializes the cipher

- gnutls\_cipher\_setkey\_func setkey

  A function which sets the key of the cipher

- gnutls\_cipher\_setiv\_func setiv

  A function which sets the nonce/IV of the cipher (non-AEAD)

- gnutls\_cipher\_encrypt\_func encrypt

  A function which performs encryption (non-AEAD)

- gnutls\_cipher\_decrypt\_func decrypt

  A function which performs decryption (non-AEAD)

- gnutls\_cipher\_deinit\_func deinit

  A function which deinitializes the cipher

## DESCRIPTION

This function will register a cipher algorithm to be used by gnutls.  Any algorithm registered will override the included algorithms and by convention kernel implemented algorithms have priority of 90 and CPU-assisted of 80.  The algorithm with the lowest priority will be used by gnutls.

In the case the registered init or setkey functions return **GNUTLS\_E\_NEED\_FALLBACK**, GnuTLS will attempt to use the next in priority registered cipher.

The functions which are marked as non-AEAD they are not required when registering a cipher to be used with the new AEAD API introduced in GnuTLS 3.4.0. Internally GnuTLS uses the new AEAD API.

## DEPRECATED

since 3.7.0 it is no longer possible to override cipher implementation

## RETURNS

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

## SINCE

3\.4.0

## 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/