---
name: "libressl-AUTHORITY_KEYID_new"
section: "3"
platform: "linux"
package: "libressl"
version: "4.4.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/libressl-AUTHORITY_KEYID_new"
---

# libressl-AUTHORITY\_KEYID\_new(3)

X.509 authority key identifier extension

## NAME

**AUTHORITY\_KEYID\_new**, **AUTHORITY\_KEYID\_free** – X.509 authority key identifier extension

## SYNOPSIS

Crypto Library (libcrypto, -lcrypto)

**#include \<openssl/x509v3.h\>**

*AUTHORITY\_KEYID* *\**\

**AUTHORITY\_KEYID\_new**(*void*);

*void*\

**AUTHORITY\_KEYID\_free**(*AUTHORITY\_KEYID \*id*);

## DESCRIPTION

Using the authority key identifier extension, an X.509 certificate or certificate revocation list can specify which key pair was used for signing it.

**AUTHORITY\_KEYID\_new**() allocates and initializes an empty *AUTHORITY\_KEYID* object, representing an ASN.1 *AuthorityKeyIdentifier* structure defined in RFC 5280 section 4.2.1.1. It can hold an issuer name, a serial number, and a key identifier.

**AUTHORITY\_KEYID\_free**() frees *id*.

## RETURN VALUES

**AUTHORITY\_KEYID\_new**() returns the new *AUTHORITY\_KEYID* object or NULL if an error occurs.

## SEE ALSO

d2i\_AUTHORITY\_KEYID(3), GENERAL\_NAMES\_new(3), X509\_CRL\_new(3), X509\_EXTENSION\_new(3), X509\_new(3)

## STANDARDS

RFC 5280: Internet X.509 Public Key Infrastructure Certificate and Certificate Revocation List (CRL) Profile:

- section 4.2.1.1: Certificate Extensions: Authority Key Identifier

- section 5.2.1: CRL Extensions: Authority Key Identifier

## HISTORY

**AUTHORITY\_KEYID\_new**() and **AUTHORITY\_KEYID\_free**() first appeared in OpenSSL 0.9.2b and have been available since OpenBSD 2.6.