AUTHORITY_KEYID_NEW(3) | Library Functions Manual | AUTHORITY_KEYID_NEW(3)

# NAME

`AUTHORITY_KEYID_new`, `AUTHORITY_KEYID_free` — X.509 authority key identifier extension

# SYNOPSIS

library “libcrypto”
`#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.

June 8, 2025 | Debian