---
name: "libressl-X509_check_issued"
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-X509_check_issued"
---

# libressl-X509\_check\_issued(3)

check whether a certificate was issued using a given CA certificate

## NAME

**X509\_check\_issued** – check whether a certificate was issued using a given CA certificate

## SYNOPSIS

Crypto Library (libcrypto, -lcrypto)

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

*int*\

**X509\_check\_issued**(*X509 \*issuer*, *X509 \*subject*);

## DESCRIPTION

This function checks whether the certificate *subject* was issued using the CA certificate *issuer*. It does the following checks:

- match the issuer field of *subject* against the subject field of *issuer*

- if **authorityKeyIdentifier** is present in the *subject* certificate, compare it to the **subjectKeyIdentifier** of *issuer*

- check the **keyUsage** field of *issuer*.

## RETURN VALUES

This function returns X509\_V\_OK if the certificate *subject* is issued by *issuer*, or some X509\_V\_ERR\* constant to indicate an error.

## SEE ALSO

X509\_check\_ca(3), X509\_new(3), X509\_verify\_cert(3)

## HISTORY

**X509\_check\_issued**() first appeared in OpenSSL 0.9.6 and has been available since OpenBSD 2.9.