X509_CHECK_ISSUED(3ossl)

📦
version 15.1 · 3 versions
, in freebsd 15.1

🎀 NAME 🎀

okay so this is the 3ossl manual page for X509_check_issued 💅 — it checks if a certificate is apparently issued by another certificate. That’s the whole vibe check, bestie.

✨ SYNOPSIS ✨

#include <openssl/x509v3.h>

int X509_check_issued(X509 *issuer, X509 *subject);

🦋 DESCRIPTION 🦋

X509_check_issued() checks if certificate subject was apparently issued using (CA) certificate issuer 🫶. It’s not just a surface-level “do these names match?” thing — no cap. Here’s the actual checklist:

  • It takes into account not only matching of the issuer field of subject with the subject field of issuer,
  • but also compares all sub-fields of the authorityKeyIdentifier extension of subject, as far as present, with the respective subjectKeyIdentifier, serial number, and issuer fields of issuer, as far as present.
  • It also checks if the keyUsage field (if present) of issuer allows certificate signing.
  • It does not actually check the certificate signature 😭.
  • An error is returned if issuer or subject are incomplete certificates.
🚨 Important caveat: this function does not actually check the certificate signature. That part is literally not its job, bestie.

🌸 RETURN VALUES 🌸

X509_check_issued() returns X509_V_OK if all checks are successful or some X509_V_ERR* constant to indicate an error ✨.

🌈 SEE ALSO 🌈

Copyright 2015-2021 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at <https://www.openssl.org/source/license.html>.

later bestie 💖 — this one’s from OpenSSL 3.5.6, dated 2026-04-07 🎀

📦 where this page comes from