---
title: kSecOIDX509V3CertificateExtensionCritical
framework: security
role: symbol
role_heading: Global Variable
path: security/ksecoidx509v3certificateextensioncritical
---

# kSecOIDX509V3CertificateExtensionCritical

## Declaration

```swift
let kSecOIDX509V3CertificateExtensionCritical: CFString
```