# certificateHandler

> Holds a reference to a CertificateHandler object, which manages certificate validation for this UnityWebRequest.

## Definition

* **Type:** Property
* **Namespace:** [UnityEngine.Networking](/engine/6000.0/script-reference/unityengine/networking.md)
* **Assembly:** UnityEngine.UnityWebRequestModule

```csharp
public CertificateHandler certificateHandler { get; set; }
```

### Remarks

Setting this property to `null` makes the platform use the default certificate validation, which will validate certificates against a root certificate authority store (most commonly Operating System store).

Not all platforms support certificate validation callbacks. See [CertificateHandler](/engine/6000.0/script-reference/unityengine/networking/certificatehandler.md) for a list of supported platforms.

This property cannot be changed after calling [UnityWebRequest.SendWebRequest](/engine/6000.0/script-reference/unityengine/networking/unitywebrequest/sendwebrequest.md).

*Default value:* `null`.