# OpcClassicAuthenticationService Enum

<span class="api-meta">since v2.32</span>

<dl class="api-definition">
<dt>Namespace</dt>
<dd><a href="../namespaces/opc.uafx.classic">Opc.UaFx.Classic</a></dd>
<dt>Assembly</dt>
<dd>Opc.UaFx.Advanced.dll</dd>
<dt>Package</dt>
<dd>Opc.UaFx.Advanced v2.59.0</dd>
</dl>

Defines authentication services by identifying the security package that provides the service, such as NTLMSSP, Kerberos or Schannel.

## Syntax

<div class="api-signature" data-lang="csharp">

```csharp
public enum OpcClassicAuthenticationService : long
```

</div>

<div class="api-signature" data-lang="vbnet">

```vbnet
Public Enum OpcClassicAuthenticationService As Long
```

</div>

## Inheritance

[Object](https://learn.microsoft.com/dotnet/api/system.object) → [ValueType](https://learn.microsoft.com/dotnet/api/system.valuetype) → [Enum](https://learn.microsoft.com/dotnet/api/system.enum) → **OpcClassicAuthenticationService**

## Fields

| Name | Value | Description |
|---|---|---|
| <a id="dcepublic"></a>`DcePublic` | `2` | DCE public key authentication. |
| <a id="decpublic"></a>`DecPublic` | `4` | DEC public key authentication.Reserved for future use. |
| <a id="default"></a>`Default` | `4294967295` | The system default authentication service. When this value is specified, COM uses its normal security blanket negotiation algorithm to pick an authentication service. |
| <a id="digest"></a>`Digest` | `21` | Digest security support provider. |
| <a id="dpa"></a>`Dpa` | `17` | DPA security support provider. |
| <a id="kerberos"></a>`Kerberos` | `16` | Kerberos security support provider. |
| <a id="kernel"></a>`Kernel` | `20` | Kernel security support provider. |
| <a id="mq"></a>`Mq` | `100` | MQ security support provider. |
| <a id="msn"></a>`Msn` | `18` | MSN security support provider. |
| <a id="negoextender"></a>`NegoExtender` | `30` | NEGO extender security support provider. |
| <a id="negotiate"></a>`Negotiate` | `9` | Snego security support provider. |
| <a id="none"></a>`None` | `0` | No authentication. |
| <a id="pku2u"></a>`Pku2u` | `31` | PKU2U security support provider. |
| <a id="private"></a>`Private` | `1` | DCE private key authentication. |
| <a id="schannel"></a>`Schannel` | `14` | Schannel security support provider. This authentication service supports SSL 2.0, SSL 3.0, TLS, and PCT. |
| <a id="winnt"></a>`WinNt` | `10` | NTLMSSP. |

## Applies to

| Package | Versions |
|---|---|
| Opc.UaFx.Advanced | v2.32–v2.59 |