SslStream.BeginAuthenticateAsServer Method (X509Certificate, Boolean, SslProtocols, Boolean, AsyncCallback, Object)

Note: This method is new in the .NET Framework version 2.0.

Called by servers to begin an asynchronous operation to authenticate the server and optionally the client using the specified certificates, requirements and security protocol.

Namespace: System.Net.Security
Assembly: System (in system.dll)

public virtual IAsyncResult BeginAuthenticateAsServer (
	X509Certificate serverCertificate,
	bool clientCertificateRequired,
	SslProtocols enabledSslProtocols,
	bool checkCertificateRevocation,
	AsyncCallback asyncCallback,
	Object asyncState
public IAsyncResult BeginAuthenticateAsServer (
	X509Certificate serverCertificate, 
	boolean clientCertificateRequired, 
	SslProtocols enabledSslProtocols, 
	boolean checkCertificateRevocation, 
	AsyncCallback asyncCallback, 
	Object asyncState
public function BeginAuthenticateAsServer (
	serverCertificate : X509Certificate, 
	clientCertificateRequired : boolean, 
	enabledSslProtocols : SslProtocols, 
	checkCertificateRevocation : boolean, 
	asyncCallback : AsyncCallback, 
	asyncState : Object
) : IAsyncResult



The X509Certificate used to authenticate the server.


A Boolean value that specifies whether the client must supply a certificate for authentication.


The SslProtocols value that represents the protocol used for authentication.


A Boolean value that specifies whether the certificate revocation list is checked during authentication.


An AsyncCallback delegate that references the method to invoke when the authentication is complete.


A user-defined object that contains information about the operation. This object is passed to the asyncCallback delegate when the operation completes.

Return Value

An IAsyncResult object that indicates the status of the asynchronous operation.

Exception typeCondition


serverCertificate is a null reference (Nothing in Visual Basic).


enabledSslProtocols is not a valid SslProtocols value.


The authentication failed and left this object in an unusable state.


Authentication has already occurred.


Server authentication using this SslStream was tried previously.


Authentication is already in progress.


This object has been closed.


The BeginAuthenticateAsServer method is not supported on Windows 95, Windows 98, or Windows Millennium.

The asynchronous authentication operation must be completed by calling the EndAuthenticateAsServer method. Typically, the method is invoked by the asyncCallback delegate.

This method does not block while the operation completes. To block until the operation completes, use one of the AuthenticateAsServer method overloads.

For detailed information about using the asynchronous programming model, see Calling Synchronous Methods Asynchronously

If you receive a AuthenticationException, this SslStream is no longer useable. You should close this object and remove all references to it so that it can be collected by the garbage collector.

Windows 95, Windows 98, Windows 98 Second Edition, Windows Millennium Edition Platform Note: The BeginAuthenticateAsServer method is not supported.

Windows 98, Windows 2000 SP4, Windows Millennium Edition, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see System Requirements.

.NET Framework

Supported in: 2.0