AuthenticationManager.PreAuthenticate Method (WebRequest, ICredentials)


Preauthenticates a request.

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

Public Shared Function PreAuthenticate (
	request As WebRequest,
	credentials As ICredentials
) As Authorization


Type: System.Net.WebRequest

A WebRequest to an Internet resource.

Type: System.Net.ICredentials

The ICredentials associated with the request.

Return Value

Type: System.Net.Authorization

An instance of the Authorization class if the request can be preauthenticated; otherwise, null. If credentials is null, this method returns null.

Exception Condition

request is null.

If the authentication module can preauthenticate the request, the PreAuthenticate method returns an Authentication instance and sends the authorization information to the server preemptively instead of waiting for the resource to issue a challenge. This behavior is outlined in section 3.3 of RFC 2617 (HTTP Authentication: Basic and Digest Access Authentication). Authentication modules that support preauthentication allow clients to improve server efficiency by avoiding extra round trips caused by authentication challenges.

Authorization modules that can preauthenticate requests set the IAuthenticationModule.CanPreAuthenticate property to true.

.NET Framework
Available since 1.1
Return to top