AuthenticationManager.PreAuthenticate Method
Preauthenticates a request.
Assembly: System (in System.dll)
'Declaration Public Shared Function PreAuthenticate ( _ request As WebRequest, _ credentials As ICredentials _ ) As Authorization
Parameters
- request
- Type: System.Net.WebRequest
A WebRequest to an Internet resource.
- credentials
- Type: System.Net.ICredentials
The ICredentials associated with the request.
Return Value
Type: System.Net.AuthorizationAn instance of the Authorization class if the request can be preauthenticated; otherwise, Nothing. If credentials is Nothing, this method returns Nothing.
| Exception | Condition |
|---|---|
| ArgumentNullException | request is Nothing. |
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.
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
