FormsAuthenticationModule Class (System.Web.Security)

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Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

FormsAuthenticationModule Class

Updated: November 2007

Sets the identity of the user for an ASP.NET application when forms authentication is enabled. This class cannot be inherited.

Namespace: System.Web.Security
Assembly: System.Web (in System.Web.dll)

Syntax

Visual Basic (Declaration)

<AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level := AspNetHostingPermissionLevel.Minimal)> _
Public NotInheritable Class FormsAuthenticationModule _
    Implements IHttpModule

Visual Basic (Usage)

Dim instance As FormsAuthenticationModule

[AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public sealed class FormsAuthenticationModule : IHttpModule

Visual C++

[AspNetHostingPermissionAttribute(SecurityAction::LinkDemand, Level = AspNetHostingPermissionLevel::Minimal)]
public ref class FormsAuthenticationModule sealed : IHttpModule

/** @attribute AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal) */
public final class FormsAuthenticationModule implements IHttpModule

JScript

public final class FormsAuthenticationModule implements IHttpModule

Remarks

The FormsAuthenticationModule sets the current HttpContext..::.User property to an IPrincipal object that represents the user identity for the current request when the authentication Mode is set to Forms in the authentication Element (ASP.NET Settings Schema) element of the application's configuration file.

The FormsAuthenticationModule exposes an Authenticate event that enables you to provide a custom IPrincipal object for the User property of the current HttpContext. The Authenticate event is accessed by specifying a subroutine named FormsAuthentication_OnAuthenticate in the Global.asax file for your ASP.NET application.

Note:
In IIS 7.0, using the WindowsAuthenticationModule with the FormsAuthenticationModule is not supported. For more information about compatibility issues in Integrated modes, see Upgrading ASP.NET Applications to IIS 7.0: Differences between IIS 7.0 Integrated Mode and Classic mode.

Examples

The following example uses the FormsAuthentication_OnAuthenticate event to set the User property of the current HttpContext to a custom IPrincipal object.

Visual Basic

Public Sub FormsAuthentication_OnAuthenticate(sender As Object, _
                                              args As FormsAuthenticationEventArgs)
  If FormsAuthentication.CookiesSupported Then
    If Not Request.Cookies(FormsAuthentication.FormsCookieName) Is Nothing Then
      Try
        Dim ticket As FormsAuthenticationTicket = FormsAuthentication.Decrypt( _
          Request.Cookies(FormsAuthentication.FormsCookieName).Value)

        args.User = New System.Security.Principal.GenericPrincipal( _
          New Samples.AspNet.Security.MyFormsIdentity(ticket), _
          New String(0) {})
      Catch e As HttpException
        ' Decrypt method failed.
      End Try
    End If
  Else
      Throw New Exception("Cookieless Forms Authentication is not " & _
                            "supported for this application.")
  End If
End Sub

public void FormsAuthentication_OnAuthenticate(object sender, FormsAuthenticationEventArgs args)
{
  if (FormsAuthentication.CookiesSupported)
  {
    if (Request.Cookies[FormsAuthentication.FormsCookieName] != null)
    {
      try
      {
        FormsAuthenticationTicket ticket = FormsAuthentication.Decrypt(
          Request.Cookies[FormsAuthentication.FormsCookieName].Value);

        args.User = new System.Security.Principal.GenericPrincipal(
          new Samples.AspNet.Security.MyFormsIdentity(ticket),
          new string[0]);
      }
      catch (Exception e)
      {
        // Decrypt method failed.
      }
    }
  }
  else
  {
    throw new HttpException("Cookieless Forms Authentication is not " +
                            "supported for this application.");
  }
}

Permissions

AspNetHostingPermission
for using the FormsAuthenticationModule class in a hosted environment. Demand value: LinkDemand. Permission value: Minimal

Inheritance Hierarchy

System..::.Object
System.Web.Security..::.FormsAuthenticationModule

Thread Safety

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

Platforms

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

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

Version Information