Defines the configuration settings that control the key generation and algorithms that are used in encryption, decryption, and media access control (MAC) operations in Windows Forms authentication, view-state validation, and session-state application isolation. This class cannot be inherited.
Assembly: System.Web (in System.Web.dll)
The class provides a way to programmatically access and modify the content of the <MachineKey> section in the configuration file. The <MachineKey> section can be configured at the machine (Machine.config) or application (Web.config) level and controls the keys and algorithms that are used for Windows Forms authentication, view-state validation, and session-state application isolation. For any of these features to work across a network of Web servers (a Web farm), the <MachineKey> attributes must be configured explicitly and identically with valid key values. The "AutoGenerate" value does not work for Web farms, because it relies on a cryptographically random secret, which is persisted using machine-local protection and will not be coherent across more than one computer.Notes to Implementers:
If it is required to specify keys in this configuration section, as is often required in Web-farm scenarios, it is recommended that you encrypt this section by using protected configuration.
The example in this section demonstrates how to specify values declaratively for several attributes of the machineKey Element (ASP.NET Settings Schema) section, which can also be accessed as members of the class.
The following example from a configuration file shows how to specify values declaratively for the machineKey Element (ASP.NET Settings Schema) section.
<system.web> <machineKey validationKey="AutoGenerate,IsolateApps" decryptionKey="AutoGenerate,IsolateApps" validation="SHA1"/> </system.web>
The following example demonstrates how to use the class.
Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, 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.