I find myself wanting to get the ASP.NET machine key for the current application. This is, of course, easy if a machine key is specified in the configuration file, but if it's set to auto generate then there doesn't seem to be a public method anywhere to get it.
Basically I want at it so I can write an encrypted/MACed cookie for myself, just like the ASP.NET Forms Authentication provider does.
Does anyone have any pointers or ideas?
If the ASP.NET Forms Authentication provider can access it then have you tried looking at the provider source code? (I think this is the correct location, ScottGu's original blog post on the subject has had broken links since they updated MSDN)
Do you actually NEED the key? Or just to encrypt and decrypt the data?
System.Web.Security.FormsAuthentication (.NET 2.0) has public Encrypt/Decrypt methods. These use System.Web.Configuration.MachineKeySection EncryptOrDecryptData, ByteArrayToHexString and HexStringToByteArray to encrypt and decrypt the data.
EncryptOrDecryptData handles loading / configuring the key data from config files/AutoGenerate as required.
Encrypt And Decrypt should be available via the source code downloads or reflector and readily converted to your purpose.