Decrypting the .ASPXAUTH Cookie WITH protection=validation

Question

For quite sometime I\'ve been trying to decipher the ASP .ASPXAUTH cookie and decrypt it using PHP. My reasons are huge and I need to do this, there is no alternative. In

Answer 1

I know what a pain is to decrypt in PHP something encrypted in .NET and vice versa.

I had to end up coding myself the Rijndael algorithm ( translated it from another language ).

Here is the link to the source code of the algorithm: http://pastebin.com/EnCJBLSY

At the end of the source code there is some usage example.

But on .NET, you should use zero padding when encrypting. Also test it with ECB mode, I'm not sure if CBC works.

Good luck and hope it helps

edit: the algorithm returns the hexadecimal string when encrypts, and also expects hexadecimal string when decrypting.