Home/ Questions/Q 8655719
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-06-12T15:06:20+00:00

In order to debug a production issue, I need a tool to decrypt an

  • 0

In order to debug a production issue, I need a tool to decrypt an authentication cookie. I wrote a quick script to decrypt it using FormAuthentication.The essence is

FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(source.Text);

The server has machineKey set and I am using the same key in this app. I am getting cookie text using Fiddler. However, I always get Unable to Validation Exception when using FormAuthentication.Decrypt. The cookie is set HttpOnly.

Am I missing something?

Note: There were a number similar questions but none of the answer has so far helped me so decided to post a new one.

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    It seems to be related to the machine or some sort of machine related identifier. When I ran the sample script on the same server as the production server (i.e where the cookie was generated). The decryption works fine. I still haven’t delve deep into finding out why so but a quick reflection of

    System.Web.Configuration.MachineKeySection.EncryptOrDecryptData

    tells that Unable_to_validate_data is thrown for pretty much any exception there.

    • 0