Leveraging ASP.NET machineKey For Encrypting My Own Data

Question

I have some data I want to encrypt in an ASP.NET MVC application to prevent users from tampering with it. I can use the Cryptography classes to do the actual encryption/decrypt

Answer 1

If you're working with 3.5 or earlier you can avoid a lot of code and just do this:

public static string Encrypt(string cookieValue)
{
    return FormsAuthentication.Encrypt(new FormsAuthenticationTicket(1,
                                                                     string.Empty,
                                                                     DateTime.Now,
                                                                     DateTime.Now.AddMinutes(20160),
                                                                     true,
                                                                     cookieValue));
}

public static string Decrypt(string encryptedTicket)
{
    return FormsAuthentication.Decrypt(encryptedTicket).UserData;
}

One of my colleagues talked me into it and I think it's fairly reasonable to do this for custom cookies, if not for general encryption needs.