Asp.net Identity Email Verifcation Token Not Recognized - asp.net

Question

We are using Microsoft's Identity Framework v2.0 in a web forms application. All is working well. We decided we want to add email verification as part of the new account set up process. If we validate the token after it is created in the same page, we are successful. But if we try to validate the token in a different page, it fails. The process is very simple:
Admin creates a new account by providing user's email and name. (we do not support self registration).
User clicks link he gets in email to validate the email was received.
Here is the code to create the email verification token:
var manager = new UserManager();
var user = new ApplicationUser() { UserName = EmailAddress.Text, Email = EmailAddress.Text, FirstName = FirstName.Text, LastName = LastName.Text };
IdentityResult result = manager.Create(user);
var provider = new DpapiDataProtectionProvider();
manager.UserTokenProvider = new DataProtectorTokenProvider<ApplicationUser>(provider.Create("EmailConfirmation"))
{
TokenLifespan = TimeSpan.FromHours(24)
};
var strToken = manager.GenerateEmailConfirmationToken(user.Id);
//IdentityResult validToken = manager.ConfirmEmail(user.Id, strToken);
strToken = HttpUtility.UrlEncode(strToken.ToString());
NOTE: If we uncomment the line beginning //IdentityResult validToken..., then it succeeds.
Here is the code on the VerifyEmail page:
string userid = Request.QueryString["id"].ToString();
string tokenReceived = Request.QueryString["token"].ToString();
//tokenReceived = HttpUtility.UrlDecode(tokenReceived);
ApplicationUser User = new ApplicationUser();
var manager = new UserManager();
User = manager.FindById(userid);
var provider = new DpapiDataProtectionProvider();
manager.UserTokenProvider = new DataProtectorTokenProvider<ApplicationUser>(provider.Create("EmailConfirmation"))
{
TokenLifespan = TimeSpan.FromHours(24)
};
IdentityResult validToken = manager.ConfirmEmail(User.Id, tokenReceived);
The validToken line does not succeed in this file. I have validated that the strings User.Id and tokenReceived match EXACTLY in both file, so there is no URL corruption going on. (That is why I commented out the UrlDecode since it seems to be decoded by the browser automatically - when I try to decode, it is not 100% the same as the string before encoding).
So I am certain we are calling the same method (ConfirmEmail) and that the two parameters that are passed are exactly the same strings. I am also aware that a token can only be validated once, so I am not trying to re-use them after once validating them.
Any ideas would be welcome.

Answer 1

I think the problem in DpapiDataProtectionProvider - If you use the same instance of this class in creating and validating the token, it'll work fine.
Any reason you are not getting UserManager from Owin Context as per VC2013 template?