kbdank71 kbdank71 - 1 year ago 104
ASP.NET (C#) Question

"The input is not a valid Base-64 string" exception on login after migrating from membership to identity 2.0

I just upgraded my website from memberhip to asp.net identity 2.0 based on the instructions found here. I created new register and login forms, and migrated my user data to the new db tables.

If I create a new user using the register.aspx form, everything works fine. The new user is saved to the db, and I can log in with the credentials.

But if I try to log in with an existing user that I migrated, I get the following System.FormatException: The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters.

From Login.aspx.cs

protected void SignIn(object sender, EventArgs e)
var userStore = new UserStore<User>(new ApplicationDBContext());
var userManager = new UserManager<User>(userStore);
var user = userManager.Find(UserName.Text, Password.Text);

if (user != null)
var authenticationManager = HttpContext.Current.GetOwinContext().Authentication;
var userIdentity = userManager.CreateIdentity(user, DefaultAuthenticationTypes.ApplicationCookie);

authenticationManager.SignIn(new AuthenticationProperties() { IsPersistent = false }, userIdentity);
StatusText.Text = "Invalid username or password.";
LoginStatus.Visible = true;

The exception occurs on this line:

var user = userManager.Find(UserName.Text, Password.Text);

I set a breakpoint to see what it was bombing on, but it just got to that line in the code and stopped.

I thought it might be due to the way I migrated the password, since new users work, but I don't see anything that matches the error in the PasswordHash column for existing users.

This is what I inserted into the PasswordHash column when I migrated the users:

(aspnet_Membership.Password+'|'+CAST(aspnet_Membership.PasswordFormat as varchar)+'|'+aspnet_Membership.PasswordSalt)

I've been working this all week, any help would be greatly appreciated.


Answer Source

In the Login.aspx.cs file, I changed

var userManager = new UserManager<User>(userStore);


var userManager = new UserManager();

This allowed me to login with both existing and new users by using my UserManager instead of identity's.

Thanks to trailmax for getting me in the right direction!