Expose UserManager<T>.GetChangeEmailTokenPurpose()

UserManager In 2.1 exposed the “purpose” constants, eg. ConfirmEmailTokenPurpose.

We relied on this in order to use userManager.VerifyUserTokenAsync().

Now those constants are gone, and there is a GetChangeEmailTokenPurpose() method in its place, which is protected.

Please make it public, otherwise the verify function is unusable.

(Subclassing just adds an unnecessary mess as this class already conceals a lot of complexity and should be usable as is.)

[HaoK]

Something for the backlog / future @blowdart

[lonix1]

Thanks for looking into this.

I’ve opted to subclass instead, to avoid magic strings (as shown by this issue, it’s a bad idea to rely on magic strings 😄).

For anyone else migrating code to 2.2, note that if you subclass, it’s important not to register the subclass with the container, but to replace the default during init:

services
.AddIdentityCore<User>()
.AddUserManager<MyUserManager<User>>()    // <--- the magic

And then it’s as easy as this:

public async Task<bool> ValidateEmailChangeToken(TUser user, string newEmail, string token) {
  return await VerifyUserTokenAsync(
    user,
    Options.Tokens.ChangeEmailTokenProvider,
    GetChangeEmailTokenPurpose(newEmail),
    token
  );
}