title: Can not use BackOfficeUserPasswordChecker to login Umbraco with external user
body: <p>I am trying to use BackOfficeUserPasswordChecker to make authentication for Umbraco (with external users).</p>
  
  <p>I customized the OwinStartup:</p>
  
  <pre><code>    public class UmbracoCustomOwinStartup
      {
          public void Configuration(IAppBuilder app)
          {
              var applicationContext = ApplicationContext.Current;
              app.ConfigureUserManagerForUmbracoBackOffice&lt;BackOfficeUserManager, BackOfficeIdentityUser&gt;(
                  applicationContext,
                  (options, context) =&gt;
                  {
                      var membershipProvider = Umbraco.Core.Security.MembershipProviderExtensions.GetUsersMembershipProvider().AsUmbracoMembershipProvider();
                      var settingContent = Umbraco.Core.Configuration.UmbracoConfig.For.UmbracoSettings().Content;
                      var userManager = BackOfficeUserManager.Create(options,
                          applicationContext.Services.UserService,
                          applicationContext.Services.EntityService,
                          applicationContext.Services.ExternalLoginService,
                          membershipProvider,
                          settingContent);
  
                      // Set your own custom IBackOfficeUserPasswordChecker   
                      userManager.BackOfficeUserPasswordChecker = new CustomPasswordChecker();
                      return userManager;
                  });
         }
    }
  </code></pre>
  
  <p>And I also defined CustomPasswordChecker which always return ValidCredentials in CheckPasswordAsync method:</p>
  
  <pre><code>public Task&lt;BackOfficeUserPasswordCheckerResult&gt; CheckPasswordAsync(BackOfficeIdentityUser user, string password)
      {
          return Task.FromResult(BackOfficeUserPasswordCheckerResult.ValidCredentials);
      }
  </code></pre>
  
  <p>When I entered an user name which don't have in Umbraco database, the Umbraco login still throw the message "login failed fo user...". I debugged, and it jumped to CustomPasswordChecker.CheckPasswordAsync() correctly, but the message still throw and I can not log in successfully.</p>
  
  <p>Did I missed something? And how can I make Umbraco accept external users (AD users/ users that is defined in other database,...)?</p>