public override async Task GrantResourceOwnerCredentials(OAuthGrantResourceOwnerCredentialsContext context) { var userManager = GebruikerManager.Create(System.Web.HttpContext.Current.GetOwinContext().Get <AppBuilderProvider>().Get().GetDataProtectionProvider()); Gebruiker user = await userManager.FindAsync(context.UserName, context.Password); if (user == null) { context.SetError("invalid_grant", "The user name or password is incorrect."); return; } ClaimsIdentity oAuthIdentity = await user.GenerateUserIdentityAsync(userManager, OAuthDefaults.AuthenticationType); ClaimsIdentity cookiesIdentity = await user.GenerateUserIdentityAsync(userManager, CookieAuthenticationDefaults.AuthenticationType); AuthenticationProperties properties = CreateProperties(user.UserName); AuthenticationTicket ticket = new AuthenticationTicket(oAuthIdentity, properties); context.Validated(ticket); context.Request.Context.Authentication.SignIn(cookiesIdentity); }