Edition 0 Updated to asp. Net core 0

Important 
The lines in the preceding code 
MUST BE IN THE ORDER SHOWN
for Identity to work correctly. 
Using ASP.NET Core Identity enables several scenarios: 
•
Create new user information using the UserManager type (userManager.CreateAsync). 
•
Authenticate users using the SignInManager type. You can use 
signInManager.SignInAsync
to 
sign in directly, or 
signInManager.PasswordSignInAsync
to confirm the user’s password is 
correct and then sign them in. 
•
Identify a user based on information stored in a cookie (which is read by ASP.NET Core Identity 
middleware) so that subsequent requests from a browser will include a signed-
in user’s identity 
and claims. 
ASP.NET Core Identity also supports 
two-factor authentication
. 
For authentication scenarios that make use of a local user data store and that persist identity between 
requests using cookies (as is typical for MVC web applications), ASP.NET Core Identity is a 
recommended solution. 
Authenticate with external providers 
ASP.NET Core also supports using 
external authentication providers
 to let users sign in via 
OAuth 2.0
 
flows. This means that users can sign in using existing authentication processes from providers like 
Microsoft, Google, Facebook, or Twitter and associate those identities with an ASP.NET Core identity 
in your application. 

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CHAPTER 8 | Make secure .NET Microservices and Web Applications 
To use external authentication, besides including the authentication middleware as mentioned before, 
using the 
app.UseAuthentication()
method, you also have to register the external provider in 
Program.cs
as shown in the following example: 
//...
services.
AddDefaultIdentity
(options => options.
SignIn
.
RequireConfirmedAccount
= 
true
) 
.
AddEntityFrameworkStores
(); 
services.
AddAuthentication
() 
.
AddMicrosoftAccount
(microsoftOptions => 
{ 
microsoftOptions.
ClientId
= 
builder.
Configuration
[
"Authentication:Microsoft:ClientId"
]; 
microsoftOptions.
ClientSecret
= 
builder.
Configuration
[
"Authentication:Microsoft:ClientSecret"
]; 
}) 
.
AddGoogle
(googleOptions => { ... }) 
.
AddTwitter
(twitterOptions => { ... }) 
.
AddFacebook
(facebookOptions => { ... }); 
//...
Popular external authentication providers and their associated NuGet packages are shown in the 
following table: