AuthEndpoints

A simple jwt authentication library for ASP.Net 6. AuthEndpoints library provides a set of minimal api endpoints to handle basic web & JWT authentication actions such as registration, email verification, reset password, create jwt, etc. It works with custom identity user model.

Supported endpoints

• Users API:
  • sign-up
  • email verification
  • user profile (retrieving)
  • reset password
  • change password
  • enable 2fa
  • login 2fa
• TokenAuth:
  • Create (login)
  • Destroy (logout)
• Simple JWT:
  • Create (login)
  • Refresh
  • Verify

Current limitations

• Only works with IdentityUser & EfCore
• 2fa via email

Installing via NuGet

The easiest way to install AuthEndpoints is via NuGet

Install the library using the following .net cli command:

dotnet add package AuthEndpoints

or in Visual Studio's Package Manager Console, enter the following command:

Install-Package AuthEndpoints

Quick start

// MyDbContext.cs


using AuthEndpoints.SimpleJwt.Core.Models;

public class MyDbContext : IdentityDbContext
{
  public DbSet<RefreshToken>? RefreshTokens { get; set; } // <--
  public MyDbContext(DbContextOptions<MyDbContext> options) : base(options) { }
}

Add migration and apply migration:

// using dotnet cli
$ dotnet ef migrations add CreateRefreshToken
$ dotnet ef database update

// or using package manager console in visual studio
PM> Add-Migration CreateRefreshToken
PM> Update-Database

Add endpoints and call app.MapEndpoints() before app.Run();

// Program.cs


// Required services
builder.Services.AddIdentityCore<IdentityUser>(); // <--

// Add core services & users api
builder.Services.AddAuthEndpointsCore<IdentityUser, MyDbContext>() // <--
                .AddUsersApiEndpoints()
                .Add2FAEndpoints();

// Add jwt endpoints
// When no options are provided
// AuthEndpoints will create a secret key and use a single security key (symmetric encryption)
// for each access jwt and refresh jwt.
// Secrets will be created under `keys/` directory.
builder.Services.AddSimpleJwtEndpoints<IdentityUser, MyDbContext>(); // <--

var app = builder.Build();

...

app.UseAuthentication(); // <--
app.UseAuthorization(); // <--

...

app.MapEndpoints(); // <--

app.Run();

Jwt endpoints (registered by AddSimpleJwtEndpoints<,>()) will return the access and refresh tokens to the client. During the authentication flow, we save the access and refresh tokens on the client storage, for instance web storage (localStorage / sessionStorage). We'll then attach the access token to the HTTP client on every request against the API. This approach does not require any backend for SPA hosting, so the SPA can be standalone. There is no SameSite requirement. Another advantage of this approach is its contents cannot be automatically sent anywhere. Therefore, immune to cross-site request forgery (CSRF) attacks. (Token storage and handling are all done on client side)

On the downside, this default approach often adds a level of complexity with potential security concerns. Let's say we store the tokens in web storage. Any JavaScript running on our site will have access to web storage. This make the tokens can be easily grabbed via cross-site scripting (XSS) attacks.

To avoid this issue, you can store the jwts inside httponly cookie instead of web storage. This adds a layer of protection to the jwts. HttpOnly flag on cookie mitigate the risk of client side script accessing the protected cookie. With this approach, token storage and handling are all done at the backend side.

To use this approach, you can simply:

builder.Services.AddSimpleJwtEndpoints<IdentityUser, MyDbContext>(options => 
{
  options.UseCookie = true;
});

When using UseCookie = true, jwts will be stored in httponly cookie with samesite flag set to lax by default. All jwt endpoints will return 204 NoContent instead of returning the access and refresh tokens to the client (tokens are no longer handled at the client side).

Keep in mind that storing jwts inside HttpOnly Cookie does not prevent XSS attacks. If site is vulnerable to XSS, with httponly cookie, attacker cannot grab the tokens. However, attacker can still make a request on of behalf of the user. Make sure to follow best practices against XSS including escaping contents.

Cookie is considered more secure, but it might be vulnerable to CSRF attacks. Antiforgery is not handled by default and so you might need some custom code to flow a CSRF token between the server and your client application.

Most of the times you may want to store JWTs in HttpOnly Cookie. It makes development process easier and considered more secure because tokens are no longer handled at the client side.

Documentations

Documentation is available at https://madeyoga.github.io/AuthEndpoints/ and in docs directory.

Contributing

Your contributions are always welcome! simply send a pull request! The up-for-grabs label is a great place to start. If you find a flaw, please open an issue or a PR and let's sort things out.

The project is far from perfect so every bit of help is more than welcome.