Use .NET Core Identity with an API - c#

i've created an API and set up JWT auth from the same API (I chose not to use IdentityServer4).
I did this through services.AddAuthentication
And then I created tokens in the controller and it works.
However I now want to add registration etc. But i prefer not to write my own code for hashing passwords, handling registration emails etc.
So I came across ASP.NET Core Identity and it seems like what I need, except from that it adds some UI stuff that I dont need (because its just an API and the UI i want completely independent).
But on MSDN is written:
ASP.NET Core Identity adds user interface (UI) login functionality to
ASP.NET Core web apps. To secure web APIs and SPAs, use one of the
following:
Azure Active Directory
Azure Active Directory B2C (Azure AD B2C)
IdentityServer4
So is it really a bad idea to use Core Identity just for hashing and registration logic for an API? Cant I just ignore the UI functionality? It's very confusing because I'd rather not use IdentityServer4 or create my own user management logic.

Let me just get off my chest that the bundling Identity does with the UI, the cookies and the confusing various extension methods that add this or that, but don't add this or that, is pretty annoying, at least when you build modern web APIs that need no cookies nor UI.
In some projects I also use manual JWT token generation with Identity for the membership features and user/password management.
Basically the simplest thing to do is to check the source code.
AddDefaultIdentity() adds authentication, adds the Identity cookies, adds the UI, and calls AddIdentityCore(); but has no support for roles:
public static IdentityBuilder AddDefaultIdentity<TUser>(this IServiceCollection services, Action<IdentityOptions> configureOptions) where TUser : class
{
services.AddAuthentication(o =>
{
o.DefaultScheme = IdentityConstants.ApplicationScheme;
o.DefaultSignInScheme = IdentityConstants.ExternalScheme;
})
.AddIdentityCookies(o => { });
return services.AddIdentityCore<TUser>(o =>
{
o.Stores.MaxLengthForKeys = 128;
configureOptions?.Invoke(o);
})
.AddDefaultUI()
.AddDefaultTokenProviders();
}
AddIdentityCore() is a more stripped down version that only adds basic services, but it doesn't even add authentication, and also no support for roles (here you can already see what individual services are added, to change/override/remove them if you want):
public static IdentityBuilder AddIdentityCore<TUser>(this IServiceCollection services, Action<IdentityOptions> setupAction)
where TUser : class
{
// Services identity depends on
services.AddOptions().AddLogging();
// Services used by identity
services.TryAddScoped<IUserValidator<TUser>, UserValidator<TUser>>();
services.TryAddScoped<IPasswordValidator<TUser>, PasswordValidator<TUser>>();
services.TryAddScoped<IPasswordHasher<TUser>, PasswordHasher<TUser>>();
services.TryAddScoped<ILookupNormalizer, UpperInvariantLookupNormalizer>();
services.TryAddScoped<IUserConfirmation<TUser>, DefaultUserConfirmation<TUser>>();
// No interface for the error describer so we can add errors without rev'ing the interface
services.TryAddScoped<IdentityErrorDescriber>();
services.TryAddScoped<IUserClaimsPrincipalFactory<TUser>, UserClaimsPrincipalFactory<TUser>>();
services.TryAddScoped<UserManager<TUser>>();
if (setupAction != null)
{
services.Configure(setupAction);
}
return new IdentityBuilder(typeof(TUser), services);
}
Now that kind of makes sense so far, right?
But enter AddIdentity(), which appears to be the most bloated, the only one that supports roles directly, but confusingly enough it doesn't seem to add the UI:
public static IdentityBuilder AddIdentity<TUser, TRole>(
this IServiceCollection services,
Action<IdentityOptions> setupAction)
where TUser : class
where TRole : class
{
// Services used by identity
services.AddAuthentication(options =>
{
options.DefaultAuthenticateScheme = IdentityConstants.ApplicationScheme;
options.DefaultChallengeScheme = IdentityConstants.ApplicationScheme;
options.DefaultSignInScheme = IdentityConstants.ExternalScheme;
})
.AddCookie(IdentityConstants.ApplicationScheme, o =>
{
o.LoginPath = new PathString("/Account/Login");
o.Events = new CookieAuthenticationEvents
{
OnValidatePrincipal = SecurityStampValidator.ValidatePrincipalAsync
};
})
.AddCookie(IdentityConstants.ExternalScheme, o =>
{
o.Cookie.Name = IdentityConstants.ExternalScheme;
o.ExpireTimeSpan = TimeSpan.FromMinutes(5);
})
.AddCookie(IdentityConstants.TwoFactorRememberMeScheme, o =>
{
o.Cookie.Name = IdentityConstants.TwoFactorRememberMeScheme;
o.Events = new CookieAuthenticationEvents
{
OnValidatePrincipal = SecurityStampValidator.ValidateAsync<ITwoFactorSecurityStampValidator>
};
})
.AddCookie(IdentityConstants.TwoFactorUserIdScheme, o =>
{
o.Cookie.Name = IdentityConstants.TwoFactorUserIdScheme;
o.ExpireTimeSpan = TimeSpan.FromMinutes(5);
});
// Hosting doesn't add IHttpContextAccessor by default
services.AddHttpContextAccessor();
// Identity services
services.TryAddScoped<IUserValidator<TUser>, UserValidator<TUser>>();
services.TryAddScoped<IPasswordValidator<TUser>, PasswordValidator<TUser>>();
services.TryAddScoped<IPasswordHasher<TUser>, PasswordHasher<TUser>>();
services.TryAddScoped<ILookupNormalizer, UpperInvariantLookupNormalizer>();
services.TryAddScoped<IRoleValidator<TRole>, RoleValidator<TRole>>();
// No interface for the error describer so we can add errors without rev'ing the interface
services.TryAddScoped<IdentityErrorDescriber>();
services.TryAddScoped<ISecurityStampValidator, SecurityStampValidator<TUser>>();
services.TryAddScoped<ITwoFactorSecurityStampValidator, TwoFactorSecurityStampValidator<TUser>>();
services.TryAddScoped<IUserClaimsPrincipalFactory<TUser>, UserClaimsPrincipalFactory<TUser, TRole>>();
services.TryAddScoped<IUserConfirmation<TUser>, DefaultUserConfirmation<TUser>>();
services.TryAddScoped<UserManager<TUser>>();
services.TryAddScoped<SignInManager<TUser>>();
services.TryAddScoped<RoleManager<TRole>>();
if (setupAction != null)
{
services.Configure(setupAction);
}
return new IdentityBuilder(typeof(TUser), typeof(TRole), services);
}
All in all what you probably need is the AddIdentityCore(), plus you have to use AddAuthentication() on your own.
Also, if you use AddIdentity(), be sure to run your AddAuthentication() configuration after calling AddIdentity(), because you have to override the default authentication schemes (I ran into problems related to this, but can't remember the details).
(Another tidbit of information that might be interesting for people reading this is the distinction between SignInManager.PasswordSignInAsync(), SignInManager.CheckPasswordSignInAsync() and UserManager.CheckPasswordAsync(). These are all public methods you can find and call for authorization purposes. PasswordSignInAsync() implements two-factor signin (also sets cookies; probably only when using AddIdentity() or AddDefaultIdentity()) and calls CheckPasswordSignInAsync(), which implements user lockout handling and calls UserManager.CheckPasswordAsync(), which just checks the password. So to get a proper authentication it's better not to call UserManager.CheckPasswordAsync() directly, but to do it through CheckPasswordSignInAsync(). But, in a single-factor JWT token scenario, calling PasswordSignInAsync() is probably not needed (and you can run into redirect issues). If you have included UseAuthentication()/AddAuthentication() in the Startup with the proper JwtBearer token schemes set, then the next time the client sends a request with a valid token attached, the authentication middleware will kick in, and the client will be 'signed in'; i.e. any valid JWT token will allow client to access controller actions protected with [Authorize].)
And IdentityServer is thankfully completely separate from Identity. In fact the decent implementation of IdentityServer is to use it as a standalone literal identity server that issues tokens for your services. But since ASP.NET Core has no token generation capability built-in, a lot of people end up running this bloated server inside their apps just to be able to use JWT tokens, even though they have a single app and they have no real use for a central authority. I don't mean to hate on it, it's a really great solution with a lot of features, but it would be nice to have something simpler for the more common use cases.

You just configure Identity to use JWT bearer tokens. In my case I'm using encrypted token, so depending on your use-case you may want to adjust the configuration:
// In Startup.ConfigureServices...
services.AddDefaultIdentity<ApplicationUser>(
options =>
{
// Configure password options etc.
})
.AddEntityFrameworkStores<ApplicationDbContext>()
.AddDefaultTokenProviders();
// Configure authentication
services.AddAuthentication(
opt =>
{
opt.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
opt.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
opt.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(options =>
{
options.TokenValidationParameters = new TokenValidationParameters
{
ValidateIssuer = false,
ValidateAudience = false,
TokenDecryptionKey =
new SymmetricSecurityKey(Encoding.UTF8.GetBytes("my key")),
RequireSignedTokens = false, // False because I'm encrypting the token instead
ValidateLifetime = true,
ClockSkew = TimeSpan.Zero
};
});
// Down in Startup.Configure add authn+authz middlewares
app.UseAuthentication();
app.UseAuthorization();
Then generate a token when the user wants to sign in:
var encKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes("my key"));
var encCreds = new EncryptingCredentials(encKey, SecurityAlgorithms.Aes256KW, SecurityAlgorithms.Aes256CbcHmacSha512);
var claimsIdentity = await _claimsIdentiyFactory.CreateAsync(user);
var desc = new SecurityTokenDescriptor
{
Subject = claimsIdentity,
Expires = DateTime.UtcNow.AddMinutes(_configuration.Identity.JwtExpirationMinutes),
Issuer = _configuration.Identity.JwtIssuer,
Audience = _configuration.Identity.JwtAudience,
EncryptingCredentials = encCreds
};
var token = new JwtSecurityTokenHandler().CreateEncodedJwt(desc);
// Return it to the user
You can then use the UserManager to handle creating new users and retrieving users, while SignInManager can be used to check for valid login/credentials before generating the token.

Related

.NET Core WebApi + Angular Authentication & Authorization via applications in Microsoft Azure

We have 2 web applications on Angular (FE_1, FE_2) and 3 API applications on .NET Core (see picture)
Need to login at once time from one site and working between two without any additional authorization processes
I mean, when we log in to site1 and receive token #1, I want this token to work with API_2 as well, and vice versa, when we log in to site2 and receive token #2, I want to use this token to work as well with API_1
So my question is how to properly configure applications in Azure and configure them internally based on the described architecture ?
Thankyou Manish. Posting your suggestion as an answer to help the other community members.
from the provided architecture in BE code add the list of valid audiences as per the below image make it to true
Below is the sample code where you can check the valid audience code.
services.AddAuthentication(cfg =>
{
cfg.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
cfg.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(opt =>
{
opt.Authority = "https://login.microsoftonline.com/common";
opt.Audience = "api://A134d6c8-8078-2924-9e90-98cef862eb9a"; // Set this to the App ID URL for the web API, which you created when you registered the web API with Azure AD.
opt.TokenValidationParameters = new TokenValidationParameters
{
ValidateIssuer = true,
ValidateAudience = true,
ValidAudiences = new List<String>
{
// you could add a list of valid audiences
"A134d6c8-8078-2924-9e90-98cef862eb9a"
},
ValidIssuers = new List<string>
{
// Add tenant id after https://sts.windows.net/
"https://sts.windows.net/{YourTenantId}"
}
};
opt.Events = new JwtBearerEvents()
{
OnAuthenticationFailed = AuthenticationFailed
};
});
For complete information check the SO.

authenticate MVC website user from Web API by using MVC Core Identity

I have two .net core 2.2 projects; the first one is an MVC project which is like presentation layer that user can login and the other Web API that handles DB operations. I want to handle login request in Web API and return the login result to MVC project by using MVC Core Identity. My DbContext is in the Web API project. Is there anyway to create identity cookie according to result of Web API request?
In this situation the authentication should be handled with an access token rather than a cookie.
For your Web API, implement Resource Owner Password Credentials grant type of OAuth2 protocol with the help of IdentityServer 4 library. At the end you should be able to get an access token from the API in exchange of login credentials.
For your MVC project, create a table to store token-sessid pairs, so when the MVC application gets an access token from the API during a session, it will save them in the table. For the subsequent requests the MVC app will get the token from the table (by using the sessid) and use it to access the Web API.
First in the startup class of your MVC on the server side
add->
services.AddAuthentication(options => {
options.DefaultScheme = "Cookies";
}).AddCookie("Cookies", options => {
options.Cookie.Name = "auth_cookie";
options.Cookie.SameSite = SameSiteMode.None;
options.Events = new CookieAuthenticationEvents
{
OnRedirectToLogin = redirectContext =>
{
redirectContext.HttpContext.Response.StatusCode = 401;
return Task.CompletedTask;
}
};
});
Then in your Login Controller of MVC
[HttpPost]
public async Task<IActionResult> Login(string username, string password)
{
if (!IsValidUsernameAndPasswod(username, password))
return BadRequest();
var user = GetUserFromUsername(username);
var claimsIdentity = new ClaimsIdentity(new[]
{
new Claim(ClaimTypes.Name, user.Username),
//...
}, "Cookies");
var claimsPrincipal = new ClaimsPrincipal(claimsIdentity);
await Request.HttpContext.SignInAsync("Cookies", claimsPrincipal);
return NoContent();
}
Notice that we are referencing the “Cookies” authentication scheme we’ve defined in Startup.cs.
Afterwards on your web api->
CookieContainer cookieContainer = new CookieContainer();
HttpClientHandler handler = new HttpClientHandler
{
CookieContainer = cookieContainer
};
handler.CookieContainer = cookieContainer;
var client = new HttpClient(handler);
var loginResponse = await client.PostAsync("http://yourdomain.com/api/account/login?username=theUsername&password=thePassword", null);
if (!loginResponse.IsSuccessStatusCode){
//handle unsuccessful login
}
var authCookie = cookieContainer.GetCookies(new Uri("http://yourdomain.com")).Cast<Cookie>().Single(cookie => cookie.Name == "auth_cookie");
//Save authCookie.ToString() somewhere
//authCookie.ToString() -> auth_cookie=CfDJ8J0_eoL4pK5Hq8bJZ8e1XIXFsDk7xDzvER3g70....
This should help you achieve your Task. Of course change values based on your requirements, but thus code would be a good reference point.
Also add the required code to set cookies from your web api application.
Hope it helps!
I am not sure I’m fully up to speed with your problem statement. I am assuming that you’re after some sort of mechanism that enables a user to pass their identity all the way from web client to your DbContext.
I also assume you then don’t really authenticate users on the MVC app and basically proxy their requests onto WebAPI.
If so, you might want to consider crafting a JWT (preferably, signed) token as your WebAPI response and then storing it on the client (I guess cookie is a good enough mechanism).
Then MVC project will naturally get the token by virtue of Session State and all you will have to do would be to pass it along with every WebAPI request you make.
1. Only two services
If your system has only two services (front and back) you could use Cookies for all your authentication schemes in your front and consume your api for user validation.
Implement the login page in your web app and verify the users from your login action method (post) calling a backend endpoint (your api) where you can validate the credentials against your database. Note that you do not need to publish this endpoint in internet.
ConfigureServices:
services.AddAuthentication(options =>
{
options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
})
.AddCookie(options =>
{
options.LoginPath = "/auth/login";
options.LogoutPath = "/auth/logout";
});
AuthController:
[HttpPost]
public IActionResult Login([FromBody] LoginViewModel loginViewModel)
{
User user = authenticationService.ValidateUserCredentials(loginViewModel.Username, loginViewModel.Password);
if (user != null)
{
var claims = new List<Claim>
{
new Claim(ClaimTypes.Name, user.UserName),
new Claim(ClaimTypes.Role, user.Role),
new Claim(ClaimTypes.Email, user.Email)
};
var identity = new ClaimsIdentity(claims, CookieAuthenticationDefaults.AuthenticationScheme);
var principal = new ClaimsPrincipal(identity);
await HttpContext.SignInAsync(principal);
return Redirect(loginViewModel.ReturnUrl);
}
ModelState.AddModelError("LoginError", "Invalid credentials");
return View(loginViewModel);
}
2. OAuth2 or OpenId Connect dedicated server
But if you want to implement your own authorization service or idenitity provider which can be used by all your applications (both front and back) I would recommend creating your own server with a standard like OAuth2 or OpenId. This service should be dedicated exclusively for this purpose.
If your services are net core you could use IdentityServer. It is a middleware that is certified by OpenIdConnect and is very complete and extensible. You have extensive documentation and it's easy to implement for both OAuth2 and OpenId. You could add your dbContext to use your user model.
Your Web app ConfigureServices:
services.AddAuthentication(options =>
{
options.DefaultScheme = "Cookies";
options.DefaultChallengeScheme = "oidc";
})
.AddCookie("Cookies")
.AddOpenIdConnect("oidc", options =>
{
options.SignInScheme = "Cookies";
options.Authority = "https://myauthority.com";
options.ClientId = "client";
options.ClientSecret = "secret";
options.SaveTokens = true;
options.Scope.Clear();
options.Scope.Add("myapi");
// ...
}
Your Identity Provider ConfigureServices:
services.AddIdentityServer()
.AddInMemoryClients(Config.GetClients())
.AddInMemoryApiResources(Config.GetApis())
.AddInMemoryIdentityResources(Config.GetIdentityResources())
.AddConfigurationStore(options =>
{
options.ConfigureDbContext = builder =>
builder.UseSqlServer(connectionString,
sql => sql.MigrationsAssembly(migrationsAssembly));
})
.AddDeveloperSigningCredential();
In this way your fronts would request access to the scopes necessary to access the apis. The front would receive an access token with this scope (if this client is allowed for the requested scopes). These apis in turn could validate the access token with a validation middleware like the following:
services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
.AddJwtBearer(options =>
{
options.Authority = "https://myauthority.com";
options.Audience = "myapi";
});
3. Custom remote handler
If you still prefer to implement something remote by yourself you can implement your custom RemoteAuthenticationHandler. This abstract class helps you to redirect to a remote login service (your api) and handles results on callback redirections with the authorization result in your web app. This result is used to populate the user ClaimsPrincipal and if you configure your web app authentication services in this way you could maintain the user session in a Cookie:
services.AddAuthentication(options =>
{
options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
options.DefaultChallengeScheme = "CustomScheme";
})
.AddCookie()
.AddRemoteScheme<CustomRemoteAuthenticationOptions, CustomRemoteAuthenticationHandler>("CustomScheme", "Custom", options =>
{
options.AuthorizationEndpoint = "https://myapi.com/authorize";
options.SignInScheme = CookieAuthenticationDefaults.AuthenticationScheme;
options.SaveTokens = true;
options.CallbackPath = "/mycallback";
});
You can see the remote handlers OAuthHandler or OpenIdConnectHandler as a guide to implement yours.
Implementing your own handler (and handler options) could be cumbersome and insecure, so you should to consider the first options.

How to disable External Logins in Identity Core?

I am in the process of integrating a simplefied authentication process into a asp.net core 2.1 application, where users are logging in via the UI by default, but there is also the possibility to aquire a token and call some secured api endpoints to retrieve some data needed for reporting.
The issue I am facing is, that with the default configuration everything works, but adding the token config throws some weird errors.
If I do not add AddCookie("Identity.External"), call to the onGet method at /Identity/Account/Login throws the exception
InvalidOperationException: No sign-out authentication handler is registered for the scheme 'Identity.External'. The registered sign-out schemes are: Identity.Application. Did you forget to call AddAuthentication().AddCookies("Identity.External",...)?
If I do not specify options.DefaultScheme = "Identity.Application"; the user is not successfully signed in.
If I do not add .AddCookie("Identity.External") and .AddCookie("Identity.TwoFactorUserId") the logout process throws the same exception as above.
For the login process, this is simply rectified by removing the line await HttpContext.SignOutAsync(IdentityConstants.ExternalScheme);. If I do not use external schemes I do not need to sign out of them, right?
This brings me to my problem: How can I disable external logins and multi factor authentication in Identity Core, so I do not have to add those cookies in the first place? Furthermore, why do I have to specifiy a cookie named "Identity.Application", which is not the case in the default configuration? I'm pretty sure this is just another issue of me not thoroughly understanding the problem at hand, so I am grateful for any clarification on this.
This is my Identity config from the Startup.cs I have also scaffolded out the complete Identity UI with a custom IdentityUser class.
var jwtAppSettingOptions = Configuration.GetSection(nameof(JwtIssuerOptions));
services.Configure<JwtIssuerOptions>(options =>
{
options.Issuer = jwtAppSettingOptions[nameof(JwtIssuerOptions.Issuer)];
options.Audience = jwtAppSettingOptions[nameof(JwtIssuerOptions.Audience)];
options.SigningCredentials = new SigningCredentials(_signingKey, SecurityAlgorithms.HmacSha256);
});
var tokenValidationParameters = new TokenValidationParameters
{
/*...*/
};
services.AddAuthentication(options =>
{
options.DefaultScheme = "Identity.Application";
})
//.AddCookie("Identity.External")
//.AddCookie("Identity.TwoFactorUserId")
.AddCookie("Identity.Application", opt =>
{
opt.SlidingExpiration = true;
})
.AddJwtBearer(options =>
{
options.ClaimsIssuer = jwtAppSettingOptions[nameof(JwtIssuerOptions.Issuer)];
options.TokenValidationParameters = tokenValidationParameters;
options.SaveToken = true;
});
var builder = services.AddIdentityCore<AppUser>(o =>
{
//removed
});
builder = new IdentityBuilder(builder.UserType, typeof(IdentityRole), builder.Services);
builder.AddEntityFrameworkStores<ApplicationDbContext>().AddDefaultTokenProviders();

Add ClaimsIdentity to ClaimsPrincipal - JwtBearer

My system consists of two authorization steps (but not the standard way).
My client application first connects with server passing login and password (it's just something like ApiSecret and ApiKey).
Next, after authentication, server returns bearer token with basic info (username, roles etc). But notice that this user is like ApiClient not a living person :)
Next, application shows login form. And this is time for a living person to login. So he passes his credentials to API which checks whether this user can be logged in.
And this is the place that I have problem with. Until now I thought it would be work like that:
If the user can be logged to the application, I create new ClaimsIdentity and ADD it to ClaimsPrincipal Identities.
The idea is great but it doesn't work :/ It turns out that next requests don't send this second identity information. I even know why. Becase ClaimsPrincipal is created based on received bearer token. But this knowledge doesn't solve my problem.
What should I do to add new ClaimsIdentity to existing ClaimsPrincipal and store this value between requests? (until user logges out of the application)
After a lot of digging and research I was able to create a solution (.Net Core 2).
You have to add Cookie Authentication in configure services and all of this should look like that:
services.AddAuthentication(options =>
{
options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(cfg =>
{
//standard settings
})
.AddCookie(AuthTypes.CLIENT_AUTHENTICATION_TYPE, cfg =>
{
//cookie settings; the most important is following event:
cfg.Events.OnValidatePrincipal = (CookieValidatePrincipalContext ctx) =>
{
ClaimsPrincipal mainUser = ctx.HttpContext.User; //get ClaimsPrincipal from JwtBearer
ClaimsPrincipal cookieUser = ctx.Principal; //get ClaimsPrincipal read from Cookie
Debug.Assert(mainUser.Identities.Count() == 1);
//now we have to add ClaimsIdentity to main ClaimsPrincipal (from JwtBearer). We add only those absent in main ClaimsPrincipal (here is simplified solution)
var claimsToAdd = cookieUser.Identities.Where(id => id.AuthenticationType != mainUser.Identities.ElementAt(0).AuthenticationType);
mainUser.AddIdentities(claimsToAdd);
return Task.CompletedTask;
};
}
);
AuthTypes.CLIENT_AUTHENTICATION_TYPE - it's just string with your authentication type name.
Next we have to configure default policy filter later on in ConfigureServices (basic configuration):
services.AddMvc(config =>
{
var defaultPolicy = new AuthorizationPolicyBuilder(new[] { JwtBearerDefaults.AuthenticationScheme, AuthTypes.CLIENT_AUTHENTICATION_TYPE })
.RequireAuthenticatedUser()
.Build();
config.Filters.Add(new AuthorizeFilter(defaultPolicy));
});
What's important here is to pass this array in AuthorizationPolicyBuilder.
Now Authorization will take under consideration JwtBearer, but cookie will also be read.
And now how to set the cookie at all. This can be additional login process (you do it at the controller level):
var authProps = new AuthenticationProperties
{
IsPersistent = true,
IssuedUtc = DateTimeOffset.Now
};
await HttpContext.SignInAsync(AuthTypes.CLIENT_AUTHENTICATION_TYPE, User, authProps);
User here is just ClaimsPrincipal with additional ClaimsIdentities.
And that's all folks :)

ASP.NET Core 2.0 disable automatic challenge

After upgrading my ASP.NET Core project to 2.0, attempts to access protected endpoints no longer returns 401, but redirects to an (non-existing) endpoint in an attempt to let the user authenticate.
The desired behaviour is for the application simply to return a 401. Previously I would set AutomaticChallenge = false when configuring authentication, but according to this article the setting is no longer relevant (in fact it doesn't exist anymore).
My authentication is configured like this:
Startup.cs.ConfigureServices():
services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
.AddCookie(o =>
{
o.Cookie.Name = options.CookieName;
o.Cookie.Domain = options.CookieDomain;
o.SlidingExpiration = true;
o.ExpireTimeSpan = options.CookieLifetime;
o.TicketDataFormat = ticketFormat;
o.CookieManager = new CustomChunkingCookieManager();
});
Configure():
app.UseAuthentication();
How can I disable automatic challenge, so that the application returns 401 when the user is not authenticated?
As pointed out by some of the other answers, there is no longer a setting to turn off automatic challenge with cookie authentication. The solution is to override OnRedirectToLogin:
services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
.AddCookie(options =>
{
options.Events.OnRedirectToLogin = context =>
{
context.Response.Headers["Location"] = context.RedirectUri;
context.Response.StatusCode = 401;
return Task.CompletedTask;
};
});
This may change in the future: https://github.com/aspnet/Security/issues/1394
After some research, I found we can deal with this problem though the bellow approach:
We can add two Authentication scheme both Identity and JWT; and use Identity scheme for authentication and use JWT schema for challenge, JWT will not redirect to any login route while challenge.
services.AddIdentity<ApplicationUser, IdentityRole>().AddEntityFrameworkStores<ApplicationDbContext>();
services.AddAuthentication((cfg =>
{
cfg.DefaultScheme = IdentityConstants.ApplicationScheme;
cfg.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
})).AddJwtBearer();
Similiar to #Serverin, setting the OnRedirectToLogin of the Application Cookie worked, but must be done in statement following services.AddIdentity in Startup.cs:ConfigureServices:
services.ConfigureApplicationCookie(options => {
options.Events.OnRedirectToLogin = context => {
context.Response.Headers["Location"] = context.RedirectUri;
context.Response.StatusCode = 401;
return Task.CompletedTask;
};
});
According to this article:
In 1.x, the AutomaticAuthenticate and AutomaticChallenge properties were intended to be set on a single authentication scheme. There was no good way to enforce this.
In 2.0, these two properties have been removed as flags on the individual AuthenticationOptions instance and have moved into the base AuthenticationOptions class. The properties can be configured in the AddAuthentication method call within the ConfigureServices method of Startup.cs
services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme);
Alternatively, use an overloaded version of the AddAuthentication method to set more than one property. In the following overloaded method example, the default scheme is set to CookieAuthenticationDefaults.AuthenticationScheme. The authentication scheme may alternatively be specified within your individual [Authorize] attributes or authorization policies.
services.AddAuthentication(options => {
options.DefaultScheme = CookieAuthenticationDefaults.AuthenticationScheme;
options.DefaultChallengeScheme = OpenIdConnectDefaults.AuthenticationScheme;
});
Define a default scheme in 2.0 if one of the following conditions is true:
You want the user to be automatically signed in
You use the [Authorize] attribute or authorization policies without specifying
schemes
An exception to this rule is the AddIdentity method. This method adds cookies for you and sets the default authenticate and challenge schemes to the application cookie IdentityConstants.ApplicationScheme. Additionally, it sets the default sign-in scheme to the external cookie IdentityConstants.ExternalScheme.
Hope this help you.
This is the source code of CookieAuthenticationEvents.OnRedirectToLogin :
public Func<RedirectContext<CookieAuthenticationOptions>, Task> OnRedirectToLogin { get; set; } = context =>
{
if (IsAjaxRequest(context.Request))
{
context.Response.Headers["Location"] = context.RedirectUri;
context.Response.StatusCode = 401;
}
else
{
context.Response.Redirect(context.RedirectUri);
}
return Task.CompletedTask;
};
You can add "X-Requested-With: XMLHttpRequest" Header to the request while making API calls from your client.
I found that in most cases the solution is to override
OnRedirectToLogin
But in my app I was using multiple authentication policies and overriding of the OnRedirectToLogin did not work for me. The solution in my case it was to add a simple middleware to redirect the incoming request.
app.Use(async (HttpContext context, Func<Task> next) => {
await next.Invoke(); //execute the request pipeline
if (context.Response.StatusCode == StatusCodes.Status302Found && context.Response.Headers.TryGetValue("Location", out var redirect)) {
var v = redirect.ToString();
if (v.StartsWith($"{context.Request.Scheme}://{context.Request.Host}/Account/Login")) {
context.Response.Headers["Location"] = $"{context.Request.Scheme}://{context.Request.Host}{context.Request.Path}";
context.Response.StatusCode = 401;
}
}
});
Another way to do this which is more DI/testing-friendly is to use AuthenticationSchemeOptions.EventsType (another answer points at it here). This will allow you to pull other components into the resolution process.
Here's an example including registration and resolution which stops the default redirect to login on an unauthenticated request, and instead just returns with a hard 401. It also has a slot for any other dependencies which may need to know about unauthenticated requests.
In Startup.cs:
services
.AddAuthentication("MyAuthScheme")
.AddCookie(CookieAuthenticationDefaults.AuthenticationScheme, options =>
{
options.EventsType = typeof(MyEventsWrapper);
};
...
services.AddTransient<MyEventsWrapper>();
services.AddSingleton<IHttpContextAccessor, HttpContextAccessor>();
Then, in MyEventsWrapper.cs:
public class MyEventsWrapper : CookieAuthenticationEvents
{
private readonly IHttpContextAccessor _accessor;
private readonly IDependency _otherDependency;
public MyEventsWrapper(IHttpContextAccessor accessor,
IDependency otherDependency)
{
_accessor = accessor;
_otherDependency = otherDependency;
}
public override async Task RedirectToLogin(RedirectContext<CookieAuthenticationOptions> context)
{
context.Response.Headers.Remove("Location");
context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;
await _otherDependency.Cleanup(_accessor.HttpContext);
}
}
I'm not sure how to generate the 401 error, however if you use the:
o.AccessDeniedPath = "{path to invalid}";
This will allow you to redirect somewhere when the challenge has failed.

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