web api get user info inside controller - c#

I'm using the standard owin asp.net.identity mechanism to authorize users using their access token. Inside my controller I would like to find out who has sent the request. How could I do it? Could I somehow retrieve the access token from the request inside my controller?
I have tried:
public HttpResponseMessage Get([FromUri] GetParameters parameters)
{
Var identity = RequestContext.Principal.Identity;
}
It does not give me a lot as majority of properties are always null.

try
string token = HttpContext.Current.Request.LogonUserIdentity.Token.ToString();

Related

Implementing custom Authorization logic for Web API on ASP.NET Core 6

I have to implement authorization for my web api using another/external API. So I have to get the JWT from the request and call another API with that token to know whether the user is authorized.
presently my authentication is working, and I am using
IServiceCollection.AddAuthentication().AddJwtBearer() // removed code to set options
in sample above, I have removed code to provide options and setting the TokenValidationParameters. So my auth logic is working as expected.
Now i am looking to implement custom Authorization. In my custom authorization logic i have to make call to another/external API and pass some parameters. The parameters will be different for different action methods in my controller. The external API will return bool (indicating whether authorized or not), I don't have need to maintain any application role/claims in my code.
is using dynamic policy name and string parsing as mentioned in doc the only/recommended option.
So i have to get jwttoken from request and call another API with that token to know if user is authorized or not.
You should try to prevent having to make an an outbound API request for each request your API gets.
It seems like you have an external authentication service which lets your users log in and returns a token of sorts. You need to know how that third party signs their tokens, then obtain some form of (public) key from them.
With this key you can validate whether the token has been signed by the party you trust. For this, you configure the appropriate TokenValidationParameters which you pass to your services.AddAuthentication().AddJwtBearer() so you can let Identity validate their token using their keys.
See:
Authorize with a specific scheme in ASP.NET Core
Microsoft.AspNetCore.Authentication.JwtBearer Namespace
Ultimately you'd also configure some sort of background job that cycles the keys of the external provider when they do, if they do, which they hopefully do.
As for your updated question: you appear to want to use an external service for authorization, i.e. who can do what.
You'll have to implement this yourself. Usually this is done using scopes, which are retrieved once, during authentication. These can contain values like "finance" to give access to financial controllers, or "finance:orders:list finance:products".
[RequiredScope("finance:orders", "finance:orders:list")]
public IActionResult Index()
{
return View();
}
If the API you're talking to does not have a way to retrieve the relevant scopes, claims or permissions during authentication (or once per resource), then you can't, for example, cache the user's roles to your controllers or entities.
You need to realise this will incur extra overhead per API call, as well as your application being down when the authentication/authorization service is down.
If you still want to do this, the most trivial way to do async authorization on a controller would be a policy:
public class AuthorizeWithAuthServiceRequirement : IAuthorizationRequirement
{
public const string PolicyName = "external-authorization-service";
}
public class AuthorizeWithAuthServiceHandler : AuthorizationHandler<AuthorizeWithAuthServiceRequirement>
{
private IYourApiService _yourApiService;
public AuthorizeWithAuthServiceHandler(IYourApiService yourApiService/* your DI here */)
{
_yourApiService = yourApiService;
}
protected override async Task HandleRequirementAsync(AuthorizationHandlerContext context, AuthorizeWithAuthServiceRequirement requirement)
{
var httpContext = context.Resource as HttpContext
?? throw new ArgumentException("Can't obtain HttpContext");
// Get the user or their claims or the ID from the route or something
var user = httpContext.User;
var claim = user.FindAll("foo-claim");
var allClaims = user.Claims;
var id = httpContext.Request.RouteValues["id"];
// TODO: response and error handling
var isUserAuthorized = _yourApiService.IsUserAuthorized(user, id, entity, claim, ...);
if (!isUserAuthorized)
{
context.Fail(/* TODO: reason */);
}
}
}
You register this with DI like this:
// Register the handler for dependency injection
services.AddSingleton<IAuthorizationHandler, AuthorizeWithAuthServiceHandler>();
// Register the policy
services.AddAuthorization(options =>
{
options.AddPolicy(AuthorizeWithAuthServiceRequirement.PolicyName, x => { x.AddRequirements(new AuthorizeWithAuthServiceRequirement()); });
});
And then apply it to a controller or action method:
[Authorize(Policy = AuthorizeWithAuthServiceRequirement.PolicyName)]
public class FooController : Controller
{
}
If you want more fine-grained control like custom attributes with parameters (like [CustomAuthorization(ApiPermission.Foo)]) per controller or action, or if you want to first load an entity and pass that to the handler, see Ilja in Asp.Net Core: Access custom AuthorizeAttribute property in AuthorizeHandler and their GitHub repository demonstrating three different approaches.

What is the purpose of JwtBearerOptions.SaveToken property in ASP.NET Core 2.0+?

The Microsoft Docs just have this description:
Defines whether the bearer token should be stored in the AuthenticationProperties after a successful authorization.
I wondered if saving the JWT allows you to revoke it somehow, but every place I read about JWTs says they are irrevocable. What would you do with a JWT being stored in the AuthenticationProperties?
Storing the JWT in the AuthenticationProperties allows you to retrieve it from elsewhere within your application.
For example, use GetTokenAsync inside of an action, like this:
public async Task<IActionResult> SomeAction()
{
// using Microsoft.AspNetCore.Authentication;
var accessToken = await HttpContext.GetTokenAsync("access_token");
// ...
}
This is useful if, for example, you want to forward the JWT in an outgoing request.

ASP.NET Web Api Authentication Methods

I am trying to implement authentication for my web api.
I have read about different techniques of api authentication and the token technique is the most reasonable for me.
I read different articles about how to implement token based authentication in asp.net but they all rely on different libraries such as OAuth or Owin which also provide their own method of database interactions.
The thing is that I have already implemented database interaction with abstract repositories and entities and I would like to find out how can I implement api authentication easily and simply without interfering with my current design.
(By the way, my project is built on top of an empty web api project, so it doesn't come with all the bootstrap and authentication classes).
Thank you
One solution I've seen is to use .NET's HttpApplicationState class and store tokens in appstate; this way you're not directly messing with Session (which would be a REST antipattern), but you can still track all currently logged in users and use HttpContext/HttpActionContext to x-ref active tokens in the app. The benefit to using HttpActionContext is that it is thread-safe, whereas HttpContext is not, so you can lock the appstate, mess with the HttpContext of an individual request, and then unlock the appstate to allow other threads in.
Since locking/unlocking appstate does tie up the app, I'm not sure how well this solution scales, but here it is anyway . . .
General outline:
When a user first logs in, a token is generated for him/her and stored in appstate. Then you can tag any API calls that require authentication (or that need other information stored on that user) with a custom attribute that checks for that token in the appstate, sending the token name as a header in the API call (e.g. "{token-name: TOKEN}").
Here's a brief example:
[in Controller method first activated at login:]
CustomUserObject user = new CustomUserObject();
//store user props
string token = Guid.NewGuid().ToString();
//create AppState instance, mine's called _appState
//...
_appState.Lock();
_appState[token] = user;
_appState.UnLock();
//...
[Then in global.asax:]
public class CustomAuthorize : System.Web.Http.AuthorizeAttribute
{
HttpRequestMessage request = actionContext.ControllerContext.Request;
string token = string.Empty;
if (request.Headers.GetValues("token-name") != null)
{
token = request.Headers.GetValues("token-name").FirstOrDefault().ToString();
IAppStateService appService; //<--- I've created a custom service tier class for appstate stuff
//Get appState instance, however makes sense for you.
//I'm using repo pattern with UnitOfWork, so mine looks like this...
//"IContainer ioc = DependencyResolution.IoC.Initialize();"
//"IAppStateService appService = ioc.GetInstance<IAppStateService>();"
appService.SetHttpApplicationState(HttpContext.Current.Application);
bool isAuthorized = appService.CheckTokenAndDoStuff(token);
//inside that method ^^^ you'll do stuff like
//"_appState.Lock();"
//"if (_appState[token] == null) return false" (or whatever)
//"_appState.Unlock();"
}
if (isAuthorized)
{
HttpResponseMessage resp = request.CreateResponse(HttpStatusCode.OK);
resp.Headers.Add("AuthenticationToken", token);
resp.Headers.Add("WWW-Authenticate", "Basic");
resp.Headers.Add("AuthenticationStatus", "Authorized");
}
return isAuthorized;
}
[then in webapi]
[HttpPost]
[CustomAuthorize]
public HttpResponseMessage NameOfMethod(...)...
...and that should x-check your appstate for your user token for you. Just make sure to include your token in your request header, and make sure to include the Basic Auth info in your response header.

Get the current user, within an ApiController action, without passing the userID as a parameter

How do we get the current user, within an secure ApiController action, without passing the userName or userId as a parameter?
We assume that this is available, because we are within a secure action. Being in a secure action means that the user has already authenticated and the request has her bearer token. Given that WebApi has authorized the user, there may be a built in way to access the userId, without having to pass it as an action parameter.
In WebApi 2 you can use RequestContext.Principal from within a method on ApiController
You can also access the principal using the User property on ApiController.
So the following two statements are basically the same:
string id;
id = User.Identity.GetUserId();
id = RequestContext.Principal.Identity.GetUserId();
Hint lies in Webapi2 auto generated account controller
Have this property with getter defined as
public string UserIdentity
{
get
{
var user = UserManager.FindByName(User.Identity.Name);
return user;//user.Email
}
}
and in order to get UserManager - In WebApi2 -do as Romans (read as AccountController) do
public ApplicationUserManager UserManager
{
get { return HttpContext.Current.GetOwinContext().GetUserManager<ApplicationUserManager>(); }
}
This should be compatible in IIS and self host mode
None of the suggestions above worked for me. The following did!
HttpContext.Current.Request.LogonUserIdentity.Name
I guess there's a wide variety of scenarios and this one worked for me. My scenario involved an AngularJS frontend and a Web API 2 backend application, both running under IIS. I had to set both applications to run exclusively under Windows Authentication.
No need to pass any user information. The browser and IIS exchange the logged on user credentials and the Web API has access to the user credentials on demand (from IIS I presume).
Karan Bhandari's answer is good, but the AccountController added in a project is very likely a Mvc.Controller. To convert his answer for use in an ApiController change HttpContext.Current.GetOwinContext() to Request.GetOwinContext() and make sure you have added the following 2 using statements:
using Microsoft.AspNet.Identity;
using Microsoft.AspNet.Identity.Owin;
In .Net Core use User.Identity.Name to get the Name claim of the user.
If you are using Asp.Identity UseManager, it automatically sets the value of
RequestContext.Principal.Identity.GetUserId()
based on IdentityUser you use in creating the IdentityDbContext.
If ever you are implementing a custom user table and owin token bearer authentication, kindly check on my answer.
How to get user context during Web Api calls?
Hope it still helps. :)
string userName;
string userId;
if (HttpContext.Current != null && HttpContext.Current.User != null
&& HttpContext.Current.User.Identity.Name != null)
{
userName = HttpContext.Current.User.Identity.Name;
userId = HttpContext.Current.User.Identity.GetUserId();
}
Or based on Darrel Miller's comment, maybe use this to retrieve the HttpContext first.
// get httpContext
object httpContext;
actionContext.Request.Properties.TryGetValue("MS_HttpContext", out httpContext);
See also:
How to access HTTPContext from within your Web API action

getting authorization code from url

When using oauth I can get an authorization code returned in the URL to me but i don't know how to get that code out of the url. For example when i give the app permission to run i get
http://localhost/?code=moBOuHmeCj.KUjTq14iwVyywiLbB44SNZ4-olDb2uFmXOwPpFzV.PQUHfFCNKAqStMp8.NMDZPjEZMJosDMC0JKZip.qHTvQ5KHI9oFIGwNh79EabwklUQjVgXzrc4Mor6mcmMRVTJTos3mv2BzIEw%3D%3D
as a response but i need to get that out of the browser and back to the server to get the long access key.How do i do this?
Set your authentication provider's returnUrl as a specific route of your site, something like http://localhost/oauth
In your OAuthController (I'm assuming your question is about a MVC app) use:
public ActionResult Index(string code)
{
// Perform any action related with 'code' value provided by auth provider.
}
Please try this code:
$code = $_GET['code'];

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