Use JwtBearerEvents with ActionFilter - c#

I'm having a hard time to use JwtBearerEvents with my custom ActionFilter that I use to authenticate users using JWT token by calling a class that contain the token validation logic.
The intention of using JwtBearerEvents is to log every attempt of logging whether successful or failed. Is it possible in my case to use JwtBearerEvents? because all documentation says that JwtBearerEvents is usually used with Authorize attribute.
I created a custom JwtBearerEvents class to log and configure it in the startup file but this class has never been triggered during authentication. any thoughts please? Thank you for your help. this is a sample code of what I have currently:
public interface IAuthenticationService
{
public bool ValidateTokenOrThrow();
}
public interface AuthenticationService
{
public bool ValidateTokenOrThrow()
{
//logic of token validation where i use SecurityTokenHandler
//....
}
}
public class CustomActionAttribute : ActionFilterAttribute
{
private readonly IAuthenticationService _authenticationService { get; set; }
public CustomActionAttribute(IAuthenticationService authenticationService)
{
_authenticationService = authenticationService;
}
public override void OnActionExecuting(ActionExecutingContext context)
{
var token = context.HttpContext.Request.Headers["Authorization"];
var isValidToken = _authenticationService.ValidateTokenOrThrow(token); // this is an error as both parameters do not exist at this moment
if (!isValidToken)
context.Result = new ForbidResult();
}
}
public CustomJwtBearerEvents : JwtBearerEvents
{
private readonly ILogger<JwtBearerEvents>_logger;
public CustomJwtBearerEvents(ILogger<JwtBearerEvents> logger)
{
_logger = logger;
}
public override Task OnAuthenticationFailed = context =>
{
context.Response.StatusCode = HttpStatusCodes.AuthenticationFailed;
context.Response.ContentType = "application/json";
var err = this.Environment.IsDevelopment() ? context.Exception.ToString() : "An error occurred processing your authentication.";
var result = JsonConvert.SerializeObject(new {err});
return context.Response.WriteAsync(result);
}
}
//Startup file
public void ConfigureServices(IServiceCollection services)
{
service.AddSingleton<CustomJwtBearerEvents>();
services.AddAuthorization();
services.AddAuthentication(options =>
{
options.DefaultScheme = JwtBearerDefaults.AuthenticationScheme;
})
.AddJwtBearer(options =>
{
options.EventType = typeof(CustomJwtBearerEvents);
});
}
public HomeController : BaseController
{
[CustomActionAttribute]
[Route("api/[controller]")]
public GetHome()
{
return service.GetHome();
}
}

Related

Reading HttpContext.Request as object?

My base Request class looks like this:
public class GetAllProjectsQuery : QueryBase<ProjectsListModel>
{
}
public abstract class QueryBase<T> : UserContext, IRequest<T> // IRequest is MediatR interface
{
}
public abstract class UserContext
{
public string ApplicationUserId { get; set; } // and other properties
}
I want to write a middleware to my .NET Core 3.1 WebApi that will grab JWT from request header amd read ApplicationUserId from it. I started to code something:
public class UserInformation
{
private readonly RequestDelegate next;
public UserInformation(RequestDelegate next)
{
this.next = next;
}
public async Task InvokeAsync(HttpContext context)
{
var jwt = context.Request.Headers["Authorization"];
// read jwt here
var userContext = (UserContext)context.Request.Body; // i know it wont work
userContext.ApplicationUserId = //whats next? Any ideas?
await this.next(context);
}
}
But to be honest i have no idea how to start so here are my questions:
As you can see, every request will be packed with my UserContext class and so on. How to cast HttpContext.Request.Body to my request object and attach ApplicationUserId to it? Is it possible? I want to acces to user credentials from my JWT from headers and i want to have that information in every request in my API (pass it to controller, then to command etc).
If getting this information from middleware is not the best practice, what is?
EDIT: Mcontroller that using MediatR:
// base controller:
[ApiController]
[Route("[controller]")]
public abstract class BaseController : ControllerBase
{
private IMediator mediator;
protected IMediator Mediator => this.mediator ?? (this.mediator = HttpContext.RequestServices.GetService<IMediator>());
}
// action in ProjectControlle
[HttpGet]
[Authorize]
public async Task<ActionResult<ProjectsListModel>> GetAllProjects()
{
return Ok(await base.Mediator.Send(new GetAllProjectsQuery()));
}
// query:
public class GetAllProjectsQuery : QueryBase<ProjectsListModel>
{
}
// handler:
public class GetAllProjectsQueryHandler : IRequestHandler<GetAllProjectsQuery, ProjectsListModel>
{
private readonly IProjectRepository projectRepository;
public GetAllProjectsQueryHandler(IProjectRepository projectRepository)
{
this.projectRepository = projectRepository;
}
public async Task<ProjectsListModel> Handle(GetAllProjectsQuery request, CancellationToken cancellationToken)
{
var projects = await this.projectRepository.GetAllProjectsWithTasksAsync();
return new ProjectsListModel
{
List = projects
};
}
}
You might not need a middleware, but need a model binder:
See: https://learn.microsoft.com/en-us/aspnet/core/mvc/models/model-binding?view=aspnetcore-3.1
Also see: https://learn.microsoft.com/en-us/aspnet/core/mvc/advanced/custom-model-binding?view=aspnetcore-3.1
public class UserContextModelBinder : IModelBinder
{
private readonly IHttpContextAccessor _httpContextAccessor;
private readonly IModelBinder _defaultModelBinder;
public UserContextModelBinder(
IHttpContextAccessor httpContextAccessor,
IOptions<MvcOptions> mvcOptions,
IHttpRequestStreamReaderFactory streamReaderFactory)
{
_httpContextAccessor = httpContextAccessor;
_defaultModelBinder = new BodyModelBinder(mvcOptions.Value.InputFormatters, streamReaderFactory);
}
public async Task BindModelAsync(ModelBindingContext bindingContext)
{
if (!typeof(UserContext).IsAssignableFrom(bindingContext.ModelType))
{
return;
}
await _defaultModelBinder.BindModelAsync(bindingContext);
if (bindingContext.Result.IsModelSet && bindingContext.Result.Model is UserContext)
{
var model = (UserContext)bindingContext.Result.Model;
var httpContext = _httpContextAccessor.HttpContext;
// Read JWT
var jwt = httpContext.Request.Headers["Authorization"];
model.ApplicationUserId = jwt;
bindingContext.Result = ModelBindingResult.Success(model);
}
}
}
Then add model binder to UserContext class:
[ModelBinder(typeof(UserContextModelBinder))]
public abstract class UserContext
{
public string ApplicationUserId { get; set; }
}
Also add IHttpContextAccessor to services in Startup.cs:
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers();
services.AddHttpContextAccessor();
}

IdentityServer: Multiple Clients with different grant types, policies not working properly

I've got an identity server setup with the following 'look a like' configuration:
return new List<Client>
{
new Client
{
[...]
AllowedGrantTypes = GrantTypes.Implicit,
[....]
},
new Client
{
[...]
AllowedGrantTypes = GrantTypes.ClientCredentials,
[....]
}
};
and controlles annotated like this:
[Route("api/forms")]
[ApiController]
[Authorize(Policy = "user.api.portfolio.manager")]
[Authorize(Policy = "application.api.portfolio.manager")]
public class FormsController : ControllerBase
{
[...]
}
and a policy
private System.Action<AuthorizationOptions> AddJwtAuthorizationPolicyForRole()
{
return options => { options.AddPolicy("**POLICY_FOR_GRANT_IMPLICIT**", policy => {
policy.AuthenticationSchemes.Add(JwtBearerDefaults.AuthenticationScheme);
policy.RequireAuthenticatedUser();
policy.RequireClaim(ClaimTypes.Role, "USER_ACCESSIBLE");
});
};
}
private System.Action<AuthorizationOptions> AddJwtAuthorizationPolicyForRole()
{
return options => { options.AddPolicy("**POLICY_FOR_CLIENT_CREDENTIALS**", policy => {
policy.AuthenticationSchemes.Add(JwtBearerDefaults.AuthenticationScheme);
policy.RequireAuthenticatedUser();
});
};
}
so I want to achieve:
Clients using the GrantType.ClientCredentials can access the controller without any further needs.
Clients using the Implicit Schema must have role USER_ACCESSIBLE
If it's configured like shown above, both policies must apply -> Both grant types are failing.
How can I achieve the described behavior using IdentityServer, that each grant-types may have an independent policy so be applied?
Thanks in advance for your help.
The most simplest solution is adding another single policy for Implicit + ClientCredential to implement logics for OR conditions .
Or you can create a custom attribute like :
MultiplePolicysAuthorizeAttribute
public class MultiplePolicysAuthorizeAttribute : TypeFilterAttribute
{
public MultiplePolicysAuthorizeAttribute(string policys, bool isAnd = false) : base(typeof(MultiplePolicysAuthorizeFilter))
{
Arguments = new object[] { policys, isAnd };
}
}
MultiplePolicysAuthorizeFilter
public class MultiplePolicysAuthorizeFilter : IAsyncAuthorizationFilter
{
private readonly IAuthorizationService _authorization;
public string Policys { get; private set; }
public bool IsAnd { get; private set; }
public MultiplePolicysAuthorizeFilter(string policys, bool isAnd, IAuthorizationService authorization)
{
Policys = policys;
IsAnd = isAnd;
_authorization = authorization;
}
public async Task OnAuthorizationAsync(AuthorizationFilterContext context)
{
var policys = Policys.Split(";").ToList();
if (IsAnd)
{
foreach (var policy in policys)
{
var authorized = await _authorization.AuthorizeAsync(context.HttpContext.User, policy);
if (!authorized.Succeeded)
{
context.Result = new ForbidResult();
return;
}
}
}
else
{
foreach (var policy in policys)
{
var authorized = await _authorization.AuthorizeAsync(context.HttpContext.User, policy);
if (authorized.Succeeded)
{
return;
}
}
context.Result = new ForbidResult();
return;
}
}
}
If actions require matching one of the policies(OR):
[MultiplePolicysAuthorize("POLICY_FOR_GRANT_IMPLICIT;POLICY_FOR_CLIENT_CREDENTIALS")]
If actions require matching all the policies(And) :
[MultiplePolicysAuthorize("POLICY_FOR_GRANT_IMPLICIT;POLICY_FOR_CLIENT_CREDENTIALS",true)]
Code sample reference : https://stackoverflow.com/a/52639938/5751404

Can I avoid using BuildServiceProvider in startup?

Can I avoid using BuildServiceProvider in ExpireToken function below? In other words...
Is there a way of avoiding BuildServiceProvider() in Startup.cs when using JWTBearer OnAuthenticationFailed event?
(Using Web API aspnet Core 3.0)
Startup.cs
public void ConfigureServices(IServiceCollection services)
{
//some code removed..
//Authentication
services.AddAuthentication(options =>
{
options.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
options.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
}).AddJwtBearer(options =>
{
options.Events = new JwtBearerEvents()
{
OnAuthenticationFailed = context =>
{
if (context.Exception.Message.Contains("The token is expired"))
{
Microsoft.Extensions.Primitives.StringValues token = string.Empty;
var logger = new LoggerManager();
logger.LogError("Token expired"); //confirming that the token expired so authentication failed
var header = context.Request.Headers;
if (!header.TryGetValue("Authorization", out token))
logger.LogError("no token found");
else
token = token.ToString().Substring("Bearer ".Length).Trim();
ExpireToken(services, token);
}
return Task.CompletedTask;
}
};
});
}
public void ExpireToken(IServiceCollection services, string tokenId)
{
var sp = services.BuildServiceProvider();
var jwtManager = sp.GetService<IJWTAuthenticationManager>();
jwtManager.ExpireToken(tokenId);
}
jwtAuthentication Manager will publish this event so that subscribers are notified (c#:event + delegates)
public delegate void TokenExpiredEventHandler(object source, TokenExpiredEventArgs args);
JWTAuthenticationManager.cs
public class JWTAuthenticationManager : IJWTAuthenticationManager
{
private readonly string _tokenKey;
public event TokenExpiredEventHandler TokenExpired;
//some code removed for brevity
public void ExpireToken(string tokenId)
{
OnTokenExpired(tokenId); //notify all subscribers
}
protected virtual void OnTokenExpired(string token) {
TokenExpired?.Invoke(this, new TokenExpiredEventArgs(token));
}
}
public class TokenExpiredEventArgs : EventArgs
{
public string token;
public TokenExpiredEventArgs(string tokenId)
{
token = tokenId;
}
}
Program.cs
public static void Main(string[] args)
{
var host = CreateWebHostBuilder(args).Build();
var jwtMgr = host.Services.GetRequiredService<IJWTAuthenticationManager>();
var cacheMgr = host.Services.GetRequiredService<ICacheManager>();
jwtMgr.TokenExpired += cacheMgr.OnTokenExpired;
host.Run();
}
Why not resolve services from context? Simply change your ExpireToken method to take an IServiceProvider:
public void ExpireToken(IServiceProvider services, string tokenId)
{
var jwtManager = services.GetService<IJWTAuthenticationManager>();
jwtManager.ExpireToken(tokenId);
}
And then pass context.HttpContext.RequestServices:
ExpireToken(context.HttpContext.RequestServices, token);

How to authenticate facebook web api in asp.net core 2

I'm currently building my very first mobile app in Xamarin.Forms. The app has a facebook login and after the user has been logged in I'm storing the facebook token because I want to use it as a bearer-token to authenticate any further requests against an API.
The API is a .NET core 2.0 project and I am struggling to get the authentication working.
In my Xamarin.Forms app the facebook token is set as bearer-token with the following code;
_httpClient.DefaultRequestHeaders.Authorization = new AuthenticationHeaderValue("Bearer", UserToken);
As far as I know, this properly sets the bearer token in the headers of the request.
I've talked to a colleague of mine about this and he told me to take a look at Identityserver4 which should support this. But for now, I've decided not to do that since for me, at this moment, it is overhead to implement this. So I've decided to stay with the idea to use the facebook token as bearer token and validate this.
So the next step for me is to find a way to authenticate the incoming bearer token with Facebook to check if it is (still) valid.
So I've configured the startup for my API projects as following;
public class Startup
{
public Startup(IConfiguration configuration)
{
Configuration = configuration;
}
public IConfiguration Configuration { get; }
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddAuthentication(o =>
{
o.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme;
o.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme;
}).AddFacebook(o =>
{
o.AppId = "MyAppId";
o.AppSecret = "MyAppSecret";
});
services.AddMvc();
}
// This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
public void Configure(IApplicationBuilder app, IHostingEnvironment env)
{
if (env.IsDevelopment())
{
app.UseDeveloperExceptionPage();
}
//Enable authentication
app.UseAuthentication();
//Enable support for default files (eg. default.htm, default.html, index.htm, index.html)
app.UseDefaultFiles();
//Configure support for static files
app.UseStaticFiles();
app.UseMvc();
}
}
But when I'm using postman to do a request and test if everything is working I'm receiving the following error;
InvalidOperationException: No authenticationScheme was specified, and there was no DefaultChallengeScheme found.
What am I doing wrong here?
EDIT:
In the mean time if been busy trying to find a solution for this. After reading a lot on Google it seems thatadding an AuthorizationHandler is the way to go at the moment. From there on I can make request to facebook to check if the token is valid. I've added the following code to my ConfigureServices method;
public void ConfigureServices(IServiceCollection services)
{
//Other code
services.AddAuthorization(options =>
{
options.AddPolicy("FacebookAuthentication", policy => policy.Requirements.Add(new FacebookRequirement()));
});
services.AddMvc();
}
And I've created a FacebookRequirement which will help me handling the policy;
public class FacebookRequirement : AuthorizationHandler<FacebookRequirement>, IAuthorizationRequirement
{
private readonly IHttpContextAccessor contextAccessor;
public FacebookRequirement(IHttpContextAccessor contextAccessor)
{
this.contextAccessor = contextAccessor;
}
protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, FacebookRequirement requirement)
{
//var socialConfig = new SocialConfig{Facebook = new SocialApp{AppId = "MyAppId", AppSecret = "MyAppSecret" } };
//var socialservice = new SocialAuthService(socialConfig);
//var result = await socialservice.VerifyFacebookTokenAsync()
var httpContext = contextAccessor.HttpContext;
if (httpContext != null && httpContext.Request.Headers.ContainsKey("Authorization"))
{
var token = httpContext.Request.Headers.Where(x => x.Key == "Authorization").ToList();
}
context.Succeed(requirement);
return Task.FromResult(0);
}
}
The problem I'm running into now is that I don't know where to get the IHttpContextAccessor. Is this being injected somehow? Am I even on the right path to solve this issue?
I ended up creating my own AuthorizationHandler to validate incoming requests against facebook using bearer tokens. In the future I'll probably start using Identityserver to handle multiple login types. But for now facebook is sufficient.
Below is the solution for future references.
First create an FacebookRequirement class inheriting from AuthorizationHandler;
public class FacebookRequirement : AuthorizationHandler<FacebookRequirement>, IAuthorizationRequirement
{
protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, FacebookRequirement requirement)
{
var socialConfig = new SocialConfig { Facebook = new SocialApp { AppId = "<FacebookAppId>", AppSecret = "<FacebookAppSecret>" } };
var socialservice = new SocialAuthService(socialConfig);
var authorizationFilterContext = context.Resource as AuthorizationFilterContext;
if (authorizationFilterContext == null)
{
context.Fail();
return Task.FromResult(0);
}
var httpContext = authorizationFilterContext.HttpContext;
if (httpContext != null && httpContext.Request.Headers.ContainsKey("Authorization"))
{
var authorizationHeaders = httpContext.Request.Headers.Where(x => x.Key == "Authorization").ToList();
var token = authorizationHeaders.FirstOrDefault(header => header.Key == "Authorization").Value.ToString().Split(' ')[1];
var user = socialservice.VerifyTokenAsync(new ExternalToken { Provider = "Facebook", Token = token }).Result;
if (!user.IsVerified)
{
context.Fail();
return Task.FromResult(0);
}
context.Succeed(requirement);
return Task.FromResult(0);
}
context.Fail();
return Task.FromResult(0);
}
}
Add the following classes which will contain the configuration an represent the user;
public class SocialConfig
{
public SocialApp Facebook { get; set; }
}
public class SocialApp
{
public string AppId { get; set; }
public string AppSecret { get; set; }
}
public class User
{
public Guid Id { get; set; }
public string SocialUserId { get; set; }
public string Email { get; set; }
public bool IsVerified { get; set; }
public string Name { get; set; }
public User()
{
IsVerified = false;
}
}
public class ExternalToken
{
public string Provider { get; set; }
public string Token { get; set; }
}
And last but not least, the SocialAuthService class which will handle the requests with facebook;
public class SocialAuthService
{
private SocialConfig SocialConfig { get; set; }
public SocialAuthService(SocialConfig socialConfig)
{
SocialConfig = socialConfig;
}
public async Task<User> VerifyTokenAsync(ExternalToken exteralToken)
{
switch (exteralToken.Provider)
{
case "Facebook":
return await VerifyFacebookTokenAsync(exteralToken.Token);
default:
return null;
}
}
private async Task<User> VerifyFacebookTokenAsync(string token)
{
var user = new User();
var client = new HttpClient();
var verifyTokenEndPoint = string.Format("https://graph.facebook.com/me?access_token={0}&fields=email,name", token);
var verifyAppEndpoint = string.Format("https://graph.facebook.com/app?access_token={0}", token);
var uri = new Uri(verifyTokenEndPoint);
var response = await client.GetAsync(uri);
if (response.IsSuccessStatusCode)
{
var content = await response.Content.ReadAsStringAsync();
dynamic userObj = (Newtonsoft.Json.Linq.JObject)Newtonsoft.Json.JsonConvert.DeserializeObject(content);
uri = new Uri(verifyAppEndpoint);
response = await client.GetAsync(uri);
content = await response.Content.ReadAsStringAsync();
dynamic appObj = (Newtonsoft.Json.Linq.JObject)Newtonsoft.Json.JsonConvert.DeserializeObject(content);
if (appObj["id"] == SocialConfig.Facebook.AppId)
{
//token is from our App
user.SocialUserId = userObj["id"];
user.Email = userObj["email"];
user.Name = userObj["name"];
user.IsVerified = true;
}
return user;
}
return user;
}
}
This will validate the Facebook token coming from the request as bearer token, with Facebook to check if it's still valid.

AuthorizationHandler exception not going through ExceptionFilter

I have an application in ASP.NET Core MVC (dnx46) RC1 with an AuthorizationHandler:
public class AppSumAuthAuthorizationHandler : AuthorizationHandler<AppSumAuthRequirement>
{
private readonly IUserRepository _userRepository;
private readonly IUserRoleRepository _userRoleRepository;
public AppSumAuthAuthorizationHandler(IUserRepository userRepository, IUserRoleRepository userRoleRepository)
{
_userRepository = userRepository;
_userRoleRepository = userRoleRepository;
}
protected override async void Handle(AuthorizationContext context, AppSumAuthRequirement requirement)
{
await HandleAsync(context,requirement);
}
protected override async Task HandleAsync(AuthorizationContext context, AppSumAuthRequirement requirement)
{
var currentUserName = context.User.Identity.Name;
var currentUser = await _userRepository.GetAsync(u => u.UserName == context.User.Identity.Name);
// Create user that does not yet exist
if(currentUser == null)
{
var user = new User(currentUserName);
/* Temporary add SysAdmin role */
using(new CreatedBySystemProvider(_userRepository))
{
_userRepository.Add(user);
await _userRepository.SaveChangesAsync();
if (string.Equals(currentUserName, #"BIJTJES\NilsG", StringComparison.CurrentCultureIgnoreCase))
{
user.AddRole(1);
}
currentUser = await _userRepository.GetAsync(u => u.Id == user.Id);
}
}
var resource = (Microsoft.AspNet.Mvc.Filters.AuthorizationContext) context.Resource;
var controllerActionDescriptor = resource.ActionDescriptor as ControllerActionDescriptor;
var controllerName = controllerActionDescriptor.ControllerName;
var actionName = controllerActionDescriptor.Name;
string moduleName;
try
{
// Get the name of the module
moduleName = ((ModuleAttribute)controllerActionDescriptor.ControllerTypeInfo.GetCustomAttributes(false).First(a => a.GetType().Name == "ModuleAttribute")).ModuleName;
}
catch(InvalidOperationException ex)
{
context.Fail();
throw new InvalidOperationException($"The Module Attribute is required on basecontroller {controllerName}.", ex);
}
var access = new Access(moduleName, controllerName, actionName);
if (await currentUser.HasPermissionTo(UrlAccessLevel.Access).OnAsync(access))
{
context.Succeed(requirement);
}
else
{
context.Fail();
}
}
}
The requirement class is empty:
public interface IAppSumAuthRequirement : IAuthorizationRequirement
{
}
public class AppSumAuthRequirement : IAppSumAuthRequirement
{
}
The Module attribute is also nothing special:
public class ModuleAttribute : Attribute
{
public string ModuleName { get; private set; }
public ModuleAttribute(string moduleName)
{
ModuleName = moduleName;
}
public override string ToString()
{
return ModuleName;
}
}
The exception filter:
public class JsonExceptionFilterAttribute : ExceptionFilterAttribute
{
public override void OnException(ExceptionContext context)
{
var exception = context.Exception;
context.HttpContext.Response.StatusCode = 500;
context.Result = new JsonResult(new Error
{
Message = exception.Message,
InnerException = exception.InnerException?.InnerException?.Message,
Data = exception.Data,
ErrorCode = exception.HResult,
Source = exception.Source,
Stacktrace = exception.StackTrace,
ErrorType = exception.GetType().ToString()
});
}
}
and policy are configured in my Startup.cs:
public IServiceProvider ConfigureServices(IServiceCollection services)
{
services.AddMvc(options =>
{
options.Filters.Add(new JsonExceptionFilterAttribute());
options.ModelBinders.Insert(0, new NullableIntModelBinder());
}).AddJsonOptions(options => {
options.SerializerSettings.ReferenceLoopHandling = Newtonsoft.Json.ReferenceLoopHandling.Ignore;
options.SerializerSettings.ContractResolver = new Newtonsoft.Json.Serialization.CamelCasePropertyNamesContractResolver();
});
// Security
services.AddAuthorization(options =>
{
options.AddPolicy("AppSumAuth",
policy => policy.Requirements.Add(new AppSumAuthRequirement()));
});
}
and the policy is set on all controllers, by inheriting BaseController:
[Authorize(Policy = "AppSumAuth")]
public class BaseController : Controller
{
public BaseController()
{
}
}
So, in my handler, I get the controllername, actionname and modulename (from the attribute set on the controllers):
[Module("Main")]
When this attribute is not set on a controller, I would like to catch the exception and report this back to the developer calling the controller and deny access. To do this, I've added:
catch(InvalidOperationException ex)
{
context.Fail();
throw new InvalidOperationException($"The Module Attribute is required on basecontroller {controllerName}.", ex);
}
The JsonExceptionFilter is called perfectly when there is an exception in the controllers. It is however not called when there is an error in the AuthorizationHandler.
So the question:
How can I get the Exceptions to be caught by the JsonExceptionFilter?
What am I doing wrong?
Solution:
Startup.cs:
public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
// For Windows Auth!
app.UseIISPlatformHandler();
app.UseStaticFiles();
app.UseExceptionHandler(AppSumExceptionMiddleware.JsonHandler());
app.UseMvc();
}
And my middleware:
public class AppSumExceptionMiddleware
{
public static Action<IApplicationBuilder> JsonHandler()
{
return errorApp =>
{
errorApp.Run(async context =>
{
var exception = context.Features.Get<IExceptionHandlerFeature>();
if (exception != null)
{
var exceptionJson = Encoding.UTF8.GetBytes(
JsonConvert.SerializeObject(new AppSumException(exception.Error),
new JsonSerializerSettings
{
ContractResolver = new CamelCasePropertyNamesContractResolver()
})
);
context.Response.ContentType = "application/json";
await context.Response.Body.WriteAsync(exceptionJson, 0, exceptionJson.Length);
}
});
};
}
}
Action filter can be used as a method filter, controller filter, or global filter only for MVC HTTP requests. In your case you need to use a middleware, as
Middleware is component that "sit" on the HTTP pipeline and examine
all requests and responses.
As you want to works with exception, you may use ready-to-use ExceptionHandler middleware:
app.UseExceptionHandler(errorApp =>
{
errorApp.Run(async context =>
{
context.Response.StatusCode = 500; // for example
var error = context.Features.Get<IExceptionHandlerFeature>();
if (error != null)
{
var ex = error.Error;
// custom logic
}
});
});

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