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Custom authorization attribute implementation [duplicate]

I'm trying to make a custom authorization attribute in ASP.NET Core. In previous versions it was possible to override bool AuthorizeCore(HttpContextBase httpContext). But this no longer exists in AuthorizeAttribute.
What is the current approach to make a custom AuthorizeAttribute?
What I am trying to accomplish: I am receiving a session ID in the Header Authorization. From that ID I'll know whether a particular action is valid.

The approach recommended by the ASP.Net Core team is to use the new policy design which is fully documented here. The basic idea behind the new approach is to use the new [Authorize] attribute to designate a "policy" (e.g. [Authorize( Policy = "YouNeedToBe18ToDoThis")] where the policy is registered in the application's Startup.cs to execute some block of code (i.e. ensure the user has an age claim where the age is 18 or older).
The policy design is a great addition to the framework and the ASP.Net Security Core team should be commended for its introduction. That said, it isn't well-suited for all cases. The shortcoming of this approach is that it fails to provide a convenient solution for the most common need of simply asserting that a given controller or action requires a given claim type. In the case where an application may have hundreds of discrete permissions governing CRUD operations on individual REST resources ("CanCreateOrder", "CanReadOrder", "CanUpdateOrder", "CanDeleteOrder", etc.), the new approach either requires repetitive one-to-one mappings between a policy name and a claim name (e.g. options.AddPolicy("CanUpdateOrder", policy => policy.RequireClaim(MyClaimTypes.Permission, "CanUpdateOrder));), or writing some code to perform these registrations at run time (e.g. read all claim types from a database and perform the aforementioned call in a loop). The problem with this approach for the majority of cases is that it's unnecessary overhead.
While the ASP.Net Core Security team recommends never creating your own solution, in some cases this may be the most prudent option with which to start.
The following is an implementation which uses the IAuthorizationFilter to provide a simple way to express a claim requirement for a given controller or action:
public class ClaimRequirementAttribute : TypeFilterAttribute
{
public ClaimRequirementAttribute(string claimType, string claimValue) : base(typeof(ClaimRequirementFilter))
{
Arguments = new object[] {new Claim(claimType, claimValue) };
}
}
public class ClaimRequirementFilter : IAuthorizationFilter
{
readonly Claim _claim;
public ClaimRequirementFilter(Claim claim)
{
_claim = claim;
}
public void OnAuthorization(AuthorizationFilterContext context)
{
var hasClaim = context.HttpContext.User.Claims.Any(c => c.Type == _claim.Type && c.Value == _claim.Value);
if (!hasClaim)
{
context.Result = new ForbidResult();
}
}
}
[Route("api/resource")]
public class MyController : Controller
{
[ClaimRequirement(MyClaimTypes.Permission, "CanReadResource")]
[HttpGet]
public IActionResult GetResource()
{
return Ok();
}
}

I'm the asp.net security person. Firstly let me apologize that none of this is documented yet outside of the music store sample or unit tests, and it's all still being refined in terms of exposed APIs. Detailed documentation is here.
We don't want you writing custom authorize attributes. If you need to do that we've done something wrong. Instead, you should be writing authorization requirements.
Authorization acts upon Identities. Identities are created by authentication.
You say in comments you want to check a session ID in a header. Your session ID would be the basis for identity. If you wanted to use the Authorize attribute you'd write an authentication middleware to take that header and turn it into an authenticated ClaimsPrincipal. You would then check that inside an authorization requirement. Authorization requirements can be as complicated as you like, for example here's one that takes a date of birth claim on the current identity and will authorize if the user is over 18;
public class Over18Requirement : AuthorizationHandler<Over18Requirement>, IAuthorizationRequirement
{
public override void Handle(AuthorizationHandlerContext context, Over18Requirement requirement)
{
if (!context.User.HasClaim(c => c.Type == ClaimTypes.DateOfBirth))
{
context.Fail();
return;
}
var dobVal = context.User.FindFirst(c => c.Type == ClaimTypes.DateOfBirth).Value;
var dateOfBirth = Convert.ToDateTime(dobVal);
int age = DateTime.Today.Year - dateOfBirth.Year;
if (dateOfBirth > DateTime.Today.AddYears(-age))
{
age--;
}
if (age >= 18)
{
context.Succeed(requirement);
}
else
{
context.Fail();
}
}
}
Then in your ConfigureServices() function you'd wire it up
services.AddAuthorization(options =>
{
options.AddPolicy("Over18",
policy => policy.Requirements.Add(new Authorization.Over18Requirement()));
});
And finally, apply it to a controller or action method with
[Authorize(Policy = "Over18")]

It seems that with ASP.NET Core 2, you can again inherit AuthorizeAttribute, you just need to also implement IAuthorizationFilter (or IAsyncAuthorizationFilter):
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true, Inherited = true)]
public class CustomAuthorizeAttribute : AuthorizeAttribute, IAuthorizationFilter
{
private readonly string _someFilterParameter;
public CustomAuthorizeAttribute(string someFilterParameter)
{
_someFilterParameter = someFilterParameter;
}
public void OnAuthorization(AuthorizationFilterContext context)
{
var user = context.HttpContext.User;
if (!user.Identity.IsAuthenticated)
{
// it isn't needed to set unauthorized result
// as the base class already requires the user to be authenticated
// this also makes redirect to a login page work properly
// context.Result = new UnauthorizedResult();
return;
}
// you can also use registered services
var someService = context.HttpContext.RequestServices.GetService<ISomeService>();
var isAuthorized = someService.IsUserAuthorized(user.Identity.Name, _someFilterParameter);
if (!isAuthorized)
{
context.Result = new StatusCodeResult((int)System.Net.HttpStatusCode.Forbidden);
return;
}
}
}

Based on Derek Greer GREAT answer, i did it with enums.
Here is an example of my code:
public enum PermissionItem
{
User,
Product,
Contact,
Review,
Client
}
public enum PermissionAction
{
Read,
Create,
}
public class AuthorizeAttribute : TypeFilterAttribute
{
public AuthorizeAttribute(PermissionItem item, PermissionAction action)
: base(typeof(AuthorizeActionFilter))
{
Arguments = new object[] { item, action };
}
}
public class AuthorizeActionFilter : IAuthorizationFilter
{
private readonly PermissionItem _item;
private readonly PermissionAction _action;
public AuthorizeActionFilter(PermissionItem item, PermissionAction action)
{
_item = item;
_action = action;
}
public void OnAuthorization(AuthorizationFilterContext context)
{
bool isAuthorized = MumboJumboFunction(context.HttpContext.User, _item, _action); // :)
if (!isAuthorized)
{
context.Result = new ForbidResult();
}
}
}
public class UserController : BaseController
{
private readonly DbContext _context;
public UserController( DbContext context) :
base()
{
_logger = logger;
}
[Authorize(PermissionItem.User, PermissionAction.Read)]
public async Task<IActionResult> Index()
{
return View(await _context.User.ToListAsync());
}
}

You can create your own AuthorizationHandler that will find custom attributes on your Controllers and Actions, and pass them to the HandleRequirementAsync method.
public abstract class AttributeAuthorizationHandler<TRequirement, TAttribute> : AuthorizationHandler<TRequirement> where TRequirement : IAuthorizationRequirement where TAttribute : Attribute
{
protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, TRequirement requirement)
{
var attributes = new List<TAttribute>();
var action = (context.Resource as AuthorizationFilterContext)?.ActionDescriptor as ControllerActionDescriptor;
if (action != null)
{
attributes.AddRange(GetAttributes(action.ControllerTypeInfo.UnderlyingSystemType));
attributes.AddRange(GetAttributes(action.MethodInfo));
}
return HandleRequirementAsync(context, requirement, attributes);
}
protected abstract Task HandleRequirementAsync(AuthorizationHandlerContext context, TRequirement requirement, IEnumerable<TAttribute> attributes);
private static IEnumerable<TAttribute> GetAttributes(MemberInfo memberInfo)
{
return memberInfo.GetCustomAttributes(typeof(TAttribute), false).Cast<TAttribute>();
}
}
Then you can use it for any custom attributes you need on your controllers or actions. For example to add permission requirements. Just create your custom attribute.
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, AllowMultiple = true)]
public class PermissionAttribute : AuthorizeAttribute
{
public string Name { get; }
public PermissionAttribute(string name) : base("Permission")
{
Name = name;
}
}
Then create a Requirement to add to your Policy
public class PermissionAuthorizationRequirement : IAuthorizationRequirement
{
//Add any custom requirement properties if you have them
}
Then create the AuthorizationHandler for your custom attribute, inheriting the AttributeAuthorizationHandler that we created earlier. It will be passed an IEnumerable for all your custom attributes in the HandleRequirementsAsync method, accumulated from your Controller and Action.
public class PermissionAuthorizationHandler : AttributeAuthorizationHandler<PermissionAuthorizationRequirement, PermissionAttribute>
{
protected override async Task HandleRequirementAsync(AuthorizationHandlerContext context, PermissionAuthorizationRequirement requirement, IEnumerable<PermissionAttribute> attributes)
{
foreach (var permissionAttribute in attributes)
{
if (!await AuthorizeAsync(context.User, permissionAttribute.Name))
{
return;
}
}
context.Succeed(requirement);
}
private Task<bool> AuthorizeAsync(ClaimsPrincipal user, string permission)
{
//Implement your custom user permission logic here
}
}
And finally, in your Startup.cs ConfigureServices method, add your custom AuthorizationHandler to the services, and add your Policy.
services.AddSingleton<IAuthorizationHandler, PermissionAuthorizationHandler>();
services.AddAuthorization(options =>
{
options.AddPolicy("Permission", policyBuilder =>
{
policyBuilder.Requirements.Add(new PermissionAuthorizationRequirement());
});
});
Now you can simply decorate your Controllers and Actions with your custom attribute.
[Permission("AccessCustomers")]
public class CustomersController
{
[Permission("AddCustomer")]
IActionResult AddCustomer([FromBody] Customer customer)
{
//Add customer
}
}

What is the current approach to make a custom AuthorizeAttribute
For pure authorization scenarios (like restricting access to specific users only), the recommended approach is to use the new authorization block: https://github.com/aspnet/MusicStore/blob/1c0aeb08bb1ebd846726232226279bbe001782e1/samples/MusicStore/Startup.cs#L84-L92
public class Startup
{
public void ConfigureServices(IServiceCollection services)
{
services.Configure<AuthorizationOptions>(options =>
{
options.AddPolicy("ManageStore", policy => policy.RequireClaim("Action", "ManageStore"));
});
}
}
public class StoreController : Controller
{
[Authorize(Policy = "ManageStore"), HttpGet]
public async Task<IActionResult> Manage() { ... }
}
For authentication, it's best handled at the middleware level.
What are you trying to achieve exactly?

What?!
I decided to add another simple answer. B/c I find most of these answers a little overengineered. And also because I needed a way to GRANT authorization, not just DENY it. Most of the answers here offer a way to "tighten" security, but I wanted to "loosen" it. For example: "if some application setting is configured, then allow access to anonymous users".
public class MyAuthAttribute : Attribute, IAuthorizationFilter
{
public void OnAuthorization(AuthorizationFilterContext context)
{
//check access
if (CheckPermissions())
{
//all good, add optional code if you want. Or don't
}
else
{
//DENIED!
//return "ChallengeResult" to redirect to login page (for example)
context.Result = new ChallengeResult(CookieAuthenticationDefaults.AuthenticationScheme);
}
}
}
That's it. No need to mess with "policies", "claims", "handlers" and other [beep]
Usage:
// GET api/Get/5
[MyAuth]
public ActionResult<string> Get(int id)
{
return "blahblah";
}

The modern way is AuthenticationHandlers
in startup.cs add
services.AddAuthentication("BasicAuthentication").AddScheme<AuthenticationSchemeOptions, BasicAuthenticationHandler>("BasicAuthentication", null);
public class BasicAuthenticationHandler : AuthenticationHandler<AuthenticationSchemeOptions>
{
private readonly IUserService _userService;
public BasicAuthenticationHandler(
IOptionsMonitor<AuthenticationSchemeOptions> options,
ILoggerFactory logger,
UrlEncoder encoder,
ISystemClock clock,
IUserService userService)
: base(options, logger, encoder, clock)
{
_userService = userService;
}
protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
{
if (!Request.Headers.ContainsKey("Authorization"))
return AuthenticateResult.Fail("Missing Authorization Header");
User user = null;
try
{
var authHeader = AuthenticationHeaderValue.Parse(Request.Headers["Authorization"]);
var credentialBytes = Convert.FromBase64String(authHeader.Parameter);
var credentials = Encoding.UTF8.GetString(credentialBytes).Split(new[] { ':' }, 2);
var username = credentials[0];
var password = credentials[1];
user = await _userService.Authenticate(username, password);
}
catch
{
return AuthenticateResult.Fail("Invalid Authorization Header");
}
if (user == null)
return AuthenticateResult.Fail("Invalid User-name or Password");
var claims = new[] {
new Claim(ClaimTypes.NameIdentifier, user.Id.ToString()),
new Claim(ClaimTypes.Name, user.Username),
};
var identity = new ClaimsIdentity(claims, Scheme.Name);
var principal = new ClaimsPrincipal(identity);
var ticket = new AuthenticationTicket(principal, Scheme.Name);
return AuthenticateResult.Success(ticket);
}
}
IUserService is a service that you make where you have user name and password.
basically it returns a user class that you use to map your claims on.
var claims = new[] {
new Claim(ClaimTypes.NameIdentifier, user.Id.ToString()),
new Claim(ClaimTypes.Name, user.Username),
};
Then you can query these claims and her any data you mapped, ther are quite a few, have a look at ClaimTypes class
you can use this in an extension method an get any of the mappings
public int? GetUserId()
{
if (context.User.Identity.IsAuthenticated)
{
var id=context.User.FindFirst(ClaimTypes.NameIdentifier);
if (!(id is null) && int.TryParse(id.Value, out var userId))
return userId;
}
return new Nullable<int>();
}
This new way, i think is better than the old way as shown here, both work
public class BasicAuthenticationAttribute : AuthorizationFilterAttribute
{
public override void OnAuthorization(HttpActionContext actionContext)
{
if (actionContext.Request.Headers.Authorization != null)
{
var authToken = actionContext.Request.Headers.Authorization.Parameter;
// decoding authToken we get decode value in 'Username:Password' format
var decodeauthToken = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(authToken));
// spliting decodeauthToken using ':'
var arrUserNameandPassword = decodeauthToken.Split(':');
// at 0th postion of array we get username and at 1st we get password
if (IsAuthorizedUser(arrUserNameandPassword[0], arrUserNameandPassword[1]))
{
// setting current principle
Thread.CurrentPrincipal = new GenericPrincipal(new GenericIdentity(arrUserNameandPassword[0]), null);
}
else
{
actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized);
}
}
else
{
actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized);
}
}
public static bool IsAuthorizedUser(string Username, string Password)
{
// In this method we can handle our database logic here...
return Username.Equals("test") && Password == "test";
}
}

If anyone just wants to validate a bearer token in the authorize phase using the current security practices you can,
add this to your Startup/ConfigureServices
services.AddSingleton<IAuthorizationHandler, BearerAuthorizationHandler>();
services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme).AddJwtBearer();
services.AddAuthorization(options => options.AddPolicy("Bearer",
policy => policy.AddRequirements(new BearerRequirement())
)
);
and this in your codebase,
public class BearerRequirement : IAuthorizationRequirement
{
public async Task<bool> IsTokenValid(SomeValidationContext context, string token)
{
// here you can check if the token received is valid
return true;
}
}
public class BearerAuthorizationHandler : AuthorizationHandler<BearerRequirement>
{
public BearerAuthorizationHandler(SomeValidationContext thatYouCanInject)
{
...
}
protected override async Task HandleRequirementAsync(AuthorizationHandlerContext context, BearerRequirement requirement)
{
var authFilterCtx = (Microsoft.AspNetCore.Mvc.Filters.AuthorizationFilterContext)context.Resource;
string authHeader = authFilterCtx.HttpContext.Request.Headers["Authorization"];
if (authHeader != null && authHeader.Contains("Bearer"))
{
var token = authHeader.Replace("Bearer ", string.Empty);
if (await requirement.IsTokenValid(thatYouCanInject, token))
{
context.Succeed(requirement);
}
}
}
}
If the code doesn't reach context.Succeed(...) it will Fail anyway (401).
And then in your controllers you can use
[Authorize(Policy = "Bearer", AuthenticationSchemes = JwtBearerDefaults.AuthenticationScheme)]

The below code worked for me in .Net Core 5
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]
public class AccessAuthorizationAttribute : AuthorizeAttribute, IAuthorizationFilter
{
public string Module { get; set; } //Permission string to get from controller
public AccessAuthorizationAttribute(string module)
{
Module = module;
}
public void OnAuthorization(AuthorizationFilterContext context)
{
//Validate if any permissions are passed when using attribute at controller or action level
if (string.IsNullOrEmpty(Module))
{
//Validation cannot take place without any permissions so returning unauthorized
context.Result = new UnauthorizedResult();
return;
}
if (hasAccess)
{
return;
}
context.Result = new UnauthorizedResult();
return;
}
}

The accepted answer (https://stackoverflow.com/a/41348219/4974715) is not realistically maintainable or suitable because "CanReadResource" is being used as a claim (but should essentially be a policy in reality, IMO). The approach at the answer is not OK in the way it was used, because if an action method requires many different claims setups, then with that answer you would have to repeatedly write something like...
[ClaimRequirement(MyClaimTypes.Permission, "CanReadResource")]
[ClaimRequirement(MyClaimTypes.AnotherPermision, "AnotherClaimVaue")]
//and etc. on a single action.
So, imagine how much coding that would take. Ideally, "CanReadResource" is supposed to be a policy that uses many claims to determine if a user can read a resource.
What I do is I create my policies as an enumeration and then loop through and set up the requirements like thus...
services.AddAuthorization(authorizationOptions =>
{
foreach (var policyString in Enum.GetNames(typeof(Enumerations.Security.Policy)))
{
authorizationOptions.AddPolicy(
policyString,
authorizationPolicyBuilder => authorizationPolicyBuilder.Requirements.Add(new DefaultAuthorizationRequirement((Enumerations.Security.Policy)Enum.Parse(typeof(Enumerations.Security.Policy), policyWrtString), DateTime.UtcNow)));
/* Note that thisn does not stop you from
configuring policies directly against a username, claims, roles, etc. You can do the usual.
*/
}
});
The DefaultAuthorizationRequirement class looks like...
public class DefaultAuthorizationRequirement : IAuthorizationRequirement
{
public Enumerations.Security.Policy Policy {get; set;} //This is a mere enumeration whose code is not shown.
public DateTime DateTimeOfSetup {get; set;} //Just in case you have to know when the app started up. And you may want to log out a user if their profile was modified after this date-time, etc.
}
public class DefaultAuthorizationHandler : AuthorizationHandler<DefaultAuthorizationRequirement>
{
private IAServiceToUse _aServiceToUse;
public DefaultAuthorizationHandler(
IAServiceToUse aServiceToUse
)
{
_aServiceToUse = aServiceToUse;
}
protected async override Task HandleRequirementAsync(AuthorizationHandlerContext context, DefaultAuthorizationRequirement requirement)
{
/*Here, you can quickly check a data source or Web API or etc.
to know the latest date-time of the user's profile modification...
*/
if (_aServiceToUse.GetDateTimeOfLatestUserProfileModication > requirement.DateTimeOfSetup)
{
context.Fail(); /*Because any modifications to user information,
e.g. if the user used another browser or if by Admin modification,
the claims of the user in this session cannot be guaranteed to be reliable.
*/
return;
}
bool shouldSucceed = false; //This should first be false, because context.Succeed(...) has to only be called if the requirement specifically succeeds.
bool shouldFail = false; /*This should first be false, because context.Fail()
doesn't have to be called if there's no security breach.
*/
// You can do anything.
await doAnythingAsync();
/*You can get the user's claims...
ALSO, note that if you have a way to priorly map users or users with certain claims
to particular policies, add those policies as claims of the user for the sake of ease.
BUT policies that require dynamic code (e.g. checking for age range) would have to be
coded in the switch-case below to determine stuff.
*/
var claims = context.User.Claims;
// You can, of course, get the policy that was hit...
var policy = requirement.Policy
//You can use a switch case to determine what policy to deal with here...
switch (policy)
{
case Enumerations.Security.Policy.CanReadResource:
/*Do stuff with the claims and change the
value of shouldSucceed and/or shouldFail.
*/
break;
case Enumerations.Security.Policy.AnotherPolicy:
/*Do stuff with the claims and change the
value of shouldSucceed and/or shouldFail.
*/
break;
// Other policies too.
default:
throw new NotImplementedException();
}
/* Note that the following conditions are
so because failure and success in a requirement handler
are not mutually exclusive. They demand certainty.
*/
if (shouldFail)
{
context.Fail(); /*Check the docs on this method to
see its implications.
*/
}
if (shouldSucceed)
{
context.Succeed(requirement);
}
}
}
Note that the code above can also enable pre-mapping of a user to a policy in your data store. So, when composing claims for the user, you basically retrieve the policies that had been pre-mapped to the user directly or indirectly (e.g. because the user has a certain claim value and that claim value had been identified and mapped to a policy, such that it provides automatic mapping for users who have that claim value too), and enlist the policies as claims, such that in the authorization handler, you can simply check if the user's claims contain requirement.Policy as a Value of a Claim item in their claims. That is for a static way of satisfying a policy requirement, e.g. "First name" requirement is quite static in nature. So, for the example above (which I had forgotten to give example on Authorize attribute in my earlier updates to this answer), using the policy with Authorize attribute is like as follows, where ViewRecord is an enum member:
[Authorize(Policy = nameof(Enumerations.Security.Policy.ViewRecord))]
A dynamic requirement can be about checking age range, etc. and policies that use such requirements cannot be pre-mapped to users.
An example of dynamic policy claims checking (e.g. to check if a user is above 18 years old) is already at the answer given by #blowdart (https://stackoverflow.com/a/31465227/4974715).
PS: I typed this on my phone. Pardon any typos and lack of formatting.

As of this writing I believe this can be accomplished with the IClaimsTransformation interface in asp.net core 2 and above. I just implemented a proof of concept which is sharable enough to post here.
public class PrivilegesToClaimsTransformer : IClaimsTransformation
{
private readonly IPrivilegeProvider privilegeProvider;
public const string DidItClaim = "http://foo.bar/privileges/resolved";
public PrivilegesToClaimsTransformer(IPrivilegeProvider privilegeProvider)
{
this.privilegeProvider = privilegeProvider;
}
public async Task<ClaimsPrincipal> TransformAsync(ClaimsPrincipal principal)
{
if (principal.Identity is ClaimsIdentity claimer)
{
if (claimer.HasClaim(DidItClaim, bool.TrueString))
{
return principal;
}
var privileges = await this.privilegeProvider.GetPrivileges( ... );
claimer.AddClaim(new Claim(DidItClaim, bool.TrueString));
foreach (var privilegeAsRole in privileges)
{
claimer.AddClaim(new Claim(ClaimTypes.Role /*"http://schemas.microsoft.com/ws/2008/06/identity/claims/role" */, privilegeAsRole));
}
}
return principal;
}
}
To use this in your Controller just add an appropriate [Authorize(Roles="whatever")] to your methods.
[HttpGet]
[Route("poc")]
[Authorize(Roles = "plugh,blast")]
public JsonResult PocAuthorization()
{
var result = Json(new
{
when = DateTime.UtcNow,
});
result.StatusCode = (int)HttpStatusCode.OK;
return result;
}
In our case every request includes an Authorization header that is a JWT. This is the prototype and I believe we will do something super close to this in our production system next week.
Future voters, consider the date of writing when you vote. As of today, this works on my machine.™ You will probably want more error handling and logging on your implementation.

Just adding to the great answer from #Shawn. If you are using dotnet 5 you need to update the class to be:
public abstract class AttributeAuthorizationHandler<TRequirement, TAttribute> : AuthorizationHandler<TRequirement> where TRequirement : IAuthorizationRequirement where TAttribute : Attribute
{
protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, TRequirement requirement)
{
var attributes = new List<TAttribute>();
if (context.Resource is HttpContext httpContext)
{
var endPoint = httpContext.GetEndpoint();
var action = endPoint?.Metadata.GetMetadata<ControllerActionDescriptor>();
if(action != null)
{
attributes.AddRange(GetAttributes(action.ControllerTypeInfo.UnderlyingSystemType));
attributes.AddRange(GetAttributes(action.MethodInfo));
}
}
return HandleRequirementAsync(context, requirement, attributes);
}
protected abstract Task HandleRequirementAsync(AuthorizationHandlerContext context, TRequirement requirement, IEnumerable<TAttribute> attributes);
private static IEnumerable<TAttribute> GetAttributes(MemberInfo memberInfo) => memberInfo.GetCustomAttributes(typeof(TAttribute), false).Cast<TAttribute>();
}
Noting the way getting the ControllerActionDescriptor has changed.

I have bearer token and I can read claims.
I use that attribute on controllers and actions
public class CustomAuthorizationAttribute : ActionFilterAttribute
{
public string[] Claims;
public override void OnActionExecuting(ActionExecutingContext context)
{
// check user
var contextUser = context?.HttpContext?.User;
if (contextUser == null)
{
throw new BusinessException("Forbidden");
}
// check roles
var roles = contextUser.FindAll("http://schemas.microsoft.com/ws/2008/06/identity/claims/role").Select(c => c.Value).ToList();
if (!roles.Any(s => Claims.Contains(s)))
{
throw new BusinessException("Forbidden");
}
base.OnActionExecuting(context);
}
}
example
[CustomAuthorization(Claims = new string[]
{
nameof(AuthorizationRole.HR_ADMIN),
nameof(AuthorizationRole.HR_SETTING)
})]
[Route("api/[controller]")]
[ApiController]
public class SomeAdminController : ControllerBase
{
private readonly IMediator _mediator;
public SomeAdminController(IMediator mediator)
{
_mediator = mediator;
}
[HttpGet("list/SomeList")]
public async Task<IActionResult> SomeList()
=> Ok(await _mediator.Send(new SomeListQuery()));
}
That is Roles
public struct AuthorizationRole
{
public static string HR_ADMIN;
public static string HR_SETTING;
}

Here's a simple 5-step guide for how to implement custom role authorization using policies for all you copy and pasters out there :) . I used these docs.
Create a requirement:
public class RoleRequirement : IAuthorizationRequirement
{
public string Role { get; set; }
}
Create a handler:
public class RoleHandler : AuthorizationHandler<RoleRequirement>
{
protected override async Task HandleRequirementAsync(AuthorizationHandlerContext context, RoleRequirement requirement)
{
var requiredRole = requirement.Role;
//custom auth logic
// you can use context to access authenticated user,
// you can use dependecy injection to call custom services
var hasRole = true;
if (hasRole)
{
context.Succeed(requirement);
}
else
{
context.Fail(new AuthorizationFailureReason(this, $"Role {requirement.Role} missing"));
}
}
}
Add the handler in Program.cs:
builder.Services.AddSingleton<IAuthorizationHandler, RoleHandler>();
Add a policy with your role requirement in program.cs:
builder.Services.AddAuthorization(options =>
{
options.AddPolicy("Read", policy => policy.Requirements.Add(new RoleRequirement{Role = "ReadAccess_Custom_System"}));
});
Use your policy:
[Authorize("Read")]
public class ExampleController : ControllerBase
{
}

A lot of people here already told this, but with Policy handlers you can come really far in terms of what you could achieve with the old way in .NET Framework.
I followed a quick writeup from this answer on SO: https://stackoverflow.com/a/61963465/7081176
For me it works flawlessly after making some classes:
The EditUserRequirement:
public class EditUserRequirement : IAuthorizationRequirement
{
public EditUserRequirement()
{
}
}
An abstract handler to make my life easier:
public abstract class AbstractRequirementHandler<T> : IAuthorizationHandler
where T : IAuthorizationRequirement
{
public async Task HandleAsync(AuthorizationHandlerContext context)
{
var pendingRequirements = context.PendingRequirements.ToList();
foreach (var requirement in pendingRequirements)
{
if (requirement is T typedRequirement)
{
await HandleRequirementAsync(context, typedRequirement);
}
}
}
protected abstract Task HandleRequirementAsync(AuthorizationHandlerContext context, T requirement);
}
An implementation of the abstract handler:
public class EditUserRequirementHandler : AbstractRequirementHandler<EditUserRequirement>
{
protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, EditUserRequirement requirement)
{
// If the user is owner of the resource, allow it.
if (IsOwner(context.User, g))
{
context.Succeed(requirement);
}
return Task.CompletedTask;
}
private static bool IsOwner(ClaimsPrincipal user, Guid userIdentifier)
{
return user.GetUserIdentifier() == userIdentifier;
}
}
Registering my handler and requirement:
services.AddSingleton<IAuthorizationHandler, EditUserRequirementHandler>();
services.AddAuthorization(options =>
{
options.AddPolicy(Policies.Policies.EditUser, policy =>
{
policy.Requirements.Add(new EditUserRequirement());
});
});
And then using my Policy in Blazor:
<AuthorizeView Policy="#Policies.EditUser" Resource="#id">
<NotAuthorized>
<Unauthorized />
</NotAuthorized>
<Authorized Context="Auth">
...
</Authorized>
</AuthorizeView>
I hope this is useful for anyone facing this issue.

I have been looking into solving a very similar issue, and settled on creating a custom ActionFilterAttribute (I'm going to call it AuthorizationFilterAttribute) instead of an AuthorizeAttribute to implement the guidance here: https://learn.microsoft.com/en-us/aspnet/core/security/authorization/resourcebased?view=aspnetcore-6.0#challenge-and-forbid-with-an-operational-resource-handler.

For authorization in our app. We had to call a service based on the parameters passed in authorization attribute.
For example, if we want to check if logged in doctor can view patient appointments we will pass "View_Appointment" to custom authorize attribute and check that right in DB service and based on results we will athorize. Here is the code for this scenario:
public class PatientAuthorizeAttribute : TypeFilterAttribute
{
public PatientAuthorizeAttribute(params PatientAccessRights[] right) : base(typeof(AuthFilter)) //PatientAccessRights is an enum
{
Arguments = new object[] { right };
}
private class AuthFilter : IActionFilter
{
PatientAccessRights[] right;
IAuthService authService;
public AuthFilter(IAuthService authService, PatientAccessRights[] right)
{
this.right = right;
this.authService = authService;
}
public void OnActionExecuted(ActionExecutedContext context)
{
}
public void OnActionExecuting(ActionExecutingContext context)
{
var allparameters = context.ActionArguments.Values;
if (allparameters.Count() == 1)
{
var param = allparameters.First();
if (typeof(IPatientRequest).IsAssignableFrom(param.GetType()))
{
IPatientRequest patientRequestInfo = (IPatientRequest)param;
PatientAccessRequest userAccessRequest = new PatientAccessRequest();
userAccessRequest.Rights = right;
userAccessRequest.MemberID = patientRequestInfo.PatientID;
var result = authService.CheckUserPatientAccess(userAccessRequest).Result; //this calls DB service to check from DB
if (result.Status == ReturnType.Failure)
{
//TODO: return apirepsonse
context.Result = new StatusCodeResult((int)System.Net.HttpStatusCode.Forbidden);
}
}
else
{
throw new AppSystemException("PatientAuthorizeAttribute not supported");
}
}
else
{
throw new AppSystemException("PatientAuthorizeAttribute not supported");
}
}
}
}
And on API action we use it like this:
[PatientAuthorize(PatientAccessRights.PATIENT_VIEW_APPOINTMENTS)] //this is enum, we can pass multiple
[HttpPost]
public SomeReturnType ViewAppointments()
{
}

How to make a class object available during the entire life of the request in Asp .Net Web API?

Here is my code. I have written login to validate the token, for valid token return user object. but unable to find way to make it available across controllers.
I don't want to use Identity.
public class CustomAuthorize : AuthorizeAttribute
{
private const string AUTH_TOKEN = "AuthToken";
public override Task OnAuthorizationAsync(HttpActionContext actionContext, CancellationToken cancellationToken)
{
AllowAnonymousAttribute allowAnonymousAttribute = actionContext.ActionDescriptor.GetCustomAttributes<AllowAnonymousAttribute>().FirstOrDefault();
if (allowAnonymousAttribute != null)
{
return Task.FromResult<object>(null);
}
if (actionContext.Request.Headers.Contains(AUTH_TOKEN))
{
var authToken = actionContext.Request.Headers.GetValues(AUTH_TOKEN).First();
var user = Utility.GetUserByToken(authToken);
if (user != null)
{
//
// how to make this `user` object available across the controllers
//
return Task.FromResult<object>(null);
}
else
{
actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized, new CustomError() { Code = 100, Message = "Invalid Access Token" });
return Task.FromResult<object>(null);
}
}
else
{
actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized, new CustomError() { Code = 100, Message = "Invalid Access Token" });
return Task.FromResult<object>(null);
}
}
}
Please help...

Your Question is a bit unclear - I assume you are referring to this line:
var user = Utility.GetUserByToken(authToken);
If so, then I might have a solution. So the fundamental problem is that you cannot simply save this variable where you currently are in the current controller, you need to understand the context you are working in - Every time a different user makes a request a different user models get created in the current controller. To have access to the user model across my app whenever a user makes a request, I do the following:
First you need to hook into the request receiving process of ASP.NET. This can be done inside the Global.asax.cs file, but I prefer to keep it clean and create a PartialGlobal class and mark the Global.asax.cs as partial.
From
public class MvcApplication : System.Web.HttpApplication
To
public partial class MvcApplication : System.Web.HttpApplication
Then create the PartialGlobal Class:
public partial class MvcApplication
{
protected void Application_PostAuthenticateRequest(Object sender, EventArgs e)
{
var request = HttpContext.Current.Request;
var authHeader = request.Headers["Authorization"];
//For API users
if (authHeader != null)
{
var authHeaderVal = AuthenticationHeaderValue.Parse(authHeader);
if (authHeaderVal.Scheme.Equals("Basic", StringComparison.OrdinalIgnoreCase))
{
if (!string.IsNullOrEmpty(authHeaderVal.Parameter))
{
AuthenticateUser(authHeaderVal.Parameter);
}
}
}
//For Regular Website Users
else
{
HttpCookie authCookie = request.Cookies[FormsAuthentication.FormsCookieName];
if (authCookie != null)
{
//Extract the forms authentication cookie
FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value);
// If caching userData field then extract
var userModel = UsersBLL.DeserializeObject(authTicket.UserData);
var principal = new UserPrincipal(userModel);
SetPrincipal(principal);
}
}
}
private static bool AuthenticateUser(string credentials)
{
var model = UsersBLL.DecryptToken(credentials);
if (!model.RefUser.HasValue)
{
return false;
}
SetPrincipal(new UserPrincipal(model));
return true;
}
private static void SetPrincipal(UserPrincipal principal)
{
Thread.CurrentPrincipal = principal;
if (HttpContext.Current != null)
{
HttpContext.Current.User = principal;
}
}
}
The UserPrincipal Class:
public class UserPrincipal : IPrincipal
{
public IIdentity Identity { get; private set; }
//Just a class with details like name,age etc.
public UserModel Model { get; set; }
public UserPrincipal(UserModel model)
{
this.Model = model;
this.Identity = new GenericIdentity(model.Email);
}
}
Note the line in the PartialGLobal class: var model = UsersBLL.DecryptToken(credentials);. Here I simply use a method I created to de-crypt my token string so it can be deserialized, you probably won't have/need this.
The essential part is this last step of the PartialGlobal class:
private static void SetPrincipal(UserPrincipal principal)
{
Thread.CurrentPrincipal = principal;
if (HttpContext.Current != null)
{
HttpContext.Current.User = principal;
}
}
If you have the context know about your user, you can access it anywhere by simply calling:
var principal = (UserPrincipal)HttpContext.Current.User;

One way is to Extend the ApiController which is what your controllers are using as the base class.
Define a CustomController
public class CustomController : ApiController
{
projected User _user;
}
For all the other controller use this as a base class and the _user object should be accessible from all the controllers.

ASP.NET Core Web API Skip Authentication

I'm writing an ASP.NET Core web application using a custom basic authentication, based on the following example:
ASP.NET Core Web API Authentication
Now I have an action in my user controller in order to register user. So I would like to pass this method my custom Attribute "SkipAuthAttribute" in order to say, if someone calls this method (action) you have to skip the authenticaion (the user which want to register, has no login).
But the type HttpContext has no ActionDescriptor to get the Custom Attributes of the action
Knows someone, how can I skip the authenticaion by some specific actions?

Updated answer:
You should try to write code according to framework. Middleware from example are unsuitable for ASP.NET Core MVC. Here is my example:
public class BasicAuthenticationHandler : AuthenticationHandler<BasicAuthenticationOptions>
{
protected override Task<AuthenticateResult> HandleAuthenticateAsync()
{
var authHeader = (string)this.Request.Headers["Authorization"];
if (!string.IsNullOrEmpty(authHeader) && authHeader.StartsWith("basic", StringComparison.OrdinalIgnoreCase))
{
//Extract credentials
string encodedUsernamePassword = authHeader.Substring("Basic ".Length).Trim();
Encoding encoding = Encoding.GetEncoding("iso-8859-1");
string usernamePassword = encoding.GetString(Convert.FromBase64String(encodedUsernamePassword));
int seperatorIndex = usernamePassword.IndexOf(':');
var username = usernamePassword.Substring(0, seperatorIndex);
var password = usernamePassword.Substring(seperatorIndex + 1);
if (username == "test" && password == "test")
{
var user = new GenericPrincipal(new GenericIdentity("User"), null);
var ticket = new AuthenticationTicket(user, new AuthenticationProperties(), Options.AuthenticationScheme);
return Task.FromResult(AuthenticateResult.Success(ticket));
}
}
return Task.FromResult(AuthenticateResult.Fail("No valid user."));
}
}
public class BasicAuthenticationMiddleware : AuthenticationMiddleware<BasicAuthenticationOptions>
{
public BasicAuthenticationMiddleware(
RequestDelegate next,
IOptions<BasicAuthenticationOptions> options,
ILoggerFactory loggerFactory,
UrlEncoder encoder)
: base(next, options, loggerFactory, encoder)
{
}
protected override AuthenticationHandler<BasicAuthenticationOptions> CreateHandler()
{
return new BasicAuthenticationHandler();
}
}
public class BasicAuthenticationOptions : AuthenticationOptions
{
public BasicAuthenticationOptions()
{
AuthenticationScheme = "Basic";
AutomaticAuthenticate = true;
}
}
Registration at Startup.cs - app.UseMiddleware<BasicAuthenticationMiddleware>();. With this code, you can restrict any controller with standart attribute Autorize:
[Authorize(ActiveAuthenticationSchemes = "Basic")]
[Route("api/[controller]")]
public class ValuesController : Controller
and use attribute AllowAnonymous if you apply authorize filter on application level.
Original answer:
From documentation
Add [AllowAnonymous] to the home controller so anonymous users can get information about the site before they register.
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Authorization;
namespace ContactManager.Controllers {
[AllowAnonymous]
public class HomeController : Controller
{
public IActionResult Index()
{
return View();
}

C# API Controller Custom Filter with HttpActionContext Redirect to controller?

Is there a way to create a custom filter with an API controller to redirect to a MVC controller?
After looking around a bit his is what i have.
public class APIHasOneOfThesePermissions : ActionFilterAttribute
{
protected UserManager<ApplicationUser> UserManager { get; set; }
private SAMPortal.DAL.SAMPortalContext db = new DAL.SAMPortalContext();
public string[] Permissions { get; set; }
public APIHasOneOfThesePermissions(string[] Permissions)
{
this.UserManager = new UserManager<ApplicationUser>(new UserStore<ApplicationUser>(this.db));
this.Permissions = Permissions;
}
public override void OnActionExecuting(HttpActionContext filterContext)
{
string userID = HttpContext.Current.User.Identity.GetUserId();
var CurrUser = db.Users.Include(u => u.Role.Permissions).Where(user => user.Id.Equals(userID)).FirstOrDefault();
bool hasPermission = false;
foreach (string x in Permissions)
{
if (hasPermission == false)
{
hasPermission = CurrUser.HasPermission(x);
}
}
if (hasPermission == false)
{
filterContext.Response = new HttpResponseMessage(HttpStatusCode.Unauthorized);
}
base.OnActionExecuting(filterContext);
}
}
However when i execute the code it doesn't redirect them to the error page. Ideally i would like to redirect to a specify non-API controller is that possible?

I've created AuthorizeRedirectAttribute in one of my projects like this:
using System;
using System.Net;
using System.Web.Mvc;
namespace MyNamespace.Attributes
{
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method)]
public class AuthorizeRedirectAttribute : AuthorizeAttribute
{
public string RedirectUrl = "~/Error/Forbidden403";
public override void OnAuthorization(AuthorizationContext filterContext)
{
base.OnAuthorization(filterContext);
}
protected override void HandleUnauthorizedRequest(AuthorizationContext filterContext)
{
base.HandleUnauthorizedRequest(filterContext);
var httpContext = filterContext.RequestContext.HttpContext;
var request = httpContext.Request;
var response = httpContext.Response;
// If AJAX request, just return appropriate code
if (request.IsAjaxRequest())
{
if (filterContext.HttpContext.User.Identity.IsAuthenticated)
response.StatusCode = (int)HttpStatusCode.Forbidden;
else
response.StatusCode = (int)HttpStatusCode.Unauthorized;
response.SuppressFormsAuthenticationRedirect = true;
response.End();
}
// Otherwise check if authenticated, and if not redirect to specified url
if (httpContext.User.Identity.IsAuthenticated)
{
httpContext.Response.Redirect(RedirectUrl);
}
}
}
}
Then I've used it like this
[AuthorizeRedirect(Roles = "Administrator")]
public class MyController : Controller
{
}
In this case I've decorated whole controller with this attribute. It can also be applied to single controller function, if necessary. Basically what it does is, it checks whether logged on user is in role Administrator. If it is not, user is redirected to "~/Error/Forbidden403" action (returning simple view displaying user has not enough permissions). Hope it helps.
You could also implement checking your own permissions, as you did in your code.

Reading every incoming request (URL) in ASP.NET WEB API

I was using ASP.NET MVC framework. In this framework, we checked every incoming request (url) for some key and assigned it to a property. We created a custom class which derived from Controller class & we override OnActionExecuting() to provide our custom logic.
How can we achieve the same in ASP.NET WEB API?
//Implementation from ASP.NET MVC
public class ApplicationController : Controller
{
public string UserID { get; set; }
protected override void OnActionExecuting(ActionExecutingContext filterContext)
{
if (!string.IsNullOrEmpty(Request.Params["uid"]))
UserID = Request.Params["uid"];
base.OnActionExecuting(filterContext);
}
}
What I have tried in ASP.NET WEB API: -- Though this is working, I wonder if this is the correct approach?
Created a base controller
public class BaseApiController : ApiController
{
public string UserID { get; set; }
}
Created another class which inherits ActionFilterAttribute class & I override OnActionExecuting()
public class TokenFilterAttribute : ActionFilterAttribute
{
public override void OnActionExecuting(System.Web.Http.Controllers.HttpActionContext actionContext)
{
var queryString = actionContext.Request.RequestUri.Query;
var items = HttpUtility.ParseQueryString(queryString);
var userId = items["uid"];
((MyApi.Data.Controllers.BaseApiController)(actionContext.ControllerContext.Controller)).UserID = userId;
}
}
Now register this class
public static void Register(HttpConfiguration config)
{
config.Filters.Add(new TokenFilterAttribute());
}

You can use message handlers from ASP.NET Web API. It is a typical security scenation, when you need to get some user token from query string, URL or HTTP Header
http://www.asp.net/web-api/overview/advanced/http-message-handlers
1.When you need simply to extract userId from URL, then use it as parameter for your Api method and ASP.NET WebAPI will do work for you, like
[HttpGet, Route("{userId}/roles")]
public UserRoles GetUserRoles(string userId, [FromUri] bool isExternalUser = true)
It work for such request
http://.../15222/roles?isExternalUser=false
2.If it is security scenario, please refer to http://www.asp.net/web-api/overview/security/authentication-and-authorization-in-aspnet-web-api
Basically you will need some MessageHandler or you can use filter attributes as well, it is mechanism in ASP.NET Web API to intercept each call.
If you need to process each request then MessageHandler is your way. You need implement MessageHanler and then register it.
To say easily, typical MessageHandler is class derived from MessageHandler or DelegatingHandler with SendAsync method overriden:
class AuthenticationHandler : DelegatingHandler
{
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
// Your code here
return base.SendAsync(request, cancellationToken);
}
}
And you need register it
static class WebApiConfig
{
public static void Register(HttpConfiguration config)
{
// Other code for WebAPI registerations here
config.MessageHandlers.Add(new AuthenticationHandler());
}
}
and call it from Global.asax.cs
WebApiConfig.Register(GlobalConfiguration.Configuration);
Some example dummy hypotetical implementation of such handler (here you need to imeplement your UidPrincipal from IPrincipal and UidIdentity from IIdentity)
public class AuthenticationHandler : DelegatingHandler
{
protected override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
try
{
var queryString = actionContext.Request.RequestUri.Query;
var items = HttpUtility.ParseQueryString(queryString);
var userId = items["uid"];
// Here check your UID and maybe some token, just dummy logic
if (userId == "D8CD2165-52C0-41E1-937F-054F24266B65")
{
IPrincipal principal = new UidPrincipal(new UidIdentity(uid), null);
// HttpContext exist only when hosting as asp.net web application in IIS or IISExpress
if (HttpContext.Current != null)
{
HttpContext.Current.User = principal;
}
else
{
Thread.CurrentPrincipal = principal;
}
return base.SendAsync(request, cancellationToken);
}
catch (Exception ex)
{
this.Log().Warn(ex.ToString());
return this.SendUnauthorizedResponse(ex.Message);
}
}
else
{
return this.SendUnauthorizedResponse();
}
}
catch (SecurityTokenValidationException)
{
return this.SendUnauthorizedResponse();
}
}
}
And lets access it from some ASP.NET WebApi method or some property in WebAPI class
var uid = ((UidIdentity)User.Identity).Uid