Skip to main content

Authorization In Blazor WebAssembly

In this article, we are going to understand the authorization flow using user roles and claims in the blazor webassembly application.

Create A Sample Blazor WebAssembly Application:

Let's create a sample blazor webassembly application for our demo. We can use any IDE for the application development but the most recommended is Visual Studio 2019(version 16.8.*) and Visual Studio Code.

Authentication Setup:

To implement authorization first user need to be authenticated. So here we will implement some fake user authentication with some roles and claims. For complete authentication, implementation checks my blogs like Access Token and Refresh Token.
Package Manager
Install-Package Microsoft.AspNetCore.Components.Authorization -Version 5.0.1
.Net CLI
dotnet add package Microsoft.AspNetCore.Components.Authorization --Version 5.0.1
A core component of blazor authentication is 'Microsoft.AspNetCore.Components.Authorization.AuthenticationStateProvider', here we going to implement it by customizing it.
Auth/CustomAuthStateProvider.cs:
using System.Security.Claims;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Components.Authorization;

namespace BW.Auth.Auth
{
  public class CustomAuthStateProvider : AuthenticationStateProvider
  {
   public override async Task<AuthenticationState> GetAuthenticationStateAsync()
   {
	var identity = new ClaimsIdentity(new []{
	 new Claim(ClaimTypes.Name,"Naveen"),
	 new Claim(ClaimTypes.Role, "user"),
	 new Claim(ClaimTypes.Role, "admin")
	},"Fake Auth");

	var user = new ClaimsPrincipal(identity);
	return await Task.FromResult(new AuthenticationState(user));
   }
  }
}
  • Here we added roles like 'user' and 'admin' to my authentication.
Now let's import required namespaces into the _Import.razor file.
_Import.razor:
@using BW.Auth.Shared
@using Microsoft.AspNetCore.Components.Authorization
@using Microsoft.AspNetCore.Authorization
Now register the required service in Program.cs file
Program.cs:
builder.Services.AddScoped<AuthenticationStateProvider,CustomAuthStateProvider>();
builder.Services.AddOptions();
builder.Services.AddAuthorizationCore();
Now add the 'CascadingAuthenticationState' and 'AuthorizeRouteView' components in the App.razor file.
App.razor:
<CascadingAuthenticationState>
<Router AppAssembly="@typeof(Program).Assembly">
  <Found Context="routeData">
	<AuthorizeRouteView RouteData="@routeData" DefaultLayout="@typeof(MainLayout)" />
  </Found>
  <NotFound>
	<LayoutView Layout="@typeof(MainLayout)">
		<p>Sorry, there's nothing at this address.</p>
	</LayoutView>
  </NotFound>
</Router>
</CascadingAuthenticationState>

Roles Authorization On AuthorizeView Component:

The AuthorizeView component supports roles based authorization base on the role we can render the content inside of it.
Index.razor:
@page "/"

<AuthorizeView Roles="superadmin">
    <Authorized >
        <div>Hi @(context.User.Identity.Name), hurray you have 'super admin' role, you can claim this offer</div>
    </Authorized>
</AuthorizeView>
<AuthorizeView Roles="admin">
    <Authorized >
        <div>Hi @(context.User.Identity.Name), hurray you have 'admin' role, you can claim this offer</div>
    </Authorized>
</AuthorizeView>
<AuthorizeView Roles="user">
     <Authorized>
        <div>Hi @(context.User.Identity.Name), hurray you have 'user' role ,Claim your user offers  </div>
    </Authorized>
</AuthorizeView>
Here we rendered 3 AuthorizeView components with respective roles to them. For my fake authentication, I have only roles like 'admin' and 'user'. So if run the application for me content inside of the 'superadmin' will not render.

We can also configure multiple roles on the AuthorizeView component with comma separation. So in this process, if we have at least one role then AuthorizeView renders.
Index.razor:
@page "/"

<AuthorizeView Roles="superadmin, admin">
    <Authorized >
        <div>Hi @(context.User.Identity.Name), this offer can claim by users with role either 'superadmin' or'admin'
        </div>
    </Authorized>
</AuthorizeView>
  • Here we configure multiple roles with comma separation, so to render this AuthorizeView component user should have at least one role.

Policy-Based Roles Authorization On AuthorizeView Component:

The policy is a set of rules. In the case of roles the policy will group the set of roles, so the user at least one role in the policy group then the user satisfied that policy, and then the AuthorizeView component renders.
Program.cs:
builder.Services.AddAuthorizationCore(options => {
	options.AddPolicy("mypolicy", policy => {
		policy.RequireRole("admin","superadmin");
	});
});
  • Here we grouped our roles under a policy named 'mypolicy'. Now we can use this policy name to authorize the user.
Pages/Index.razor:
@page "/"

<AuthorizeView Policy="mypolicy">
    <Authorized >
        <div>Hi @(context.User.Identity.Name), this offer can claim by users with role either 'superadmin' or'admin'
        </div>
    </Authorized>
</AuthorizeView>
  • Here AuthorizeView component renders the users who matched with at least one role that is grouped under the policy.

Roles Authorize Attribute To Page Components:

The Authorize attribute will be used on Page components. One thing to remember this will not work for normal components.  Based on the user role using the authorize attribute we can deny or allow the page access to the user.
Index.razor:
@page "/"
@attribute [Authorize(Roles="admin")]
  • Here our Index page component only accessed by the users who have an 'admin' role.
We can pass multiple roles with command separation, in this case, the user that matches at least one role can access the page.
Index.razor:
@page "/"
@attribute [Authorize(Roles="admin,superadmin")]
We can set multiple Authorize attributes on our Page Component, in this case, the user should have match the roles specified in each attribute.
Index.razor:
@page "/"
@attribute [Authorize(Roles="admin")]
@attribute [Authorize(Roles="user")]
  • User's having both roles only can access the Index page component.
we can also use the roles policy with this authorized attribute.
Index.razor:
@page "/"
@attribute [Authorize(Policy="admin")]
  • Here users that match at least one role under the policy group will access this page.

Claims-Based Authorization:

The Claims mean key-value pair of data which something like user information. To use claims-based authorization we need to write the policy for it, which means we can't use claims directly like we do in the case of roles.

Let's update some claims to my login.
Auth/CustomAuthStateProvider.cs:
var identity = new ClaimsIdentity(new []{
	new Claim(ClaimTypes.Name,"Naveen"),
	new Claim("PageAccesskey", "1"),
	new Claim("PageAccesskey", "2")
},"Fake Auth");
  • Here I have claims like 'PageAccessKey' with 2 different values like '1' and '2'.
In claims-based authorization, we need to write a policy for authorization. So policy can be written in such a way to check whether a user is having a specific claim or not that is independent of value to that claim.
Program.cs:
builder.Services.AddAuthorizationCore(options => {
	options.AddPolicy("myAccessPolicy", policy => {
		policy.RequireClaim("PageAccesskey");
	});
});
  • Here we check a claims policy where users must have the claim to satisfy this policy. One more thing if we observe here we are not checking the value of the cliams.
Now we can use this claims policy on AuthorizeViewComponent
Pages/Index.razor:
<AuthorizeView Policy="myAccessPolicy" >
    <Authorized >
        <div>Hi @(context.User.Identity.Name)
        </div>
    </Authorized>
</AuthorizeView>
  • So here claims policy check whether the user has the registered claim or not.
Another way of writing claims policy is by defining the values of the claim and then the user should at least have one claim value registered under the policy.
Program.cs:
options.AddPolicy("myAccessPolicy", policy => {
	policy.RequireClaim("PageAccesskey","1","2","3");
});
  • Here now claims policy registered values of the claims as well. So in this case users should have this claim and also should match with at least one of the values of the claim.
We can also use the Authorize attribute with the claim policy to protect the page component like we did use the roles policy.

So that's all about the authorization in the blazor webassembly application.

Support Me!
Buy Me A Coffee PayPal Me

Wrapping Up:

Hopefully, I think this article delivered some useful information about Authorization in the Blazor WebAssembly Application. I love to have your feedback, suggestions, and better techniques in the comment section below.

Refer:

Follow Me:

Comments

Popular posts from this blog

Blazor WebAssembly Custom Authentication From Scratch

In this article, we are going to explore and implement custom authentication from the scratch. In this sample, we will use JWT authentication for user authentication. Main Building Blocks Of Blazor WebAssembly Authentication: The core concepts of blazor webassembly authentication are: AuthenticationStateProvider Service AuthorizeView Component Task<AuthenticationState> Cascading Property CascadingAuthenticationState Component AuthorizeRouteView Component AuthenticationStateProvider Service - this provider holds the authentication information about the login user. The 'GetAuthenticationStateAsync()' method in the Authentication state provider returns user AuthenticationState. The 'NotifyAuthenticationStateChaged()' to notify the latest user information within the components which using this AuthenticationStateProvider. AuthorizeView Component - displays different content depending on the user authorization state. This component uses the AuthenticationStateProvider

How Response Caching Works In Asp.Net Core

What Is Response Caching?: Response Caching means storing of response output and using stored response until it's under it's the expiration time. Response Caching approach cuts down some requests to the server and also reduces some workload on the server. Response Caching Headers: Response Caching carried out by the few Http based headers information between client and server. Main Response Caching Headers are like below Cache-Control Pragma Vary Cache-Control Header: Cache-Control header is the main header type for the response caching. Cache-Control will be decorated with the following directives. public - this directive indicates any cache may store the response. private - this directive allows to store response with respect to a single user and can't be stored with shared cache stores. max-age - this directive represents a time to hold a response in the cache. no-cache - this directive represents no storing of response and always fetch the fr

.Net5 Web API Managing Files Using Azure Blob Storage

In this article, we are going to understand the different file operations like uploading, reading, downloading, and deleting in .Net5 Web API application using Azure Blob Storage. Azure Blob Storage: Azure blob storage is Microsoft cloud storage. Blob storage can store a massive amount of file data as unstructured data. The unstructured data means not belong to any specific type, which means text or binary data. So something like images or pdf or videos to store in the cloud, then the most recommended is to use the blob store. The key component to creating azure blob storage resource: Storage Account:- A Storage account gives a unique namespace in Azure for all the data we will save. Every object that we store in Azure Storage has an address. The address is nothing but the unique name of our Storage Account name. The combination of the account name and the Azure Storage blob endpoint forms the base address for each object in our Storage account. For example, if our Storage Account is n

.Net5 Web API Redis Cache Using StackExchange.Redis.Extensions.AspNetCore Library

In this article, we are going to explore the integration of Redis cache in .Net5 Web API application using the 'StackExchange.Redis.Exntensions' library. Note:- Microsoft has introduced an 'IDistributedCache' interface in dotnet core which supports different cache stores like In-Memory, Redis, NCache, etc. It is simple and easy to work with  'IDistributedCache', for the Redis store with limited features but if we want more features of the Redis store we can choose to use 'StackExchange.Redis.Extensions'.  Click here for Redis Cache Integration Using IDistributedCache Interface . Overview On StackExchange.Redis.Extnesions Library: The 'StackExchange.Redis.Extension' library extended from the main library 'StackExchange.Redis'. Some of the key features of this library like: Default serialization and deserialization. Easy to save and fetch complex objects. Search key. Multiple Database Access Setup Redis Docker Instance: For this sampl

Endpoint Routing In Asp.Net Core

How Routing Works In  Core 2.1 And Below Versions?: In Asp.Net Core routing is configured using app.UseRouter() or app.UseMvc() middleware. app.UseMvc(routes => { routes.MapRoute( name: "default", template: "{controller=Home}/{action=Index}/{id?}"); }); Here in Dotnet Core version 2.1 or below versions on the execution of route middleware request will be navigated appropriate controller matched to the route. An operation or functionality which is dependent on route URL or route values and that need to be implemented before the execution of route middleware can be done by accessing the route path from the current request context as below app.Use(async (context, next) => { if(context.Request.Path.Value.IndexOf("oldvehicle") != -1) { context.Response.Redirect("vehicle"); } else { await next(); } }); app.UseMvc(routes => { routes.MapRoute( name: "vehicleRoute", template: "vehicle", defaul

Asp.Net Core MVC Form Validation Techniques

Introduction: Form validations in any applications are like assures that a valid data is storing on servers. All programing frameworks have their own individual implementations for form validations. In Dotnet Core MVC application server-side validations carried on by the models with the help of Data Annotations and the client-side validations carried by the plugin jQuery Unobtrusive Validation. jQuery Unobtrusive Validation is a custom library developed by Microsoft based on the popular library  jQuery Validate . In this article, we are going to learn how the model validation and client-side validation works in Asp.Net Core MVC Application with sample examples. Getting Started: Let's create an Asp.Net Core MVC application project using preferred editors like Microsoft Visual Studio or Microsoft Visual Studio Code. Here I'm using Visual Studio. Let's create an MVC controller and name it as 'PersonController.cs' and add an action method as bel

NestJS File Upload

In this article, we are going to understand the steps to create a file uploading endpoint in the NestJS application. Key Features In NestJS File Upload: Let us know some key features of NestJS file upload before implementing a sample application. FileInterceptor: The 'FileInterceptor' will be decorated on top of the file upload endpoint. This interceptor will read single file data from the form posted to the endpoint. export declare function FilesInterceptor(fieldName: string, localOptions?: MulterOptions): Type<NestInterceptor>; Here we can observe the 'fieldName' first input parameter this value should be a match with our 'name' attribute value on the form file input field. So our interceptor read our files that are attached to the file input field. Another input parameter of 'MulterOptions' that provides configuration like file destination path, customizing file name, etc. FilesInterceptor: The 'FilesInterceptor' will be decorated on t

.NET Core MVC Application File Upload To Physical Location With Buffered Technique

Buffering Technique In File Upload: The server will use its Memory(RAM) or Disk Storage to save the files on receiving a file upload request from the client.  Usage of Memory(RAM) or Disk depends on the number of file requests and the size of the file.  Any single buffered file exceeding 64KB is moved from Memory to a temp file on disk.  If an application receives heavy traffic of uploading files there might be a chance of out of Disk or RAM memory which leads to crash application. So this Buffer technique used for small files uploading. In the following article, we create a sample for the file uploading using .NET Core MVC application. Create The .NET Core MVC Project: Let's create a .NET Core MVC project, here for this sample I'm using Visual Studio Code as below.   Check the link to use the Visual Studio Code for .NET Core Application . IFormFile: Microsoft.AspNetCore.Http.IFormFile used for file upload with buffered technique. On uploading files f

Ionic Picker Sample Code In Angular

Introduction: Ionic Picker(ion-picker) is a popup slides up from the bottom of the device screen, which contains rows with selectable column separated items. The main building block of ion-picker as follows: PickerController PickerOptions PickerController: PickerController object helps in creating an ion-picker overlay. create(opts?: Opts): Promise<Overlay> PickerController create method helps in create the picker overlay with the picker options PickerOptions: PickerOptions is a configuration object used by PickerController to display ion-picker. Single Column Ionic Picker: single.item.picker.ts: import { Component } from "@angular/core"; import { PickerController } from "@ionic/angular"; import { PickerOptions } from "@ionic/core"; @Component({ selector: "single-column-picker", templateUrl:"single.item.picker.html" }) export class SingleItemPicker { animals: string[] = ["Tiger&quo

.Net Core HttpClient JSON Extension Methods Using System.Net.Http.Json Package

.Net Core 3.0 onwards Microsoft brought up a new package called System.Net.Http.Json. This new package provides JSON extension methods for HttpClient. These JSON extension methods will have a prebuild mechanism for serializing or deserializing response data or payload of HttpClient call. System.Net.Http.Json extension methods that are provided to HttpClient, few of them are mentioned below. GetFromJsonAsync PostAsJsonAsync PutAsJsonAsync ReadFromJsonAsync In this article, we understand System.Net.Http.Json package by implementing the HttpClient samples by with and without JSON extension methods and compare them. Create A .Net Core Web API Sample Application: Let's create a .Net Core sample Web API application, from this application we will consume another Web API by implementing HttpClient calls. We can create a Web API sample application using IDE like Visual Studio 2019(Supports .Net Core 3.0 plus) or  Visual Studio Code . Create A Typed Client: In .Net Core using the Http