Skip to main content

Part-2 |Blazor WebAssembly[.NET 7] JWT Authentication Series | User Login Using JWT Access Token

The main objectives of this article are:
  • Generating JWT Access Token 
  • Creating Login API Endpoint.
  • Creating The Login Form In Blazor WebAssembly Application

Create 'LoginVm' As A Form Model In The BlazorWasm Application:

Let's create a 'LoginVm' as a form model in the Blazor WebAssembly application.
BlazorWasm_Project/ViewModels/Accounts/LoginVm.cs:
namespace JWT.Auth.BlazorUI.ViewModels.Account
{
    public class LoginVm
    {
        public string Email { get; set; }
        public string Password { get; set; }
    }
}

Create 'LoginValidationVm' Validator For 'LoginVm':

Let's create the validation model for 'LoginVm' like 'LoginValidationVm' in the Blazor application.
BlazorWasm_Project/ViewModels/Accounts/LoginValidationVm:
using FluentValidation;

namespace JWT.Auth.BlazorUI.ViewModels.Account
{
    public class LoginValidationVm:AbstractValidator<LoginVm>
    {
        public LoginValidationVm()
        {
            RuleFor(_ => _.Email).NotEmpty()
               .EmailAddress()
               .WithMessage("Invalid email");

            RuleFor(_ => _.Password).NotEmpty().WithMessage("Your password cannot be empty")
                    .MaximumLength(16).WithMessage("Invalid Password")
                    .Matches(@"[A-Z]+").WithMessage("Invalid Password")
                    .Matches(@"[a-z]+").WithMessage("Invalid Password")
                    .Matches(@"[0-9]+").WithMessage("Invalid Password")
                    .Matches(@"[\@\!\?\*\.]+").WithMessage("Invalid Password");
        }

        public Func<object, string, Task<IEnumerable<string>>> ValidateValue => async (model, propertyName) =>
        {
            var result = await ValidateAsync(ValidationContext<LoginVm>.CreateWithOptions((LoginVm)model, x => x.IncludeProperties(propertyName)));
            if (result.IsValid)
                return Array.Empty<string>();
            return result.Errors.Select(e => e.ErrorMessage);
        };
    }
}
  • Here added 'Email' & 'Password' validation rules. Here 'ValidateValue' Func returns the validation error message, this function will be used by the 'Login' form.

Create A 'Login.razor' Component:

Let's create a new blazor component like 'Login.razor' in the 'Pages/Accounts' folder.
BlazorWasm/Pages/Accounts/Login.razor:(HTML Part)
@page "/login"
<div class="ma-6 d-flex justify-center">
    <MudChip Color="Color.Primary">
        <h3>Login Form</h3>
    </MudChip>
</div>
<div class="ma-6 d-flex  justify-center">
    <MudCard Width="500px">
        <MudForm Model="loginModel" @ref="form" Validation="loginValidation.ValidateValue">
            <MudCardContent>

                <MudTextField @bind-Value="loginModel.Email"
                              For="@(() => loginModel.Email)"
                              Immediate="true"
                              Label="Email" />
                <MudTextField @bind-Value="loginModel.Password"
                              For="@(() => loginModel.Password)"
                              Immediate="true"
                              Label="Password" InputType="InputType.Password" />
                <MudCardActions>
                    <MudButton Variant="Variant.Filled" Color="Color.Primary" Class="ml-auto" OnClick="LoginAsync">Login</MudButton>
                </MudCardActions>
            </MudCardContent>
        </MudForm>
    </MudCard>
</div>
  • (Line: 9) Here 'Model' attribute is assigned with the 'loginModel' variable of type 'LoginVm'. Here '@ref' gives control over the form. The 'Validation' attribute is assigned with 'loginValidation.ValidateValue'.
  • (Line: 21) Here 'Login' button click registered with the 'LoginAsync' method.
BlazorWasm/Pages/Accounts/Login.razor:(C# Part) 
@code {
    LoginVm loginModel = new LoginVm();

    LoginValidationVm loginValidation = new LoginValidationVm();

    MudForm form;

    private async Task LoginAsync()
    {
        await form.Validate();
        if (form.IsValid)
        {
            // Invoke Login API call.
        }
    }
}
  • (Line: 2) Initialized the 'LoginVm' form model
  • (Line: 4) Initialized the 'LoginValidationVm' validation model.
  • (Line: 8-15)  The 'LoginAsync' method validates form data and then invokes a login API call.
Now add the 'Login' menu item in 'MainLayout.razor'.
BlazorWasm/Shared/MainLayout.razor:
<MudLink Underline="Underline.None" Color="Color.Inherit" Href="/login" Class="mr-2">Login</MudLink>

Configure Required Token Settings In JSON File In API Project:

Let's add the following token settings in 'appsettings.Development.json' in the API project.
API_Project/appsettings.Development.json:
"TokenSettings": {
    "SecretKey": "yx9UH7K3CPUcQ2xsB8KjEb1vxvnSA1GZhRXbRePN",
    "Issuer": "localhost:7045",
    "Audience": "localhost:7256"
}
  • The 'SecretKey' value is some sort of security key. Any random value can be used as this 'SecretKey'.
  • The 'Issuer' is like the identification of the server that generates the token. In the JWT access token, we will have claims like 'iss' which is an application claim. So 'Issuer' value will be the API domain.
  • The 'Audience' is like the client application which receives our token. It makes sure that a valid client application requests our JWT endpoint. In JWT we will have claims like 'aud'. So the 'Audience' value will be the domain name of the client application.
Let's create the entity for the token settings like 'TokenSettings' in the 'Shared/Settings' folder (new folder).
API_Project/Shared/Settings/TokenSettings.cs:
namespace JWT.Auth.API.Shared.Settings
{
    public class TokenSettings
    {
        public string SecretKey { get;set; }
        public string Issuer { get; set; }
        public string Audience { get; set; }
    }
}
Register the token settings in the 'Program.cs'.
API_Project/Program.cs:
builder.Services.Configure<TokenSettings>(builder.Configuration.GetSection("TokenSettings"));

Create Login Endpoint Response Entity Like 'JWTTokenResponseDto':

Let's create the login endpoint response entity like 'JWTTokeResponseDto' in the 'Dtos' folder.
API_Project/Dtos/JWTTokenResponseDto.cs:
namespace JWT.Auth.API.Dtos
{
    public class JWTTokenResponseDto
    {
        public string AccessToken { get; set; }
    }
}

Create Login Payload Entity Like 'LoginDto':

Let's create the login payload entity like 'LoginDto' in the 'Dtos' folder.
API_Project/Dtos/LoginDto.cs:
namespace JWT.Auth.API.Dtos
{
    public class LoginDto
    {
        public string Email { get; set; }
        public string Password { get; set; }
    }
}

Generate JWT(JSON Web Token) Access Token:

In 'IUserService' add a method definition like 'LoginAsync'.
API_Project/Services/IUserService.cs:
Task<(bool IsLoginSucess, JWTTokenResponseDto TokenResponse)> LoginAsync(LoginDto loginpayload);
Inject the 'TokenSettings' into the 'UserService' constructor.
API_Project/Services/UserService.cs:
public class UserService : IUserService
{
	private readonly MyWorldDbContext _dbContext;
	private readonly TokenSettings _tokenSettings;
	public UserService(MyWorldDbContext dbContext,
		IOptions<TokenSettings> tokenSettings)
	{
		_dbContext = dbContext;
		_tokenSettings = tokenSettings.Value;
	}
}
Now add logic for user login password validation in 'UserService'.
API_Project/Services/UserService.cs:
private bool PasswordVerification(string plainPassword, string dbPassword)
{
	byte[] dbPasswordHash = Convert.FromBase64String(dbPassword);

	byte[] salt = new byte[16];
	Array.Copy(dbPasswordHash, 0, salt, 0, 16);

	var rfcPassowrd = new Rfc2898DeriveBytes(plainPassword, salt, 1000, HashAlgorithmName.SHA1);
	byte[] rfcPasswordHash = rfcPassowrd.GetBytes(20);

	for (int i = 0; i < rfcPasswordHash.Length; i++)
	{
		if (dbPasswordHash[i + 16] != rfcPasswordHash[i])
		{
			return false;
		}
	}
	return true;
}
  • Here 'PasswordVerification' is a private method it has input parameters like user login payload plain password and database password(hashed user password in the database).
  • (Line: 3) Extract byte array data from the database password and assigned it to the 'dbPasswordHash' variable.
  • (Lines: 5&6) In the 'dbPasswordHash' variable first 16 bytes are the salt keys for the password hash. So read the salt key data and assign it to the 'salt' byte array variable.
  • (Lines: 8&9) So here we hash our plain password using the salt key with help of the 'Rfc2898DeriveBytes' instance.
  • (Line: 11-18) Compare each byte of our database password and the plain password, if they match then the password provided by the login form is valid else invalid password.
Now add the logic to generate the JWT access token in 'UserService.cs'
API_Project/Services/UserService.cs:
private string GenerateJwtAccessToken(User user)
{
	var symmetricSecurityKey = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(_tokenSettings.SecretKey));

	var credentials = new SigningCredentials(symmetricSecurityKey, SecurityAlgorithms.HmacSha256);

	var claims = new List<Claim>();
	claims.Add(new Claim("Sub", user.Id.ToString()));
	claims.Add(new Claim("FirstName", user?.FirstName ?? string.Empty));
	claims.Add(new Claim("LastName", user?.LastName ?? string.Empty));
	claims.Add(new Claim("Email", user?.Email ?? string.Empty));

	var securityToken = new JwtSecurityToken(
		issuer: _tokenSettings.Issuer,
		audience: _tokenSettings.Audience,
		expires: DateTime.Now.AddMinutes(30),
		signingCredentials: credentials,
		claims: claims);

	return new JwtSecurityTokenHandler().WriteToken(securityToken);
}
  • Here 'GenerateJWTAccessToken' private method to generate the JWT access token.
  • (Line: 3) Generate the 'Microsoft.IdentityModel.Tokens.SymmetricSecurityKey' instance using our 'SecretKey' value.
  • (Line: 5) Generate the 'Microsoft.IdentityModel.Tokens.SigninCredentials' instance using 'SymmetricSecurityKey' & 'SecurityAlgorithm.HmacSha256'.
  • (Line: 7-11) Creating user claims that we will store JWT access tokens.
  • (Line: 13-18) Generates the 'System.IdntityModel.Tokens.Jwt.JwtSecurityToken' with input parameters like 'Issuer', 'Audience', 'Expiration'(token expiration), 'SignInCredentials', and 'Claims'.
  • (Line: 20) Return the user's JWT access token.
Let's implement the 'LoginAsync' method in the 'UserService'.
API_Project/Services/UserService.cs:
public async Task<(bool IsLoginSucess, JWTTokenResponseDto TokenResponse)> LoginAsync(LoginDto loginpayload)
{
	if (string.IsNullOrEmpty(loginpayload.Email) ||
		string.IsNullOrEmpty(loginpayload.Password))
	{
		return (false, null);
	}

	var user = await _dbContext.User.Where(_ => _.Email.ToLower() == loginpayload.Email.ToLower())
		.FirstOrDefaultAsync();

	if (user == null) { return (false, null); }

	bool validUserPassowrd = PasswordVerification(loginpayload.Password, user.Password);
	if (!validUserPassowrd) { return (false, null); }

	string jwtAccessToken = GenerateJwtAccessToken(user);
	var result = new JWTTokenResponseDto
	{
		AccessToken = jwtAccessToken,
	};
	return (true, result);
}
  • (Line: 3-7) Checking user payload is not empty.
  • (Lines: 9&10) Query the database with the user's email address.
  • (Line: 12) Checking whether user data exists or not.
  • (Lines: 14&15) Checking whether the user password is valid or not.
  • (Line: 17-22) Generate the JWT access token.

Create An User Login Endpoint:

Let's add a user login endpoint in our 'UserController'.
API_Project/Controllers/UserController.cs:
[HttpPost("login")]
public async Task<IActionResult> LoginAsync(LoginDto loginPayload)
{
	var result = await _userService.LoginAsync(loginPayload);
	if (result.IsLoginSucess)
	{
		return Ok(result.TokenResponse);
	}

	ModelState.AddModelError("LoginError", "Invalid email or password");
	return BadRequest(ModelState);
}

Invoke Login API From Blazor WebAssembly Login Form:

Let's update the logic in the 'Login.razor' component to invoke the login API call.
BlazorWasm/Pages/Account/Login.razor:(HTM Part)
@page "/login"
@using System.Text.Json;
@using System.Text;
@inject HttpClient _http
<div class="ma-6 d-flex justify-center">
    <MudChip Color="Color.Primary">
        <h3>Login Form</h3>
    </MudChip>

</div>
<div class="ma-6 d-flex  justify-center">
    <MudCard Width="500px">
        <MudForm Model="loginModel" @ref="form" Validation="loginValidation.ValidateValue">
            <MudCardContent>
                @if (!string.IsNullOrEmpty(APIErrorMessage))
                {
                    <MudChip Class="d-flex justify-center" Color="Color.Error">
                        <h3>@APIErrorMessage</h3>
                    </MudChip>
                }
                <MudTextField @bind-Value="loginModel.Email"
                              For="@(() => loginModel.Email)"
                              Immediate="true"
                              Label="Email" />
                <MudTextField @bind-Value="loginModel.Password"
                              For="@(() => loginModel.Password)"
                              Immediate="true"
                              Label="Password" InputType="InputType.Password" />
                <MudCardActions>
                    <MudButton Variant="Variant.Filled" Color="Color.Primary" Class="ml-auto" OnClick="LoginAsync">Login</MudButton>
                </MudCardActions>
            </MudCardContent>
        </MudForm>
    </MudCard>
</div>
  • (Line: 4) Inject the 'HttpClient' instance
  • (Line: 15-20) Rendering the API response.
BlazorWasm/Pages/Account/Login.razor:(C# Part) 
@code {
    LoginVm loginModel = new LoginVm();

    LoginValidationVm loginValidation = new LoginValidationVm();

    MudForm form;

    string APIErrorMessage = string.Empty;

    private async Task LoginAsync()
    {
        await form.Validate();
        if (form.IsValid)
        {
            var jsonPayload = JsonSerializer.Serialize(loginModel);
            var requestContent = new StringContent(jsonPayload, Encoding.UTF8, "application/json");


            var response = await _http.PostAsync("/api/User/login", requestContent);
            
            if (response.StatusCode == System.Net.HttpStatusCode.BadRequest)
            {
                var errors = await response.Content
                .ReadFromJsonAsync<Dictionary<string, List<string>>>();
                if (errors.Count > 0)
                {
                    foreach (var item in errors)
                    {
                        foreach (var errorMessage in item.Value)
                        {
                            APIErrorMessage = $"{errorMessage} | ";
                        }
                    }
                }
            }
            else if (response.StatusCode == System.Net.HttpStatusCode.OK)
            {
                // On successful user authentication.
            }
            else
            {
                APIErrorMessage = "Unable to do login, please try later";
            }
        }
    }
}
  • (Line: 8) Declared variable like 'ApiErrorMessage'.
  • (Line: 10-45) Here invoking the user login post API call. If the API returns BadRequest or any other error value to the 'APIErrorMessage' variable. If the API return success then we receive the JWT access token as response.
In the next article, we will implement the Blazor WebAssembly AuthenticationState provider to read the JWT token.

Video Session:

Wrapping Up:

Hopefully, I think this article delivered some useful information on the.NET7 Blazor WebAssembly JWT Authentication. using I love to have your feedback, suggestions, and better techniques in the comment section below.

Refer:

Follow Me:

Labels:

Comments

  1. AnonymousApril 18, 2023 at 10:22 AM

    Is there any link to download a working code base?

    ReplyDelete

Post a Comment

Popular posts from this blog

Angular 14 Reactive Forms Example

In this article, we will explore the Angular(14) reactive forms with an example. Reactive Forms: Angular reactive forms support model-driven techniques to handle the form's input values. The reactive forms state is immutable, any form filed change creates a new state for the form. Reactive forms are built around observable streams, where form inputs and values are provided as streams of input values, which can be accessed synchronously. Some key notations that involve in reactive forms are like: FormControl - each input element in the form is 'FormControl'. The 'FormControl' tracks the value and validation status of form fields. FormGroup - Track the value and validate the state of the group of 'FormControl'. FormBuilder - Angular service which can be used to create the 'FormGroup' or FormControl instance quickly. Form Array - That can hold infinite form control, this helps to create dynamic forms. Create An Angular(14) Application: Let'
3 comments
Read more

.NET 7 Web API CRUD Using Entity Framework Core

In this article, we are going to implement a sample .NET 7 Web API CRUD using the Entity Framework Core. Web API: Web API is a framework for building HTTP services that can be accessed from any client like browser, mobile devices, and desktop apps. In simple terminology API(Application Programming Interface) means an interface module that contains programming functions that can be requested via HTTP calls either to fetch or update data for their respective clients. Some of the Key Characteristics of API: Supports HTTP verbs like 'GET', 'POST', 'PUT', 'DELETE', etc. Supports default responses like 'XML' and 'JSON'. Also can define custom responses. Supports self-hosting or individual hosting, so that all different kinds of apps can consume it. Authentication and Authorization are easy to implement. The ideal platform to build the REST full services. Install The SQL Server And SQL Management Studio: Let's install the SQL server on our l
3 comments
Read more

ReactJS(v18) JWT Authentication Using HTTP Only Cookie

In this article, we will implement the ReactJS application authentication using the HTTP-only cookie. HTTP Only Cookie: In a SPA(Single Page Application) Authentication JWT token either can be stored in browser 'LocalStorage' or in 'Cookie'. Storing the JWT token inside of the cookie then the cookie should be HTTP Only. The HTTP-ONly cookie nature is that it will be only accessible by the server application. Client apps like javascript-based apps can't access the HTTP-Only cookie. So if we use the authentication with HTTP-only JWT cookie then we no need to implement the custom logic like adding authorization header or storing token data, etc at our client application. Because once the user authenticated cookie will be automatically sent to the server by the browser on every API call. Authentication API: To authenticate our client application with JWT HTTP-only cookie, I developed a NetJS(which is a node) Mock API. Check the GitHub link and read the document on G
3 comments
Read more

.NET6 Web API CRUD Operation With Entity Framework Core

In this article, we are going to do a small demo on AspNetCore 6 Web API CRUD operations. What Is Web API: Web API is a framework for building HTTP services that can be accessed from any client like browser, mobile devices, desktop apps. In simple terminology API(Application Programming Interface) means an interface module that contains a programming function that can be requested via HTTP calls to save or fetch the data for their respective clients. Some of the key characteristics of API: Supports HTTP verbs like 'GET', 'POST', 'PUT', 'DELETE', etc. Supports default responses like 'XML' and 'JSON'. Also can define custom responses. Supports self-hosting or individual hosting, so that all different kinds of apps can consume it. Authentication and Authorization are easy to implement. The ideal platform to build REST full services. Create A .NET6 Web API Application: Let's create a .Net6 Web API sample application to accomplish our
6 comments
Read more

Angular 14 State Management CRUD Example With NgRx(14)

In this article, we are going to implement the Angular(14) state management CRUD example with NgRx(14) NgRx Store For State Management: In an angular application to share consistent data between multiple components, we use NgRx state management. Using NgRx state helps to avoid unwanted API calls, easy to maintain consistent data, etc. The main building blocks for the NgRx store are: Actions - NgRx actions represents event to trigger the reducers to save the data into the stores. Reducer - Reducer's pure function, which is used to create a new state on data change. Store - The store is the model or entity that holds the data. Selector - Selector to fetch the slices of data from the store to angular components. Effects - Effects deals with external network calls like API. The effect gets executed based the action performed Ngrx State Management flow: The angular component needs data for binding.  So angular component calls an action that is responsible for invoking the API call.  Aft
8 comments
Read more

Unit Testing Asp.NetCore Web API Using xUnit[.NET6]

In this article, we are going to write test cases to an Asp.NetCore Web API(.NET6) application using the xUnit. xUnit For .NET: The xUnit for .Net is a free, open-source, community-focused unit testing tool for .NET applications. By default .Net also provides a xUnit project template to implement test cases. Unit test cases build upon the 'AAA' formula that means 'Arrange', 'Act' and 'Assert' Arrange - Declaring variables, objects, instantiating mocks, etc. Act - Calling or invoking the method that needs to be tested. Assert - The assert ensures that code behaves as expected means yielding expected output. Create An API And Unit Test Projects: Let's create a .Net6 Web API and xUnit sample applications to accomplish our demo. We can use either Visual Studio 2022 or Visual Studio Code(using .NET CLI commands) to create any.Net6 application. For this demo, I'm using the 'Visual Studio Code'(using the .NET CLI command) editor. Create a fo
7 comments
Read more

Angular 14 Crud Example

In this article, we will implement CRUD operation in the Angular 14 application. Angular: Angular is a framework that can be used to build a single-page application. Angular applications are built with components that make our code simple and clean. Angular components compose of 3 files like TypeScript File(*.ts), Html File(*.html), CSS File(*.cs) Components typescript file and HTML file support 2-way binding which means data flow is bi-directional Component typescript file listens for all HTML events from the HTML file. Create Angular(14) Application: Let's create an Angular(14) application to begin our sample. Make sure to install the Angular CLI tool into our local machine because it provides easy CLI commands to play with the angular application. Command To Install Angular CLI npm install -g @angular/cli Run the below command to create the angular application. Command To Create Angular Application ng new name_of_your_app Note: While creating the app, you will see a noti
4 comments
Read more

Part-1 Angular JWT Authentication Using HTTP Only Cookie[Angular V13]

In this article, we are going to implement a sample angular application authentication using HTTP only cookie that contains a JWT token. HTTP Only JWT Cookie: In a SPA(Single Page Application) Authentication JWT token either can be stored in browser 'LocalStorage' or in 'Cookie'. Storing JWT token inside of the cookie then the cookie should be HTTP Only. The HTTP-Only cookie nature is that it will be only accessible by the server application. Client apps like javascript-based apps can't access the HTTP-Only cookie. So if we use authentication with HTTP only JWT cookie then we no need to implement custom logic like adding authorization header or storing token data, etc at our client application. Because once the user authenticated cookie will be automatically sent to the server by the browser on every API call. Authentication API: To implement JWT cookie authentication we need to set up an API. For that, I had created a mock authentication API(Using the NestJS Se
Post a Comment
Read more

ReactJS(v18) Authentication With JWT AccessToken And Refresh Token

In this article, we are going to do ReactJS(v18) application authentication using the JWT Access Token and Refresh Token. JSON Web Token(JWT): JSON Web Token is a digitally signed and secured token for user validation. The JWT is constructed with 3 important parts: Header Payload Signature Create ReactJS Application: Let's create a ReactJS application to accomplish our demo. npx create-react-app name-of-your-app Configure React Bootstrap Library: Let's install the React Bootstrap library npm install react-bootstrap bootstrap Now add the bootstrap CSS reference in 'index.js'. src/index.js: import 'bootstrap/dist/css/bootstrap.min.css' Create A React Component 'Layout': Let's add a React component like 'Layout' in 'components/shared' folders(new folders). src/components/shared/Layout.js: import Navbar from "react-bootstrap/Navbar"; import { Container } from "react-bootstrap"; import Nav from "react-boot
1 comment
Read more

A Small Guide On NestJS Queues

NestJS Application Queues helps to deal with application scaling and performance challenges. When To Use Queues?: API request that mostly involves in time taking operations like CPU bound operation, doing them synchronously which will result in thread blocking. So to avoid these issues, it is an appropriate way to make the CPU-bound operation separate background job.  In nestjs one of the best solutions for these kinds of tasks is to implement the Queues. For queueing mechanism in the nestjs application most recommended library is '@nestjs/bull'(Bull is nodejs queue library). The 'Bull' depends on Redis cache for data storage like a job. So in this queueing technique, we will create services like 'Producer' and 'Consumer'. The 'Producer' is used to push our jobs into the Redis stores. The consumer will read those jobs(eg: CPU Bound Operations) and process them. So by using this queues technique user requests processed very fastly because actually
9 comments
Read more