Detailed explanation of token using c#

Install-Package Microsoft.AspNetCore.Authentication.JwtBearer

Add JWT Settings in appsettings.json

"Jwt": {

"Key": "ThisIsMySecretKey12345",

"Issuer": "yourapp",

"Audience": "yourapp-users",

"ExpiresInMinutes": 60

}

Configure JWT in Program.cs

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddAuthentication("Bearer")

.AddJwtBearer("Bearer", options =>

{

options.TokenValidationParameters = new TokenValidationParameters

{

ValidateIssuer = true,

ValidateAudience = true,

ValidateLifetime = true,

ValidateIssuerSigningKey = true,

ValidIssuer = builder.Configuration["Jwt:Issuer"],

ValidAudience = builder.Configuration["Jwt:Audience"],

IssuerSigningKey = new SymmetricSecurityKey(

Encoding.UTF8.GetBytes(builder.Configuration["Jwt:Key"]))

};

});

builder.Services.AddAuthorization();

var app = builder.Build();

app.UseAuthentication();

app.UseAuthorization();

app.MapControllers();

app.Run();

Create a Method to Generate JWT Token

private string GenerateJwtToken(string username)

{

var securityKey = new SymmetricSecurityKey(

Encoding.UTF8.GetBytes(_config["Jwt:Key"]));

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

var claims = new[]

{

new Claim(ClaimTypes.Name, username)

};

var token = new JwtSecurityToken(

issuer: _config["Jwt:Issuer"],

audience: _config["Jwt:Audience"],

claims: claims,

expires: DateTime.Now.AddMinutes(Convert.ToDouble(_config["Jwt:ExpiresInMinutes"])),

signingCredentials: credentials

);

return new JwtSecurityTokenHandler().WriteToken(token);

}

Create Login API That Returns Token

[HttpPost("login")]

public IActionResult Login([FromBody] LoginModel model)

{

if (model.Username == "admin" && model.Password == "123")

{

var token = GenerateJwtToken(model.Username);

return Ok(new { token });

}

return Unauthorized();

}

Secure Your API Endpoints

[Authorize]

[HttpGet("get-data")]

public IActionResult GetData()

{

return Ok("This is protected data");

}

Angular Side – Store & Send Token

Save token after login:

localStorage.setItem('token', response.token);

Add token to every API request using interceptor:

const token = localStorage.getItem('token');

req = req.clone({

setHeaders: {

Authorization: Bearer ${token}

}

});