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Exercise 1: JWT Authentication Implementation

Objective​

Implement JWT authentication with refresh tokens

Steps​

1. Create Project​

dotnet new webapi -n JwtAuthDemo
cd JwtAuthDemo
dotnet add package Microsoft.AspNetCore.Authentication.JwtBearer
dotnet add package BCrypt.Net-Next

2. Create Models​

public record LoginRequest(string Email, string Password);
public record TokenResponse(string AccessToken, string RefreshToken);
public record User(int Id, string Email, string PasswordHash, string Role);

3. Implement TokenService​

public class TokenService
{
    // Generate access token (15 min expiry)
    // Generate refresh token (7 days expiry)
    // Validate refresh token
}

4. Create Endpoints​

  • POST /api/auth/register
  • POST /api/auth/login
  • POST /api/auth/refresh
  • GET /api/auth/me (protected)

Expected Outcome​

  • Working JWT authentication
  • Refresh token flow
  • Protected endpoints

Challenge​

  • Add email verification
  • Implement token revocation/blacklist
  • Add role-based authorization