🔐 Authentication Service

Overview

The Authentication Service handles user registration, login, logout, and session management for the HandFit application. Built with ASP.NET Core and Entity Framework, it provides secure JWT-based authentication with MySQL database storage.

🏗️ Architecture

• Framework: ASP.NET Core 8.0 with C#
• Database: MySQL with Entity Framework Core
• Authentication: JWT tokens + HTTP-only cookies
• Password Security: BCrypt hashing

🔧 Core Features

1. User Registration

• Email validation with regex pattern matching
• Username uniqueness checking (minimum 3 characters)
• Password strength validation (minimum 6 characters)
• BCrypt password hashing for security
• Automatic JWT token generation

2. User Authentication

• Email/password login with secure validation
• JWT token generation with user claims
• HTTP-only cookie session management
• Last login tracking for user analytics
• Cookie-based authentication with 7-day expiration

3. Session Management

• Secure logout with cookie clearing
• Current user retrieval from JWT claims
• Session persistence across requests
• Authentication state validation

📡 API Endpoints

Authentication Routes

POST /api/auth/register - User registration
POST /api/auth/login    - User login
POST /api/auth/logout   - User logout (requires auth)
GET  /api/auth/me       - Get current user (requires auth)

🔒 Security Features

• BCrypt password hashing with salt
• JWT token validation with claims
• HTTP-only cookies to prevent XSS
• CORS configuration for frontend integration
• Input validation and sanitization
• Secure cookie options (SameSite, Path, Expires)

🗄️ Database Schema

Users Table

- Id (int, primary key, auto-increment)
- Username (varchar, unique, not null)
- Email (varchar, unique, not null)
- PasswordHash (varchar, not null)
- IsActive (boolean, default true)
- CreatedAt (datetime, not null)
- UpdatedAt (datetime, not null)
- LastLoginAt (datetime, nullable)

🚀 Quick Start

Run Service

cd deploy
docker-compose up --build

🔄 Service Integration

• API Gateway: Routes authentication requests
• Users Service: Shares user data for profiles
• Training Service: Validates user sessions
• Frontend: Receives JWT tokens and manages sessions

📊 Logging & Monitoring

• Structured logging with Microsoft.Extensions.Logging
• Authentication events tracking
• Error handling with detailed messages
• Security event logging (failed logins, registrations)
• Performance monitoring for database operations

🛡️ Error Handling

• Validation errors with descriptive messages
• Duplicate email/username detection
• Password strength enforcement
• Database connection error handling
• JWT token validation errors