Custom Authentication Implementations

Definitions

• Authentication: The process of verifying the identity of a user or system.
• Authorization: The process of determining what permissions a user has after authentication.
• JWT (JSON Web Token): A compact, URL-safe means of representing claims to be transferred between two parties.
• OAuth: An open standard for access delegation, commonly used for token-based authentication.

Step-by-Step Implementation

1. Setup Your Backend: Create an API that handles authentication requests. Use a library like Express.js for Node.js.
2. User Registration: Create a registration endpoint that stores user credentials securely (hash passwords).
3. User Login: Create a login endpoint that verifies user credentials and generates a JWT.

   
                           app.post('/login', (req, res) => {
                               const { username, password } = req.body;
                               // Verify credentials...
                               const token = jwt.sign({ id: user.id }, secretKey, { expiresIn: '1h' });
                               res.json({ token });
                           });
                           

4. Token Storage: Store the JWT in local storage or a cookie on the client side.
5. Token Validation: Implement middleware to validate the JWT on protected routes.
6. Logout Functionality: Create a logout endpoint that invalidates the token (optional, depending on your strategy).

Security Best Practices

• Always use HTTPS to protect sensitive data in transit.
• Implement secure password storage using hashing algorithms like bcrypt.
• Keep JWT expiration times short and implement refresh tokens for long-lived sessions.
• Validate and sanitize user inputs to prevent SQL injection and XSS attacks.
• Use environment variables to store sensitive information like secret keys.