How to set up user authentication in CodeIgniter?

Setting up user authentication in CodeIgniter involves implementing a system that manages user accounts, including user registration, login, and user session management. While CodeIgniter does not provide a built-in authentication library, you can create a robust authentication system by following these steps:

1. Database Setup: Start by setting up a database table to store user information, including usernames, email addresses, hashed passwords, and any additional user data you require. Use CodeIgniter’s database library to interact with the database.

2. User Registration: Create a user registration form in your view that collects user details. When a user submits the form, validate the input data, hash the password using PHP’s `password_hash()` function, and insert the user’s data into the database.

3. User Login: Design a login form where users can enter their credentials. Upon form submission, retrieve the user’s data from the database based on the provided username or email. Verify the password using `password_verify()` and create a user session if authentication is successful.

4. Session Management: Use CodeIgniter’s session library to manage user sessions. When a user logs in, store their user ID in the session to track their authenticated status. Check the session data on protected pages to determine whether a user is logged in or not.

5. Access Control: Implement access control mechanisms to restrict certain parts of your application to authenticated users. You can use CodeIgniter’s built-in functions like `$this->session->userdata()` to check user authentication status and redirect users accordingly.

6. Password Reset: Create a password reset feature that allows users to reset their passwords via email. This involves generating a unique token, sending a reset link via email, and updating the password in the database after verifying the token.

7. Security: Ensure security by implementing measures such as secure password storage, email verification for registration, and protection against common web vulnerabilities like SQL injection and cross-site scripting (XSS).

8. Remember Me: Optionally, you can implement a “Remember Me” feature to allow users to stay logged in across sessions using long-lived cookies.

While CodeIgniter doesn’t provide a specific authentication library, you can build a robust authentication system by following these steps and leveraging CodeIgniter’s libraries and functions for database interaction, session management, and form handling. Additionally, you may consider using third-party libraries or packages specifically designed for authentication in CodeIgniter to streamline the process further.