Form-Based Authentication

Form-based authentication is a common method of user authentication used in web applications. It involves presenting the user with a form that requests credentials, typically a username and a password. This method is widely used due to its simplicity and effectiveness in providing a basic level of security for web-based applications.

The user is presented with a form on a web page, where they are required to enter their credentials (usually a username and password). Upon submission, the form data is sent to the server, typically via an HTTP POST request. The server then checks the submitted credentials against a stored database of user information. This process usually involves comparing the provided password with a stored [[Password Hashes|password hash]].

If the credentials are correct, the server creates a session for the user. It often sends back a session cookie to the user's browser, which is used for tracking the session on subsequent requests. Once authenticated, the user can access protected areas of the application during that session.

Form-based authentication should always be used in conjunction with [[HTTPS Protocol|HTTPS]] to encrypt the data transmitted between the client and the server, protecting it from being intercepted and read by unauthorized parties (a security issue known as "[[Man-in-the-Middle (MitM) attack|man-in-the-middle attack]]").

Passwords should never be stored in plain text; they should be securely hashed (and [[Salt|salted]]) in the database. The application should manage sessions securely, protecting against [[session hijacking]] and [[Session Fixation|fixation]] attacks. This includes setting secure attributes for cookies and implementing proper session expiration.

It's important to validate and sanitize all inputs to prevent attacks such as [[SQL injection]]. To prevent automated login attempts ([[Brute Force Attack|brute force attacks]]), implementing [[CAPTCHA]] can be an effective measure.