HTTP Authentication

HTTP authentication is a mechanism for controlling access to web resources. It involves the server requiring the client to authenticate itself before granting access to protected resources.

The HTTP protocol provides several authentication schemes that can be used to verify the identity of clients attempting to access protected resources.

Basic authentication is a simple authentication scheme built into the HTTP protocol. It involves the client sending the username and password, encoded in Base64, in the Authorization header.

Digest authentication is a more secure authentication scheme than Basic authentication. It involves the server sending a challenge to the client, which the client then uses to compute a hash of the username, password, and other information.

The client sends the hash back to the server, which verifies it without ever transmitting the actual password.

Bearer token authentication involves the client sending a bearer token in the Authorization header. The bearer token is typically a JSON Web Token (JWT) or an opaque token.

This method is widely used in modern web applications and APIs due to its stateless nature and scalability.

OAuth 2.0 is an authorization framework that enables applications to obtain limited access to user accounts. OpenID Connect builds on top of OAuth 2.0 to provide authentication capabilities.

These protocols are commonly used for third-party authentication (e.g., "Login with Google") and API access control.

• Always use HTTPS to encrypt authentication credentials in transit
• Implement proper session management and token expiration
• Use strong, unique passwords and consider multi-factor authentication
• Implement rate limiting to prevent brute force attacks
• Validate and sanitize all input to prevent injection attacks
• Use secure token storage mechanisms (HttpOnly cookies, secure storage)
• Implement proper logout functionality that invalidates sessions