How to Check Username and Password with PHP

Checking Username and Password with PHP

When it comes to web development, ensuring secure user authentication is paramount. In PHP, checking usernames and passwords involves following specific steps:

1. Retrieve user input for username and password
2. Sanitize and validate input to prevent SQL injection and other attacks
3. Query the database to match the input with stored credentials
4. Provide access or display an error message accordingly

Remember to use secure hashing algorithms like bcrypt to store passwords safely. Here's a simple example:

<?php $username = $_POST['username']; $password = $_POST['password']; $hashed_password = password_hash($password, PASSWORD_DEFAULT); // Check against database $stored_password = getPasswordFromDB($username); if(password_verify($password, $stored_password)) { echo 'Login successful!'; } else { echo 'Incorrect username or password.'; } ?>