What are the implications of using case-insensitive comparisons in PHP for user authentication?

Using case-insensitive comparisons in PHP for user authentication can lead to security vulnerabilities, as it can allow attackers to bypass authentication by manipulating the case of their input. To solve this issue, always use case-sensitive string comparisons when verifying user credentials. 

$username = "admin";
$password = "password";

$userInputUsername = $_POST['username'];
$userInputPassword = $_POST['password'];

if ($userInputUsername === $username && $userInputPassword === $password) {
    // Authentication successful
} else {
    // Authentication failed
}

Keywords

case-insensitive comparisons user authentication PHP implications security

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