Make Username and Password Input Case Sensitive - php

Question

Hi I would like to add here a case sensitive error trap on my login function, by the way i am using MVC FRAMEWORK anyone be of help ? I want to make the username and password case sensitive so that is the input doesn't match an error exception will occur............... I have tried but failed maybe someone can assist me on hot to go about this dilemma
//THIS IS THE CODE OF MY CONTROLLER
public function login() {
if(isLoggedIn()) {
header("Location: " .URLROOT . "/");
}
$data = [
'title' => 'Login page',
'username' => '',
'password' => '',
'usernameError' => '',
'passwordError' => ''
];
//Check for post
if($_SERVER['REQUEST_METHOD'] == 'POST'){
//Sanitize post data
$_POST = filter_input_array(INPUT_POST);
$data = [
'username' => trim($_POST['username']),
'password' => trim($_POST['password']),
'usernameError' => '',
'passwordError' => '',
];
$findUser = $this->userModel->findUser($data);
//Validate username
if(empty($data['username'])){
$data['usernameError'] = 'Please enter a username.';
}else if($findUser === false){
$data['usernameError'] = "Username not registered";
}
//Validate username
if(empty($data['password'])){
$data['passwordError'] = 'Please enter a password.';
}else if($findUser === false){
$data['passwordError'] = "Password not registered";
}
$findUser = $this->userModel->getUserDetails($data);
//Check if all errors are empty
if(empty($data['usernameError']) && empty($data['passwordError'])){
$loggedInUser = $this->userModel->login($data['username'], $data['password']);
if($loggedInUser){
$this->createUserSession($loggedInUser);
}else {
$data['passwordError'] = 'Password is incorrect. Please try again.';
$this->view('users/login',$data);
}
}
}else{
$data = [
'username' => '',
'password' => '',
'usernameError' => '',
'passwordError' => ''
];
}
//THIS IS THE CODE OF MY MODEL
public function login($username, $password) {
$this->db->query('SELECT * FROM user WHERE username = :username');
//Bind value
$this->db->bind(':username', $username);
$row = $this->db->single();
$hashedPassword = !empty($row) ? $row->password:'';
if(password_verify($password, $hashedPassword)){
return $row;
}else {
return false;
}
}
$this->view('users/login', $data);
}
Case sensitive error trap

Answer 1

If you need to make a case-sensitive query, it is very easy to do using the BINARY operator, which forces a byte by byte comparison:
SELECT * FROM `table` WHERE BINARY `column` = 'value'

Answer 2

The password is already case-sensitive, since it's using the native password_hash and password_verify functions, it can be easily tested with:
var_dump(password_verify('AAA', password_hash('AAA', PASSWORD_DEFAULT))); // true
var_dump(password_verify('AAA', password_hash('aaa', PASSWORD_DEFAULT))); // false
If you really want to have the username case-sensitive, you can also use a case-sensitive collation for the username field, such as utf8mb4_0900_as_cs, more info here.
ALTER TABLE `users` CHANGE COLUMN `username` `username` VARCHAR(255) CHARACTER SET 'utf8mb4' COLLATE 'utf8mb4_0900_as_cs' NOT NULL;
Test case:
INSERT INTO `users` (`username`) VALUES ('test');
SELECT * FROM `users` WHERE `username`='TEST'; /* returns nothing as expected */