I thought I finished my login system but it turned out I could write random letters and to be able to proceed to my tab bar controller. The information didn't authenticate. This is my first app and I'm not sure where to start. Any help on this problem?
Here is my login.php code:
<?php
//Step 1 Check variables passing to this file via POST
$username = htmlentities($_REQUEST["username"]);
$password = htmlentities($_REQUEST["password"]);
if (empty($username) || empty($password)) {
  $returnArray["status"] = "400";
  $returnArray["message"] = "Missing required information";
  echo json_encode($returnArray);
  return;
}
//Step 2. Build connection
//Secure way to build conn
$file = parse_ini_file("../../../iHertzmusic.ini");
// store in php var inf from ini var
$host = trim($file["dbhost"]);
$user = trim($file["dbuser"]);
$pass = trim($file["dbpass"]);
$name = trim($file["dbname"]);
// include access.php to call func from access.php file
require ("secure/access.php");
$access = new access($host, $user, $pass, $name);
$access->connect();
//Step 3. Get user information
//Assign result of execution of getUser to $user var
$user = $access->getUser($username);
//if we did not get any user information
if (empty($user)) {
    $returnArray["statusCode"] = "403";
    $returnArray["message"] = "User is not found";
    echo json_encode($returnArray);
    return;
}
//Step 4. Check validity of entered password
//get password and salt from db
$secured_password = $user["password"];
$salt = $user["salt"];
// check do passwords match: from db & entered one
if ($secured_password == sha1($password . $salt)) {
    $returnArray["statusCode"] = "200";
    $returnArray["message"] = "Logged in successfully";
    $returnArray["id"] = $user["id"];
    $returnArray["username"] = $user["username"];
    $returnArray["email"] = $user["email"];
    $returnArray["fullname"] = $user["fullname"];
} else {
    $returnArray["statusCode"] = "403"; //changed
    $returnArray["message"] = "passwords do not match";
  }
//STEP 5. Close connection
$access->disconnect();
//STEP 6. Throw back all infomation to users
echo json_encode($returnArray);
 ?>
Here is my .swift code
@IBAction func loginTapped(_ sender: Any) {
        // If no text entered
        if usernameTextfield.text!.isEmpty || passwordTextField.text!.isEmpty {
            //send message if fields are not filled
            print("User name \(String(describing: usernameTextfield)) or password \(String(describing: passwordTextField)) is empty")
            self.errorLabel.alpha = 1
            return
        } else {
            //Shortcuts
            let username = usernameTextfield.text
            let password = passwordTextField.text
            //send request to sql db
            let url = "http://10.0.0.157/iHertzmusic/login.php"
            let parameters: Parameters=[
             "username":usernameTextfield.text!,
             "password":passwordTextField.text!
            ]
            AF.request(url, method: .post, parameters: parameters as Parameters, encoding:
            URLEncoding.default).validate().response { (response) in
                    switch response.result {
                         case .success:
                         //sign in
                         let tabVC =
                         self.storyboard?.instantiateViewController(identifier: Constants.Storyboard.TabBarController) as? UITabBarController
                         self.view.window?.rootViewController = tabVC
                         self.view.window?.makeKeyAndVisible()
                         case .failure(let error):
                         // Couldn't sign in
                            self.errorLabel.text = error.localizedDescription
                         self.errorLabel.alpha = 1
                    }
                  }
 
     
    