Why PHP authentication works incorrect? - php

Question

I am newbie in PHP.
I have simple authentication script. It works incorrect: user "test" (100% existing in table in DB) can not pass auth (error text - "User is not found!").
Use PHP7, MySQL, connection method is PDO.
Need some help please.
$data = $_POST;
// check if button is pressed
if (isset($data['enter-auth'])) {
// check fileds
$errors = array();
if (trim($data['login_auth']) == '' ) {
$errors[] = 'Enter login';
}
if (($data['password_auth']) == '' ) {
$errors[] = 'Enter password';
}
// If all fields are filled, save user's data in vars
$login = $data['login_auth'];
$password = password_hash($data['password_auth'], PASSWORD_DEFAULT);
// ... and look in table
try {
if (empty($errors)) {
// Check if login and password exists in table
$stmt = $pdo->prepare("SELECT count(*) FROM users WHERE login=? AND password=?");
$stmt->execute([$login, $password]);
$count = $stmt->fetchColumn();
// If login and pwd found in table counter will be > 0, so ...
if ($count > 0) {
// ... then we can check if password is correct
if (password_verify($data['password_auth'], $password)) {
// if entered and stored passwords match, user is welcome
$_SESSION['auth_name'] = $data['login_auth'];
echo '<div style="color: green;">Welcome, '.$_SESSION['auth_name'].';
echo 'Exit';
header('Location: /a/index.php');
} else {
$errors[] = 'Password is incorrect';
echo '<p id="message">Wrong password!</p>';
}
} else {
$errors[] = 'User not found';
echo '<p id="message">User is not found!</p>';
}
} else {
echo '<div style="color: red;">'.array_shift($errors).'</div>';
}
} catch(PDOException $e) {
echo $e->getMessage();
}
// close condition check if button is pressed
}
Notes:
I tryed debugging this script using var_dump.
If I use fetchAll() when searching in table, any entered ldin is accepted (even if there is no such user).
Used try/catch construction with debug aim, I've heard that in production it is deprecated because of security reason.

Answer 1

Found mistakes, rewrote the code according to https://phpdelusions.net/pdo_examples/password_hash
So, correct fragment is:
try {
if (empty($errors)) {
$stmt = $pdo->prepare("SELECT login, password FROM users WHERE login=?");
$stmt->execute([$login]);
$user = $stmt->fetch();
if ($user && password_verify($data['password_auth'], $user['password'])) {
$_SESSION['auth_name'] = $data['login_auth'];
echo '<div style="color: green;">Welcome, '.$_SESSION['auth_name'].';
echo 'Exit';
header('Location: /a/index.php');
} else {
$errors[] = 'Login or password error';
echo '<p id="message-auth">Login or password is incorrect!</p>';
}
} else {
echo '<div style="color: red;">'.array_shift($errors).'</div>';
}
} catch(PDOException $e) {
echo $e->getMessage();
}