servnest/fn/common.php

<?php

$final_message = NULL;

function output($code, $msg = '', $logs = ['']) {
	global $final_message;
	$shortCode = $code / 100 % 10;
	$final_message = match ($shortCode) {
		2 => ($msg === '') ? '' : '<p><output><strong>Succès</strong> : <em>' . $msg . '</em></output></p>' . LF,
		4 => '<p><output><strong>Erreur utilisataire</strong> : <em>' . $msg . '</em></output></p>' . LF,
		5 => '<p><output><strong>Server error</strong>: The server encountered an error: <em>' . $msg . '</em></output></p>' . LF,
	};
	http_response_code($code);
	if ($shortCode === 5)
		error_log('Niver internal error: ' . strip_tags($msg) . implode(LF, $logs));
	if ($code !== 200)
		executePage();
}

function processForm($requireLogin = true) {
	if (http_response_code() !== 200)
		return false;
	if ($_POST === []) {
		if ($requireLogin AND !isset($_SESSION['id']))
			echo '<p>Ce formulaire ne sera pas accepté car il faut <a class="auth" href="' . redirUrl('auth/login') . '">se connecter</a> avant.</p>';
		return false;
	}
	if ($requireLogin) {
		if (isset($_SESSION['id']) !== true)
			output(403, 'Vous devez être connecté·e à un compte pour effectuer cette action.');
		if (isset(query('select', 'users', ['id' => $_SESSION['id']], 'id')[0]) !== true)
			output(403, 'Ce compte n\'existe plus. Déconnectez-vous pour terminer cette session fantôme.');
	}
	return true;
}

function insert($table, $values) {
	$query = 'INSERT INTO "' . $table . '"(';

	foreach ($values as $key => $val) {
		if ($key === array_key_last($values))
			$query .= "$key";
		else
			$query .= "$key, ";
	}

	$query .= ') VALUES(';
	foreach ($values as $key => $val) {
		if ($key === array_key_last($values))
			$query .= ":$key";
		else
			$query .= ":$key, ";
	}
	$query .= ')';

	DB->prepare($query)
	->execute($values);
}

function query($action, $table, $conditions = [], $column = NULL) {

	$query = match ($action) {
		'select' => 'SELECT *',
		'delete' => 'DELETE',
	};

	$query .= ' FROM "' . $table . '"';

	foreach ($conditions as $key => $val) {
		if ($key === array_key_first($conditions))
			$query .= " WHERE $key = :$key";
		else
			$query .= " AND $key = :$key";
	}

	$stmt = DB->prepare($query);
	$stmt->execute($conditions);

	return array_column($stmt->fetchAll(PDO::FETCH_ASSOC), $column);
}

function displayIndex() { ?>
<nav>
	<dl>
<?php foreach (PAGES[SERVICE] as $pageId => $page) {
	if ($pageId === 'index') continue;
?>
		<dt><a href="<?= $pageId ?>"><?= $page['title'] ?></a></dt>
		<dd>
			<?= $page['description'] ?>
		</dd>
<?php } ?>
	</dl>
</nav>
<?php
}

function redirUrl($pageId) {
	return CONF['common']['prefix'] . '/' . $pageId . '?redir=' . PAGE_URL;
}

function redir() {
	if (isset($_GET['redir'])) {
		if (preg_match('/^[0-9a-z\/-]{0,128}$/D', $_GET['redir']) !== 1)
			output(403, 'Wrong character in <code>redir</code>.');
		header('Location: ' . CONF['common']['prefix'] . '/' . $_GET['redir']);
	} else {
		header('Location: ' . CONF['common']['prefix'] . '/');
	}
	exit();
}

// PHP rmdir() only works on empty directories
function removeDirectory($dir) {
	$dirObj = new RecursiveDirectoryIterator($dir, RecursiveDirectoryIterator::SKIP_DOTS);
	$files = new RecursiveIteratorIterator($dirObj, RecursiveIteratorIterator::CHILD_FIRST);
	foreach ($files as $file)
		$file->isDir() && !$file->isLink() ? rmdir($file->getPathname()) : unlink($file->getPathname());
	if (rmdir($dir) !== true)
		output(500, 'Unable to remove directory.');
}

function equalArrays($a, $b) {
	return array_diff($a, $b) === [] AND array_diff($b, $a) === [];
}

function linkToDocs($ref, $title) {
	return '<a rel="help" href="' . CONF['common']['docs_prefix'] . $ref . '.html">' . $title . '</a>';
}

/*
	This token authenticates the user to the server through a public communication (the DNS).
	It is therefore also designed to keep private:
	- the user's id
	- that a same user used a token multiple times (by using a unique salt for each token)
*/
define('SECRET_KEY_FILE', sys_get_temp_dir() . '/Niver.key');
if (!file_exists(SECRET_KEY_FILE)) {
	$original_umask = umask(0077);
	file_put_contents(SECRET_KEY_FILE, random_bytes(32));
	umask($original_umask);
}
define('SECRET_KEY', file_get_contents(SECRET_KEY_FILE));
function getAuthToken() {
	$salt = bin2hex(random_bytes(4));
	$hash = hash_hmac('sha256', $salt . ($_SESSION['id'] ?? ''), SECRET_KEY);
	return $salt . '-' .  substr($hash, 0, 32);
}
function checkAuthToken($salt, $hash) {
	$correctProof = substr(hash_hmac('sha256', $salt . $_SESSION['id'], SECRET_KEY), 0, 32);
	if (hash_equals($correctProof, $hash) !== true)
		output(403, 'Preuve incorrecte');
}