bibis/util.php

<?php
// 共通処理

// HTTP関連

function get_fp() {
	return md5(
		($_SERVER['HTTP_USER_AGENT'] ?? '')
		. ($_SERVER['HTTP_ACCEPT_LANGUAGE'] ?? '')
		. ($_SERVER['HTTP_ACCEPT_ENCODING'] ?? '')
		. ($_SERVER['HTTP_ACCEPT'] ?? '')
	);
}

function has_cookie() {
	return isset($_COOKIE['bibis']);
}

function on_error($code, $errors) {
	http_response_code(400);
	if (function_exists('bibis_http_header')) { bibis_http_header(); }

	$view['errors'] = $errors;
	require(__DIR__ . '/view/header.php');
	exit;
}

function output_html($view, $_components) {
	if (ENABLE_FAKE_ERROR) { http_response_code(400); }

	if (function_exists('bibis_http_header')) { bibis_http_header(); }

	foreach ($_components as $_name) {
		require(__DIR__ . "/view/$_name");
	}
	exit;
}

// CSRFトークン関連

function set_csrf_token() {
	if (empty($_SESSION['csrf_token'])) {
		$_SESSION["csrf_token"] = bin2hex(random_bytes(32));
	}
}

function get_csrf_token() {
	if (!REQUIRE_COOKIE && !isset($_SESSION['user'])) {
		$date = date('YmdH');
		return $date . get_fp();
	}
	return $_SESSION['csrf_token'] ?? null;

}

function get_csrf_token_2($force_cookie = false) {
	if (!REQUIRE_COOKIE && !isset($_SESSION['user'])) {
		$date = date('YmdH', strtotime('-1 hour'));
		return $date . get_fp();
	}
	return $_SESSION['csrf_token'] ?? null;
}

function get_csrf_token_hashed($prefix = '', $token = null) {
	if ($token === null) { $token = get_csrf_token(); }
	if ($token === null) { return null; }
	return md5($prefix . $token);
}

function check_csrf_token() {
	$hashed = get_csrf_token_hashed();
	$hashed_2 = get_csrf_token_hashed('', get_csrf_token_2());
	if ($hashed === null || $hashed_2 === null) { return ['CSRF トークンが不正。要再試行。']; }
	$token_key = get_csrf_token_hashed('csrf_token');
	$csrf_token = $_POST[$token_key] ?? '';
	if ($csrf_token !== $hashed && $csrf_token !== $hashed_2) { return ['CSRF トークンが不正。要再試行。']; }
	return [];
}

function output_csrf_token_hidden() {
	$hashed = get_csrf_token_hashed();
	if ($hashed === null) { return ''; }
	$token_key = get_csrf_token_hashed('csrf_token');
	return '<input type="hidden" name="' . htmlspecialchars($token_key) . '" value="' . $hashed . '">';
}

// 文字列関連

function post_default_title($id) {
	return '無題#' . mb_substr($id, 0, 7);
}

function anchor_to_link($s, $thread_id) {
	return preg_replace(
		'/&gt;&gt;([1-9]+[0-9]{0,10})/',
		'<a href="' . sitebase('post/?id=') . $thread_id . '&amp;res=\1">&gt;&gt;\1</a>',
		$s
	);
}

function url_to_link($s) {
	return preg_replace(
		'/((http|https):\/\/[\w-]+(\.[\w-]+)+([\w.,@?^=%&amp;:\/~+#-]*[\w@?^=%&amp;\/~+#-])?)/',
		'<a href="\1" rel="noopener noreferrer">\1</a>',
		$s
	);
}

function mbtrim($s) {
	return preg_replace('/^\s+|\s+$/u', '', $s);
}

function twochan_trip($tripkey) {

	// twochan_trip('atomikka') -> '◆.../5Betyws'
	// Thanks: https://refirio.org/view/62
	// Test data: https://trip-table.kokage.cc/sample01.php

	$tripkey = mb_convert_encoding($tripkey, 'sjis-win');
	$salt = substr($tripkey . 'H.', 1, 2);
	$salt = preg_replace('/[^\.-z]/', '.', $salt);
	$salt = strtr($salt, ':;<=>?@[\\]^_`', 'ABCDEFGabcdef');

	$trip = crypt($tripkey, $salt);
	$trip = substr($trip, -10);

	return '◆' . $trip;
}

function parse_key_value($s, $key_list) {
	$result = [];
	$lines = explode(PHP_EOL, $s);
	foreach ($lines as $line) {
		foreach ($key_list as $key) {
			if (strpos($line, "{$key}=") === 0) {
				$result[$key] = explode('=', $line, 2)[1] ?? null;
			}
		}
		unset($key);
        }
	unset($lines, $line);

	return $result;
}

// ファイル関連

function mkdir_p($path, $permission = 0700) {
	if (file_exists($path)) { return true; }
	return mkdir($path, $permission);
}

function get_image_type($s) {
	$finfo = finfo_open(FILEINFO_MIME_TYPE);
	$type = finfo_buffer($finfo, $s);
	if (isset($type) && in_array($type, ACCEPT_IMAGE_TYPE)) {
		return $type;
	}
	return null;
}

function sitebase($path = '') {
	return SITEBASE . $path;
}

function get_style_css() {
	if (THEME === null || THEME === '') { return sitebase('style.css'); }
	return sitebase('theme/' . THEME);
}

// 制限・権限

function is_logged_in() {
	return isset($_SESSION['user']);
}

function can_post() {
	if (!post_limited()) { return false; }
	if (!ENABLE_GUEST && !is_logged_in()) { return false; }
	return true;
}

function post_limited() {
	return ENABLE_POST && (count_post_today() < POST_LIMIT_PER_DAY) && (count_post() < POST_LIMIT);
}

function can_regist() {
	return ENABLE_REGISTER;
}