libreqr/index.php

<?php // This file is part of LibreQR, which is distributed under the GNU AGPLv3+ license

use Endroid\QrCode\Builder\Builder;
use Endroid\QrCode\ErrorCorrectionLevel\ErrorCorrectionLevelLow;
use Endroid\QrCode\ErrorCorrectionLevel\ErrorCorrectionLevelMedium;
use Endroid\QrCode\ErrorCorrectionLevel\ErrorCorrectionLevelQuartile;
use Endroid\QrCode\ErrorCorrectionLevel\ErrorCorrectionLevelHigh;
use Endroid\QrCode\Color\Color;

require "config.inc.php";
require "vendor/autoload.php";

const CONTRAST_THRESHOLD = 64;
const LIBREQR_VERSION = '2.0.1+dev';

// Defines the locale to be used
$locale = DEFAULT_LOCALE;
if (isset($_SERVER['HTTP_ACCEPT_LANGUAGE'])) {
	$clientLocales = $_SERVER['HTTP_ACCEPT_LANGUAGE'];
	$clientLocales = preg_replace("#[A-Z0-9]|q=|;|-|\.#", "", $clientLocales);
	$clientLocales = explode(',', $clientLocales);
	foreach (array_diff(scandir("locales"), array('..', '.')) as $key => $localeFile)
		$availableLocales[$key] = basename($localeFile, ".php");
	foreach ($clientLocales as $clientLocale) {
		if (in_array($clientLocale, $availableLocales)) {
			$locale = $clientLocale;
			break;
		}
	}
}

require "locales/" . $locale . ".php";
$chosen_loc = $loc;

if ($locale != DEFAULT_LOCALE) {
	require "locales/" . DEFAULT_LOCALE . ".php";
	$default_loc = $loc;
} else
	$default_loc = $chosen_loc;

require "locales/template.php";
$template_loc = $loc;

// Function to get a specific string from the locale file, fall back on default then template if missing
function getIntlString(
	$string_label,
	$raw = false
) {
	global $chosen_loc, $default_loc, $template_loc, $locale;

	if (array_key_exists($string_label, $chosen_loc))
		return $chosen_loc[$string_label];

	if ($locale != DEFAULT_LOCALE AND array_key_exists($string_label, $default_loc)) {
		if ($raw)
			return $default_loc[$string_label];
		return "<span lang=\"" . DEFAULT_LOCALE . "\">" . $default_loc[$string_label] . "</span>";
	}

	if ($raw)
		return $template_loc[$string_label];
	return "<span lang=\"en\">" . $template_loc[$string_label] . "</span>";
}

preg_match('#.*/(?<page>.*)$#', $_SERVER['REQUEST_URI'], $matches);
define('PAGE', match ($matches['page']) {
	'wifi' => 'wifi',
	'' => 'home',
	default => 'unknown',
});

define('ICONS_DIR', 'themes/' . THEME . '/icons');
$icon_files = array_diff(scandir(ICONS_DIR), ['.', '..']);
if (PAGE === 'unknown') {
	$allowed_filenames['style.css'] = 'text/css';
	$allowed_filenames['themes/' . THEME . '/theme.css'] = 'text/css';
	$allowed_filenames['themes/' . THEME . '/logo-dark.png'] = 'image/png';
	$allowed_filenames['themes/' . THEME . '/logo-light.png'] = 'image/png';
	foreach ($icon_files as $icon_file)
		$allowed_filenames[ICONS_DIR . '/' . $icon_file] = 'image/png';
	foreach ($allowed_filenames as $filename => $type) {
		if (str_ends_with($_SERVER['REQUEST_URI'], $filename)) {
			header('Content-Type: ' . $type);
			echo file_get_contents($filename);
			exit();
		}
	}
	http_response_code(404);
}

$_POST = [
	"form" => $_POST['form'] ?? NULL,
	"wifi" => [
		"ssid" => $_POST['wifi']['ssid'] ?? "",
		"password" => $_POST['wifi']['password'] ?? "",
	],
	"main" => [
		"txt" => $_POST['main']['txt'] ?? "",
		"redundancy" => $_POST['main']['redundancy'] ?? DEFAULT_REDUNDANCY,
		"margin" => $_POST['main']['margin'] ?? DEFAULT_MARGIN,
		"size" => $_POST['main']['size'] ?? DEFAULT_SIZE,
		"bgColor" => $_POST['main']['bgColor'] ?? "#" . DEFAULT_BGCOLOR,
		"fgColor" => $_POST['main']['fgColor'] ?? "#" . DEFAULT_FGCOLOR,
	],
];

if ($_POST['wifi']['ssid'] !== "") {
	if (!(strlen($_POST['wifi']['ssid']) >= 1 AND strlen($_POST['wifi']['ssid']) <= 4096)) {
		http_response_code(400);
		exit("Wrong value for ssid");
	}
	$escaped_ssid = preg_replace("/([\\\;\,\"\:])/", "\\\\$1", $_POST['wifi']['ssid']);

	if ($_POST['wifi']['password'] === "")
		$_POST['main']['txt'] = "WIFI:T:nopass;S:{$escaped_ssid};;";
	else {
		if (strlen($_POST['wifi']['password']) > 4096) {
			http_response_code(400);
			exit("Wrong value for password");
		}

		$escaped_password = preg_replace("/([\\\;\,\"\:])/", "\\\\$1", $_POST['wifi']['password']);

		$_POST['main']['txt'] = "WIFI:T:WPA;S:{$escaped_ssid};P:{$escaped_password};;";
	}
}

$qrCodeAvailable = NULL;

if ($_POST['main']['txt'] !== "") {
	$qrCodeAvailable = true;

	if (!(strlen($_POST['main']['txt']) >= 1 AND strlen($_POST['main']['txt']) <= 4096)) {
		http_response_code(400);
		exit("Wrong value for txt");
	}

	if (!in_array($_POST['main']['redundancy'], ["low", "medium", "quartile", "high"], strict: true)) {
		http_response_code(400);
		exit("Wrong value for redundancy");
	}

	if (!(is_numeric($_POST['main']['margin']) AND $_POST['main']['margin'] >= 0 AND $_POST['main']['margin'] <= 1024)) {
		http_response_code(400);
		exit("Wrong value for margin");
	}

	if (!(is_numeric($_POST['main']['size']) AND $_POST['main']['size'] >= 21 AND $_POST['main']['size'] <= 4096)) {
		http_response_code(400);
		exit("Wrong value for size");
	}

	if (preg_match("/^#[abcdefABCDEF0-9]{6}$/", $_POST['main']['bgColor']) === false) {
		http_response_code(400);
		exit("Wrong value for bgColor");
	}

	if (preg_match("/^#[abcdefABCDEF0-9]{6}$/", $_POST['main']['fgColor']) === false) {
		http_response_code(400);
		exit("Wrong value for fgColor");
	}

	$rgbBgColor = [
		'r' => hexdec(substr($_POST['main']['bgColor'],1,2)),
		'g' => hexdec(substr($_POST['main']['bgColor'],3,2)),
		'b' => hexdec(substr($_POST['main']['bgColor'],5,2)),
	];

	$qrCode = Builder::create()
		->data($_POST['main']['txt'])
		->margin($_POST['main']['margin'])
		->size($_POST['main']['size'])
		->errorCorrectionLevel(match ($_POST['main']['redundancy']) {
			"low" => new ErrorCorrectionLevelLow(),
			"medium" => new ErrorCorrectionLevelMedium(),
			"quartile" => new ErrorCorrectionLevelQuartile(),
			"high" => new ErrorCorrectionLevelHigh(),
		})
		->backgroundColor(new Color(
			$rgbBgColor['r'],
			$rgbBgColor['g'],
			$rgbBgColor['b'],
		))
		->foregroundColor(new Color(
			hexdec(substr($_POST['main']['fgColor'],1,2)),
			hexdec(substr($_POST['main']['fgColor'],3,2)),
			hexdec(substr($_POST['main']['fgColor'],5,2)),
		));

	try {
		$result = $qrCode->build();
	} catch (Exception $ex) {
		http_response_code(500);
		$qrCodeAvailable = false;
		error_log("FbIN QR encountered an error while generating a QR code: " . $ex);
	}
}

?>
<!DOCTYPE html>
<html lang="<?= $locale ?>">
	<head>
		<meta charset="utf-8">
		<title><?=
match (PAGE) {
	'home' => 'FbIN QR' . getIntlString('subtitle'),
	'wifi' => 'FbIN QR' .getIntlString('tab_wifi_title'),
	'unknown' => 'FbIN QR' .getIntlString('error_404'),
}
?></title>
		<meta name="description" content="<?= getIntlString('description', raw: true) ?>">
		<meta name="viewport" content="width=device-width, initial-scale=1">
		<meta name="color-scheme" content="dark light">
		<meta name="application-name" content="FbIN QR">
		<meta name="referrer" content="no-referrer">
		<meta http-equiv="Content-Security-Policy" content="default-src 'none'; img-src 'self' data:; style-src 'self'; form-action 'self';">

		<!-- Avoids leaking the "prefers-color-scheme" media query to the server -->
		<link rel="preload" as="image" href="themes/<?= THEME ?>/logo-dark.png">
		<link rel="preload" as="image" href="themes/<?= THEME ?>/logo-light.png">

		<link rel="stylesheet" media="screen" href="style.css">
		<link rel="stylesheet" media="screen" href="themes/<?= THEME ?>/theme.css">
<?php
natsort($icon_files);
foreach($icon_files as $icon_file) {
	if (ctype_digit($icon_size = substr($icon_file, 0, -4)))
		echo '		<link rel="icon" type="image/png" href="' . ICONS_DIR . '/' . $icon_size . '.png" sizes="' . $icon_size . 'x' . $icon_size . '">' . "\n";
}
?>
	</head>

	<body>

		<header>
			<a id="linkTitles" href="./">
				<hgroup id="titles">
					<h1>FbIN QR</h1>
					<p><?= getIntlString('subtitle') ?></p>
				</hgroup>
			</a>
		</header>

		<nav>
			<h2 class="sr-only">Type de code QR</h2>
			<ul>
				<li<?php if (PAGE == 'home') echo ' class="tab-selected"' ?>><a href="./"><div><?= getIntlString('tab_text') ?></div></a></li>
				<li<?php if (PAGE == 'wifi') echo ' class="tab-selected"' ?>><a href="./wifi"><div><?= getIntlString('tab_wifi') ?></div></a></li>
			</ul>
		</nav>

<?php if (PAGE === 'wifi') { ?>
		<form method="post" action="./wifi#output">
			<div class="param textboxParam">
				<label for="ssid"><?= getIntlString('label_wifi_ssid') ?></label>
				<input type="text" id="ssid" placeholder="<?= getIntlString('placeholder_wifi_ssid', raw: true) ?>" name="wifi[ssid]" required maxlength="4096" value="<?= htmlspecialchars($_POST['wifi']['ssid']) ?>">
			</div>
			<div class="param textboxParam">
				<details>
					<summary><label for="password"><?= getIntlString('label_wifi_password') ?></label></summary>
					<div class="helpText">
						<?= getIntlString('help_wifi_password') ?>
					</div>
				</details>
				<input type="text" id="password" placeholder="<?= getIntlString('placeholder_wifi_password', raw: true) ?>" name="wifi[password]" maxlength="4096" value="<?= htmlspecialchars($_POST['wifi']['password']) ?>">
			</div>
			<?php require 'common.php' ?>
		</form>
<?php } else if (PAGE === 'home') { ?>
		<form method="post" action="./#output">
			<div class="param textboxParam" id="txtParam">
				<details>
					<summary><label for="txt"><?= getIntlString('label_content') ?></label></summary>
					<div class="helpText">
						<?= getIntlString('help_content') ?>
					</div>
				</details>
				<textarea rows="3" id="txt" placeholder="<?= getIntlString('placeholder', raw: true) ?>" name="main[txt]"><?= htmlspecialchars($_POST['main']['txt']) ?></textarea>
			</div>
			<?php require 'common.php' ?>
		</form>
<?php } else { ?>
		<p>
			<?= getIntlString('error_404') ?>
		</p>
<?php } ?>

<?php

if ($qrCodeAvailable) {
	$dataUri = $result->getDataUri();

	$qrSize = $_POST['main']['size'] + 2 * $_POST['main']['margin'];

?>

		<section id="output">
			<div class="centered" id="downloadQR">
				<a href="<?= $dataUri ?>" class="button" download="<?= htmlspecialchars($_POST['main']['txt']); ?>.png"><?= getIntlString('button_download') ?></a>
			</div>

			<div class="centered" id="showOnlyQR">
				<a title="<?= getIntlString('title_showOnlyQR', raw: true) ?>" href="<?= $dataUri ?>"><img width="<?= $qrSize ?>" height="<?= $qrSize ?>" alt='<?= getIntlString('alt_QR_before', raw: true) ?><?= htmlspecialchars($_POST['main']['txt']); ?><?= getIntlString('alt_QR_after', raw: true) ?>' id="qrCode"<?php

	// Compute the difference between the QR code and theme background colors to determine whether a CSS corner is needed to let the user see the margin of the QR code
	preg_match(
		'/prefers-color-scheme: light.+--bg: (?<bg_light>#[A-Fa-f0-9]{6});.+prefers-color-scheme: dark.+--bg: (?<bg_dark>#[A-Fa-f0-9]{6});.+/s',
		file_get_contents('themes/' . THEME . '/theme.css'),
		$css,
	);
	if (
		  abs($rgbBgColor['r'] - hexdec(substr($css['bg_light'], -6, 2)))
		+ abs($rgbBgColor['g'] - hexdec(substr($css['bg_light'], -4, 2)))
		+ abs($rgbBgColor['b'] - hexdec(substr($css['bg_light'], -2, 2)))
		< CONTRAST_THRESHOLD
	)
		echo " class='needLightContrast'";
	if (
		  abs($rgbBgColor['r'] - hexdec(substr($css['bg_dark'], -6, 2)))
		+ abs($rgbBgColor['g'] - hexdec(substr($css['bg_dark'], -4, 2)))
		+ abs($rgbBgColor['b'] - hexdec(substr($css['bg_dark'], -2, 2)))
		< CONTRAST_THRESHOLD
	)
		echo " class='needDarkContrast'";

?> src="<?= $dataUri ?>"></a>
			</div>
<?php if (PAGE === "wifi") { ?>
			<p>
				<?= getIntlString('wifi_raw_content_before') ?><code><?= htmlspecialchars($_POST['main']['txt']) ?></code><?= getIntlString('wifi_raw_content_after') ?>
			</p>
			<form method="POST" action="./">
	<?php foreach ($_POST['main'] as $name => $value) { ?>
				<input type="hidden" name="main[<?= htmlspecialchars($name) ?>]" value="<?= htmlspecialchars($value) ?>" />
	<?php } ?>
				<input type="submit" value="<?= getIntlString('button_edit') ?>" />
			</form>
<?php } ?>
		</section>

<?php
} else if ($qrCodeAvailable === false) {
	echo "		<p><strong>" . getIntlString('error_generation') . "</strong></p></body></html>";
}
?>

		<footer>

<?php if (CUSTOM_TEXT_ENABLED) { ?>
			<section class="metaText">
				<?= CUSTOM_TEXT ?>
			</section>
<?php } ?>

		</footer>

	</body>
</html>