.
*/
namespace Fisharebest\Webtrees;
use HTMLPurifier;
use HTMLPurifier_Config;
use Michelf\MarkdownExtra;
/**
* Filter input and escape output.
*/
class Filter {
// REGEX to match a URL
// Some versions of RFC3987 have an appendix B which gives the following regex
// (([^:/?#]+):)?(//([^/?#]*))?([^?#]*)(\?([^#]*))?(#(.*))?
// This matches far too much while a “precise” regex is several pages long.
// This is a compromise.
const URL_REGEX = '((https?|ftp]):)(//([^\s/?#<>]*))?([^\s?#<>]*)(\?([^\s#<>]*))?(#[^\s?#<>]+)?';
/**
* Escape a string for use in HTML
*
* @param string $string
*
* @return string
*/
public static function escapeHtml($string) {
if (defined('ENT_SUBSTITUTE')) {
// PHP5.4 allows us to substitute invalid UTF8 sequences
return htmlspecialchars($string, ENT_QUOTES | ENT_SUBSTITUTE, 'UTF-8');
} else {
return htmlspecialchars($string, ENT_QUOTES, 'UTF-8');
}
}
/**
* Escape a string for use in a URL
*
* @param string $string
*
* @return string
*/
public static function escapeUrl($string) {
return rawurlencode($string);
}
/**
* Escape a string for use in Javascript
*
* @param string $string
*
* @return string
*/
public static function escapeJs($string) {
return preg_replace_callback('/[^A-Za-z0-9,. _]/Su', function ($x) {
if (strlen($x[0]) === 1) {
return sprintf('\\u%04s', strtoupper(bin2hex(mb_convert_encoding($x[0], 'UTF-16BE', 'UTF-8'))));
} else {
return $x[0];
}
}, $string);
}
/**
* Escape a string for use in a SQL "LIKE" clause
*
* @param string $string
*
* @return string
*/
public static function escapeLike($string) {
return strtr(
$string,
[
'\\' => '\\\\',
'%' => '\%',
'_' => '\_',
]
);
}
/**
* Unescape an HTML string, giving just the literal text
*
* @param string $string
*
* @return string
*/
public static function unescapeHtml($string) {
return html_entity_decode(strip_tags($string), ENT_QUOTES, 'UTF-8');
}
/**
* Format block-level text such as notes or transcripts, etc.
*
* @param string $text
* @param Tree $WT_TREE
*
* @return string
*/
public static function formatText($text, Tree $WT_TREE) {
switch ($WT_TREE->getPreference('FORMAT_TEXT')) {
case 'markdown':
return '
' . self::markdown($text) . '
';
default:
return '
' . self::expandUrls($text) . '
';
}
}
/**
* Escape a string for use in HTML, and additionally convert URLs to links.
*
* @param string $text
*
* @return string
*/
public static function expandUrls($text) {
return preg_replace_callback(
'/' . addcslashes('(?!>)' . self::URL_REGEX . '(?!)', '/') . '/i',
function ($m) {
return '' . $m[0] . '';
},
self::escapeHtml($text)
);
}
/**
* Format a block of text, using "Markdown".
*
* @param string $text
*
* @return string
*/
public static function markdown($text) {
$parser = new MarkdownExtra;
$parser->empty_element_suffix = '>';
$parser->no_markup = true;
$text = $parser->transform($text);
// HTMLPurifier needs somewhere to write temporary files
$HTML_PURIFIER_CACHE_DIR = WT_DATA_DIR . 'html_purifier_cache';
if (!is_dir($HTML_PURIFIER_CACHE_DIR)) {
mkdir($HTML_PURIFIER_CACHE_DIR);
}
$config = HTMLPurifier_Config::createDefault();
$config->set('Cache.SerializerPath', $HTML_PURIFIER_CACHE_DIR);
$purifier = new HTMLPurifier($config);
$text = $purifier->purify($text);
return $text;
}
/**
* Validate INPUT parameters
*
* @param string $source
* @param string $variable
* @param string|null $regexp
* @param string|null $default
*
* @return string|null
*/
private static function input($source, $variable, $regexp = null, $default = null) {
if ($regexp) {
return filter_input(
$source,
$variable,
FILTER_VALIDATE_REGEXP,
[
'options' => [
'regexp' => '/^(' . $regexp . ')$/u',
'default' => $default,
],
]
);
} else {
$tmp = filter_input(
$source,
$variable,
FILTER_CALLBACK,
[
'options' => function ($x) {
return mb_check_encoding($x, 'UTF-8') ? $x : false;
},
]
);
return ($tmp === null || $tmp === false) ? $default : $tmp;
}
}
/**
* Validate array INPUT parameters
*
* @param string $source
* @param string $variable
* @param string|null $regexp
* @param string|null $default
*
* @return string[]
*/
private static function inputArray($source, $variable, $regexp = null, $default = null) {
if ($regexp) {
return filter_input_array($source, [
$variable => [
'flags' => FILTER_REQUIRE_ARRAY,
'filter' => FILTER_VALIDATE_REGEXP,
'options' => [
'regexp' => '/^(' . $regexp . ')$/u',
'default' => $default,
],
],
])[$variable] ?: [];
} else {
return filter_input_array($source, [
$variable => [
'flags' => FILTER_REQUIRE_ARRAY,
'filter' => FILTER_CALLBACK,
'options' => function ($x) {
return mb_check_encoding($x, 'UTF-8') ? $x : false;
},
],
])[$variable] ?: [];
}
}
/**
* Validate GET parameters
*
* @param string $variable
* @param string|null $regexp
* @param string|null $default
*
* @return null|string
*/
public static function get($variable, $regexp = null, $default = null) {
return self::input(INPUT_GET, $variable, $regexp, $default);
}
/**
* Validate array GET parameters
*
* @param string $variable
* @param string|null $regexp
* @param string|null $default
*
* @return string[]
*/
public static function getArray($variable, $regexp = null, $default = null) {
return self::inputArray(INPUT_GET, $variable, $regexp, $default);
}
/**
* Validate boolean GET parameters
*
* @param string $variable
*
* @return bool
*/
public static function getBool($variable) {
return (bool) filter_input(INPUT_GET, $variable, FILTER_VALIDATE_BOOLEAN);
}
/**
* Validate integer GET parameters
*
* @param string $variable
* @param int $min
* @param int $max
* @param int $default
*
* @return int
*/
public static function getInteger($variable, $min = 0, $max = PHP_INT_MAX, $default = 0) {
return filter_input(INPUT_GET, $variable, FILTER_VALIDATE_INT, ['options' => ['min_range' => $min, 'max_range' => $max, 'default' => $default]]);
}
/**
* Validate email GET parameters
*
* @param string $variable
* @param string|null $default
*
* @return null|string
*/
public static function getEmail($variable, $default = null) {
return filter_input(INPUT_GET, $variable, FILTER_VALIDATE_EMAIL) ?: $default;
}
/**
* Validate URL GET parameters
*
* @param string $variable
* @param string|null $default
*
* @return null|string
*/
public static function getUrl($variable, $default = null) {
return filter_input(INPUT_GET, $variable, FILTER_VALIDATE_URL) ?: $default;
}
/**
* Validate POST parameters
*
* @param string $variable
* @param string|null $regexp
* @param string|null $default
*
* @return null|string
*/
public static function post($variable, $regexp = null, $default = null) {
return self::input(INPUT_POST, $variable, $regexp, $default);
}
/**
* Validate array POST parameters
*
* @param string $variable
* @param string|null $regexp
* @param string|null $default
*
* @return string[]
*/
public static function postArray($variable, $regexp = null, $default = null) {
return self::inputArray(INPUT_POST, $variable, $regexp, $default);
}
/**
* Validate boolean POST parameters
*
* @param string $variable
*
* @return bool
*/
public static function postBool($variable) {
return (bool) filter_input(INPUT_POST, $variable, FILTER_VALIDATE_BOOLEAN);
}
/**
* Validate integer POST parameters
*
* @param string $variable
* @param int $min
* @param int $max
* @param int $default
*
* @return int
*/
public static function postInteger($variable, $min = 0, $max = PHP_INT_MAX, $default = 0) {
return filter_input(INPUT_POST, $variable, FILTER_VALIDATE_INT, ['options' => ['min_range' => $min, 'max_range' => $max, 'default' => $default]]);
}
/**
* Validate email POST parameters
*
* @param string $variable
* @param string|null $default
*
* @return null|string
*/
public static function postEmail($variable, $default = null) {
return filter_input(INPUT_POST, $variable, FILTER_VALIDATE_EMAIL) ?: $default;
}
/**
* Validate URL GET parameters
*
* @param string $variable
* @param string|null $default
*
* @return null|string
*/
public static function postUrl($variable, $default = null) {
return filter_input(INPUT_POST, $variable, FILTER_VALIDATE_URL) ?: $default;
}
/**
* Validate COOKIE parameters
*
* @param string $variable
* @param string|null $regexp
* @param string|null $default
*
* @return null|string
*/
public static function cookie($variable, $regexp = null, $default = null) {
return self::input(INPUT_COOKIE, $variable, $regexp, $default);
}
/**
* Validate SERVER parameters
*
* @param string $variable
* @param string|null $regexp
* @param string|null $default
*
* @return null|string
*/
public static function server($variable, $regexp = null, $default = null) {
// On some servers, variables that are present in $_SERVER cannot be
// found via filter_input(INPUT_SERVER). Instead, they are found via
// filter_input(INPUT_ENV). Since we cannot rely on filter_input(),
// we must use the superglobal directly.
if (array_key_exists($variable, $_SERVER) && ($regexp === null || preg_match('/^(' . $regexp . ')$/',
$_SERVER[$variable]))) {
return $_SERVER[$variable];
} else {
return $default;
}
}
/**
* Cross-Site Request Forgery tokens - ensure that the user is submitting
* a form that was generated by the current session.
*
* @return string
*/
public static function getCsrfToken() {
if (!Session::has('CSRF_TOKEN')) {
$charset = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcedfghijklmnopqrstuvwxyz0123456789';
$csrf_token = '';
for ($n = 0; $n < 32; ++$n) {
$csrf_token .= substr($charset, mt_rand(0, 61), 1);
}
Session::put('CSRF_TOKEN', $csrf_token);
}
return Session::get('CSRF_TOKEN');
}
/**
* Generate an element - to protect the current form from CSRF attacks.
*
* @return string
*/
public static function getCsrf() {
return '';
}
/**
* Check that the POST request contains the CSRF token generated above.
*
* @return bool
*/
public static function checkCsrf() {
if (self::post('csrf') !== self::getCsrfToken()) {
// Oops. Something is not quite right
Log::addAuthenticationLog('CSRF mismatch - session expired or malicious attack');
FlashMessages::addMessage(I18N::translate('This form has expired. Try again.'), 'error');
return false;
}
return true;
}
}