<?php /** * Shaarli utilities */ /** * Logs a message to a text file * * The log format is compatible with fail2ban. * * @param string $logFile where to write the logs * @param string $clientIp the client's remote IPv4/IPv6 address * @param string $message the message to log */ function logm($logFile, $clientIp, $message) { file_put_contents( $logFile, date('Y/m/d H:i:s').' - '.$clientIp.' - '.strval($message).PHP_EOL, FILE_APPEND ); } /** * Returns the small hash of a string, using RFC 4648 base64url format * * Small hashes: * - are unique (well, as unique as crc32, at last) * - are always 6 characters long. * - only use the following characters: a-z A-Z 0-9 - _ @ * - are NOT cryptographically secure (they CAN be forged) * * In Shaarli, they are used as a tinyurl-like link to individual entries, * built once with the combination of the date and item ID. * e.g. smallHash('20111006_131924' . 142) --> eaWxtQ * * @warning before v0.8.1, smallhashes were built only with the date, * and their value has been preserved. * * @param string $text Create a hash from this text. * * @return string generated small hash. */ function smallHash($text) { $t = rtrim(base64_encode(hash('crc32', $text, true)), '='); return strtr($t, '+/', '-_'); } /** * Tells if a string start with a substring * * @param string $haystack Given string. * @param string $needle String to search at the beginning of $haystack. * @param bool $case Case sensitive. * * @return bool True if $haystack starts with $needle. */ function startsWith($haystack, $needle, $case = true) { if ($case) { return (strcmp(substr($haystack, 0, strlen($needle)), $needle) === 0); } return (strcasecmp(substr($haystack, 0, strlen($needle)), $needle) === 0); } /** * Tells if a string ends with a substring * * @param string $haystack Given string. * @param string $needle String to search at the end of $haystack. * @param bool $case Case sensitive. * * @return bool True if $haystack ends with $needle. */ function endsWith($haystack, $needle, $case = true) { if ($case) { return (strcmp(substr($haystack, strlen($haystack) - strlen($needle)), $needle) === 0); } return (strcasecmp(substr($haystack, strlen($haystack) - strlen($needle)), $needle) === 0); } /** * Htmlspecialchars wrapper * Support multidimensional array of strings. * * @param mixed $input Data to escape: a single string or an array of strings. * * @return string escaped. */ function escape($input) { if (is_array($input)) { $out = array(); foreach($input as $key => $value) { $out[$key] = escape($value); } return $out; } return htmlspecialchars($input, ENT_COMPAT, 'UTF-8', false); } /** * Reverse the escape function. * * @param string $str the string to unescape. * * @return string unescaped string. */ function unescape($str) { return htmlspecialchars_decode($str); } /** * Sanitize link before rendering. * * @param array $link Link to escape. */ function sanitizeLink(&$link) { $link['url'] = escape($link['url']); // useful? $link['title'] = escape($link['title']); $link['description'] = escape($link['description']); $link['tags'] = escape($link['tags']); } /** * Checks if a string represents a valid date * @param string $format The expected DateTime format of the string * @param string $string A string-formatted date * * @return bool whether the string is a valid date * * @see http://php.net/manual/en/class.datetime.php * @see http://php.net/manual/en/datetime.createfromformat.php */ function checkDateFormat($format, $string) { $date = DateTime::createFromFormat($format, $string); return $date && $date->format($string) == $string; } /** * Generate a header location from HTTP_REFERER. * Make sure the referer is Shaarli itself and prevent redirection loop. * * @param string $referer - HTTP_REFERER. * @param string $host - Server HOST. * @param array $loopTerms - Contains list of term to prevent redirection loop. * * @return string $referer - final referer. */ function generateLocation($referer, $host, $loopTerms = array()) { $finalReferer = '?'; // No referer if it contains any value in $loopCriteria. foreach ($loopTerms as $value) { if (strpos($referer, $value) !== false) { return $finalReferer; } } // Remove port from HTTP_HOST if ($pos = strpos($host, ':')) { $host = substr($host, 0, $pos); } $refererHost = parse_url($referer, PHP_URL_HOST); if (!empty($referer) && (strpos($refererHost, $host) !== false || startsWith('?', $refererHost))) { $finalReferer = $referer; } return $finalReferer; } /** * Validate session ID to prevent Full Path Disclosure. * * See #298. * The session ID's format depends on the hash algorithm set in PHP settings * * @param string $sessionId Session ID * * @return true if valid, false otherwise. * * @see http://php.net/manual/en/function.hash-algos.php * @see http://php.net/manual/en/session.configuration.php */ function is_session_id_valid($sessionId) { if (empty($sessionId)) { return false; } if (!$sessionId) { return false; } if (!preg_match('/^[a-zA-Z0-9,-]{2,128}$/', $sessionId)) { return false; } return true; } /** * Sniff browser language to set the locale automatically. * Note that is may not work on your server if the corresponding locale is not installed. * * @param string $headerLocale Locale send in HTTP headers (e.g. "fr,fr-fr;q=0.8,en;q=0.5,en-us;q=0.3"). **/ function autoLocale($headerLocale) { // Default if browser does not send HTTP_ACCEPT_LANGUAGE $locales = array('en_US', 'en_US.utf8', 'en_US.UTF-8'); if (! empty($headerLocale)) { if (preg_match_all('/([a-z]{2,3})[-_]?([a-z]{2})?,?/i', $headerLocale, $matches, PREG_SET_ORDER)) { $attempts = []; foreach ($matches as $match) { $first = [strtolower($match[1]), strtoupper($match[1])]; $separators = ['_', '-']; $encodings = ['utf8', 'UTF-8']; if (!empty($match[2])) { $second = [strtoupper($match[2]), strtolower($match[2])]; $items = [$first, $separators, $second, ['.'], $encodings]; } else { $items = [$first, $separators, $first, ['.'], $encodings]; } $attempts = array_merge($attempts, iterator_to_array(cartesian_product_generator($items))); } if (! empty($attempts)) { $locales = array_merge(array_map('implode', $attempts), $locales); } } } setlocale(LC_ALL, $locales); } /** * Build a Generator object representing the cartesian product from given $items. * * Example: * [['a'], ['b', 'c']] * will generate: * [ * ['a', 'b'], * ['a', 'c'], * ] * * @param array $items array of array of string * * @return Generator representing the cartesian product of given array. * * @see https://en.wikipedia.org/wiki/Cartesian_product */ function cartesian_product_generator($items) { if (empty($items)) { yield []; } $subArray = array_pop($items); if (empty($subArray)) { return; } foreach (cartesian_product_generator($items) as $item) { foreach ($subArray as $value) { yield $item + [count($item) => $value]; } } } /** * Generates a default API secret. * * Note that the random-ish methods used in this function are predictable, * which makes them NOT suitable for crypto. * BUT the random string is salted with the salt and hashed with the username. * It makes the generated API secret secured enough for Shaarli. * * PHP 7 provides random_int(), designed for cryptography. * More info: http://stackoverflow.com/questions/4356289/php-random-string-generator * @param string $username Shaarli login username * @param string $salt Shaarli password hash salt * * @return string|bool Generated API secret, 12 char length. * Or false if invalid parameters are provided (which will make the API unusable). */ function generate_api_secret($username, $salt) { if (empty($username) || empty($salt)) { return false; } return str_shuffle(substr(hash_hmac('sha512', uniqid($salt), $username), 10, 12)); } /** * Trim string, replace sequences of whitespaces by a single space. * PHP equivalent to `normalize-space` XSLT function. * * @param string $string Input string. * * @return mixed Normalized string. */ function normalize_spaces($string) { return preg_replace('/\s{2,}/', ' ', trim($string)); } /** * Format the date according to the locale. * * Requires php-intl to display international datetimes, * otherwise default format '%c' will be returned. * * @param DateTime $date to format. * @param bool $intl Use international format if true. * * @return bool|string Formatted date, or false if the input is invalid. */ function format_date($date, $intl = true) { if (! $date instanceof DateTime) { return false; } if (! $intl || ! class_exists('IntlDateFormatter')) { return strftime('%c', $date->getTimestamp()); } $formatter = new IntlDateFormatter( setlocale(LC_TIME, 0), IntlDateFormatter::LONG, IntlDateFormatter::LONG ); return $formatter->format($date); }