<?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($message).PHP_EOL,
FILE_APPEND
);
}
/**
* Returns the small hash of a string, using RFC 4648 base64url format
*
* Small hashes:
* - are unique (well, as unique as crc32, at last)
* - are always 6 characters long.
* - only use the following characters: a-z A-Z 0-9 - _ @
* - are NOT cryptographically secure (they CAN be forged)
*
* In Shaarli, they are used as a tinyurl-like link to individual entries,
* e.g. smallHash('20111006_131924') --> yZH23w
*/
function smallHash($text)
{
$t = rtrim(base64_encode(hash('crc32', $text, true)), '=');
return strtr($t, '+/', '-_');
}
/**
* Tells if a string start with a substring
*/
function startsWith($haystack, $needle, $case=true)
{
if ($case) {
return (strcmp(substr($haystack, 0, strlen($needle)), $needle) === 0);
}
return (strcasecmp(substr($haystack, 0, strlen($needle)), $needle) === 0);
}
/**
* Tells if a string ends with a substring
*/
function endsWith($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
*
* @param string $str the string to escape.
*
* @return string escaped.
*/
function escape($str)
{
return htmlspecialchars($str, 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($str);
}
/**
* Link sanitization before templating
*/
function sanitizeLink(&$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;
}
/**
* In a string, converts URLs to clickable links.
*
* @param string $text input string.
* @param string $redirector if a redirector is set, use it to gerenate links.
*
* @return string returns $text with all links converted to HTML links.
*
* @see Function inspired from http://www.php.net/manual/en/function.preg-replace.php#85722
*/
function text2clickable($text, $redirector)
{
$regex = '!(((?:https?|ftp|file)://|apt:|magnet:)\S+[[:alnum:]]/?)!si';
if (empty($redirector)) {
return preg_replace($regex, '<a href="$1">$1</a>', $text);
}
// Redirector is set, urlencode the final URL.
return preg_replace_callback(
$regex,
function ($matches) use ($redirector) {
return '<a href="' . $redirector . urlencode($matches[1]) .'">'. $matches[1] .'</a>';
},
$text
);
}
/**
* This function inserts where relevant so that multiple spaces are properly displayed in HTML
* even in the absence of <pre> (This is used in description to keep text formatting).
*
* @param string $text input text.
*
* @return string formatted text.
*/
function space2nbsp($text)
{
return preg_replace('/(^| ) /m', '$1 ', $text);
}
/**
* Format Shaarli's description
* TODO: Move me to ApplicationUtils when it's ready.
*
* @param string $description shaare's description.
* @param string $redirector if a redirector is set, use it to gerenate links.
*
* @return string formatted description.
*/
function format_description($description, $redirector) {
return nl2br(space2nbsp(text2clickable($description, $redirector)));
}
/**
* 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
$attempts = array('en_US');
if (isset($headerLocale)) {
// (It's a bit crude, but it works very well. Preferred language is always presented first.)
if (preg_match('/([a-z]{2})-?([a-z]{2})?/i', $headerLocale, $matches)) {
$loc = $matches[1] . (!empty($matches[2]) ? '_' . strtoupper($matches[2]) : '');
$attempts = array(
$loc.'.UTF-8', $loc, str_replace('_', '-', $loc).'.UTF-8', str_replace('_', '-', $loc),
$loc . '_' . strtoupper($loc).'.UTF-8', $loc . '_' . strtoupper($loc),
$loc . '_' . $loc.'.UTF-8', $loc . '_' . $loc, $loc . '-' . strtoupper($loc).'.UTF-8',
$loc . '-' . strtoupper($loc), $loc . '-' . $loc.'.UTF-8', $loc . '-' . $loc
);
}
}
setlocale(LC_ALL, $attempts);
}
