application/Utils.php

   1 <?php
   2 /**
   3  * Shaarli utilities
   4  */
   5
   6 /**
   7  * Logs a message to a text file
   8  *
   9  * The log format is compatible with fail2ban.
  10  *
  11  * @param string $logFile  where to write the logs
  12  * @param string $clientIp the client's remote IPv4/IPv6 address
  13  * @param string $message  the message to log
  14  */
  15 function logm($logFile, $clientIp, $message)
  16 {
  17     file_put_contents(
  18         $logFile,
  19         date('Y/m/d H:i:s').' - '.$clientIp.' - '.strval($message).PHP_EOL,
  20         FILE_APPEND
  21     );
  22 }
  23
  24 /**
  25  *  Returns the small hash of a string, using RFC 4648 base64url format
  26  *
  27  *  Small hashes:
  28  *   - are unique (well, as unique as crc32, at last)
  29  *   - are always 6 characters long.
  30  *   - only use the following characters: a-z A-Z 0-9 - _ @
  31  *   - are NOT cryptographically secure (they CAN be forged)
  32  *
  33  *  In Shaarli, they are used as a tinyurl-like link to individual entries,
  34  *  e.g. smallHash('20111006_131924') --> yZH23w
  35  */
  36 function smallHash($text)
  37 {
  38     $t = rtrim(base64_encode(hash('crc32', $text, true)), '=');
  39     return strtr($t, '+/', '-_');
  40 }
  41
  42 /**
  43  * Tells if a string start with a substring
  44  */
  45 function startsWith($haystack, $needle, $case=true)
  46 {
  47     if ($case) {
  48         return (strcmp(substr($haystack, 0, strlen($needle)), $needle) === 0);
  49     }
  50     return (strcasecmp(substr($haystack, 0, strlen($needle)), $needle) === 0);
  51 }
  52
  53 /**
  54  * Tells if a string ends with a substring
  55  */
  56 function endsWith($haystack, $needle, $case=true)
  57 {
  58     if ($case) {
  59         return (strcmp(substr($haystack, strlen($haystack) - strlen($needle)), $needle) === 0);
  60     }
  61     return (strcasecmp(substr($haystack, strlen($haystack) - strlen($needle)), $needle) === 0);
  62 }
  63
  64 /**
  65  * Htmlspecialchars wrapper
  66  *
  67  * @param string $str the string to escape.
  68  *
  69  * @return string escaped.
  70  */
  71 function escape($str)
  72 {
  73     return htmlspecialchars($str, ENT_COMPAT, 'UTF-8', false);
  74 }
  75
  76 /**
  77  * Reverse the escape function.
  78  *
  79  * @param string $str the string to unescape.
  80  *
  81  * @return string unescaped string.
  82  */
  83 function unescape($str)
  84 {
  85     return htmlspecialchars_decode($str);
  86 }
  87
  88 /**
  89  * Link sanitization before templating
  90  */
  91 function sanitizeLink(&$link)
  92 {
  93     $link['url'] = escape($link['url']); // useful?
  94     $link['title'] = escape($link['title']);
  95     $link['description'] = escape($link['description']);
  96     $link['tags'] = escape($link['tags']);
  97 }
  98
  99 /**
 100  * Checks if a string represents a valid date
 101
 102  * @param string $format The expected DateTime format of the string
 103  * @param string $string A string-formatted date
 104  *
 105  * @return bool whether the string is a valid date
 106  *
 107  * @see http://php.net/manual/en/class.datetime.php
 108  * @see http://php.net/manual/en/datetime.createfromformat.php
 109  */
 110 function checkDateFormat($format, $string)
 111 {
 112     $date = DateTime::createFromFormat($format, $string);
 113     return $date && $date->format($string) == $string;
 114 }
 115
 116 /**
 117  * Generate a header location from HTTP_REFERER.
 118  * Make sure the referer is Shaarli itself and prevent redirection loop.
 119  *
 120  * @param string $referer - HTTP_REFERER.
 121  * @param string $host - Server HOST.
 122  * @param array $loopTerms - Contains list of term to prevent redirection loop.
 123  *
 124  * @return string $referer - final referer.
 125  */
 126 function generateLocation($referer, $host, $loopTerms = array())
 127 {
 128     $finalReferer = '?';
 129
 130     // No referer if it contains any value in $loopCriteria.
 131     foreach ($loopTerms as $value) {
 132         if (strpos($referer, $value) !== false) {
 133             return $finalReferer;
 134         }
 135     }
 136
 137     // Remove port from HTTP_HOST
 138     if ($pos = strpos($host, ':')) {
 139         $host = substr($host, 0, $pos);
 140     }
 141
 142     $refererHost = parse_url($referer, PHP_URL_HOST);
 143     if (!empty($referer) && (strpos($refererHost, $host) !== false || startsWith('?', $refererHost))) {
 144         $finalReferer = $referer;
 145     }
 146
 147     return $finalReferer;
 148 }
 149
 150 /**
 151  * Validate session ID to prevent Full Path Disclosure.
 152  *
 153  * See #298.
 154  * The session ID's format depends on the hash algorithm set in PHP settings
 155  *
 156  * @param string $sessionId Session ID
 157  *
 158  * @return true if valid, false otherwise.
 159  *
 160  * @see http://php.net/manual/en/function.hash-algos.php
 161  * @see http://php.net/manual/en/session.configuration.php
 162  */
 163 function is_session_id_valid($sessionId)
 164 {
 165     if (empty($sessionId)) {
 166         return false;
 167     }
 168
 169     if (!$sessionId) {
 170         return false;
 171     }
 172
 173     if (!preg_match('/^[a-zA-Z0-9,-]{2,128}$/', $sessionId)) {
 174         return false;
 175     }
 176
 177     return true;
 178 }
 179
 180 /**
 181  * In a string, converts URLs to clickable links.
 182  *
 183  * @param string $text       input string.
 184  * @param string $redirector if a redirector is set, use it to gerenate links.
 185  *
 186  * @return string returns $text with all links converted to HTML links.
 187  *
 188  * @see Function inspired from http://www.php.net/manual/en/function.preg-replace.php#85722
 189  */
 190 function text2clickable($text, $redirector)
 191 {
 192     $regex = '!(((?:https?|ftp|file)://|apt:|magnet:)\S+[[:alnum:]]/?)!si';
 193
 194     if (empty($redirector)) {
 195         return preg_replace($regex, '<a href="$1">$1</a>', $text);
 196     }
 197     // Redirector is set, urlencode the final URL.
 198     return preg_replace_callback(
 199         $regex,
 200         function ($matches) use ($redirector) {
 201             return '<a href="' . $redirector . urlencode($matches[1]) .'">'. $matches[1] .'</a>';
 202         },
 203         $text
 204     );
 205 }
 206
 207 /**
 208  * This function inserts &nbsp; where relevant so that multiple spaces are properly displayed in HTML
 209  * even in the absence of <pre>  (This is used in description to keep text formatting).
 210  *
 211  * @param string $text input text.
 212  *
 213  * @return string formatted text.
 214  */
 215 function space2nbsp($text)
 216 {
 217     return preg_replace('/(^| ) /m', '$1&nbsp;', $text);
 218 }
 219
 220 /**
 221  * Format Shaarli's description
 222  * TODO: Move me to ApplicationUtils when it's ready.
 223  *
 224  * @param string $description shaare's description.
 225  * @param string $redirector  if a redirector is set, use it to gerenate links.
 226  *
 227  * @return string formatted description.
 228  */
 229 function format_description($description, $redirector) {
 230     return nl2br(space2nbsp(text2clickable($description, $redirector)));
 231 }
 232
 233 /**
 234  * Sniff browser language to set the locale automatically.
 235  * Note that is may not work on your server if the corresponding locale is not installed.
 236  *
 237  * @param string $headerLocale Locale send in HTTP headers (e.g. "fr,fr-fr;q=0.8,en;q=0.5,en-us;q=0.3").
 238  **/
 239 function autoLocale($headerLocale)
 240 {
 241     // Default if browser does not send HTTP_ACCEPT_LANGUAGE
 242     $attempts = array('en_US');
 243     if (isset($headerLocale)) {
 244         // (It's a bit crude, but it works very well. Preferred language is always presented first.)
 245         if (preg_match('/([a-z]{2})-?([a-z]{2})?/i', $headerLocale, $matches)) {
 246             $loc = $matches[1] . (!empty($matches[2]) ? '_' . strtoupper($matches[2]) : '');
 247             $attempts = array(
 248                 $loc.'.UTF-8', $loc, str_replace('_', '-', $loc).'.UTF-8', str_replace('_', '-', $loc),
 249                 $loc . '_' . strtoupper($loc).'.UTF-8', $loc . '_' . strtoupper($loc),
 250                 $loc . '_' . $loc.'.UTF-8', $loc . '_' . $loc, $loc . '-' . strtoupper($loc).'.UTF-8',
 251                 $loc . '-' . strtoupper($loc), $loc . '-' . $loc.'.UTF-8', $loc . '-' . $loc
 252             );
 253         }
 254     }
 255     setlocale(LC_ALL, $attempts);
 256 }