Extension:Crypto/Version 1.0

<?php
//adds self to proper hooks & parser functions
$wgHooks['EditFilter'][] = 'fnCheckEncryptHook';
$wgHooks['ArticleSave'][] = 'fnEncryptHook';
$wgExtensionFunctions[] = 'efCryptoParserFunction_Setup';
$wgHooks['LanguageGetMagic'][]  = 'efCryptoParserFunction_Magic';
 
//the tag name that will be searched for to find text to encrypt
$encryptTag = 'encrypt';
 
//setsup the crypto name as a parser function
function efCryptoParserFunction_Setup() {
        global $wgParser;
 
        $wgParser->setFunctionHook( 'crypto', 'decryptoParserFunction_Render' );
 
}
 
//adding to magic words
function efCryptoParserFunction_Magic( &$magicWords, $langCode ) {
 
        $magicWords['crypto'] = array( 0, 'crypto' );
        return true;
}
 
//parser function to decrypt the thext
function decryptoParserFunction_Render( &$parser, $group = '', $text = '', $alt = '' ) {
 
   global $wgUser, $cryptoGroupMap, $encryptTag;
 
   $parser->disableCache();
 
   $groups = $wgUser->getEffectiveGroups();
 
   if ($wgUser->isLoggedIn() && in_array($group , $groups )) {
 
      if (stripos($text, $encryptTag)) {
 
         $tags = array('<'.$encyrptTag.'>', '</'.$encyrptTag.'>');
         return str_replace($tags, "", $text);
      }
      else {
 
         return XORDecrypt($text, $cryptoGroupMap[$group]);
 
      }
   }
   else {
 
      return $alt;
   }
}
 
 
//Check if user is able to use the encryption hook
function fnCheckEncryptHook($editor, &$text, $section, &$error) {
 
   global $cryptoGroupMap, $wgUser;
 
   $idx = 0;
 
   while (($idx = strpos($text, '{{', $idx)) > -1) {
 
      $idx = $idx + 2;
 
      $repIdx = $idx;
 
      while($text[$idx] == ' ') {
 
         $idx++;
      }
 
      if (substr($text, $idx, strlen('#crypto:')) == '#crypto:') {
 
         $idx = $idx + strlen('#crypto:');
 
         while($text[$idx] == ' ') {
 
            $idx++;
         }
 
         $group = '';
 
         while($text[$idx] != '|') {
 
            if ($text[$idx] != ' ') {
 
               $group = $group . $text[$idx];
            }
 
            $idx++;
 
         }
 
         $groups = $wgUser->getEffectiveGroups();
 
         $crypt = $cryptoGroupMap[$group];
 
         if ($crypt) {
 
            if (!$wgUser->isLoggedIn() || !in_array( $group, $groups )) {
 
               $error = "<p class='error'>You do not have permission to use the '$group' tag.  To use this you need to be a member of that group.</p>";
               break;
            }
 
         }
         else {
 
            $error = "<p class='error'>The group '$group' does not have a crypto key associated with it.</p>" .  $cryptoGroupMap[$arr[0]];
 
            break;
         }
      }
   }
 
   return true;
}
 
//the hook that does the encryption.  I may later try to clean up this code with the method above
function fnEncryptHook(&$article, &$user, &$text, &$summary, $minor, $watch, $sectionanchor, &$flags) {
 
   global $cryptoGroupMap, $wgUser, $encryptTag;
 
   $idx = 0;
 
   while (($idx = strpos($text, '{{', $idx)) > -1) {
 
      $idx = $idx + 2;
 
      $repIdx = $idx;
 
      while($text[$idx] == ' ') {
 
         $idx++;
      }
 
      if (substr($text, $idx, strlen('#crypto:')) == '#crypto:') {
 
         $idx = $idx + strlen('#crypto:');
 
         while($text[$idx] == ' ') {
 
            $idx++;
         }
 
         $group = '';
 
         while($text[$idx] != '|') {
 
            if ($text[$idx] != ' ') {
 
               $group = $group . $text[$idx];
            }
 
            $idx++;
 
         }
 
         $idx++;
 
         while($text[$idx] == ' ') {
 
            $idx++;
         }
 
         $beginTag = '<' . $encryptTag . '>';
 
         if ($beginTag == substr($text, $idx, strlen($beginTag))) {
 
            $beginRepIdx = $idx;
 
            $endTag = '</' . $encryptTag . '>';
 
            $endTagLen = stripos($text, $endTag, $idx) - $idx - strlen($beginTag);
 
            $crypt = $cryptoGroupMap[$group];
 
            if ($crypt) {
 
               $subText = substr($text, $beginRepIdx + strlen($beginTag), $endTagLen);
 
               $encText = XOREncrypt($subText, $crypt);
 
               $text = substr_replace($text, $encText, $beginRepIdx, strlen($beginTag) + $endTagLen + strlen($endTag));
 
            }
 
 
         }
 
      }
   }
 
   return true;
 
}
 
// Pilfered from http://www.jonasjohn.de/snippets/php/xor-encryption.htm
 
function XOREncryption($InputString, $KeyPhrase){
 
    $KeyPhraseLength = strlen($KeyPhrase);
 
    // Loop trough input string
    for ($i = 0; $i < strlen($InputString); $i++){
 
        // Get key phrase character position
        $rPos = $i % $KeyPhraseLength;
 
        // Magic happens here:
        $r = ord($InputString[$i]) ^ ord($KeyPhrase[$rPos]);
 
        // Replace characters
        $InputString[$i] = chr($r);
    }
 
    return $InputString;
}
 
function XOREncrypt($InputString, $KeyPhrase){
    $InputString = XOREncryption($InputString, $KeyPhrase);
    $InputString = base64_encode($InputString);
    return $InputString;
}
 
function XORDecrypt($InputString, $KeyPhrase){
    $InputString = base64_decode($InputString);
    $InputString = XOREncryption($InputString, $KeyPhrase);
    return $InputString;
}