New Captcha Method

2 files changed, 1064 insertions, 205 deletions

diff --git a/modules/captcha/captcha.php b/modules/captcha/captcha.php
index aab8bab7..40963c18 100644
--- a/modules/captcha/captcha.php
+++ b/modules/captcha/captcha.php
@@ -1,289 +1,1148 @@
 <?php
 /*
-   Does emit a CAPTCHA graphic and form fields, which allows to tell real
-   people from bots.
-   Though a textual description is generated as well, this sort of access
-   restriction will knock out visually impaired users, and frustrate all
-   others anyhow. Therefore this should only be used as last resort for
-   defending against spambots. Because of the readable text and the used
-   colorspaces this is a weak implementation, not completely OCR-secure.
-
-   captcha::form() will return a html string to be inserted into textarea/
-   [save] <forms> and alike. User input is veryfied with captcha::check().
-   You should leave the sample COLLEGE.ttf next to this script, else you
-   have to define the _FONT_DIR constant correctly. Use only one type.
-
-   Includes a sluggish workaround for Internet Explorer; but this script
-   must reside in a www-accessible directory then.
+   api: php
+   title: Easy_CAPTCHA
+   description: highly configurable, user-friendly and accessible CAPTCHA
+   version: 2.0
+   author: milki
+   url: http://freshmeat.net/p/captchaphp
+   config:
+      <const name="CAPTCHA_PERSISTENT" value="1"  type="boolean" title="persistent cookie" description="sets a cookie after user successfully solved it, spares further captchas for a few days" />
+      <const name="CAPTCHA_NEW_URLS" value="1"  type="boolean" title="new URLs only Javascript" description="uses Javascript detection to engage CAPTCHA only if a new URL was entered into any input box" />
+      <const name="CAPTCHA_AJAX" value="1" type="boolean" title="AJAX quickcheck" description="verfies the solution (visually) while user enters it" />
+      <const name="CAPTCHA_IMAGE_SIZE" value="200x60" type="string" regex="\d+x\d+" title="image size" description="height x width of CAPTCHA image" />
+      <const name="CAPTCHA_INVERSE" value="1"  type="boolean" title="inverse color" description="make captcha white on black" />
+      <const name="CAPTCHA_PIXEL" value="1" type="multi" multi="1=single pixel|2=greyscale 2x2|3=smooth color" title="smooth drawing" description="image pixel assembly method and speed" />
+      <const name="CAPTCHA_ONCLICK_HIRES" value="1" type="boolean" title="onClick-HiRes" description="reloads a finer resolution version of the CAPTCHA if user clicks on it" />
+      <const name="CAPTCHA_TIMEOUT" value="5000" type="string" regex="\d+" title="verification timeout" description="in seconds, maxiumum time to elaps from CAPTCHA display to verification" />
+   type: intercept
+   category: antispam
+   priority: optional
+
+
+   This library operates CAPTCHA form submissions, to block spam bots and
+   alike. It is easy to hook into existing web sites and scripts. It also
+   tries to be "smart" and more user-friendly.
+   
+   While the operation logic and identifier processing are extremley safe,
+   this is a "weak" implementation. Specifically targetted and tweaked OCR
+   software could overcome the visual riddle. And if enabled, the textual
+   or mathematical riddles are rather simple to overcome if attacked.
+   Generic spambots are however blocked already with the default settings.
+   
+   PRINT captcha::form()
+     emits the img and input fields for inclusion into your submit <form>
+   
+   IF (captcha::solved())
+     tests for a correctly entered solution on submit, returns true if ok
+   
+   Temporary files are created for tracking, verification and basic data
+   storage, but will get automatically removed once a CAPTCHA was solved
+   to prevent replay attacks. Additionally this library uses "AJAX" super
+   powers *lol* to enhance usability. And a short-lasting session cookie
+   is also added site-wide, so users may only have to solve the captcha
+   once (can be disabled, because that's also just security by obscurity).
+   
    Public Domain, available via http://freshmeat.net/p/captchaphp
 */
 
+#-- behaviour
+define("CAPTCHA_PERSISTENT", 0);     // cookie-pass after it's solved once (does not work if headers were already sent on innovocation of captcha::solved() check)
+define("CAPTCHA_NEW_URLS", 1);       // force captcha only when URLs submitted
+define("CAPTCHA_AJAX", 1);           // visual feedback while entering letters
+define("CAPTCHA_LOG", 0);            // create /tmp/captcha/log file
+define("CAPTCHA_NOTEXT", 0);         // disables the accessible text/math riddle
 
-#-- config
-define("EWIKI_FONT_DIR", dirname(__FILE__));  // which fonts to use
-define("CAPTCHA_INVERSE", 0);                 // white or black(=1)
-define("CAPTCHA_TIMEOUT", 5000);              // in seconds (=max 4 hours)
+#-- look
+define("CAPTCHA_IMAGE_TYPE", 2);     // 1=wave, 2=whirly
+define("CAPTCHA_INVERSE", 1);        // white or black(=1)
+define("CAPTCHA_IMAGE_SIZE", "200x60");  // randomly adapted a little
+define("CAPTCHA_INPUT_STYLE", "height:46px; font-size:34px; font-weight:450;");
+define("CAPTCHA_PIXEL", 1);          // set to 2 for smoother 2x2 grayscale pixel transform
+define("CAPTCHA_ONCLICK_HIRES", 1);  // use better/slower drawing mode on reloading
 
+#-- solving
+define("CAPTCHA_FUZZY", 0.65);       // easier solving: accept 1 or 2 misguessed letters
+define("CAPTCHA_TRIES", 5);          // maximum failures for solving the captcha
+define("CAPTCHA_AJAX_TRIES", 25);    // AJAX testing limit (prevents brute-force cracking via check API)
+define("CAPTCHA_MAXPASSES", 2);      // 2 passes prevent user annoyment with caching/reload failures
+define("CAPTCHA_TIMEOUT", 5000);     // (in seconds/2) = 3:00 hours to solve a displayed captcha
+define("CAPTCHA_MIN_CHARS", 7);      // how many letters to use
+define("CAPTCHA_MAX_CHARS", 9);
 
-/* static - (you could instantiate it, but...) */
-class captcha {
+#-- operation
+define("CAPTCHA_TEMP_DIR", (@$_SERVER['TEMP'] ? $_SERVER['TEMP'] : '/tmp') . "/captcha/");
+define("CAPTCHA_PARAM_ID", "__ec_i");
+define("CAPTCHA_PARAM_INPUT", "__ec_s");
+define("CAPTCHA_BGCOLOR", 0xFFFFFF);   // initial background color (non-inverse, white)
+define("CAPTCHA_SALT", ",e?c:7<");
+#define("CAPTCHA_DATA_URLS", 0);     // RFC2397-URLs exclude MSIE users
+define("CAPTCHA_FONT_DIR", dirname(__FILE__));
+//define("CAPTCHA_BASE_URL", "http://$_SERVER[SERVER_NAME]:$_SERVER[SERVER_PORT]/" . substr(realpath(__FILE__), strlen(realpath($_SERVER["DOCUMENT_ROOT"]))));
+define("CAPTCHA_BASE_URL", Config::get('web_path') . "/modules/captcha/captcha.php");
 
+/* simple API */
+class captcha {
 
-   /* gets parameter from $_REQUEST[] array (POST vars) and so can
-      verify input, @returns boolean
-   */
+   #-- tests submitted CAPTCHA solution against tracking data
+   function solved() {
+      $c = new easy_captcha();
+      return $c->solved();
+   }
    function check() {
-      if (($hash = $_REQUEST["captcha_hash"])
-      and ($pw = trim($_REQUEST["captcha_input"]))) {
-         return((captcha::hash($pw)==$hash) || (captcha::hash($pw,-1)==$hash));
+      return captcha::solved();
+   }
+
+   #-- returns string with "<img> and <input>" fields for display in your <form>
+   function form($text="") {
+      $c = new easy_captcha();
+      return $c->form("$text");
+   }
+}
+
+
+
+#-- init (triggered if *this* script is called directly)
+if (realpath(strtok("$_SERVER[DOCUMENT_ROOT]/$_SERVER[REQUEST_URI]","?#"))==realpath(__FILE__)) {
+   easy_captcha_utility::API();
+}
+
+
+
+
+
+
+
+
+
+
+/* base logic and data storare */
+class easy_captcha {
+
+
+   #-- init data
+   function easy_captcha($id=NULL, $ignore_expiration=0) {
+
+      #-- load
+      if (($this->id = $id) or ($this->id = preg_replace("/[^-,.\w]+/", "", @$_REQUEST[CAPTCHA_PARAM_ID]))) {
+         $this->load();
+      }
+
+      #-- create new
+      if (empty($this->id) || !$ignore_expiration && !$this->is_valid() && $this->log("new()", "EXPIRED", "regenerating store")) {
+         $this->generate();
       }
    }
 
+
+   #-- create solutions
+   function generate() {
+
+      #-- init
+      srand(microtime() + time()/2 - 21017);
+      if ($this->id) { $this->prev[] = $this->id; }
+      $this->id = $this->new_id();
+      
+      #-- meta informations
+      $this->created = time();
+      $this->{'created$'} = gmdate("r", $this->created);
+      $this->expires = $this->created + CAPTCHA_TIMEOUT;
+      //$this->tries = 0;
+      $this->passed = 0;
+
+      #-- captcha processing info
+      $this->sent = 0;
+      $this->tries = CAPTCHA_TRIES;  // 5
+      $this->ajax_tries = CAPTCHA_AJAX_TRIES;  // 25
+      $this->passed = 0;
+      $this->maxpasses = CAPTCHA_MAXPASSES;   // 2
+      $this->failures = 0;
+      $this->shortcut = array();
+      $this->grant = 0;  // unchecked access
+      
+      #-- mk IMAGE/GRAPHIC
+      $this->image = (CAPTCHA_IMAGE_TYPE <= 1)
+                   ? new easy_captcha_graphic_image_waved()
+                   : new easy_captcha_graphic_image_disturbed();
+    //$this->image = new easy_captcha_graphic_cute_ponys();
+      
+      #-- mk MATH/TEXT riddle
+      $this->text = (CAPTCHA_NOTEXT >= 1)
+                  ? new easy_captcha_text_disable()
+                  : new easy_captcha_text_math_formula();
+    //$this->text = new easy_captcha_text_riddle();
+
+      #-- process granting cookie
+      if (CAPTCHA_PERSISTENT)
+      $this->shortcut[] = new easy_captcha_persistent_grant();
+
+      #-- spam-check: no URLs submitted
+      if (CAPTCHA_NEW_URLS)
+      $this->shortcut[] = new easy_captcha_spamfree_no_new_urls();
+
+      #-- store record   
+      $this->save();
+   }
    
-   /* yields <input> fields html string (no complete form), with captcha
-      image already embedded as data:-URI
-   */
-   public static function form($title="&rarr; retype that here", $more="<small><br>Enter the correct letters and numbers from the image into the text box. <br>This small test serves as access restriction against malicious bots. <br>Simply reload the page if this graphic is too hard to read.</small>") {
-      $pw = captcha::mkpass();
-      $hash = captcha::hash($pw);
-     $maxsize = (strpos("MSIE", $_SERVER["HTTP_USER_AGENT"]) ? 1000 : 6000);
-      @header("Vary: User-Agent");
-      $img = "data:image/jpeg;base64,"
-           . base64_encode(captcha::image($pw, 200, 60, CAPTCHA_INVERSE, $maxsize));
-      $alt = htmlentities(captcha::textual_riddle($pw));
-      $test = substr($img,22);
-      $html = 
-        '<table summary="captcha input"><tr>'
-      . '<td><img name="captcha_image" id="captcha_image" src="'.$img. '" height="60" width="200" alt="'.$alt. '" /></td>'
-      . '<td>'.$title. '<br/><input name="captcha_hash" type="hidden" value="'.$hash. '" />'
-      . '<font color="red">*</font><input name="captcha_input" type="text" size="7" maxlength="16" style="height:23px; font-size:16px; font-weight:450;" />'
-      . '</td><td>'.$more.'</td>'
-      . '</tr></table>';
-
-      #-- js/html fix if ("MSIE")
-      {
-//         $base = "http://$_SERVER[SERVER_NAME]:$_SERVER[SERVER_PORT]".$conf('web_path')."/modules/captcha/captcha.php";
-	 $base = $_SERVER['PHP_SELF'];
-         $html .= <<<END
-<script language="Javascript"><!--
-if (/Microsoft/.test(navigator.appName)) {
-//    var msg= "You are using IE Please download firefox in order to register. http://www.mozilla.org/products/firefox";
-//    alert(msg);
-   var img = document.captcha_image;
-  img.src = "$base?_ddu=$test"; 
-  //alert (img.src);
-    }
---></script>
-END;
-      }
-      $html = "<div class=\"captcha\">$html</div>";
-      return($html);
-   }
-
-
-   /* generates alternative (non-graphic), human-understandable
-      representation of the passphrase
-   */
-   public static function textual_riddle($phrase) {
-      $symbols0 = '"\'-/_:';
-      $symbols1 = array("\n,", "\n;", ";", "\n&", "\n-", ",", ",", "\nand then", "\nfollowed by", "\nand", "\nand not a\n\"".chr(65+rand(0,26))."\",\nbut");
-      $s = "Guess the letters and numbers\n(passphrase riddle)\n--\n";
-      for ($p=0; $p<strlen($phrase); $p++) {
-         $c = $phrase[$p];
-         $add = "";
-         #-- asis
-         if (!rand(0,3)) {
-            $i = $symbols0[rand(0,strlen($symbols0)-1)];
-            $add = "$i$c$i";
+   
+   #-- examine if captcha data is fresh
+   function is_valid() {
+      return isset($this->id) && ($this->created)
+          && ($this->expires > time())
+          && ($this->tries > 0)
+          && ($this->failures < 500)
+          && ($this->passed < $this->maxpasses)
+          || $this->delete() || $this->log("is_valid", "EXPIRED", "and deleted") && false;
+   }
+
+
+   #-- new captcha tracking/storage id
+   function new_id() {
+      return "ec." . time() . "." . md5( $_SERVER["SERVER_NAME"] . CAPTCHA_SALT . rand(0,1<<30) );
+   }
+
+
+   #-- check backends for correctness of solution
+   function solved() {
+      $ok = false;
+
+      #-- failure
+      if ((0 >= $this->tries--) || !$this->is_valid()) {
+         // log, this is either a frustrated user or a bot knocking
+         $this->log("::solved", "INVALID", "tries exhausted ($this->tries) or expired(?) captcha");
+      }
+      
+      #-- test
+      elseif ($this->sent) {
+         $in = $_REQUEST[CAPTCHA_PARAM_INPUT];  // might be empty string
+      
+         #-- check individual modules
+         $ok = $this->grant;
+         foreach ($this->shortcut as $test) {
+            $ok = $ok || $test->solved($in);    // cookie & nourls
          }
-         #-- letter
-         elseif ($c >= 'A') {
-            $type = ($c >= 'a' ? "small " : "");
-            do {
-               $n = rand(-3,3);
-               $c2 = chr((ord($c) & 0x5F) + $n);
-            }
-            while (($c2 < 'A') || ($c2 > 'Z'));
-            if ($n < 0) {
-               $n = -$n;
-               $add .= "$type'$c2' +$n letters";
-            }
-            else {
-               $add .= "$n chars before $type$c2";
+         $ok = $ok  // either letters or math formula submitted
+             || isset($this->image) && $this->image->solved($in)
+             || isset($this->text) && $this->text->solved($in);
+               
+         #-- update state
+         if ($ok) {
+            $this->passed++;
+            $this->log("::solved", "OKAY", "captcha passed ($in) for image({$this->image->solution}) and text({$this->text->solution})");
+            
+            #-- set cookie on success
+            if (CAPTCHA_PERSISTENT) {
+               $this->shortcut[0/*FIXME*/]->grant();
+               $this->log("::solved", "PERSISTENT", "cookie granted");
             }
          }
-         #-- number
          else {
-            $add = "???";
-            $n = (int) $c;
-            do {
-               do { $x = rand(1, 10); } while (!$x);
-               $op = rand(0,11);
-               if ($op <= 2) {
-                  $add = "($add * $x)"; $n *= $x;
-               }
-               elseif ($op == 3) {
-                  $x = 2 * rand(1,2);
-                  $add = "($add / $x)"; $n /= $x;
-               }
-               elseif ($sel % 2) {
-                  $add = "($add + $x)"; $n += $x;
-               }
-               else {
-                  $add = "($add - $x)"; $n -= $x;
-               }
+            $this->failures++;
+            $this->log("::solved", "WRONG", "solution failure ($in) for image({$this->image->solution}) and text({$this->text->solution})");
+         }
+      }
+
+      #-- remove if done
+      if (!$this->is_valid() /*&& !$this->delete()*/) {
+         $this->generate(); // ensure object instance can be reused - for quirky form processing logic
+      }
+      #-- store state/result
+      else {
+         $this->save();
+      }
+
+      #-- return result
+      return($ok);
+   }
+   
+   
+   #-- combines ->image and ->text data into form fields
+   function form($add_text="") {
+
+      #-- store object data
+      $this->sent++;
+      $this->save();
+      
+      #-- prepare output vars
+      $p_id = CAPTCHA_PARAM_ID;
+      $p_input = CAPTCHA_PARAM_INPUT;
+      $base_url = CAPTCHA_BASE_URL . '?' . CAPTCHA_PARAM_ID . '=';
+      $id = htmlentities($this->id);
+      $img_url = $base_url . $id;
+      $alt_text = htmlentities($this->text->question);
+      $new_urls = CAPTCHA_NEW_URLS ? 0 : 1;
+      $onClick = CAPTCHA_ONCLICK_HIRES ? 'onClick="this.src += this.src.match(/hires/) ? \'.\' : \'hires=1&\';"' : 'onClick="this.src += \'.\';"';
+      $onKeyDown = CAPTCHA_AJAX ? 'onKeyDown="captcha_check_solution()"' : '';
+      $javascript = CAPTCHA_AJAX ? '<script src="'.$base_url.'base.js&captcha_new_urls='.$new_urls.'" type="text/javascript" language="JavaScript" id="captcha_ajax_1"></script>' : '';
+
+      #-- assemble
+      $HTML =
+         '<div id="captcha" class="captcha">' .
+         '<input type="hidden" id="'.$p_id.'" name="'.$p_id.'" value="'.$id.'" />' .
+         '<img src="'.$img_url .'&" width="'.$this->image->width.'" height="'.$this->image->height.'" alt="'.$alt_text.'" align="middle" '.$onClick.' title="click on image to redraw" />' .
+         '&nbsp;' .
+         $add_text .
+         '<input title="please enter the letters you recognize in the CAPTCHA image to the left" type="text" '.$onKeyDown.' id="'.$p_input.'" name="'.$p_input.'" value="'.htmlentities($_REQUEST[$p_input]) .
+         '" size="8" style="'.CAPTCHA_INPUT_STYLE.'" />' .
+         $javascript .
+         '</div>';
+
+      return($HTML);
+   }
+
+
+
+   #-- noteworthy stuff goes here
+   function log($error, $category, $message) {
+      // append to text file
+      if (CAPTCHA_LOG && ($log = @fopen(CAPTCHA_TEMP_DIR . "log", "a+"))) {
+         flock($log, LOCK_EX);
+         fwrite($log, "[$error] -$category- \"$message\" $_SERVER[REMOTE_ADDR] id={$this->id} tries={$this->tries} failures={$this->failures} created/time/expires=$this->created/".time()."/$this->expires \n");
+         fclose($log);
+      }
+      return(TRUE);   // for if-chaining
+   }
+
+
+   #-- load object from saved captcha tracking data
+   function load() {
+      $fn = $this->data_file();
+      if (file_exists($fn)) {
+         $saved = (array)@unserialize(fread(fopen($fn, "r"), 1<<20));
+         foreach ($saved as $i=>$v) {
+            $this->{$i} = $v;
+         }
+      }
+      else {
+        // log
+      }
+   }
+
+   #-- save $this captcha state
+   function save() {
+      $this->straighten_temp_dir();
+      if ($fn = $this->data_file()) {
+         $f = fopen($fn, "a");
+         if (flock($f, LOCK_EX)) {
+            ftruncate($f, 0);
+            fwrite($f, serialize($this));
+         }
+         fclose($f);
+      }
+   }
+   
+   #-- remove $this data file
+   function delete() {
+      // delete current and all previous data files
+      $this->prev[] = $this->id;
+      if (isset($this->prev)) {
+         foreach ($this->prev as $id) {
+            @unlink($this->data_file($id));
+         }
+      }
+      // clean object
+      foreach ((array)$this as $name=>$val) {
+         unset($this->{$name});
+      }
+      return(FALSE);  // far if-chaining in ->is_valid()
+   }
+   
+   #-- clean-up or init temporary directory
+   function straighten_temp_dir() {
+      // create dir
+      if (!file_exists($dir=CAPTCHA_TEMP_DIR)) {
+         mkdir($dir);
+      }
+      // clean up old files
+      if ((!rand(0,50)) && ($dh = opendir($dir))) {
+         $t_kill = time() - CAPTCHA_TIMEOUT * 2;
+         while($fn = readdir($dh)) if ($fn[0] != ".") {
+            if (filemtime("$dir/$fn") < $t_kill) {
+               @unlink("$dir/$fn");
             }
-            while (rand(0,1));
-            $add .= " = $n";
          }
-         $s .= "$add";
-         $s .= $symbols1[rand(0,count($symbols1)-1)] . "\n";
       }
+   }
+
+   #-- where's the storage?
+   function data_file($id=NULL) {
+      return CAPTCHA_TEMP_DIR . preg_replace("/[^-,.\w]/", "", ($id?$id:$this->id)) . ".a()";
+   }
+
+
+   #-- unreversable hash from passphrase, with time() slice encoded
+   function hash($text, $dtime=0, $length=1) {
+      $text = strtolower($text);
+      $pfix = (int) (time() / $length*CAPTCHA_TIMEOUT) + $dtime;
+      return md5("captcha::$pfix:$text::".__FILE__.":$_SERVER[SERVER_NAME]:80");
+   }
+   
+}
+
+
+
+
+
+
+
+
+
+#-- checks the supplied solution, allows differences (incorrectly guessed letters)
+class easy_captcha_fuzzy extends easy_captcha {
+
+   #-- ratio of letters that may differ between solution and real password
+   var $fuzzy = CAPTCHA_FUZZY;
+
+   #-- compare
+   function solved($in) {
+      if ($in) {
+         $pw = strtolower($this->solution);
+         $in = strtolower($in);
+         $diff = levenshtein($pw, $in);
+         $maxdiff = strlen($pw) * (1 - $this->fuzzy);
+         return ($pw == $in) or ($diff <= $maxdiff);  // either matches, or allows around 2 divergent letters
+      }
+   }
+
+}
+
+
+
+
+
+
+
+
+
+#-- image captchas, base and utility code
+class easy_captcha_graphic extends easy_captcha_fuzzy {
+
+   #-- config
+   function easy_captcha_graphic($x=NULL, $y=NULL) {
+      if (!$y) {
+         $x = strtok(CAPTCHA_IMAGE_SIZE, "x,|/*;:");
+         $y = strtok(",.");
+         $x = rand($x * 0.9, $x * 1.2);
+         $y = rand($y - 5, $y + 15);
+      }
+      $this->width = $x;
+      $this->height = $y;
+      $this->inverse = CAPTCHA_INVERSE;
+      $this->bg = CAPTCHA_BGCOLOR;
+      $this->maxsize = 0xFFFFF;
+      $this->quality = 66;
+      $this->solution = $this->mkpass();
+   }
+
+
+   #-- return a single .ttf font filename
+   function font() {
+      $fonts = array(/*"FreeMono-Medium.ttf"*/);
+      $fonts += glob(CAPTCHA_FONT_DIR."/*.ttf");
+      return $fonts[rand(0,count($fonts)-1)];
+   }
+
+
+   #-- makes string of random letters (for embedding into image)
+   function mkpass() {
+      $s = "";
+      for ($n=0; $n<10; $n++) {
+         $s .= chr(rand(0, 255));
+      }
+      $s = base64_encode($s);   // base64-set, but filter out unwanted chars
+      $s = preg_replace("/[+\/=IG0ODQR]/i", "", $s);  // strips hard to discern letters, depends on used font type
+      $s = substr($s, 0, rand(CAPTCHA_MIN_CHARS, CAPTCHA_MAX_CHARS));
       return($s);
    }
 
 
-   /* returns jpeg file stream with unscannable letters encoded
+   #-- return GD color
+   function random_color($a,$b) {
+      $R = $this->inverse ? 0xFF : 0x00;
+      return imagecolorallocate($this->img, rand($a,$b)^$R, rand($a,$b)^$R, rand($a,$b)^$R);
+   }
+   function rgb ($r,$g,$b) {
+      $R = $this->inverse ? 0xFF : 0x00;
+      return imagecolorallocate($this->img, $r^$R, $g^$R, $b^$R);
+   }
+
+
+   #-- generate JPEG output
+   function output() {
+      ob_start();
+      ob_implicit_flush(0);
+        imagejpeg($this->img, "", $this->quality);
+        $jpeg = ob_get_contents();
+      ob_end_clean();
+      imagedestroy($this->img);
+      unset($this->img);
+      return($jpeg);
+   }
+}
+
+
+
+
+
+
+
+
+
+#-- waived captcha image II
+class easy_captcha_graphic_image_waved extends easy_captcha_graphic {
+
+
+   /* returns jpeg file stream with unscannable letters encoded 
       in front of colorful disturbing background
    */
-   public static function image($phrase, $width=200, $height=60, $inverse=0, $maxsize=0xFFFFF) {
+   function jpeg() {
+      #-- step by step
+      $this->create();
+      $this->text();
+      //$this->debug_grid();
+      $this->fog();
+      $this->distort();
+      return $this->output();
+   }
+
+
+   #-- initialize in-memory image with gd library
+   function create() {
+      $this->img = imagecreatetruecolor($this->width, $this->height);
+     // imagealphablending($this->img, TRUE);
+      imagefilledrectangle($this->img, 0,0, $this->width,$this->height, $this->inverse ? $this->bg ^ 0xFFFFFF : $this->bg); //$this->rgb(255,255,255)
+      if (function_exists("imageantialias")) {
+         imageantialias($this->img, true);
+      }
+   }
+
+
+   #-- add the real text to it
+   function text() {
+      $w = $this->width;
+      $h = $this->height;
+      $SIZE = rand(30,36);
+      $DEG = rand(-2,9);
+      $LEN = strlen($this->solution);
+      $left = $w - $LEN * 25;
+      $top = ($h - $SIZE - abs($DEG*2));
+      imagettftext($this->img, $SIZE, $DEG, rand(5,$left-5), $h-rand(3, $top-3), $this->rgb(0,0,0), $this->font(), $this->solution);
+   }
+
+   #-- to visualize the sinus waves
+   function debug_grid() {
+      for ($x=0; $x<250; $x+=10) {
+         imageline($this->img, $x, 0, $x, 70, 0x333333);
+         imageline($this->img, 0, $x, 250, $x, 0x333333);
+      }
+   }
    
-      #-- initialize in-memory image with gd library
-      srand(microtime()*21017);
-      $img = imagecreatetruecolor($width, $height);
-      $R = $inverse ? 0xFF : 0x00;
-      imagefilledrectangle($img, 0,0, $width,$height, captcha::random_color($img, 222^$R, 255^$R));
-      $c1 = rand(150^$R, 185^$R);
-      $c2 = rand(195^$R, 230^$R);
+   #-- add lines
+   function fog() {
+      $num = rand(10,25);
+      $x = $this->width;
+      $y = $this->height;
+      $s = rand(0,270);
+      for ($n=0; $n<$num; $n++) {
+         imagesetthickness($this->img, rand(1,2));
+         imagearc($this->img,
+            rand(0.1*$x, 0.9*$x), rand(0.1*$y, 0.9*$y),  //x,y
+            rand(0.1*$x, 0.3*$x), rand(0.1*$y, 0.3*$y),  //w,h
+            $s, rand($s+5, $s+90),     // s,e
+            rand(0,1) ? 0xFFFFFF : 0x000000   // col
+         );
+      }
+      imagesetthickness($this->img, 1);
+   }
+
+   
+   #-- distortion: wave-transform
+   function distort() {
+
+      #-- init
+      $single_pixel = (CAPTCHA_PIXEL<=1);   // very fast
+      $greyscale2x2 = (CAPTCHA_PIXEL<=2);   // quicker than exact smooth 2x2 copy
+      $width = $this->width;
+      $height = $this->height;
+      $i = & $this->img;
+      $dest = imagecreatetruecolor($width, $height);
       
-      #-- configuration
-      $fonts = array();
-      $fonts += glob(EWIKI_FONT_DIR."/*.ttf");
+      #-- URL param ?hires=1 influences used drawing scheme
+      if (isset($_GET["hires"])) {
+         $single_pixel = 0;
+      }
+
+      #-- prepare distortion
+      $wave = new easy_captcha_dxy_wave($width, $height);
+      $spike = new easy_captcha_dxy_spike($width, $height);
+
+      #-- generate each new x,y pixel individually from orig $img
+      for ($y = 0; $y < $height; $y++) {
+         for ($x = 0; $x < $width; $x++) {
+
+            #-- pixel movement
+            list($dx, $dy) = $wave->dxy($x, $y);   // x- and y- sinus wave
+           // list($qx, $qy) = $spike->dxy($x, $y);
+            
+            #-- get source pixel, paint dest
+            if ($single_pixel) {
+               // single source dot: one-to-one duplicate (unsmooth, hard edges)
+               imagesetpixel($dest, $x, $y, @imagecolorat($i, (int)$dx+$x, (int)$dy+$y));
+            }
+            elseif ($greyscale2x2) {
+               // merge 2x2 simple/greyscale (3 times as slow)
+               $cXY = $this->get_2x2_greyscale($i, $x+$dx, $y+$dy);
+               imagesetpixel($dest, $x,$y, imagecolorallocate($dest, $cXY, $cXY, $cXY));
+            }
+            else {
+               // exact and smooth transformation (5 times as slow)
+               list($cXY_R, $cXY_G, $cXY_B) = $this->get_2x2_smooth($i, $x+$dx, $y+$dy);
+               imagesetpixel($dest, $x,$y, imagecolorallocate($dest, (int)$cXY_R, (int)$cXY_G, (int)$cXY_B));
+            }
+
+         }
+      }
+
+      #-- simply overwrite ->img
+      imagedestroy($i);      
+      $this->img = $dest;
+   }
+   
+   #-- get 4 pixels from source image, merges BLUE value simply
+   function get_2x2_greyscale(&$i, $x, $y) {
+       // this is pretty simplistic method, actually adds more artefacts
+       // than it "smoothes"
+       // it just merges the brightness from 4 adjoining pixels into one
+       $cXY = (@imagecolorat($i, $x+$dx, $y+$dy) & 0xFF)
+            + (@imagecolorat($i, $x+$dx, $y+$dy+1) & 0xFF)
+            + (@imagecolorat($i, $x+$dx+1, $y+$dy) & 0xFF)
+            + (@imagecolorat($i, $x+$dx+1, $y+$dy+1) & 0xFF);
+       $cXY = (int) ($cXY / 4);
+       return $cXY;
+   }
+
+   #-- smooth pixel reading (with x,y being reals, not integers)
+   function get_2x2_smooth(&$i, $x, $y) {
+       // get R,G,B values from 2x2 source area
+       $c00 = $this->get_RGB($i, $x, $y);      //  +------+------+
+       $c01 = $this->get_RGB($i, $x, $y+1);    //  |dx,dy | x1,y0|
+       $c10 = $this->get_RGB($i, $x+1, $y);    //  | rx-> |      | 
+       $c11 = $this->get_RGB($i, $x+1, $y+1);  //  +----##+------+
+       // weighting by $dx/$dy fraction part   //  |    ##|<-ry  |
+       $rx = $x - floor($x);  $rx_ = 1 - $rx;  //  |x0,y1 | x1,y1|
+       $ry = $y - floor($y);  $ry_ = 1 - $ry;  //  +------+------+
+       // this is extremely slow, but necessary for correct color merging,
+       // the source pixel lies somewhere in the 2x2 quadrant, that's why
+       // RGB values are added proportionately (rx/ry/_)
+       // we use no for-loop because that would slow it even further
+       $cXY_R = (int) (($c00[0]) * $rx_ * $ry_)
+              + (int) (($c01[0]) * $rx_ * $ry)      // division by 4 not necessary,
+              + (int) (($c10[0]) * $rx * $ry_)      // because rx/ry/rx_/ry_ add up
+              + (int) (($c11[0]) * $rx * $ry);      // to 255 (=1.0) at most
+       $cXY_G = (int) (($c00[1]) * $rx_ * $ry_)
+              + (int) (($c01[1]) * $rx_ * $ry)
+              + (int) (($c10[1]) * $rx * $ry_)
+              + (int) (($c11[1]) * $rx * $ry);
+       $cXY_B = (int) (($c00[2]) * $rx_ * $ry_)
+              + (int) (($c01[2]) * $rx_ * $ry)
+              + (int) (($c10[2]) * $rx * $ry_)
+              + (int) (($c11[2]) * $rx * $ry);
+       return array($cXY_R, $cXY_G, $cXY_B);
+   }
+
+   #-- imagegetcolor from current ->$img split up into RGB array
+   function get_RGB(&$img, $x, $y) {
+      $rgb = @imagecolorat($img, $x, $y);
+      return array(($rgb >> 16) &0xFF, ($rgb >>8) &0xFF, ($rgb) &0xFF);
+   }
+}
+
+
+
+
+
+
+#-- xy-wave deviation (works best for around 200x60)
+#   cos(x,y)-idea taken from imagemagick
+class easy_captcha_dxy_wave {
+
+   #-- init params
+   function easy_captcha_dxy_wave($max_x, $max_y) {
+      $this->dist_x = $this->real_rand(2.5, 3.5);     // max +-x/y delta distance
+      $this->dist_y = $this->real_rand(2.5, 3.5);
+      $this->slow_x = $this->real_rand(7.5, 20.0);    // =wave-width in pixel/3
+      $this->slow_y = $this->real_rand(7.5, 15.0);
+   }
+   
+   #-- calculate source pixel position with overlapping sinus x/y-displacement
+   function dxy($x, $y) {
+      #-- adapting params
+      $this->dist_x *= 1.000035;
+      $this->dist_y *= 1.000015;
+      #-- dest pixels (with x+y together in each of the sin() calcs you get more deformation, else just yields y-ripple effect)
+      $dx = $this->dist_x * cos(($x/$this->slow_x) - ($y/1.1/$this->slow_y));
+      $dy = $this->dist_y * sin(($y/$this->slow_y) - ($x/0.9/$this->slow_x));
+      #-- result
+      return array($dx, $dy);
+   }
+   
+   #-- array of values with random start/end values
+   function from_to_rand($max, $a, $b) {
+      $BEG = $this->real_rand($a, $b);
+      $DIFF = $this->real_rand($a, $b) - $BEG;
+      $r = array();
+      for ($i = 0; $i <= $max; $i++) {
+         $r[$i] = $BEG + $DIFF * $i / $max;
+      }
+      return($r);
+   }
+
+   #-- returns random value in given interval
+   function real_rand($a, $b) {
+      $r = rand(0, 1<<30);
+      return(  $r / (1<<30) * ($b-$a) + $a  );   // base + diff * (0..1)
+   }
+}
+
+
+#-- with spike
+class easy_captcha_dxy_spike {
+   function dxy($x,$y) {
+      #-- centre spike
+      $y += 0.0;
+      return array($x,$y);
+   }
+}
+
+
+
+
+
+
+
+
+#-- colorful captcha image I
+class easy_captcha_graphic_image_disturbed extends easy_captcha_graphic {
+
+
+   /* returns jpeg file stream with unscannable letters encoded 
+      in front of colorful disturbing background
+   */
+   function jpeg() {
+      #-- step by step
+      $this->create();
+      $this->background_lines();
+      $this->background_letters();
+      $this->text();
+      return $this->output();
+   }
+
+
+   #-- initialize in-memory image with gd library
+   function create() {
+      $this->img = imagecreatetruecolor($this->width, $this->height);
+      imagefilledrectangle($this->img, 0,0, $this->width,$this->height, $this->random_color(222, 255));
       
       #-- encolour bg
       $wd = 20;
       $x = 0;
-      while ($x < $width) {
-         imagefilledrectangle($img, $x, 0, $x+=$wd, $height, captcha::random_color($img, 222^$R, 255^$R));
+      while ($x < $this->width) {
+         imagefilledrectangle($this->img, $x, 0, $x+=$wd, $this->height, $this->random_color(222, 255));
          $wd += max(10, rand(0, 20) - 10);
       }
+   }
+   
 
-      #-- make interesting background I, lines
+   #-- make interesting background I, lines
+   function background_lines() {
+      $c1 = rand(150, 185);
+      $c2 = rand(195, 230);
       $wd = 4;
       $w1 = 0;
       $w2 = 0;
-      for ($x=0; $x<$width; $x+=(int)$wd) {
-         if ($x < $width) {   // verical
-            imageline($img, $x+$w1, 0, $x+$w2, $height-1, captcha::random_color($img,$c1,$c2));
+      for ($x=0; $x<$this->width; $x+=(int)$wd) {
+         if ($x < $this->width) {   // verical
+            imageline($this->img, $x+$w1, 0, $x+$w2, $this->height-1, $this->random_color($c1++,$c2));
          }
-         if ($x < $height) {  // horizontally ("y")
-            imageline($img, 0, $x-$w2, $width-1, $x-$w1, captcha::random_color($img,$c1,$c2));
+         if ($x < $this->height) {  // horizontally ("y")
+            imageline($this->img, 0, $x-$w2, $this->width-1, $x-$w1, $this->random_color($c1,$c2--));
          }
          $wd += rand(0,8) - 4;
          if ($wd < 1) { $wd = 2; }
          $w1 += rand(0,8) - 4;
          $w2 += rand(0,8) - 4;
-         if (($x > $height) && ($y > $height)) {
+         if (($x > $this->height) && ($y > $this->height)) {
             break;
          }
       }
+   }
+   
       
-      #-- more disturbing II, random letters
+   #-- more disturbing II, random letters
+   function background_letters() {
       $limit = rand(30,90);
       for ($n=0; $n<$limit; $n++) {
          $letter = "";
          do {
             $letter .= chr(rand(31,125)); // random symbol
          } while (rand(0,1));
-         $size = rand(5, $height/2);
+         $size = rand(5, $this->height/2);
          $half = (int) ($size / 2);
-         $x = rand(-$half, $width+$half);
-         $y = rand(+$half, $height);
+         $x = rand(-$half, $this->width+$half);
+         $y = rand(+$half, $this->height);
          $rotation = rand(60, 300);
-         $c1  = captcha::random_color($img, 130^$R, 240^$R);
-         $font = $fonts[rand(0, count($fonts)-1)];
-         imagettftext($img, $size, $rotation, $x, $y, $c1, $font, $letter);
+         imagettftext($this->img, $size, $rotation, $x, $y, $this->random_color(130, 240), $this->font(), $letter);
       }
+   }
+   
 
-      #-- add the real text to it
+   #-- add the real text to it
+   function text() {
+      $phrase = $this->solution;
       $len = strlen($phrase);
       $w1 = 10;
-      $w2 = $width / ($len+1);
+      $w2 = $this->width / ($len+1);
       for ($p=0; $p<$len; $p++) {
          $letter = $phrase[$p];
-         $size = rand(18, $height/2.2);
+         $size = rand(18, $this->height/2.2);
          $half = (int) $size / 2;
          $rotation = rand(-33, 33);
-         $y = rand($size+3, $height-3);
+         $y = rand($size+3, $this->height-3);
          $x = $w1 + $w2*$p;
-         $w1 += rand(-$width/90, $width/40);  // @BUG: last char could be +30 pixel outside of image
-         $font = $fonts[rand(0, count($fonts)-1)];
-         $r=rand(30,99); $g=rand(30,99); $b=rand(30,99); // two colors for shadow
-         $c1  = imagecolorallocate($img, $r*1^$R, $g*1^$R, $b*1^$R);
-         $c2  = imagecolorallocate($img, $r*2^$R, $g*2^$R, $b*2^$R);
-         imagettftext($img, $size, $rotation, $x+1, $y, $c2, $font, $letter);
-         imagettftext($img, $size, $rotation, $x, $y-1, $c1, $font, $letter);
-      }
-
-      #-- let JFIF stream be generated
-/* Drop down quality if browser is MSIE */
-if (preg_match('|MSIE ([0-9].[0-9]{1,2})|',$_SERVER["HTTP_USER_AGENT"],$matched)){
-      $quality = 8;
-      } else {
-      $quality = 100;
-      }
-
-      $s = array();
-      do {
-         ob_start(); ob_implicit_flush(0);
-         imagejpeg($img, "", (int)$quality);
-         $jpeg = ob_get_contents(); ob_end_clean();
-         $size = strlen($jpeg);
-         $s_debug[] = ((int)($quality*10)/10) . "%=$size";
-         $quality = $quality * ($maxsize/$size) * 0.93 - 1.7;  // -($quality/7.222)*
-      }
-      while (($size > $maxsize) && ($quality >= 16));
-      imagedestroy($img);
-#print_r($s_debug);
-      return($jpeg);
+         $w1 += rand(-$this->width/90, $this->width/40);  // @BUG: last char could be +30 pixel outside of image
+         $font = $this->font();
+         list($r,$g,$b) = array(rand(30,99), rand(30,99), rand(30,99));
+         imagettftext($this->img, $size, $rotation, $x+1, $y, $this->rgb($r*2,$g*2,$b*2), $font, $letter);
+         imagettftext($this->img, $size, $rotation, $x, $y-1, $this->rgb($r,$g,$b), $font, $letter);
+      }
    }
 
+}
+
+
+
+
+
 
-   /* helper code */
-   public static function random_color($img, $a,$b) {
-      return imagecolorallocate($img, rand($a,$b), rand($a,$b), rand($a,$b));
+
+
+
+#-- arithmetic riddle
+class easy_captcha_text_math_formula extends easy_captcha {
+
+   var $question = "1+1";
+   var $solution = "2";
+
+   #-- set up
+   function easy_captcha_text_math_formula() {
+      $this->question = "What is " . $this->create_formula() . " = ";
+      $this->solution = $this->calculate_formula($this->question);
+      // we could do easier with iterated formula+result generation here, of course
+      // but I had this code handy already ;) and it's easier to modify
    }
 
+   #-- simple IS-EQUAL check
+   function solved($result) {
+      return (int)$this->solution == (int)$result;
+   }
 
-   /* unreversable hash from passphrase, with time() slice encoded */
-   public static function hash($text, $dtime=0) {
-      $text = strtolower($text);
-      $pfix = (int) (time() / CAPTCHA_TIMEOUT) + $dtime;
-      return md5("captcha::$pfix:$text::".__FILE__.":$_SERVER[SERVER_NAME]:80");
+   #-- make new captcha formula string
+   function create_formula() {
+      $formula = array(
+         rand(20,100) . " / " . rand(2,10),
+         rand(50,150) . " - " . rand(2,100),
+         rand( 2,100) . " + " . rand(2,100),
+         rand( 2, 15) . " * " . rand(2,12),
+         rand( 5, 10) . " * " . rand(5,10) . " - " . rand(1,20),
+         rand(30,100) . " + " . rand(5,99) . " - " . rand(1,50),
+   //    rand(20,100) . " / " . rand(2,10) . " + " . rand(1,50),
+      );
+      return $formula[rand(0,count($formula)-1)];
    }
 
+   #-- remove non-arithmetic characters
+   function clean($s) {
+      return preg_replace("/[^-+*\/\d]/", "", $s);
+   }
 
-   /* makes string of random letters for embedding into image and for
-      encoding as hash, later verification
-   */
-   public static function mkpass() {
-      $s = "";
-      for ($n=0; $n<10; $n++) {
-         $s .= chr(rand(0, 255));
+   #-- "solve" simple calculations
+   function calculate_formula($formula) {
+      preg_match("#^(\d+)([-+/*])(\d+)([-+/*])?(\d+)?$#", $this->clean($formula), $uu);
+      @list($uu, $X, $op1, $Y, $op2, $Z) = $uu;
+      if ($Y) $calc = array(
+        "/" => $X / $Y,  // PHP+ZendVM catches division by zero already, and CAPTCHA "attacker" would get no advantage herefrom anyhow
+        "*" => $X * $Y,
+        "+" => $X + $Y,
+        "-" => $X - $Y,
+        "*-" => $X * $Y - $Z,
+        "+-" => $X + $Y - $Z,
+        "/+" => $X / $Y + $Z,
+      );
+      return(  $calc[$op1.$op2] ? $calc[$op1.$op2] : rand(0,1<<23)  );
+   }
+
+}
+
+#-- to disable textual captcha part
+class easy_captcha_text_disable extends easy_captcha {
+   var $question = "";
+   function solved($in) {
+      return false;
+   }
+}
+
+
+
+
+
+
+
+
+#-- shortcut, allow access for an user if captcha was previously solved
+#   (should be identical in each instantiation, cookie is time-bombed)
+class easy_captcha_persistent_grant extends easy_captcha {
+
+   function easy_captcha_persistent_grant() {
+   }
+   
+
+   #-- give ok, if captach had already been solved recently
+   function solved($ignore=0) {
+      if (CAPTCHA_PERSISTENT && isset($_COOKIE[$this->cookie()])) {
+         return in_array($_COOKIE[$this->cookie()], array($this->validity_token(), $this->validity_token(-1)));
       }
-      $s = base64_encode($s);   // base64-set, but filter out unwanted chars
-      $s = preg_replace("/[+\/=IG0ODQR]/i", "", $s);  // (depends on YOUR font)
-      $s = substr($s, 0, rand(5,7));
-      return($s);
+   }
+   
+   #-- set captcha persistence cookie
+   function grant() {
+      if (!headers_sent()) {
+         setcookie($this->cookie(), $this->validity_token(), time() + 175*CAPTCHA_TIMEOUT);
+      }
+      else {
+         // $this->log("::grant", "COOKIES", "too late for cookies");
+      }
+   }
+
+   #-- pseudo password (time-bombed)
+   function validity_token($deviation=0) {
+      return easy_captcha::hash("PERSISTENCE", $deviation, $length=100);
+   }
+   function cookie() {
+      return "captcha_pass";
    }
 }
 
 
-#-- IE workaround
-if (isset($_REQUEST["_ddu"])) {
-   header("Content-Type: image/jpeg");
-   die(base64_decode(substr($_REQUEST["_ddu"], 0)));
+
+
+
+
+
+
+
+
+#-- simply check if no URLs were submitted - that's what most spambots do,
+#   and simply grant access then
+class easy_captcha_spamfree_no_new_urls {
+
+   #-- you have to adapt this, to check for newly added URLs only, in Wikis e.g.
+   #   - for simple comment submission forms, this default however suffices:
+   function solved($ignore=0) {
+      $r = !preg_match("#(https?://\w+[^/,.]+)#ims", serialize($_GET+$_POST), $uu);
+      return $r;
+   }
 }
 
 
+
+
+
+
+
+
+
+
+#-- "AJAX" and utility code
+class easy_captcha_utility {
+
+
+
+
+   #-- script was called directly
+   /*static*/ function API() {
+
+      #-- load data
+      if ($id = @$_GET[CAPTCHA_PARAM_ID]) {
+
+         #-- special case
+         if ($id == 'base.js') {
+            easy_captcha_utility::js_base();
+         }
+
+         else {
+            $c = new easy_captcha($id=NULL, $ignore_expiration=1);
+            $expired = !$c->is_valid();
+
+            #-- JS-RPC request, check entered solution on the fly
+            if ($test = @$_REQUEST[CAPTCHA_PARAM_INPUT]) {
+  
+               #-- check
+               if ($expired) {
+               }
+               if (0 >= $c->ajax_tries--) {
+                  $c->log("::API", "JS-RPC", "ajax_tries exhausted ($c->ajax_tries)");
+               }
+               $ok = $c->image->solved($test) || $c->text->solved($test);
+
+               #-- sendresult
+               easy_captcha_utility::js_rpc($ok);
+            }
+
+            #-- generate and send image file
+            else { 
+               if ($expired) {
+                  $type = "image/png";
+                  $bin = easy_captcha_utility::expired_png();
+               }
+               else {
+                  $type = "image/jpeg";
+                  $bin = $c->image->jpeg();
+               }
+               header("Pragma: no-cache");
+               header("Cache-Control: no-cache, no-store, must-revalidate, private");
+               header("Expires: " . gmdate("r", time()));
+               header("Content-Length: " . strlen($bin));
+               header("Content-Type: $type");
+               print $bin;
+            }
+         }
+         exit;
+      }
+   }
+
+   #-- hardwired error img
+   function expired_png() {
+      return base64_decode("iVBORw0KGgoAAAANSUhEUgAAADwAAAAUAgMAAACsbba6AAAADFBMVEUeEhFcMjGgWFf9jIrTTikpAAAACXBIWXMAAAsTAAALEwEAmpwYAAAA3UlEQVQY01XPzwoBcRAH8F9RjpSTm9xR9qQwtnX/latX0DrsA3gC8QDK0QO4bv7UOtmM+x4oZ4X5FQc1hlb41dR8mm/9ZhT/P7X/dDcpZPU3FYft9kWbLuWp4Bgt9v1oGG07Ja8ojfjxQFym02DVmoixkV/m2JI/TUtefR7nD9rkrhkC+6D77/8mUhDvw0ymLPwxf8esghEFRq8hqKcu2iG16Vlun1zYTO7RwCeFyoJqAgC3LQwzYiCokDj0MWRxb+Z6R8mPJb8Q77zlPbuCoJE8a/t7P773uv36tdcTmsXfRycoRJ8AAAAASUVORK5CYII=");
+   }
+
+
+
+
+
+   #-- send base javascript
+   function js_base() {
+      $captcha_new_urls = $_GET["captcha_new_urls"] ? 0 : 1;
+      $base_url = CAPTCHA_BASE_URL;
+      $param_id = "?" . CAPTCHA_PARAM_ID . "=";
+      $param_input = "&" . CAPTCHA_PARAM_INPUT . "=";
+      header("Content-Type: text/javascript");
+      print<<<END_____BASE__BASE__BASE__BASE__BASE__BASE__BASE__BASE_____END
+
+
+/* easy_captcha utility code */
+
+// global vars
+captcha_url_rx = /(https?:\/\/\w[^\/,\]\[=#]+)/ig;  //   
+captcha_form_urls = new Array();
+captcha_sol_cb = "";
+captcha_rpc = 0;
+
+// set up watchers
+if ($captcha_new_urls) {
+  window.setTimeout("captcha_form_urls = captcha_find_urls_in_form()", 500);
+  window.setInterval("captcha_spamfree_no_new_urls()", 3000);
+}
+
+// scans for URLs in any of the form fields
+function captcha_find_urls_in_form() {
+   var nf, ne, nv;
+   for (nf=0; nf<document.forms.length; nf++) {
+      for (ne=0; ne<document.forms[nf].elements.length; ne++) {
+         nv += "\\n" + document.forms[nf].elements[ne].value;
+      }
+   }
+   var r = nv.match(captcha_url_rx);
+   if (!r) { r = new Array(); }
+   return r;
+}
+// diff URL lists and hide captcha if nothing new was entered
+function captcha_spamfree_no_new_urls() {
+   var has_new_urls = captcha_find_urls_in_form().join(",") != captcha_form_urls.join(",");
+   var s = document.getElementById("captcha").style;
+   if (s.opacity) {
+      s.opacity = has_new_urls ? "0.9" : "0.1";
+   }
+   else {
+      s.display = has_new_urls ? "block" : "none";
+   }
+}
+
+// if a certain solution length is reached, check it remotely (JS-RPC)
+function captcha_check_solution() {
+   var cid = document.getElementById("__ec_i");
+   var inf = document.getElementById("__ec_s");
+   var len = inf.value.length;
+   // visualize processissing
+   if (len >= 4) {
+      inf.style.border = "2px solid #FF9955";
+   }
+   // if enough letters entered
+   if (len >= 5) {
+      // remove old <script> node
+      var scr;
+      if (src = document.getElementById("captcha_ajax_1")) {
+         src.parentNode.removeChild(src);
+      }
+      // create new <script> node, initiate JS-RPC call thereby
+      scr = document.createElement("script");
+      scr.setAttribute("language", "JavaScript");
+      scr.setAttribute("type", "text/javascript");
+      scr.setAttribute("src", "$base_url" + "$param_id" + cid.value + "$param_input" + inf.value);
+      scr.setAttribute("id", "captcha_ajax_1");
+      document.getElementById("captcha").appendChild(scr);
+      captcha_rpc = 1;
+   }
+   // visual feedback for editing
+   var col = 10 + len*3;
+   inf.style.background = "#"+col+col+col;
+}
+
+
+END_____BASE__BASE__BASE__BASE__BASE__BASE__BASE__BASE_____END;
+   }
+
+
+
+
+
+
+
+   #-- response javascript
+   function js_rpc($yes) {
+      $yes = $yes ? 1 : 0;
+      header("Content-Type: text/javascript");
+      print<<<END_____JSRPC__JSRPC__JSRPC__JSRPC__JSRPC__JSRPC_____END
+
+
+// JS-RPC response
+if (1) {
+   captcha_rpc = 0;
+   var inf = document.getElementById("__ec_s");
+   inf.style.borderColor = $yes ? "#22AA22" : "#AA2222";
+}
+
+
+END_____JSRPC__JSRPC__JSRPC__JSRPC__JSRPC__JSRPC_____END;
+   }
+
+
+
+}
+
+
+
+
+
+
+
 ?>
diff --git a/register.php b/register.php
index 28981e30..2ea93fc3 100644
--- a/register.php
+++ b/register.php
@@ -68,7 +68,7 @@ switch ($_REQUEST['action']) {
 
 		/* If we're using the captcha stuff */
 		if (Config::get('captcha_public_reg')) { 
-		    	$captcha 		= captcha::check(); 
+		    	$captcha 		= captcha::solved(); 
 			if(!isset ($captcha)) {
 				Error::add('captcha',_('Error Captcha Required'));
 			}