<?php

/*

 * Enano - an open-source CMS capable of wiki functions, Drupal-like sidebar blocks, and everything in between

 * Version 1.1.1

 * Copyright (C) 2006-2007 Dan Fuhry

 * captcha.php - visual confirmation system used during registration

 *

 * This program is Free Software; you can redistribute and/or modify it under the terms of the GNU General Public License

 * as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version.

 *

 * This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied

 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for details.

 *

 * This file contains code written by Paul Sohier (www.paulscripts.nl). The CAPTCHA code was ported from the phpBB Better

 * Captcha mod, and has been released under the GPLv2 by the original author.

 *

 * This file contains code written by the phpBB team (www.phpbb.com). phpBB is licensed under the GPLv2.

 */

class captcha

{

  var $chars, $confirm_id, $compat, $code, $captcha_config;

  function __construct($code)

  {

    global $db, $session, $paths, $template, $plugins; // Common objects

    // Check if GD exists, otherwise we will use the fallback phpBB confirm image

    $this->compat = false;

    if(!extension_loaded("gd")){

      $this->compat = true;

    }

    if(!function_exists("gd_info") || !function_exists('imagettftext')){

      $this->compat = true;

    }

    $this->code = $code;

    $hex = Array('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F');

    $latticecolor = '#';

    for($i=0;$i<6;$i++) $latticecolor .= $hex[mt_rand(0, 15)];

    $this->captcha_config = array (

      'width' => '350',

      'height' => '90',

      'background_color' => '#E5ECF9',

      'jpeg' => '0',

      'jpeg_quality' => '95',

      'pre_letters' => '1',

      'pre_letters_great' => '0',

      'font' => '1',

      'chess' => '2',

      'ellipses' => '2',

      'arcs' => '2',

      'lines' => '2',

      'image' => '0',

      'gammacorrect' => '0.8',

      'foreground_lattice_x' => (string)mt_rand(25, 30),

      'foreground_lattice_y' => (string)mt_rand(25, 30),

      'lattice_color' => $latticecolor,

    );

  }

  function captcha($code)

  {

    $this->__construct($code);    

  }

  function dss_rand()

  {

    global $db;

    $val = microtime() .  mt_rand();

    $val = md5($val . 'a');

    return substr($val, 4, 16);

  }

  function make_image()

  {

    $code=$this->code;

    if($this->compat)

    {

      // We can we will generate a single filtered png 

      // Thanks to DavidMJ for emulating zlib within the code :)

      $_png = $this->define_filtered_pngs();

      $total_width = 320;

      $total_height = 50;

      $img_height = 40;

      $img_width = 0;

      $l = 0;

      list($usec, $sec) = explode(' ', microtime()); 

      mt_srand($sec * $usec); 

      $char_widths = array();

      for ($i = 0; $i < strlen($code); $i++)

      {

        $char = $code{$i};

        $width = mt_rand(0, 4);

        $char_widths[] = $width;

        $img_width += $_png[$char]['width'] - $width;

      }

      $offset_x = mt_rand(0, $total_width - $img_width);

      $offset_y = mt_rand(0, $total_height - $img_height);

      $image = '';

      $hold_chars = array();

      for ($i = 0; $i < $total_height; $i++)

      {

        $image .= chr(0);

        if ($i > $offset_y && $i < $offset_y + $img_height)

        {

          $j = 0;

          for ($k = 0; $k < $offset_x; $k++)

          {

            $image .= chr(mt_rand(140, 255));

          }

          for ($k = 0; $k < strlen($code); $k++)

          {

            $char = $code{$k};

            if (empty($hold_chars[$char]))

            {

              $hold_chars[$char] = explode("\n", chunk_split(base64_decode($_png[$char]['data']), $_png[$char]['width'] + 1, "\n"));

            }

            $image .= $this->randomise(substr($hold_chars[$char][$l], 1), $char_widths[$j]);

            $j++;

          }

          for ($k = $offset_x + $img_width; $k < $total_width; $k++)

          {

            $image .= chr(mt_rand(140, 255));

          }

          $l++;

        }

        else

        {

          for ($k = 0; $k < $total_width; $k++)

          {

            $image .= chr(mt_rand(140, 255));

          }

        }

      }

      unset($hold);

      $image = $this->create_png($image, $total_width, $total_height);

      // Output image

      header('Content-Type: image/png');

      header('Cache-control: no-cache, no-store');

      echo $image;

      unset($image);

      unset($_png);

    } elseif(defined('ENANO_CAPTCHA_BIGNFAT')) {

      // Prefs

      $total_width = $this->captcha_config['width'];

      $total_height = $this->captcha_config['height'];

      $hex_bg_color = $this->get_rgb($this->captcha_config['background_color']);

      $bg_color = array();

      $bg_color = explode(",", $hex_bg_color);

      $jpeg = $this->captcha_config['jpeg'];

      $img_quality = $this->captcha_config['jpeg_quality'];

      // Max quality is 95

      $pre_letters = $this->captcha_config['pre_letters'];

      $pre_letter_great = $this->captcha_config['pre_letters_great'];

      $rnd_font = $this->captcha_config['font'];

      $chess = $this->captcha_config['chess'];

      $ellipses = $this->captcha_config['ellipses'];

      $arcs = $this->captcha_config['arcs'];

      $lines = $this->captcha_config['lines'];

      $image = $this->captcha_config['image'];

      $gammacorrect = $this->captcha_config['gammacorrect'];

      $foreground_lattice_y = $this->captcha_config['foreground_lattice_y'];

      $foreground_lattice_x = $this->captcha_config['foreground_lattice_x'];

      $hex_lattice_color = $this->get_rgb($this->captcha_config['lattice_color']);

      $rgb_lattice_color = array();

      $rgb_lattice_color = explode(",", $hex_lattice_color);

      $font_debug = false;

      // Fonts and images init

      if ($image)

      {

        $bg_imgs = array();

        if ($img_dir = opendir(ENANO_ROOT.'/includes/captcha/pics/'))

        {

          while (true == ($file = @readdir($img_dir))) 

          { 

            if ((substr(strtolower($file), -3) == 'jpg') || (substr(strtolower($file), -3) == 'gif'))    

            {         

              $bg_imgs[] = $file; 

            }     

          }

          closedir($img_dir);

        }

        // Grab a random Background Image or set FALSE if none was found

        $bg_img = ( count($bg_imgs) ) ? rand(0, (count($bg_imgs)-1)) : false;

      }

      $fonts = array();

      if ($fonts_dir = opendir(ENANO_ROOT.'/includes/captcha/fonts/'))

      {

        while (true == ($file = @readdir($fonts_dir))) 

        { 

          if ((substr(strtolower($file), strlen($file)-3, strlen($file)) == 'ttf'))

          {         

            $fonts[] = $file; 

          }     

        }

        closedir($fonts_dir);

      } else {

        die('Error reading directory: '.ENANO_ROOT.'/includes/captcha/fonts/');

      }

      $font = rand(0, (count($fonts)-1));

      // Generate

      $image = ($this->gdVersion() >= 2) ? imagecreatetruecolor($total_width, $total_height) : imagecreate($total_width, $total_height);

      $background_color = imagecolorallocate($image, $bg_color[0], $bg_color[1], $bg_color[2]);

      imagefill($image, 0, 0, $background_color);

      // Generate backgrund

      if ($chess == '1' || $chess == '2' && rand(0,1))

      {

        // Draw rectangles

        for($i = 0; $i <= 8; $i++)

        {

          $rectanglecolor = imagecolorallocate($image, rand(100,200),rand(100,200),rand(100,200));

          imagefilledrectangle($image, 0, 0, round($total_width-($total_width/8*$i)), round($total_height), $rectanglecolor);

          $rectanglecolor = imagecolorallocate($image, rand(100,200),rand(100,200),rand(100,200));

          imagefilledrectangle($image, 0, 0, round($total_width-($total_width/8*$i)), round($total_height/2), $rectanglecolor);

        }

      }

      if ($ellipses == '1' || $ellipses == '2' && rand(0,1))

      {

        // Draw random ellipses

        for ($i = 1; $i <= 60; $i++)

        {

          $ellipsecolor = imagecolorallocate($image, rand(100,250),rand(100,250),rand(100,250));

          imagefilledellipse($image, round(rand(0, $total_width)), round(rand(0, $total_height)), round(rand(0, $total_width/8)), round(rand(0, $total_height/4)), $ellipsecolor);	

        }

      }

      if ($arcs == '1' || $arcs == '2' && rand(0,1))

      {

        // Draw random partial ellipses

        for ($i = 0; $i <= 30; $i++)

        {

          $linecolor = imagecolorallocate($image, rand(120,255),rand(120,255),rand(120,255));

          $cx = round(rand(1, $total_width));

          $cy = round(rand(1, $total_height));

          $int_w = round(rand(1, $total_width/2));

          $int_h = round(rand(1, $total_height));

          imagearc($image, $cx, $cy, $int_w, $int_h, round(rand(0, 190)), round(rand(191, 360)), $linecolor);

          imagearc($image, $cx-1, $cy-1, $int_w, $int_h, round(rand(0, 190)), round(rand(191, 360)), $linecolor);

        }

      }

      if ($lines == '1' || $lines == '2' && rand(0,1))

      {

        // Draw random lines

        for ($i = 0; $i <= 50; $i++)

        {

          $linecolor = imagecolorallocate($image, rand(120,255),rand(120,255),rand(120,255));

          imageline($image, round(rand(1, $total_width*3)), round(rand(1, $total_height*5)), round(rand(1, $total_width/2)), round(rand(1, $total_height*2)), $linecolor);

        }

      }

      $text_color_array = array('255,51,0', '51,77,255', '204,51,102', '0,153,0', '255,166,2', '255,0,255', '255,0,0', '0,255,0', '0,0,255', '0,255,255');

      shuffle($text_color_array);

      $pre_text_color_array = array('255,71,20', '71,20,224', '224,71,122', '20,173,20', '255,186,22', '25,25,25');

      shuffle($pre_text_color_array);

      $white = imagecolorallocate($image, 255, 255, 255);

      $gray = imagecolorallocate($image, 100, 100, 100);

      $black = imagecolorallocate($image, 0, 0, 0);

      $lattice_color = imagecolorallocate($image, $rgb_lattice_color[0], $rgb_lattice_color[1], $rgb_lattice_color[2]);

      $x_char_position = (round(($total_width - 12) / strlen($code)) + mt_rand(-3, 5));

      for ($i = 0; $i < strlen($code); $i++)

      {

        mt_srand((double)microtime()*1000000);

        $char = $code{$i};

        $size = mt_rand(floor($total_height / 3.5), ceil($total_height / 2.8));

        $font = ($rnd_font) ? rand(0, (count($fonts)-1)) : $font;

        $angle = mt_rand(-30, 30);

        $char_pos = array();

        $char_pos = imagettfbbox($size, $angle, ENANO_ROOT.'/includes/captcha/fonts/'.$fonts[$font], $char);

        $letter_width = abs($char_pos[0]) + abs($char_pos[4]);

        $letter_height = abs($char_pos[1]) + abs($char_pos[5]);

        $x_pos = ($x_char_position / 4) + ($i * $x_char_position);

        ($i == strlen($code)-1 && $x_pos >= ($total_width - ($letter_width + 5))) ? $x_pos = ($total_width - ($letter_width + 5)) : '';

        $y_pos = mt_rand(($size * 1.4 ), $total_height - ($size * 0.4));

      //	Pre letters

        $size = ($pre_letter_great) ? $size + (2 * $pre_letters) : $size - (2 * $pre_letters);

        for ($count = 1; $count <= $pre_letters; $count++)

        {

          $pre_angle = $angle + mt_rand(-20, 20);

          $text_color = $pre_text_color_array[mt_rand(0,count($pre_text_color_array)-1)];

          $text_color = explode(",", $text_color);

          $textcolor = imagecolorallocate($image, $text_color[0], $text_color[1], $text_color[2]);

          imagettftext($image, $size, $pre_angle, $x_pos, $y_pos-2, $white, ENANO_ROOT.'/includes/captcha/fonts/'.$fonts[$font], $char);

          imagettftext($image, $size, $pre_angle, $x_pos+2, $y_pos, $black, ENANO_ROOT.'/includes/captcha/fonts/'.$fonts[$font], $char);

          imagettftext($image, $size, $pre_angle, $x_pos+1, $y_pos-1, $textcolor, ENANO_ROOT.'/includes/captcha/fonts/'.$fonts[$font], $char);

          $size = ($pre_letter_great) ? $size - 2 : $size + 2;

        }

      //	Final letters

        $text_color = $text_color_array[mt_rand(0,count($text_color_array)-1)];

        $text_color = explode(",", $text_color);

        $textcolor = imagecolorallocate($image, $text_color[0], $text_color[1], $text_color[2]);

        imagettftext($image, $size, $angle, $x_pos, $y_pos-2, $white, ENANO_ROOT.'/includes/captcha/fonts/'.$fonts[$font], $char);

        imagettftext($image, $size, $angle, $x_pos+2, $y_pos, $black, ENANO_ROOT.'/includes/captcha/fonts/'.$fonts[$font], $char);

        imagettftext($image, $size, $angle, $x_pos+1, $y_pos-1, $textcolor, ENANO_ROOT.'/includes/captcha/fonts/'.$fonts[$font], $char);

      }

      ($gammacorrect) ? imagegammacorrect($image, 1.0, $gammacorrect) : '';

      // Generate a white lattice in foreground

      if ($foreground_lattice_y)

      {

        // x lines

        $ih = round($total_height / $foreground_lattice_y);

        for ($i = 0; $i <= $ih; $i++)

        {

          imageline($image, 0, $i*$foreground_lattice_y, $total_width, $i*$foreground_lattice_y, $lattice_color);

        }

      }

      if ($foreground_lattice_x)

      {

        // y lines

        $iw = round($total_width / $foreground_lattice_x);

        for ($i = 0; $i <= $iw; $i++)

        {

          imageline($image, $i*$foreground_lattice_x, 0, $i*$foreground_lattice_x, $total_height, $lattice_color);

        }

      }

      // Font debug

      if ($font_debug && !$rnd_font)

      {

        imagestring($image, 5, 2, 0, $fonts[$font], $white);

        imagestring($image, 5, 5, 0, $fonts[$font], $white);

        imagestring($image, 5, 4, 2, $fonts[$font], $gray);

        imagestring($image, 5, 3, 1, $fonts[$font], $black);

      }

      // Display

      header("Last-Modified: " . gmdate("D, d M Y H:i:s") ." GMT"); 

      header("Pragma: no-cache"); 

      header("Cache-Control: no-store, no-cache, max-age=0, must-revalidate");

      (!$jpeg) ? header("Content-Type: image/png") : header("Content-Type: image/jpeg");

      (!$jpeg) ? imagepng($image) : imagejpeg($image, '', $img_quality);

      imagedestroy($image);

    } else {

      /**

        * The next part is orginnaly written by ted from mastercode.nl and modified for use in Enano.

        **/

      header("content-type:image/png");

      header('Cache-control: no-cache, no-store');

      $breedte = 320;

      $hoogte = 60;

      $img = imagecreatetruecolor($breedte,$hoogte);

      $achtergrond = imagecolorallocate($img, $this->color("bg"), $this->color("bg"), $this->color("bg"));

      imagefilledrectangle($img, 0, 0, $breedte-1, $hoogte-1, $achtergrond);

      for($g = 0;$g < 30; $g++)

      {

        $t = $this->dss_rand();

        $t = $t[0];

        $ypos = rand(0,$hoogte);

        $xpos = rand(0,$breedte);

        $kleur = imagecolorallocate($img, $this->color("bgtekst"), $this->color("bgtekst"), $this->color("bgtekst"));

        imagettftext($img, $this->size(), $this->move(), $xpos, $ypos, $kleur, $this->font(), $t);

      } 			

      $stukje = $breedte / (strlen($code) + 3);

      for($j = 0;$j < strlen($code); $j++)

      {

        $tek = $code[$j];

        $ypos = rand(33,43);

        $xpos = $stukje * ($j+1);

        $kleur2 = imagecolorallocate($img, $this->color("tekst"), $this->color("tekst"), $this->color("tekst"));

        imagettftext($img, $this->size(), $this->move(), $xpos, $ypos, $kleur2, $this->font() , $tek);

      }

      imagepng($img);

    }

  }

  /**

    * Some functions :)

    * Also orginally written by mastercode.nl

    **/

  /**

    * Function to create a random color

    * @param $type string Mode for the color

    * @return int

    **/

  function color($type)

  {

    switch($type)

    {

      case "bg": 

        $kleur = rand(224,255); 

      break;

      case "tekst": 

        $kleur = rand(0,127); 

      break;

      case "bgtekst": 

        $kleur = rand(200,224); 

      break;

      default: 

        $kleur = rand(0,255); 

      break;

    }

    return $kleur;

  }

  /**

    * Function to ranom the size

    * @return int

    **/

  function size()

  {

    $grootte = rand(14,30);

    return $grootte;

  }

  /**

    * Function to random the posistion

    * @return int

    **/

  function move()

  {

    $draai = rand(-25,25);

    return $draai;

  }

  /**

    * Function to return a ttf file from fonts map

    * @return string

    **/

  function font()

  {

    $f = @opendir(ENANO_ROOT . '/includes/captcha/fonts/');

    if(!$f) die('Can\'t open '.ENANO_ROOT.'/includes/captcha/fonts/ for reading');

    $ar = array();

    while(($file = @readdir($f)) !== false)

    {

      if(!in_array($file, array('.','..')) && strstr($file, '.ttf'))

      {

        $ar[] = $file;

      }

    }

    if(count($ar))

    {

      shuffle($ar);

      $i = rand(0,(count($ar) - 1));

      return ENANO_ROOT . '/includes/captcha/fonts/' . $ar[$i];

    }

  }

  // This is designed to randomise the pixels of the image data within

  // certain limits so as to keep it readable. It also varies the image

  // width a little

  function randomise($scanline, $width)

  {

    $new_line = '';

    $start = floor($width/2);

    $end = strlen($scanline) - ceil($width/2);

    for ($i = $start; $i < $end; $i++)

    {

      $pixel = ord($scanline{$i});

      if ($pixel < 190)

      {

        $new_line .= chr(mt_rand(0, 205));

      }

      else if ($pixel > 190)

      {

        $new_line .= chr(mt_rand(145, 255));

      }

      else

      {

        $new_line .= $scanline{$i};

      }

    }

    return $new_line;

  }

  // This creates a chunk of the given type, with the given data

  // of the given length adding the relevant crc

  function png_chunk($length, $type, $data)

  {

    $raw = $type;

    $raw .= $data;

    $crc = crc32($raw);

    $raw .= pack('C4', $crc >> 24, $crc >> 16, $crc >> 8, $crc);

    return pack('C4', $length >> 24, $length >> 16, $length >> 8, $length) . $raw;

  }

  // Creates greyscale 8bit png - The PNG spec can be found at

  // http://www.libpng.org/pub/png/spec/PNG-Contents.html we use