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   1  <?php
   2  /* ----------------------------------------------------------------------------
   3    SPAF_FormValidator.class.php
   4   ------------------------------------------------------------------------------
   5    version  : 1.01
   6    author   : martynas@solmetra.com
   7   ------------------------------------------------------------------------------
   8    Form validation class
   9   --------------------------------------------------------------------------- */
  10   
  11  class SPAF_FormValidator {
  12    // {{{
  13    // !!! EDITABLE CONFIGURATION ===============================================
  14    var $lib_dir      = 'lib/';
  15    var $backgrounds  = array('01.png', '02.png', '03.png', '04.png', '05.png', 
  16                              '06.png', '07.png', '08.png', '09.png', '10.png', 
  17                              '11.png', '12.png');
  18    var $fonts        = array('solmetra1.ttf', 'solmetra2.ttf', 'solmetra3.ttf', 
  19                              'solmetra4.ttf');
  20    var $font_sizes   = array(13, 14, 15);
  21    var $colors       = array(
  22      array(221, 27, 27),
  23      array(94, 71, 212),
  24      array(212, 71, 210),
  25      array(8, 171, 0),
  26      array(234, 142, 0)
  27    );
  28    var $shadow_color = array(255, 255, 255);
  29    var $hide_shadow  = false;
  30    var $char_num     = 5;
  31    var $chars        = array('A', 'C', 'D', 'E', 'F', 'H', 'J', 'K', 'L', 'M', 
  32                              'N', 'O', 'P', 'R', 'S', 'T', 'Y', '3', '4', '6', 
  33                              '7', '9');
  34    var $session_var  = 'spaf_form_validator_tag';
  35    
  36    var $no_session   = false;  // If this is set to true following config 
  37                                // variables must also be set
  38    
  39    var $work_dir     = 'work'; // If $no_session is set to true set this variable
  40                                // to the directory in which FormValidator will 
  41                                // create its temporary files.
  42                                // If path begins with a backslash (i.e. /tmp), 
  43                                // FormValidator will assume it's an absolute path
  44                                // Otherwise path will be treated as relative to
  45                                // FormValidator class location. 
  46                                // Please note that this directory must be 
  47                                // writable to PHP scripts.
  48    
  49    var $work_ext     = 'spaf'; // An extention to use for temporary work files
  50    
  51    var $tag_ttl      = 120;    // Number of minutes to consider user tag valid  
  52                                // Used only in conjunction with: 
  53                                // $no_session = true
  54    
  55    var $tag_cookie   = 'spaf_formvalidator'; // the name of cookie to be used 
  56                                              // for tagging a user 
  57    
  58    var $gc_prob      = 1;      // Percental probability for garbage collector to
  59                                // launch per each instance of FormValidator 
  60                                // class. Garbage collector is needed to remove
  61                                // old user tag files from disk if you use 
  62                                // $no_session = true
  63                                // 0 means GC will never launch
  64                                // 100 means GC will launch everytime you 
  65                                // instantiate this class 
  66    
  67    // !!! DO NOT CHANGE ANYTHING BELOW THIS LINE ===============================
  68    // }}}
  69    // {{{
  70    var $img_func_suffix = 'png';
  71    // }}}
  72    // {{{
  73    function SPAF_FormValidator () {
  74      // set properties that might have been accidentally removed
  75      if (!isset($this->session_var)) { $this->session_var = 'spaf_formvalidator'; }
  76      if (!isset($this->no_session))  { $this->no_session = false; }
  77      
  78      // below tasks are only required if $no_session is set to true
  79      if (isset($this->no_session) && $this->no_session) {
  80        // set class directory if none specified
  81        if ($this->work_dir == '') {
  82          $this->work_dir = dirname(__FILE__).'/';
  83        }
  84        // set a relative path
  85        elseif (substr($this->work_dir, 0, 1) != '/') {
  86          $this->work_dir = dirname(__FILE__).'/'.$this->work_dir;
  87        }
  88        
  89        // add backslash at the end of path if necessary
  90        if (substr($this->work_dir, -1) != '/') {
  91          $this->work_dir .= '/';
  92        }
  93        
  94        // launch garbage collector
  95        if (mt_rand(1, 100) < $this->gc_prob) {
  96          $this->launchGC();
  97        }
  98      }
  99      // tasks that are required for session enabled operation
 100      else {
 101        // check if session is started
 102        if (!isset($_SESSION)) {
 103          session_start();
 104        }
 105      }
 106    }
 107    // }}}
 108    // {{{
 109    function setLibDir ($dir) {
 110      $this->lib_dir = $dir;
 111    }
 112    // }}}
 113    // {{{
 114    function tagUser () {
 115      if ($this->no_session) {
 116        // generate validation word and secret identity cookie
 117        $tag = $this->getRandomString($this->char_num);
 118        $cookie = md5(microtime().$_SERVER['REMOTE_ADDR']);
 119        
 120        // set cookie
 121        setcookie($this->tag_cookie, $cookie, 0, '/');
 122        $_COOKIE[$this->tag_cookie] = $cookie;
 123        
 124        // write to a file
 125        $this->writeFile($this->work_dir.$cookie.'.'.$this->work_ext, $tag);
 126      }
 127      else {
 128        // set session variable
 129        // ATTENTION! Session must be already started with session_start()
 130        $_SESSION[$this->session_var] = $this->getRandomString($this->char_num);
 131      }
 132      return true;
 133    }
 134    // }}}
 135    // {{{
 136    function getUserTag () {
 137      // get current tag
 138      if ($this->no_session) {
 139        if (!isset($_COOKIE[$this->tag_cookie]) || isset($_GET['regen'])) {
 140          // user is not tagged - issue new tag
 141          $this->tagUser();
 142        }
 143        
 144        // get the work file
 145        if (!file_exists($this->work_dir.$_COOKIE[$this->tag_cookie].'.'.$this->work_ext)) {
 146          // file does not exist - reissue the tag once again to recreate the file
 147          $this->tagUser();
 148        }
 149        return @file_get_contents($this->work_dir.$_COOKIE[$this->tag_cookie].'.'.$this->work_ext);
 150      }
 151      else {
 152        if (!isset($_SESSION[$this->session_var]) || isset($_GET['regen'])) {
 153          // user is not tagged - issue new tag
 154          $this->tagUser();
 155        }
 156        return $_SESSION[$this->session_var];
 157      }
 158    }
 159    // }}}
 160    // {{{
 161    function validRequest ($req) {
 162      return strtolower($this->getUserTag()) == strtolower($req)
 163        ? true 
 164        : false;
 165    }
 166    // }}}
 167    // {{{
 168    function getRandomString ($chars = 5) {
 169      $str = '';
 170      $cnt = sizeof($this->chars);
 171      for ($i = 0; $i < $chars; $i++) {
 172        $str .= $this->chars[mt_rand(0, $cnt-1)];
 173      }
 174      return $str;
 175    }
 176    // }}}
 177    // {{{
 178    function streamImage () {
 179      // select random background
 180      $background = $this->backgrounds[mt_rand(0, sizeof($this->backgrounds)-1)];
 181      
 182      // set proper image format according to selected background image
 183      $this->setImageFormat($background);
 184      
 185      // create image resource
 186      $function = "imagecreatefrom".$this->img_func_suffix;
 187      $image = $function($this->lib_dir.$background);
 188      
 189      // create color resources
 190      $colors = array();
 191      $color_count = sizeof($this->colors);
 192      for ($i = 0; $i < $color_count; $i++) {
 193        $colors[] = imagecolorallocate($image, 
 194                                       $this->colors[$i][0], 
 195                                       $this->colors[$i][1], 
 196                                       $this->colors[$i][2]);
 197      }
 198      $shadow = imagecolorallocate($image, 
 199                                   $this->shadow_color[0], 
 200                                   $this->shadow_color[1], 
 201                                   $this->shadow_color[2]);
 202      
 203      // get secret word from session
 204      $word = $this->getUserTag();
 205      
 206      // calculate geometrics
 207      $width  = imagesx($image);
 208      $height = imagesy($image);
 209      $lenght = strlen($word);
 210      $step   = floor(($width / $lenght) * 0.9);
 211  
 212      // put letters on background
 213      for ($i = 0; $i < $lenght; $i++) {
 214        // get current character
 215        $char = substr($word, $i, 1);
 216  
 217        // randomize letter display characteristics
 218        $font_size = $this->font_sizes[mt_rand(0, sizeof($this->font_sizes)-1)];
 219        $data = array(
 220          'size'  => $font_size,
 221          'angle' => mt_rand(-20, 20),
 222          'x'     => $step * $i + 5,
 223          'y'     => mt_rand($font_size+5, $height-5 ),
 224          'color' => $colors[mt_rand(0, $color_count-1)],
 225          'font'  => $this->lib_dir.$this->fonts[mt_rand(0, sizeof($this->fonts)-1)]
 226        );
 227        
 228        // put a shadow
 229        if (!isset($this->hide_shadow) || !$this->hide_shadow) {
 230        
 231          imagettftext($image, 
 232                       $font_size, 
 233                       $data['angle'], 
 234                       $data['x'] + 1, 
 235                       $data['y'] + 1, 
 236                       $shadow, 
 237                       $data['font'], 
 238                       $char);
 239  
 240        }
 241  
 242        // put a letter
 243        imagettftext($image, 
 244                     $font_size, 
 245                     $data['angle'], 
 246                     $data['x'], 
 247                     $data['y'], 
 248                     $data['color'], 
 249                     $data['font'], 
 250                     $char);
 251      }
 252      
 253      // stream image to browser
 254      $function = "image".$this->img_func_suffix;
 255  
 256      header('Content-Type: image/'.$this->img_func_suffix);
 257      $function($image);
 258      imagedestroy($image);
 259      
 260      return true;
 261    } 
 262    // }}}
 263    // {{{
 264    function setImageFormat ($file) {
 265      // get extention
 266      $arr = explode('.', $file);
 267      $ext = strtolower($arr[sizeof($arr) - 1]);
 268      
 269      // set appropriate formats
 270      switch ($ext) {
 271        case 'gif':
 272        case 'png':
 273        case 'jpeg':
 274          $this->img_func_suffix = $ext;
 275          break;
 276        case 'jpg':
 277          $this->img_func_suffix = 'jpeg';
 278          break;
 279        default:
 280          // critical error - unsupported format
 281          die('ERROR: Unsupported format!');
 282          break;
 283      }
 284    }
 285    // }}}
 286    // {{{
 287    function destroy () {
 288      if ($this->no_session) {
 289        // remove physical file and cookie
 290        @unlink($this->work_dir.$_COOKIE[$this->tag_cookie].'.'.$this->work_ext);
 291        unset($_COOKIE[$this->tag_cookie]);
 292        setcookie($this->tag_cookie, '', 0, '/');
 293      }
 294      else {
 295        // remove session variable
 296        unset($_SESSION[$this->session_var]);
 297      }
 298      return true;
 299    }
 300    // }}}
 301    // {{{
 302    function launchGC () {
 303      // open work directory
 304      if ($dir = @opendir($this->work_dir)) {
 305        // check each file
 306        while (false !== ($file = @readdir($dir))) { 
 307          $fdata = pathinfo($file);
 308          if (
 309              $fdata['extension'] == $this->work_ext
 310              &&
 311              (filemtime($this->work_dir.$file) < (time() - ($this->tag_ttl * 60)))
 312             )
 313          {
 314            // remove expired file
 315            @unlink($this->work_dir.$file);
 316          }
 317        }
 318        @closedir($dir); 
 319      }
 320      return true;
 321    }
 322    // }}}
 323    // {{{
 324    function writeFile ($file, $content) {
 325      $fl = @fopen($file, 'w');
 326      $ret = @fwrite($fl, $content);
 327      @fclose($fl);
 328      return $ret;
 329    }
 330    // }}}
 331  }   
 332  ?>