inc/captcha.php

   1 <?php
   2    /***************************************************************/
   3    /* PhpCaptcha - A visual and audio CAPTCHA generation library
   4
   5       Software License Agreement (BSD License)
   6
   7       Copyright (C) 2005-2006, Edward Eliot.
   8       All rights reserved.
   9
  10       Redistribution and use in source and binary forms, with or without
  11       modification, are permitted provided that the following conditions are met:
  12
  13          * Redistributions of source code must retain the above copyright
  14            notice, this list of conditions and the following disclaimer.
  15          * Redistributions in binary form must reproduce the above copyright
  16            notice, this list of conditions and the following disclaimer in the
  17            documentation and/or other materials provided with the distribution.
  18          * Neither the name of Edward Eliot nor the names of its contributors
  19            may be used to endorse or promote products derived from this software
  20            without specific prior written permission of Edward Eliot.
  21
  22       THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS IS" AND ANY
  23       EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
  24       WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
  25       DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY
  26       DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
  27       (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
  28       LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
  29       ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  30       (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
  31       SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  32
  33       Last Updated:  18th April 2006                               */
  34    /***************************************************************/
  35
  36    /************************ Documentation ************************/
  37    /*
  38
  39    Documentation is available at http://www.ejeliot.com/pages/2
  40
  41    */
  42    /************************ Default Options **********************/
  43
  44    // start a PHP session - this class uses sessions to store the generated
  45    // code. Comment out if you are calling already from your application
  46    //session_start();
  47
  48    // class defaults - change to effect globally
  49
  50    define('CAPTCHA_SESSION_ID', 'php_captcha');
  51    define('CAPTCHA_WIDTH', 200); // max 500
  52    define('CAPTCHA_HEIGHT', 50); // max 200
  53    define('CAPTCHA_NUM_CHARS', 5);
  54    define('CAPTCHA_NUM_LINES', 70);
  55    define('CAPTCHA_CHAR_SHADOW', false);
  56    define('CAPTCHA_OWNER_TEXT', '');
  57    define('CAPTCHA_CHAR_SET', ''); // defaults to A-Z
  58    define('CAPTCHA_CASE_INSENSITIVE', true);
  59    define('CAPTCHA_BACKGROUND_IMAGES', '');
  60    define('CAPTCHA_MIN_FONT_SIZE', 16);
  61    define('CAPTCHA_MAX_FONT_SIZE', 25);
  62    define('CAPTCHA_USE_COLOUR', false);
  63    define('CAPTCHA_FILE_TYPE', 'jpeg');
  64    define('CAPTCHA_FLITE_PATH', '/usr/bin/flite');
  65    define('CAPTCHA_AUDIO_PATH', '/tmp/'); // must be writeable by PHP process
  66
  67    /************************ End Default Options **********************/
  68
  69    // don't edit below this line (unless you want to change the class!)
  70
  71    class PhpCaptcha {
  72       var $oImage;
  73       var $aFonts;
  74       var $iWidth;
  75       var $iHeight;
  76       var $iNumChars;
  77       var $iNumLines;
  78       var $iSpacing;
  79       var $bCharShadow;
  80       var $sOwnerText;
  81       var $aCharSet;
  82       var $bCaseInsensitive;
  83       var $vBackgroundImages;
  84       var $iMinFontSize;
  85       var $iMaxFontSize;
  86       var $bUseColour;
  87       var $sFileType;
  88       var $sCode = '';
  89
  90       function PhpCaptcha(
  91          $aFonts, // array of TrueType fonts to use - specify full path
  92          $iWidth = CAPTCHA_WIDTH, // width of image
  93          $iHeight = CAPTCHA_HEIGHT // height of image
  94       ) {
  95          // get parameters
  96          $this->aFonts = $aFonts;
  97          $this->SetNumChars(CAPTCHA_NUM_CHARS);
  98          $this->SetNumLines(CAPTCHA_NUM_LINES);
  99          $this->DisplayShadow(CAPTCHA_CHAR_SHADOW);
 100          $this->SetOwnerText(CAPTCHA_OWNER_TEXT);
 101          $this->SetCharSet(CAPTCHA_CHAR_SET);
 102          $this->CaseInsensitive(CAPTCHA_CASE_INSENSITIVE);
 103          $this->SetBackgroundImages(CAPTCHA_BACKGROUND_IMAGES);
 104          $this->SetMinFontSize(CAPTCHA_MIN_FONT_SIZE);
 105          $this->SetMaxFontSize(CAPTCHA_MAX_FONT_SIZE);
 106          $this->UseColour(CAPTCHA_USE_COLOUR);
 107          $this->SetFileType(CAPTCHA_FILE_TYPE);
 108          $this->SetWidth($iWidth);
 109          $this->SetHeight($iHeight);
 110       }
 111
 112       function CalculateSpacing() {
 113          $this->iSpacing = (int)($this->iWidth / $this->iNumChars);
 114       }
 115
 116       function SetWidth($iWidth) {
 117          $this->iWidth = $iWidth;
 118          if ($this->iWidth > 500) $this->iWidth = 500; // to prevent perfomance impact
 119          $this->CalculateSpacing();
 120       }
 121
 122       function SetHeight($iHeight) {
 123          $this->iHeight = $iHeight;
 124          if ($this->iHeight > 200) $this->iHeight = 200; // to prevent performance impact
 125       }
 126
 127       function SetNumChars($iNumChars) {
 128          $this->iNumChars = $iNumChars;
 129          $this->CalculateSpacing();
 130       }
 131
 132       function SetNumLines($iNumLines) {
 133          $this->iNumLines = $iNumLines;
 134       }
 135
 136       function DisplayShadow($bCharShadow) {
 137          $this->bCharShadow = $bCharShadow;
 138       }
 139
 140       function SetOwnerText($sOwnerText) {
 141          $this->sOwnerText = $sOwnerText;
 142       }
 143
 144       function SetCharSet($vCharSet) {
 145          // check for input type
 146          if (is_array($vCharSet)) {
 147             $this->aCharSet = $vCharSet;
 148          } else {
 149             if ($vCharSet != '') {
 150                // split items on commas
 151                $aCharSet = explode(',', $vCharSet);
 152
 153                // initialise array
 154                $this->aCharSet = array();
 155
 156                // loop through items
 157                foreach ($aCharSet as $sCurrentItem) {
 158                   // a range should have 3 characters, otherwise is normal character
 159                   if (strlen($sCurrentItem) == 3) {
 160                      // split on range character
 161                      $aRange = explode('-', $sCurrentItem);
 162
 163                      // check for valid range
 164                      if (count($aRange) == 2 && $aRange[0] < $aRange[1]) {
 165                         // create array of characters from range
 166                         $aRange = range($aRange[0], $aRange[1]);
 167
 168                         // add to charset array
 169                         $this->aCharSet = array_merge($this->aCharSet, $aRange);
 170                      }
 171                   } else {
 172                      $this->aCharSet[] = $sCurrentItem;
 173                   }
 174                }
 175             }
 176          }
 177       }
 178
 179       function CaseInsensitive($bCaseInsensitive) {
 180          $this->bCaseInsensitive = $bCaseInsensitive;
 181       }
 182
 183       function SetBackgroundImages($vBackgroundImages) {
 184          $this->vBackgroundImages = $vBackgroundImages;
 185       }
 186
 187       function SetMinFontSize($iMinFontSize) {
 188          $this->iMinFontSize = $iMinFontSize;
 189       }
 190
 191       function SetMaxFontSize($iMaxFontSize) {
 192          $this->iMaxFontSize = $iMaxFontSize;
 193       }
 194
 195       function UseColour($bUseColour) {
 196          $this->bUseColour = $bUseColour;
 197       }
 198
 199       function SetFileType($sFileType) {
 200          // check for valid file type
 201          if (in_array($sFileType, array('gif', 'png', 'jpeg'))) {
 202             $this->sFileType = $sFileType;
 203          } else {
 204             $this->sFileType = 'jpeg';
 205          }
 206       }
 207
 208       function DrawLines() {
 209          for ($i = 0; $i < $this->iNumLines; $i++) {
 210             // allocate colour
 211             if ($this->bUseColour) {
 212                $iLineColour = imagecolorallocate($this->oImage, rand(100, 250), rand(100, 250), rand(100, 250));
 213             } else {
 214                $iRandColour = rand(100, 250);
 215                $iLineColour = imagecolorallocate($this->oImage, $iRandColour, $iRandColour, $iRandColour);
 216             }
 217
 218             // draw line
 219             imageline($this->oImage, rand(0, $this->iWidth), rand(0, $this->iHeight), rand(0, $this->iWidth), rand(0, $this->iHeight), $iLineColour);
 220          }
 221       }
 222
 223       function DrawOwnerText() {
 224          // allocate owner text colour
 225          $iBlack = imagecolorallocate($this->oImage, 0, 0, 0);
 226          // get height of selected font
 227          $iOwnerTextHeight = imagefontheight(2);
 228          // calculate overall height
 229          $iLineHeight = $this->iHeight - $iOwnerTextHeight - 4;
 230
 231          // draw line above text to separate from CAPTCHA
 232          imageline($this->oImage, 0, $iLineHeight, $this->iWidth, $iLineHeight, $iBlack);
 233
 234          // write owner text
 235          imagestring($this->oImage, 2, 3, $this->iHeight - $iOwnerTextHeight - 3, $this->sOwnerText, $iBlack);
 236
 237          // reduce available height for drawing CAPTCHA
 238          $this->iHeight = $this->iHeight - $iOwnerTextHeight - 5;
 239       }
 240
 241       function GenerateCode() {
 242          // reset code
 243          $this->sCode = '';
 244
 245          // loop through and generate the code letter by letter
 246          for ($i = 0; $i < $this->iNumChars; $i++) {
 247             if (count($this->aCharSet) > 0) {
 248                // select random character and add to code string
 249                $this->sCode .= $this->aCharSet[array_rand($this->aCharSet)];
 250             } else {
 251                // select random character and add to code string
 252                $this->sCode .= chr(rand(65, 90));
 253             }
 254          }
 255
 256          // save code in session variable
 257          if ($this->bCaseInsensitive) {
 258             $_SESSION[CAPTCHA_SESSION_ID] = strtoupper($this->sCode);
 259          } else {
 260             $_SESSION[CAPTCHA_SESSION_ID] = $this->sCode;
 261          }
 262       }
 263
 264       function DrawCharacters() {
 265          // loop through and write out selected number of characters
 266          for ($i = 0; $i < strlen($this->sCode); $i++) {
 267             // select random font
 268             $sCurrentFont = $this->aFonts[array_rand($this->aFonts)];
 269
 270             // select random colour
 271             if ($this->bUseColour) {
 272                $iTextColour = imagecolorallocate($this->oImage, rand(0, 100), rand(0, 100), rand(0, 100));
 273
 274                if ($this->bCharShadow) {
 275                   // shadow colour
 276                   $iShadowColour = imagecolorallocate($this->oImage, rand(0, 100), rand(0, 100), rand(0, 100));
 277                }
 278             } else {
 279                $iRandColour = rand(0, 100);
 280                $iTextColour = imagecolorallocate($this->oImage, $iRandColour, $iRandColour, $iRandColour);
 281
 282                if ($this->bCharShadow) {
 283                   // shadow colour
 284                   $iRandColour = rand(0, 100);
 285                   $iShadowColour = imagecolorallocate($this->oImage, $iRandColour, $iRandColour, $iRandColour);
 286                }
 287             }
 288
 289             // select random font size
 290             $iFontSize = rand($this->iMinFontSize, $this->iMaxFontSize);
 291
 292             // select random angle
 293             $iAngle = rand(-30, 30);
 294
 295             // get dimensions of character in selected font and text size
 296             $aCharDetails = imageftbbox($iFontSize, $iAngle, $sCurrentFont, $this->sCode[$i], array());
 297
 298             // calculate character starting coordinates
 299             $iX = $this->iSpacing / 4 + $i * $this->iSpacing;
 300             $iCharHeight = $aCharDetails[2] - $aCharDetails[5];
 301             $iY = $this->iHeight / 2 + $iCharHeight / 4;
 302
 303             // write text to image
 304             imagefttext($this->oImage, $iFontSize, $iAngle, $iX, $iY, $iTextColour, $sCurrentFont, $this->sCode[$i], array());
 305
 306             if ($this->bCharShadow) {
 307                $iOffsetAngle = rand(-30, 30);
 308
 309                $iRandOffsetX = rand(-5, 5);
 310                $iRandOffsetY = rand(-5, 5);
 311
 312                imagefttext($this->oImage, $iFontSize, $iOffsetAngle, $iX + $iRandOffsetX, $iY + $iRandOffsetY, $iShadowColour, $sCurrentFont, $this->sCode[$i], array());
 313             }
 314          }
 315       }
 316
 317       function WriteFile($sFilename) {
 318          if ($sFilename == '') {
 319             // tell browser that data is jpeg
 320             header("Content-type: image/$this->sFileType");
 321          }
 322
 323          switch ($this->sFileType) {
 324             case 'gif':
 325                $sFilename != '' ? imagegif($this->oImage, $sFilename) : imagegif($this->oImage);
 326                break;
 327             case 'png':
 328                $sFilename != '' ? imagepng($this->oImage, $sFilename) : imagepng($this->oImage);
 329                break;
 330             default:
 331                $sFilename != '' ? imagejpeg($this->oImage, $sFilename) : imagejpeg($this->oImage);
 332          }
 333       }
 334
 335       function Create($sFilename = '') {
 336          // check for required gd functions
 337          if (!function_exists('imagecreate') || !function_exists("image$this->sFileType") || ($this->vBackgroundImages != '' && !function_exists('imagecreatetruecolor'))) {
 338             return false;
 339          }
 340
 341          // get background image if specified and copy to CAPTCHA
 342          if (is_array($this->vBackgroundImages) || $this->vBackgroundImages != '') {
 343             // create new image
 344             $this->oImage = imagecreatetruecolor($this->iWidth, $this->iHeight);
 345
 346             // create background image
 347             if (is_array($this->vBackgroundImages)) {
 348                $iRandImage = array_rand($this->vBackgroundImages);
 349                $oBackgroundImage = imagecreatefromjpeg($this->vBackgroundImages[$iRandImage]);
 350             } else {
 351                $oBackgroundImage = imagecreatefromjpeg($this->vBackgroundImages);
 352             }
 353
 354             // copy background image
 355             imagecopy($this->oImage, $oBackgroundImage, 0, 0, 0, 0, $this->iWidth, $this->iHeight);
 356
 357             // free memory used to create background image
 358             imagedestroy($oBackgroundImage);
 359          } else {
 360             // create new image
 361             $this->oImage = imagecreate($this->iWidth, $this->iHeight);
 362          }
 363
 364          // allocate white background colour
 365          imagecolorallocate($this->oImage, 255, 255, 255);
 366
 367          // check for owner text
 368          if ($this->sOwnerText != '') {
 369             $this->DrawOwnerText();
 370          }
 371
 372          // check for background image before drawing lines
 373          if (!is_array($this->vBackgroundImages) && $this->vBackgroundImages == '') {
 374             $this->DrawLines();
 375          }
 376
 377          $this->GenerateCode();
 378          $this->DrawCharacters();
 379
 380          // write out image to file or browser
 381          $this->WriteFile($sFilename);
 382
 383          // free memory used in creating image
 384          imagedestroy($this->oImage);
 385
 386          return true;
 387       }
 388
 389       // call this method statically
 390       function Validate($sUserCode, $bCaseInsensitive = true) {
 391          if ($bCaseInsensitive) {
 392             $sUserCode = strtoupper($sUserCode);
 393          }
 394
 395          if (!empty($_SESSION[CAPTCHA_SESSION_ID]) && $sUserCode == $_SESSION[CAPTCHA_SESSION_ID]) {
 396             // clear to prevent re-use
 397             unset($_SESSION[CAPTCHA_SESSION_ID]);
 398
 399             return true;
 400          }
 401
 402          return false;
 403       }
 404    }
 405
 406    // this class will only work correctly if a visual CAPTCHA has been created first using PhpCaptcha
 407    class AudioPhpCaptcha {
 408       var $sFlitePath;
 409       var $sAudioPath;
 410       var $sCode;
 411
 412       function AudioPhpCaptcha(
 413          $sFlitePath = CAPTCHA_FLITE_PATH, // path to flite binary
 414          $sAudioPath = CAPTCHA_AUDIO_PATH // the location to temporarily store the generated audio CAPTCHA
 415       ) {
 416          $this->SetFlitePath($sFlitePath);
 417          $this->SetAudioPath($sAudioPath);
 418
 419          // retrieve code if already set by previous instance of visual PhpCaptcha
 420          if (isset($_SESSION[CAPTCHA_SESSION_ID])) {
 421             $this->sCode = $_SESSION[CAPTCHA_SESSION_ID];
 422          }
 423       }
 424
 425       function SetFlitePath($sFlitePath) {
 426          $this->sFlitePath = $sFlitePath;
 427       }
 428
 429       function SetAudioPath($sAudioPath) {
 430          $this->sAudioPath = $sAudioPath;
 431       }
 432
 433       function Mask($sText) {
 434          $iLength = strlen($sText);
 435
 436          // loop through characters in code and format
 437          $sFormattedText = '';
 438          for ($i = 0; $i < $iLength; $i++) {
 439             // comma separate all but first and last characters
 440             if ($i > 0 && $i < $iLength - 1) {
 441                $sFormattedText .= ', ';
 442             } elseif ($i == $iLength - 1) { // precede last character with "and"
 443                $sFormattedText .= ' and ';
 444             }
 445             $sFormattedText .= $sText[$i];
 446          }
 447
 448          $aPhrases = array(
 449             "The %1\$s characters are as follows: %2\$s",
 450             "%2\$s, are the %1\$s letters",
 451             "Here are the %1\$s characters: %2\$s",
 452             "%1\$s characters are: %2\$s",
 453             "%1\$s letters: %2\$s"
 454          );
 455
 456          $iPhrase = array_rand($aPhrases);
 457
 458          return sprintf($aPhrases[$iPhrase], $iLength, $sFormattedText);
 459       }
 460
 461       function Create() {
 462          $sText = $this->Mask($this->sCode);
 463          $sFile = md5($this->sCode.time());
 464
 465          // create file with flite
 466          shell_exec("$this->sFlitePath -t \"$sText\" -o $this->sAudioPath$sFile.wav");
 467
 468          // set headers
 469          header('Content-type: audio/x-wav');
 470          header("Content-Disposition: attachment;filename=$sFile.wav");
 471
 472          // output to browser
 473          echo file_get_contents("$this->sAudioPath$sFile.wav");
 474
 475          // delete temporary file
 476          @unlink("$this->sAudioPath$sFile.wav");
 477       }
 478    }
 479
 480    // example sub class
 481    class PhpCaptchaColour extends PhpCaptcha {
 482       function PhpCaptchaColour($aFonts, $iWidth = CAPTCHA_WIDTH, $iHeight = CAPTCHA_HEIGHT) {
 483          // call parent constructor
 484          parent::PhpCaptcha($aFonts, $iWidth, $iHeight);
 485
 486          // set options
 487          $this->UseColour(true);
 488       }
 489    }
 490 ?>