PHP CAPTCHA script

phpTextCaptcha is an open-source, free PHP CAPTCHA script to create complex images and protect forms from spam and abuse.

Features

Small code structure.

It's using phptextClass to create a captcha image.

Customizable code.

Security features, such as random lines and noise.

Live Demo Download Script

  phptextClass.php

Main class file with phpcaptcha, hexToRGB and ImageTTFCenter function.

  <?php  /*phptext class, version 1.0  created by www.w3schools.in (Gautam kumar)  April 26, 2014  */  class phptextClass  {          public function phpcaptcha($textColor,$backgroundColor,$imgWidth,$imgHeight,$noiceLines=0,$noiceDots=0,$noiceColor='#162453')          {                         /* Settings */                  $text=$this->random();                  $font = './font/monofont.ttf';/* font */                  $textColor=$this->hexToRGB($textColor);                        $fontSize = $imgHeight * 0.75;                                    $im = imagecreatetruecolor($imgWidth, $imgHeight);                        $textColor = imagecolorallocate($im, $textColor['r'],$textColor['g'],$textColor['b']);                                                      $backgroundColor = $this->hexToRGB($backgroundColor);                  $backgroundColor = imagecolorallocate($im, $backgroundColor['r'],$backgroundColor['g'],$backgroundColor['b']);                                                    /* generating lines randomly in background of image */                  if($noiceLines>0){                  $noiceColor=$this->hexToRGB($noiceColor);                      $noiceColor = imagecolorallocate($im, $noiceColor['r'],$noiceColor['g'],$noiceColor['b']);                  for( $i=0; $i<$noiceLines; $i++ ) {                                                    imageline($im, mt_rand(0,$imgWidth), mt_rand(0,$imgHeight),                          mt_rand(0,$imgWidth), mt_rand(0,$imgHeight), $noiceColor);                  }}                                                                                  if($noiceDots>0){/* generating the dots randomly in background */                  for( $i=0; $i<$noiceDots; $i++ ) {                          imagefilledellipse($im, mt_rand(0,$imgWidth),                          mt_rand(0,$imgHeight), 3, 3, $textColor);                  }}                                                  imagefill($im,0,0,$backgroundColor);                      list($x, $y) = $this->ImageTTFCenter($im, $text, $font, $fontSize);                    imagettftext($im, $fontSize, 0, $x, $y, $textColor, $font, $text);                                  imagejpeg($im,NULL,90);/* Showing image */                  header('Content-Type: image/jpeg');/* defining the image type to be shown in browser widow */                  imagedestroy($im);/* Destroying image instance */                  if(isset($_SESSION)){                          $_SESSION['captcha_code'] = $text;/* set random text in session for captcha validation*/                  }          }                    /*function to convert hex value to rgb array*/          protected function hexToRGB($colour)          {          if ( $colour[0] == '#' ) {                          $colour = substr( $colour, 1 );          }          if ( strlen( $colour ) == 6 ) {                          list( $r, $g, $b ) = array( $colour[0] . $colour[1], $colour[2] . $colour[3], $colour[4] . $colour[5] );          } elseif ( strlen( $colour ) == 3 ) {                          list( $r, $g, $b ) = array( $colour[0] . $colour[0], $colour[1] . $colour[1], $colour[2] . $colour[2] );          } else {                          return false;          }          $r = hexdec( $r );          $g = hexdec( $g );          $b = hexdec( $b );          return array( 'r' => $r, 'g' => $g, 'b' => $b );          }                                              /*function to get center position on image*/          protected function ImageTTFCenter($image, $text, $font, $size, $angle = 8)           {                  $xi = imagesx($image);                  $yi = imagesy($image);                  $box = imagettfbbox($size, $angle, $font, $text);                  $xr = abs(max($box[2], $box[4]))+5;                  $yr = abs(max($box[5], $box[7]));                  $x = intval(($xi - $xr) / 2);                  $y = intval(($yi + $yr) / 2);                  return array($x, $y);             }    }  ?>

demo.php

This file is used to obtain submitted form data and used to validate the captcha image.

  <?php session_start();    if(isset($_POST['Submit'])){          // code for check server side validation          if(empty($_SESSION['captcha_code'] ) || strcasecmp($_SESSION['captcha_code'], $_POST['captcha_code']) != 0){                    $msg="<span style='color:red'>The Validation code does not match!</span>";// Captcha verification is incorrect.                       }else{// Captcha verification is Correct. Final Code Execute here!                                $msg="<span style='color:green'>The Validation code has been matched.</span>";                        }  }         ?>        <form action="" method="post" name="form1" id="form1" >    <table width="400" border="0" align="center" cellpadding="5" cellspacing="1" class="table">      <?php if(isset($msg)){?>      <tr>        <td colspan="2" align="center" valign="top"><?php echo $msg;?></td>      </tr>      <?php } ?>      <tr>        <td align="right" valign="top"> Validation code:</td>        <td><img src="captcha.php?rand=<?php echo rand();?>" id='captchaimg'><br>          <label for='message'>Enter the code above here :</label>          <br>          <input id="captcha_code" name="captcha_code" type="text">          <br>          Can't read the image? click <a href='javascript: refreshCaptcha();'>here</a> to refresh.</td>      </tr>      <tr>        <td> </td>        <td><input name="Submit" type="submit" onclick="return validate();" value="Submit" class="button1"></td>      </tr>    </table>  </form>

captcha.php

This file is used to generate a captcha image.

  <?php          session_start();          include("./phptextClass.php");                      /*create class object*/          $phptextObj = new phptextClass();                 /*phptext function to genrate image with text*/          $phptextObj->phpcaptcha('#162453','#fff',120,40,10,25);         ?>

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