* @link http://www.yiiframework.com/
* @copyright Copyright © 2008 Yii Software LLC
* @license http://www.yiiframework.com/license/
*/
/**
* CCaptchaAction renders a CAPTCHA image.
*
* CCaptchaAction is used together with {@link CCaptcha} and {@link CCaptchaValidator}
* to provide the {@link http://en.wikipedia.org/wiki/Captcha CAPTCHA} feature.
*
* You must configure properties of CCaptchaAction to customize the appearance of
* the generated image.
*
* Note, CCaptchaAction requires PHP GD2 extension.
*
* Using CAPTCHA involves the following steps:
*
* - Override {@link CController::actions()} and register an action of class CCaptchaAction with ID 'captcha'.
* - In the form model, declare an attribute to store user-entered verification code, and declare the attribute
* to be validated by the 'captcha' validator.
* - In the controller view, insert a {@link CCaptcha} widget in the form.
*
*
* @author Qiang Xue
* @version $Id$
* @package system.web.actions
* @since 1.0
*/
class CCaptchaAction extends CAction
{
/**
* The name of the GET parameter indicating whether the CAPTCHA image should be regenerated.
*/
const REFRESH_GET_VAR='refresh';
/**
* Prefix to the session variable name used by the action.
*/
const SESSION_VAR_PREFIX='Yii.CCaptchaAction.';
/**
* @var integer how many times should the same CAPTCHA be displayed. Defaults to 3.
*/
public $testLimit=3;
/**
* @var integer the width of the generated CAPTCHA image. Defaults to 120.
*/
public $width=120;
/**
* @var integer the height of the generated CAPTCHA image. Defaults to 50.
*/
public $height=50;
/**
* @var integer padding around the text. Defaults to 2.
*/
public $padding=2;
/**
* @var integer the background color. For example, 0x55FF00.
* Defaults to 0xFFFFFF, meaning white color.
*/
public $backColor=0xFFFFFF;
/**
* @var integer the font color. For example, 0x55FF00. Defaults to 0x2040A0 (blue color).
*/
public $foreColor=0x2040A0;
/**
* @var integer the minimum length for randomly generated word. Defaults to 6.
*/
public $minLength=6;
/**
* @var integer the maximum length for randomly generated word. Defaults to 7.
*/
public $maxLength=7;
/**
* @var string the TrueType font file. Defaults to Duality.ttf which is provided
* with the Yii release.
*/
public $fontFile;
/**
* Runs the action.
* If the GET parameter {@link wsdlVar} exists, the action will serve WSDL content;
* If not, the action will handle the remote method invocation.
*/
public function run()
{
if(isset($_GET[self::REFRESH_GET_VAR])) // AJAX request for regenerating code
{
$code=$this->getVerifyCode(true);
// we add a random 'v' parameter so that FireFox can refresh the image
// when src attribute of image tag is changed
echo $this->getController()->createUrl($this->getId(),array('v'=>rand(0,10000)));
}
else
{
$session=Yii::app()->session;
$session->open();
$name=$this->getSessionKey().'count';
if($session[$name]===null || $session[$name]>=$this->testLimit)
$regenerate=true;
else
{
$session[$name]=$session[$name]+1;
$regenerate=false;
}
$this->renderImage($this->getVerifyCode($regenerate));
Yii::app()->end();
}
}
/**
* Gets the verification code.
* @param string whether the verification code should be regenerated.
* @return string the verification code.
*/
public function getVerifyCode($regenerate=false)
{
$session=Yii::app()->session;
$session->open();
$name=$this->getSessionKey();
if($session[$name]===null || $regenerate)
{
$session[$name]=$this->generateVerifyCode();
$session[$name.'count']=1;
}
return $session[$name];
}
/**
* Validates the input to see if it matches the generated code.
* @param string user input
* @param boolean whether the comparison should be case-sensitive
* @return whether the input is valid
*/
public function validate($input,$caseSensitive)
{
$code=$this->getVerifyCode();
return $caseSensitive?($input===$code):!strcasecmp($input,$code);
}
/**
* Generates a new verification code.
* @return string the generated verification code
*/
protected function generateVerifyCode()
{
if($this->minLength<3)
$this->minLength=3;
if($this->maxLength>20)
$this->maxLength=20;
if($this->minLength>$this->maxLength)
$this->maxLength=$this->minLength;
$length=rand($this->minLength,$this->maxLength);
$letters='bcdfghjklmnpqrstvwxyz';
$vowels='aeiou';
$code='';
for($i=0;$i<$length;++$i)
{
if($i%2 && rand(0,10)>2 || !($i%2) && rand(0,10)>9)
$code.=$vowels[rand(0,4)];
else
$code.=$letters[rand(0,20)];
}
return $code;
}
/**
* Returns the session variable name used to store verification code.
* @return string the session variable name
*/
protected function getSessionKey()
{
return self::SESSION_VAR_PREFIX.Yii::app()->getId().'.'.$this->getController()->getId().'.'.$this->getId();
}
/**
* Renders the CAPTCHA image based on the code.
* @param string the verification code
* @return string image content
*/
protected function renderImage($code)
{
$image=imagecreatetruecolor($this->width,$this->height);
$backColor=imagecolorallocate($image,
(int)($this->backColor%0x1000000/0x10000),
(int)($this->backColor%0x10000/0x100),
$this->backColor%0x100);
imagefilledrectangle($image,0,0,$this->width,$this->height,$backColor);
imagecolordeallocate($image,$backColor);
$foreColor=imagecolorallocate($image,
(int)($this->foreColor%0x1000000/0x10000),
(int)($this->foreColor%0x10000/0x100),
$this->foreColor%0x100);
if($this->fontFile===null)
$this->fontFile=dirname(__FILE__).'/captcha/Duality.ttf';
$offset=2;
$length=strlen($code);
$box=imagettfbbox(30,0,$this->fontFile,$code);
$w=$box[4]-$box[0]-$offset*($length-1);
$h=$box[1]-$box[5];
$scale=min(($this->width-$this->padding*2)/$w,($this->height-$this->padding*2)/$h);
$x=10;
$y=round($this->height*27/40);
for($i=0;$i<$length;++$i)
{
$fontSize=(int)(rand(26,32)*$scale*0.8);
$angle=rand(-10,10);
$letter=$code[$i];
$box=imagettftext($image,$fontSize,$angle,$x,$y,$foreColor,$this->fontFile,$letter);
$x=$box[2]-$offset;
}
imagecolordeallocate($image,$foreColor);
header('Pragma: public');
header('Expires: 0');
header('Cache-Control: must-revalidate, post-check=0, pre-check=0');
header('Content-Transfer-Encoding: binary');
header("Content-type: image/png");
imagepng($image);
imagedestroy($image);
}
}