Improved Captcha Component
I have created a very good and strong capture component for cakephp which has additional filters and various image format outputs and settings. I have used some code from an author named Pascal-Rehfeldt and have updated and modified it for use and easy implentation into cakephp
A easy captcha component implentation into cakephp.
First save the code below into a file called captcha.php and put it in your controller components folder
Then very important create a folder called "fonts" in your files which is located in webroot/files/ copy the fonts you want to use inside that folder you can add as many fonts as you like and use only true type fonts but here is a link to the fonts i used. www.getkeywords.co.za/files/fonts.tar.gz
Component Class:
Download code
<?php
/******************************************************************
Projectname: CAPTCHA Component class
Version: 1.0
Author: Michael James (mikeyjsa@gmail.com)
Website: http://www.getkeywords.co.za
Last modified: 11. June 2008
* GNU General Public License (Version 2, June 1991)
*
* This program is free software; you can redistribute
* it 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 more details.
Description:
This component is used to generate CAPTCHAs.
******************************************************************/
uses('security');
class CaptchaComponent extends Object {
var $length = 6;
var $fontpath;
var $fonts;
var $components = array('Session');
var $controller = array();
var $sessionKey = 'Captcha';
var $case = false;
var $filters = array();
var $imgFormat = "png";
var $bgColor = array(255, 255, 255);
var $stringColor = array(0, 0, 0);
function startup(&$controller) {
if (strtolower($controller->name) == 'app' || (strtolower($controller->name) == 'tests' && Configure::read() > 0)) {
return;
}
$this->controller = $controller;
if (!method_exists($controller, 'captcha')) {
trigger_error(__('Could not find function captcha. Please create a captcha function in Controller::$controller.', true), E_USER_WARNING);
die();
}
$this->fontpath = $this->__getFontPath();
if(is_null($this->__getFonts())) {
trigger_error(__('Could not find any fonts in webroot/files/fonts/ please confirm you have created directory and have uploaded only true type fonts!', true), E_USER_WARNING);
die();
}
}
// Add this to controller action which you want to use captcha
// for and the model that has the capchta variable in.
function protect($model = 'Captcha') {
if(isset($this->controller->data[$model]['captcha']) && !empty($this->controller->data[$model]['captcha'])) {
if($this->__check($this->controller->data[$model]['captcha'])) {
$this->Session->del($this->sessionKey);
unset($this->controller->data[$model]['captcha']);
return true;
} else {
$this->__generate();
$this->Session->setFlash(__('Incorrect image verification please retry!',true));
unset($this->controller->data[$model]['captcha']);
return false;
}
} else {
$this->__generate();
return false;
}
}
// Create a function called captcha in a controller and reference
// the captcha image src in the view to it.
function show() {
header("Pragma: public");
header("Expires: 0");
header("Cache-Control: no-store, no-cache");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: public");
$this->fontpath = $this->__getFontPath();
$this->fonts = $this->__getFonts();
$this->__makeCaptcha();
$this->controller->autoRender=false;
} //captcha
function __check($string) {
return ($string === $this->Session->read($this->sessionKey));
}
function __generate($protect = false) {
if(!$protect) {
$protect = !$this->Session->check($this->sessionKey);
}
if ($protect) {
$this->Session->write($this->sessionKey, $this->__stringGen());
}
}
function __getFontPath() {
return WWW_ROOT . 'files' . DS . 'fonts' . DS;
}
function __getFonts() {
$fonts = array();
if ($handle = @opendir($this->fontpath)) {
while (($file = readdir($handle)) !== FALSE) {
$extension = strtolower(substr($file, strlen($file) - 3, 3));
if ($extension == 'ttf') {
$fonts[] = $file;
}
}
closedir($handle);
} else {
return null;
}
if (count($fonts) == 0) {
return null;
} else {
return $fonts;
}
} //getFonts
function __getRandFont() {
return $this->fontpath . $this->fonts[mt_rand(0, count($this->fonts) - 1)];
} //getRandFont
function __stringGen() {
$results = null;
$uppercase = range('A', 'Z');
$numeric = range(0, 9);
$CharPool = array_merge($uppercase, $numeric);
if($this->case) {
$lowercase = range('a', 'z');
$CharPool = array_merge($CharPool, $lowercase);
}
$PoolLength = count($CharPool) - 1;
for ($i = 0; $i < $this->length; $i++) {
$results .= $CharPool[mt_rand(0, $PoolLength)];
}
return $results;
} //StringGen
function __makeCaptcha() {
$this->__generate(true);
$captchaString = $this->Session->read($this->sessionKey);
$imagelength = $this->length * 25 + 16;
$imageheight = 75;
$image = imagecreate($imagelength, $imageheight);
$bgcolor = imagecolorallocate($image, $this->bgColor[0], $this->bgColor[1], $this->bgColor[2]);
$stringcolor = imagecolorallocate($image, $this->stringColor[0], $this->stringColor[1], $this->stringColor[2]);
$this->__signs($image, $this->__getRandFont());
for ($i = 0; $i < strlen($captchaString); $i++) {
imagettftext($image, 25, mt_rand(-15, 15), $i * 25 + 10,
mt_rand(30, 70),
$stringcolor,
$this->__getRandFont(),
$captchaString{$i});
}
if(isset($this->filters['noise']) && is_numeric($this->filters['noise'])) {
$this->__noise($image, $this->filters['noise']);
}
if(isset($this->filters['blur']) && is_numeric($this->filters['blur'])) {
$this->__blur($image, $this->filters['blur']);
}
switch($this->imgFormat) {
case "png" : header('Content-type: image/png');
imagepng($image);
break;
case "jpg" : header('Content-type: image/jpg');
imagejpeg($image);
break;
case "jpeg" : header('Content-type: image/jpg');
imagejpeg($image);
break;
case "gif" : header('Content-type: image/gif');
imagegif($image);
break;
default : header('Content-type: image/png');
imagejpeg($image);
break;
}
imagedestroy($image);
} //MakeCaptcha
/*-----------------------------
* FILTER FOR CAPTCHA
*
*
*------------------------------*/
function __noise(&$image, $runs = 30) {
$w = imagesx($image);
$h = imagesy($image);
for ($n = 0; $n < $runs; $n++) {
for ($i = 1; $i <= $h; $i++) {
$randcolor = imagecolorallocate($image,
mt_rand(0, 255),
mt_rand(0, 255),
mt_rand(0, 255));
imagesetpixel($image,
mt_rand(1, $w),
mt_rand(1, $h),
$randcolor);
}
}
} //noise
function __signs(&$image, $font, $cells = 3) {
$w = imagesx($image);
$h = imagesy($image);
for ($i = 0; $i < $cells; $i++) {
$centerX = mt_rand(1, $w);
$centerY = mt_rand(1, $h);
$amount = mt_rand(1, 15);
$stringcolor = imagecolorallocate($image, 175, 175, 175);
for ($n = 0; $n < $amount; $n++) {
$signs = range('A', 'Z');
$sign = $signs[mt_rand(0, count($signs) - 1)];
imagettftext($image, 25,
mt_rand(-15, 15),
$centerX + mt_rand(-50, 50),
$centerY + mt_rand(-50, 50),
$stringcolor, $font, $sign);
}
}
} //signs
function __blur(&$image, $radius = 3) {
$radius = round(max(0, min($radius, 50)) * 2);
$w = imagesx($image);
$h = imagesy($image);
$imgBlur = imagecreate($w, $h);
for ($i = 0; $i < $radius; $i++) {
imagecopy ($imgBlur, $image, 0, 0, 1, 1, $w - 1, $h - 1);
imagecopymerge($imgBlur, $image, 1, 1, 0, 0, $w, $h, 50.0000);
imagecopymerge($imgBlur, $image, 0, 1, 1, 0, $w - 1, $h, 33.3333);
imagecopymerge($imgBlur, $image, 1, 0, 0, 1, $w, $h - 1, 25.0000);
imagecopymerge($imgBlur, $image, 0, 0, 1, 0, $w - 1, $h, 33.3333);
imagecopymerge($imgBlur, $image, 1, 0, 0, 0, $w, $h, 25.0000);
imagecopymerge($imgBlur, $image, 0, 0, 0, 1, $w, $h - 1, 20.0000);
imagecopymerge($imgBlur, $image, 0, 1, 0, 0, $w, $h, 16.6667);
imagecopymerge($imgBlur, $image, 0, 0, 0, 0, $w, $h, 50.0000);
imagecopy ($image , $imgBlur, 0, 0, 0, 0, $w, $h);
}
imagedestroy($imgBlur);
} //blur
} //class: captcha
?>
Then create a helper called captcha.php and put it in your helpers folder.
Helper Class:
Download code
<?php
/******************************************************************
Projectname: CAPTCHA Helper class
Version: 1.0
Author: Michael James (mikeyjsa@gmail.com)
Website: http://www.getkeywords.co.za
Last modified: 11. June 2008
* GNU General Public License (Version 2, June 1991)
*
* This program is free software; you can redistribute
* it 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 more details.
Description:
This helper is used to generate CAPTCHAs.
******************************************************************/
class CaptchaHelper extends AppHelper {
var $helpers = array('html', 'form');
function input($controller = null) {
if(is_null($controller)) {
$controller = $this->params['controller'];
}
$output = array();
$output[] = $this->html->image('/' . $controller . '/captcha/image.png', array('id' => 'captcha_image'));
$output[] = $this->form->input('Captcha/captcha', array('div' => 'captcha_input', 'label' => '(Case Sensitive!)'));
return implode("\r\n", $output);
}
}
?>
First in the controller you want to implement it into add the component then create a function called captcha and and in the following and on the form you want to protect where it checks if the data is empty just add "&& $this->Captcha->protect()". That will return a boolean back.
Controller Class:
Download code
<?php
var $components = array('Captcha');
var $helpers = array('Captcha');
function captcha() {
$this->Captcha->show();
}
function add() {
if (!empty($this->data) && $this->Captcha->protect()) {
$this->ModelName->save($this->data);
}
}
?>
In the capture function below you can add additional functions for example for filtering you can add
Download code
$this->Captcha->filter = array('blur' => 1, 'noise' => 5)
The numeric is how intense you would like the filter to be
And to also use smallcase as well as uppercase just insert this into the function
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$this->Captcha->case = true
Okay once you have done that now its time for the view which is very easy. Just insert that one line into you form your done.
View Template:
Download code
echo $captcha->input();
Okay now you are done and you are protected now with captcha.
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