Subversion-Projekte lars-tiefland.php_share

<?php

/**

 * Text_CAPTCHA - creates a CAPTCHA for Turing tests

 *

 * Class to create a Turing test for websites by

 * creating an image, ASCII art or something else

 * with some (obfuscated) characters

 *

 * @category Text

 * @package  Text_CAPTCHA

 * @author   Christian Wenz <wenz@php.net>

 * @license  BSD License

 */

/**

 *

 * Require PEAR class for error handling.

 *

 */

require_once 'PEAR.php';

/**

 *

 * Require Text_Password class for generating the phrase.

 *

 */

require_once 'Text/Password.php';

/**

 * Text_CAPTCHA - creates a CAPTCHA for Turing tests

 *

 * Class to create a Turing test for websites by

 * creating an image, ASCII art or something else

 * with some (obfuscated) characters

 *

 * @package Text_CAPTCHA

 */

/*

    // This is a simple example script

    <?php

    if (!function_exists('file_put_contents')) {

        function file_put_contents($filename, $content) {

            if (!($file = fopen($filename, 'w'))) {

                return false;

            }

            $n = fwrite($file, $content);

            fclose($file);

            return $n ? $n : false;

        }

    }

    // Start PHP session support

    session_start();

    $ok = false;

    $msg = 'Please enter the text in the image in the field below!';

    if ($_SERVER['REQUEST_METHOD'] == 'POST') {

        if (isset($_POST['phrase']) && is_string($_SESSION['phrase']) && isset($_SESSION['phrase']) &&

            strlen($_POST['phrase']) > 0 && strlen($_SESSION['phrase']) > 0 &&

            $_POST['phrase'] == $_SESSION['phrase']) {

            $msg = 'OK!';

            $ok = true;

            unset($_SESSION['phrase']);

        } else {

            $msg = 'Please try again!';

        }

        unlink(sha1(session_id()) . '.png');

    }

    print "<p>$msg</p>";

    if (!$ok) {

        require_once 'Text/CAPTCHA.php';

        // Set CAPTCHA image options (font must exist!)

        $imageOptions = array(

            'font_size'        => 24,

            'font_path'        => './',

            'font_file'        => 'COUR.TTF',

            'text_color'       => '#DDFF99',

            'lines_color'      => '#CCEEDD',

            'background_color' => '#555555',

            'antialias'        => true

        );

        // Set CAPTCHA options

        $options = array(

            'width' => 200,

            'height' => 80,

            'output' => 'png',

            'imageOptions' => $imageOptions

        );

        // Generate a new Text_CAPTCHA object, Image driver

        $c = Text_CAPTCHA::factory('Image');

        $retval = $c->init($options);

        if (PEAR::isError($retval)) {

            printf('Error initializing CAPTCHA: %s!',

                $retval->getMessage());

            exit;

        }

        // Get CAPTCHA secret passphrase

        $_SESSION['phrase'] = $c->getPhrase();

        // Get CAPTCHA image (as PNG)

        $png = $c->getCAPTCHA();

        if (PEAR::isError($png)) {

            printf('Error generating CAPTCHA: %s!',

                $png->getMessage());

            exit;

        }

        file_put_contents(sha1(session_id()) . '.png', $png);

        echo '<form method="post">' .

             '<img src="' . sha1(session_id()) . '.png?' . time() . '" />' .

             '<input type="text" name="phrase" />' .

             '<input type="submit" /></form>';

    }

    ?>

*/

class Text_CAPTCHA

{

    /**

     * Version number

     *

     * @access private

     * @var string

     */

    var $_version = '0.4.2';

    /**

     * Phrase

     *

     * @access private

     * @var string

     */

    var $_phrase;

    /**

     * Create a new Text_CAPTCHA object

     *

     * @param string $driver name of driver class to initialize

     *

     * @return mixed a newly created Text_CAPTCHA object, or a PEAR

     * error object on error

     *

     * @see PEAR::isError()

     */

    function &factory($driver)

    {

        if ($driver == '') {

            return PEAR::raiseError('No CAPTCHA type specified ... aborting. You must call ::factory() with one parameter, the CAPTCHA type.', true);

        }

        $driver = basename($driver);

        include_once "Text/CAPTCHA/Driver/$driver.php";

        $classname = "Text_CAPTCHA_Driver_$driver";

        $obj = new $classname;

        return $obj;

    }

    /**

     * Create random CAPTCHA phrase

     *

     * This method creates a random phrase, 8 characters long

     *

     * @param array $options optionally supply advanced options for the phrase creation

     *

     * @access private

     * @return void

     */

    function _createPhrase($options = array())

    {

        $len = 8;

        if (!is_array($options) || count($options) === 0) {

            $this->_phrase = Text_Password::create($len);

        } else {

            if (count($options) === 1) {

                $this->_phrase = Text_Password::create($len, $options[0]);

            } else {

                $this->_phrase = Text_Password::create($len, $options[0], $options[1]);

            }

        }

    }

    /**

     * Return secret CAPTCHA phrase

     *

     * This method returns the CAPTCHA phrase

     *

     * @access public

     * @return phrase secret phrase

     */

    function getPhrase()

    {

        return $this->_phrase;

    }

    /**

     * Sets secret CAPTCHA phrase

     *

     * This method sets the CAPTCHA phrase

     * (use null for a random phrase)

     *

     * @param string $phrase the (new) phrase

     *

     * @access  public

     * @return void

     */

    function setPhrase($phrase = null)

    {

        if (!empty($phrase)) {

            $this->_phrase = $phrase;

        } else {

            $this->_createPhrase();

        }

    }

    /**

     * Place holder for the real init() method

     * used by extended classes to initialize CAPTCHA

     *

     * @access private

     * @return PEAR_Error

     */

    function init()

    {

        return PEAR::raiseError('CAPTCHA type not selected', true);

    }

    /**

     * Place holder for the real _createCAPTCHA() method

     * used by extended classes to generate CAPTCHA from phrase

     *

     * @access private

     * @return PEAR_Error

     */

    function _createCAPTCHA()

    {

        return PEAR::raiseError('CAPTCHA type not selected', true);

    }

    /**

     * Place holder for the real getCAPTCHA() method

     * used by extended classes to return the generated CAPTCHA

     * (as an image resource, as an ASCII text, ...)

     *

     * @access private

     * @return PEAR_Error

     */

    function getCAPTCHA()

    {

        return PEAR::raiseError('CAPTCHA type not selected', true);

    }

}