source: trunk/content/plugins/akismet/libs/Akismet.class.php @ 1081

<?php

/**
 * Akismet anti-comment spam service
 *
 * The class in this package allows use of the {@link http://akismet.com Akismet} anti-comment spam service in any PHP5 application.
 *
 * This service performs a number of checks on submitted data and returns whether or not the data is likely to be spam.
 *
 * Please note that in order to use this class, you must have a vaild {@link http://wordpress.com/api-keys/ WordPress API key}.  They are free for non/small-profit types and getting one will only take a couple of minutes.  
 *
 * For commercial use, please {@link http://akismet.com/commercial/ visit the Akismet commercial licensing page}.
 *
 * Please be aware that this class is PHP5 only.  Attempts to run it under PHP4 will most likely fail.
 *
 * See the Akismet class documentation page linked to below for usage information.
 *
 * @package             akismet
 * @author              Alex Potsides, {@link http://www.achingbrain.net http://www.achingbrain.net}
 * @version             0.4
 * @copyright   Alex Potsides, {@link http://www.achingbrain.net http://www.achingbrain.net}
 * @license             http://www.opensource.org/licenses/bsd-license.php BSD License
 */

/**
 *      The Akismet PHP5 Class
 *
 *  This class takes the functionality from the Akismet WordPress plugin written by {@link http://photomatt.net/ Matt Mullenweg} and allows it to be integrated into any PHP5 application or website.
 *
 *  The original plugin is {@link http://akismet.com/download/ available on the Akismet website}.
 *
 *  <b>Usage:</b>
 *  <code>
 *    $akismet = new Akismet('http://www.example.com/blog/', 'aoeu1aoue');
 *    $akismet->setCommentAuthor($name);
 *    $akismet->setCommentAuthorEmail($email);
 *    $akismet->setCommentAuthorURL($url);
 *    $akismet->setCommentContent($comment);
 *    $akismet->setPermalink('http://www.example.com/blog/alex/someurl/');
 *    if($akismet->isCommentSpam())
 *      // store the comment but mark it as spam (in case of a mis-diagnosis)
 *    else
 *      // store the comment normally
 *  </code>
 *
 *  Optionally you may wish to check if your WordPress API key is valid as in the example below.
 * 
 * <code>
 *   $akismet = new Akismet('http://www.example.com/blog/', 'aoeu1aoue');
 *   
 *   if($akismet->isKeyValid()) {
 *     // api key is okay
 *   } else {
 *     // api key is invalid
 *   }
 * </code>
 *
 *      @package        akismet
 *      @name           Akismet
 *      @version        0.4
 *  @author             Alex Potsides
 *  @link               http://www.achingbrain.net/
 */
class Akismet
        {
        private $version = '0.4';
        private $cage;
        private $wordPressAPIKey;
        private $blogURL;
        private $comment;
        private $apiPort;
        private $akismetServer;
        private $akismetVersion;
        
        // This prevents some potentially sensitive information from being sent accross the wire.
        private $ignore = array('HTTP_COOKIE', 
                                                        'HTTP_X_FORWARDED_FOR', 
                                                        'HTTP_X_FORWARDED_HOST', 
                                                        'HTTP_MAX_FORWARDS', 
                                                        'HTTP_X_FORWARDED_SERVER', 
                                                        'REDIRECT_STATUS', 
                                                        'SERVER_PORT', 
                                                        'PATH',
                                                        'DOCUMENT_ROOT',
                                                        'SERVER_ADMIN',
                                                        'QUERY_STRING',
                                                        'PHP_SELF' );
        
        /**
         *      @param  string  $blogURL                        The URL of your blog.
         *      @param  string  $wordPressAPIKey        WordPress API key.
         */
        public function __construct($cage, $blogURL, $wordPressAPIKey) {
            $this->cage = $cage;
                $this->blogURL = $blogURL;
                $this->wordPressAPIKey = $wordPressAPIKey;
                
                // Set some default values
                $this->apiPort = 80;
                $this->akismetServer = 'rest.akismet.com';
                $this->akismetVersion = '1.1';
                
                // Start to populate the comment data
                $this->comment['blog'] = $blogURL;
                //$this->comment['user_agent'] = $_SERVER['HTTP_USER_AGENT'];
                $this->comment['user_agent'] = $this->cage->server->getRaw('HTTP_USER_AGENT');
                
                if(isset($this->cage->server->getRaw['HTTP_REFERER'])) {
                        //$this->comment['referrer'] = $_SERVER['HTTP_REFERER'];
                        $this->comment['referrer'] = $this->cage->server->getRaw('HTTP_REFERER');
                }
                
                /* 
                 * This is necessary if the server PHP5 is running on has been set up to run PHP4 and
                 * PHP5 concurently and is actually running through a separate proxy al a these instructions:
                 * http://www.schlitt.info/applications/blog/archives/83_How_to_run_PHP4_and_PHP_5_parallel.html
                 * and http://wiki.coggeshall.org/37.html
                 * Otherwise the user_ip appears as the IP address of the PHP4 server passing the requests to the 
                 * PHP5 one...
                 */
                //$this->comment['user_ip'] = $_SERVER['REMOTE_ADDR'] != getenv('SERVER_ADDR') ? $_SERVER['REMOTE_ADDR'] : getenv('HTTP_X_FORWARDED_FOR');
                $this->comment['user_ip'] = $this->cage->server->getRaw('REMOTE_ADDR') != $this->cage->server->getRaw('SERVER_ADDR') ? $this->cage->server->getRaw('REMOTE_ADDR') : $this->cage->server->getRaw('HTTP_X_FORWARDED_FOR');
        }
        
        /**
         * Makes a request to the Akismet service to see if the API key passed to the constructor is valid.
         * 
         * Use this method if you suspect your API key is invalid.
         * 
         * @return bool True is if the key is valid, false if not.
         */
        public function isKeyValid() {
                // Check to see if the key is valid
                $response = $this->sendRequest('key=' . $this->wordPressAPIKey . '&blog=' . $this->blogURL, $this->akismetServer, '/' . $this->akismetVersion . '/verify-key');
                return $response[1] == 'valid';
        }
        
        // makes a request to the Akismet service
        private function sendRequest($request, $host, $path) {
                $http_request  = "POST " . $path . " HTTP/1.0\r\n";
                $http_request .= "Host: " . $host . "\r\n";
                $http_request .= "Content-Type: application/x-www-form-urlencoded; charset=utf-8\r\n";
                $http_request .= "Content-Length: " . strlen($request) . "\r\n";
                $http_request .= "User-Agent: Akismet PHP5 Class " . $this->version . " | Akismet/1.11\r\n";
                $http_request .= "\r\n";
                $http_request .= $request;
                
                $socketWriteRead = new SocketWriteRead($host, $this->apiPort, $http_request);
                $socketWriteRead->send();
                
                return explode("\r\n\r\n", $socketWriteRead->getResponse(), 2);
        }
        
        // Formats the data for transmission
        private function getQueryString() {
                foreach($this->cage->server as $key => $value) {
                        if(!in_array($key, $this->ignore)) {
                                if($key == 'REMOTE_ADDR') {
                                        $this->comment[$key] = $this->comment['user_ip'];
                                } else {
                                        $this->comment[$key] = $value;
                                }
                        }
                }

                $query_string = '';
                
                foreach($this->comment as $key => $data) {
                        if(!is_array($data) && ($key != 'argv') && ($key != 'argc')) {
                                $query_string .= $key . '=' . urlencode(stripslashes($data)) . '&';
                        }
                }
                
                return $query_string;
        }
        
        /**
         *      Tests for spam.
         *
         *      Uses the web service provided by {@link http://www.akismet.com Akismet} to see whether or not the submitted comment is spam.  Returns a boolean value.
         *
         *      @return         bool    True if the comment is spam, false if not
         *  @throws             Will throw an exception if the API key passed to the constructor is invalid.
         */
        public function isCommentSpam() {
                $response = $this->sendRequest($this->getQueryString(), $this->wordPressAPIKey . '.rest.akismet.com', '/' . $this->akismetVersion . '/comment-check');
                
                if($response[1] == 'invalid' && !$this->isKeyValid()) {
                        throw new exception('The Wordpress API key passed to the Akismet constructor is invalid.  Please obtain a valid one from http://wordpress.com/api-keys/');
                }
                
                return ($response[1] == 'true');
        }

        /**
         *      Submit spam that is incorrectly tagged as ham.
         *
         *      Using this function will make you a good citizen as it helps Akismet to learn from its mistakes.  This will improve the service for everybody.
         */
        public function submitSpam() {
                $this->sendRequest($this->getQueryString(), $this->wordPressAPIKey . '.' . $this->akismetServer, '/' . $this->akismetVersion . '/submit-spam');
        }
        
        /**
         *      Submit ham that is incorrectly tagged as spam.
         *
         *      Using this function will make you a good citizen as it helps Akismet to learn from its mistakes.  This will improve the service for everybody.
         */
        public function submitHam() {
                $this->sendRequest($this->getQueryString(), $this->wordPressAPIKey . '.' . $this->akismetServer, '/' . $this->akismetVersion . '/submit-ham');
        }
        
        /**
         *      To override the user IP address when submitting spam/ham later on
         *
         *      @param string $userip   An IP address.  Optional.
         */
        public function setUserIP($userip) {
                $this->comment['user_ip'] = $userip;
        }
        
        /**
         *      To override the referring page when submitting spam/ham later on
         *
         *      @param string $referrer The referring page.  Optional.
         */
        public function setReferrer($referrer) {
                $this->comment['referrer'] = $referrer;
        }
        
        /**
         *      A permanent URL referencing the blog post the comment was submitted to.
         *
         *      @param string $permalink        The URL.  Optional.
         */
        public function setPermalink($permalink) {
                $this->comment['permalink'] = $permalink;
        }
        
        /**
         *      The type of comment being submitted.  
         *
         *      May be blank, comment, trackback, pingback, or a made up value like "registration" or "wiki".
         */
        public function setCommentType($commentType) {
                $this->comment['comment_type'] = $commentType;
        }
        
        /**
         *      The name that the author submitted with the comment.
         */
        public function setCommentAuthor($commentAuthor) {
                $this->comment['comment_author'] = $commentAuthor;
        }
        
        /**
         *      The email address that the author submitted with the comment.
         *
         *      The address is assumed to be valid.
         */
        public function setCommentAuthorEmail($authorEmail) {
                $this->comment['comment_author_email'] = $authorEmail;
        }
        
        /**
         *      The URL that the author submitted with the comment.
         */     
        public function setCommentAuthorURL($authorURL) {
                $this->comment['comment_author_url'] = $authorURL;
        }
        
        /**
         *      The comment's body text.
         */
        public function setCommentContent($commentBody) {
                $this->comment['comment_content'] = $commentBody;
        }
        
        /**
         *      Defaults to 80
         */
        public function setAPIPort($apiPort) {
                $this->apiPort = $apiPort;
        }
        
        /**
         *      Defaults to rest.akismet.com
         */
        public function setAkismetServer($akismetServer) {
                $this->akismetServer = $akismetServer;
        }
        
        /**
         *      Defaults to '1.1'
         */
        public function setAkismetVersion($akismetVersion) {
                $this->akismetVersion = $akismetVersion;
        }
}

/**
 *      Utility class used by Akismet
 *
 *  This class is used by Akismet to do the actual sending and receiving of data.  It opens a connection to a remote host, sends some data and the reads the response and makes it available to the calling program.
 *
 *  The code that makes up this class originates in the Akismet WordPress plugin, which is {@link http://akismet.com/download/ available on the Akismet website}.
 *
 *      N.B. It is not necessary to call this class directly to use the Akismet class.  This is included here mainly out of a sense of completeness.
 *
 *      @package        akismet
 *      @name           SocketWriteRead
 *      @version        0.1
 *  @author             Alex Potsides
 *  @link               http://www.achingbrain.net/
 */
class SocketWriteRead {
        private $host;
        private $port;
        private $request;
        private $response;
        private $responseLength;
        private $errorNumber;
        private $errorString;
        
        /**
         *      @param  string  $host                   The host to send/receive data.
         *      @param  int             $port                   The port on the remote host.
         *      @param  string  $request                The data to send.
         *      @param  int             $responseLength The amount of data to read.  Defaults to 1160 bytes.
         */
        public function __construct($host, $port, $request, $responseLength = 1160) {
                $this->host = $host;
                $this->port = $port;
                $this->request = $request;
                $this->responseLength = $responseLength;
                $this->errorNumber = 0;
                $this->errorString = '';
        }
        
        /**
         *  Sends the data to the remote host.
         *
         * @throws      An exception is thrown if a connection cannot be made to the remote host.
         */
        public function send() {
                $this->response = '';
                
                $fs = fsockopen($this->host, $this->port, $this->errorNumber, $this->errorString, 3);
                
                if($this->errorNumber != 0) {
                        throw new Exception('Error connecting to host: ' . $this->host . ' Error number: ' . $this->errorNumber . ' Error message: ' . $this->errorString);
                }
                
                if($fs !== false) {
                        @fwrite($fs, $this->request);
                        
                        while(!feof($fs)) {
                                $this->response .= fgets($fs, $this->responseLength);
                        }
                        
                        fclose($fs);
                }
        }
        
        /**
         *  Returns the server response text
         *
         *  @return     string
         */
        public function getResponse() {
                return $this->response;
        }
        
        /**
         *      Returns the error number
         *
         *      If there was no error, 0 will be returned.
         *
         *      @return int
         */
        public function getErrorNumner() {
                return $this->errorNumber;
        }
        
        /**
         *      Returns the error string
         *
         *      If there was no error, an empty string will be returned.
         *
         *      @return string
         */
        public function getErrorString() {
                return $this->errorString;
        }
}

?>