getVal( $var ); $digest = $wgCaptchaSecret . $salt . $answer . $wgCaptchaSecret . $salt; $answerHash = substr( md5( $digest ), 0, 16 ); if( $answerHash == $hash ) { wfDebug( "FancyCaptcha: answer hash matches expected $hash\n" ); return true; } else { wfDebug( "FancyCaptcha: answer hashes to $answerHash, expected $hash\n" ); return false; } } function formCallback( &$out ) { $dest = 'wpCaptchaWord' . mt_rand(); $img = $this->pickImage(); if( !$img ) { die( 'aaargh' ); } $_SESSION['ceAnswerVar'] = $dest; $_SESSION['captchaHash'] = $img['hash']; $_SESSION['captchaSalt'] = $img['salt']; $_SESSION['captchaViewed'] = false; wfDebug( "Picked captcha with hash ${img['hash']}, salt ${img['salt']}.\n" ); $title = Title::makeTitle( NS_SPECIAL, 'Captcha/image' ); $url = $title->getLocalUrl(); $out->addWikiText( wfMsg( "captcha-short" ) ); $out->addHTML( <<

END ); } function pickImage() { global $wgCaptchaDirectory; $dir = opendir( $wgCaptchaDirectory ); $n = mt_rand( 0, 16 ); $count = 0; $entry = readdir( $dir ); while( false !== $entry ) { $entry = readdir( $dir ); if( preg_match( '/^image_([0-9a-f]+)_([0-9a-f]+)\\.png$/', $entry, $matches ) ) { if( $count++ % 16 == $n ) { return array( 'salt' => $matches[1], 'hash' => $matches[2], ); } } } return false; } function showImage() { global $wgOut; $wgOut->disable(); if( !empty( $_SESSION['captchaViewed'] ) ) { wfHttpError( 403, 'Access Forbidden', "Can't view captcha image a second time." ); return false; } $_SESSION['captchaViewed'] = wfTimestamp(); if( isset( $_SESSION['captchaSalt'] ) ) { $salt = $_SESSION['captchaSalt']; if( isset( $_SESSION['captchaHash'] ) ) { $hash = $_SESSION['captchaHash']; global $wgCaptchaDirectory; $file = $wgCaptchaDirectory . DIRECTORY_SEPARATOR . "image_{$salt}_{$hash}.png"; if( file_exists( $file ) ) { header( 'Content-type: image/png' ); readfile( $file ); } } } else { wfHttpError( 500, 'Internal Error', 'Requested bogus captcha image' ); } } } } # End invocation guard ?>