PHP detects image Trojans

Practice php detection of image Trojans

  /**
 +------------------------------------------------ -------------------------------
 * Upload file upload class
 +--------------------- -------------------------------------------------- ----------------
 * @package Upload
 * @author nicegy
 * @version $Id: Upload.class.php 2014-4-11 19:00:23 nicegy $
 +------------------------------------------------ -------------------------------
*/
 class Upload {

 private static $image = null;
 private static $status = 0;
 private static $suffix = null ;
 private static $imageType = array('.jpg', '.bmp','.gif','.png');
 private static $message = array(
 '0' => 'No error occurred, The file uploaded successfully. ',
 '1' => 'The uploaded file exceeded the value of the upload_max_filesize option in php.ini',
 '2' => 'The size of the uploaded file exceeded the MAX_FILE_SIZE option in the HTML form. Specified value. ',
 '3' => 'Only part of the file was uploaded',
 '4' => 'No file uploaded',
 '5' => 'Failed to pass security check. File. ',
 '6' => 'Temp folder not found. ',
 '7' => 'File writing failed.',
 '8' => 'File type not supported',
 '9' => 'The uploaded temporary file is lost. ',
 );

 //@ Start file upload
 public static function start($feild = 'file') {
 if (!empty($_FILES) )) {
 self::$status = $_FILES[$feild]['error'];
 if (self::$status > 0)
 return array('status' => self::$status, 'msg' => self::$message[self::$status]);
 self::$image = $_FILES[$feild]['tmp_name'];
 self::$suffix = strtolower(strrchr( $_FILES[$feild]['name'], '.'));
 return array('status' => self::_upload(), 'path' => self::$image, 'msg' => self::$message[self::$status]);
 } else {
 return array('status' => self::$status, 'msg' => self::$message[self ::$status]);
 }
 }

 //@ Private upload starts
 private static function _upload($path = './upload/') {
 date_default_timezone_set('PRC');
 $newFile = $path . date('Y/m/d/His') . rand(100, 999) . self::$suffix;
 self::umkdir(dirname($newFile));
 if (is_uploaded_file(self::$image ) && move_uploaded_file(self::$image, $newFile)) {
 self::$image = $newFile;
 if (in_array(self::$suffix, self::$imageType))
 return self::checkHex( );
 else
 return self::$status = 0;
 } else {
 return self::$status = 9;
 }
 }

 //@ Private hexadecimal detection hacker
 private static function checkHex() {
 if (file_exists(self::$image)) {
 $resource = fopen(self::$image, 'rb');
 $fileSize = filesize(self::$image);
 fseek($resource, 0);
 if ($fileSize > 512) { // Get the head and tail
 $hexCode = bin2hex(fread($resource, 512));
 fseek($resource, $fileSize - 512);
 $hexCode . = bin2hex(fread($resource, 512));
 } else { // Get all
 $hexCode = bin2hex(fread($resource, $fileSize));
 }
 fclose($resource);
 /* Match 16 */ in base
 /* matches */ in hexadecimal
 /* matches

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