pwd.php

<?php

class PwdImg{
	
	private $password; 
	private $chars = "abcdefghijklmnopqrstuvwxyz0123456789";
	private $long;
	
	public function __construct($pwd){
		$this->long = strlen($this->chars);
		$this->password = $pwd;
	}
	
	public function compare_pwd($pwd){
		if($this->read_image($pwd) === $this->_count_chars($this->password))
			return true;
		else
			return false;
	}
	
	public function pwd_img($pass){
		$this->create_image($this->_count_chars(hash('sha256', $pass)));
	}
	
	public function _count_chars($string){
		$arr = array();
		for($i = 0; $i < $this->long; $i++){
			$regex = '/['.$this->chars[$i].']/i';
			$arr[$this->chars[$i]] = preg_match_all($regex, $string, $matches);
		}
		return $arr;
	}
	
	public function create_image($arr){
		header("Content-Type: image/png");
		$im = imagecreate($this->long, $this->long);
		$background_color = imagecolorallocate($im, 0, 0, 0);
		$text_color = imagecolorallocate($im, 255, 255, 255);
		for($y = 0; $y < $this->long; $y++){
			$x = $arr[$this->chars[$y]];
			imagesetpixel($im, $x, $y, $text_color);
		}
		imagepng($im);
		imagedestroy($im);
	}
	
	public function read_image($image){
		$arr = array();
		$img = imagecreatefrompng($image);
		for($y = 0; $y < $this->long; $y++){
			for($x = 0; $x < $this->long; $x++){
				if(imagecolorat($img, $x , $y)== 1){
					$arr[$this->chars[$y]] = $x;
				}
			}
		}
		return $arr;
	}
}
$connection = new mysqli("localhost", "root", "", "pwd");
$q = $connection->query("SELECT * FROM usuario WHERE usuario = 'asfo' LIMIT 1");
$res = $q->fetch_object();
$a = new PwdImg($res->contrasena);
//$a->pwd_img("helloworld1");
if($a->compare_pwd("pwd/pwd.png")){
	echo "Bien";
}else{
	echo "Mal";
}
?>