/class/Security.class.php

<?php

	/*

	 * This STATIC class, implements encryption and decryption of data.

	 * Also create a password cypher string

	 */

class Security{



	public function decrypt($data, $key){

		$data = base64_decode($data);

		$salt = substr($data, 0, 16);

		$ct = substr($data, 16);



		$rounds = 3; //Because the server maybe slow...

		$data00 = $key . $salt;

		$hash = array();

		$hash[0] = hash('sha256', $data00, true);



		$result = $hash[0];

		for($i = 1; $i < $rounds; $i++){

			$hash[$i] = hash('sha256', $hash[$i - 1] . $data00, true);

			$result .= $hash[$i];

		}



		$dKey = substr($result, 0, 32);

		$iv = substr($result, 32, 16);



		return openssl_decrypt($ct, 'AES-256-CBC', $dKey, true, $iv);

	}



	public function encrypt($data){



		$salt = openssl_random_pseudo_bytes(16);



		$saltedData = '';

		$dx = '';

		// Salt the key(32) and iv(16) = 48

		while (strlen($saltedData) < 48) {

			$dx = hash('sha256', true);

			$saltedData .= $dx;

		}



		$eKey = substr($saltedData, 0, 32);

		$iv  = substr($saltedData, 32,16);



		$encrypted_data = openssl_encrypt($data, 'AES-256-CBC', $eKey, true, $iv);

		return base64_encode($salt . $encrypted_data);

	}



	/*

	 *  generate a randon 32 bits data and encrypt it

	 *  @param void

	 *  @return (String) random encrypted string

	 */



	public function generateKey(){

		//$key = openssl_random_pseudo_bytes(32);

        //Can't use this in PHP versions below 5.4

		//$key = password_hash($key, PASSWORD_DEFAULT);

         return substr(str_shuffle(".ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz012346789@?#"), 0, 64);

	}



	/*

	 *  Validades the user token, this function will be called upon each client request

	 *  @param (String) $userToken

	 *  @return (String) a "true" or "false" string that the user was validadeted

	 *	if the session was not validadeted destroy the session and deny the connection_aborted

	 *

	 */



	public function authSession($userToken, $isSigned, $HTTP, $REMOTE){

        session_start();

		//session_regenerate_id(true);

        //print $userToken . '<br />';

        //print $_SESSION['userToken'];

		//print $_SESSION['isSigned'] . '<br />';

		//print $_SESSION['HTTP_USER_AGENT'] . '<br />';

		//print $_SESSION['REMOTE_ADDR'] . '<br />';

		//print_r($_SESSION);

		if(isset($isSigned) and isset($userToken) and isset($HTTP) and isset($REMOTE)){

			//print 'var setadas';

			//verify the identity of the user

			if($isSigned == 'true'){

				//print 'here';

                return true;

			}

		} else {

			//print 'deu treta';

			session_destroy();

			unset($_SESSION);

			return false;

		}

		session_write_close();

	}



    /*

	 *  generate a randon 32 bits data and encrypt it

	 *  @param void

	 *  @return (Array) [requestStatus:boolean, newToken:string]

	 */

     function validadeRequest($userToken, $isSigned, $HTTP, $REMOTE){

        session_start();



        if($this->authSession($userToken, $isSigned, $HTTP, $REMOTE)){

			//print 'entrei if';

            $_SESSION["userToken"] = $this->generateKey();

            return array('requestStatus' => true, 'userToken' => $_SESSION["userToken"]);

        } else {

			//print 'nao entrei if';

            return array('requestStatus' => false, 'userToken' => "");

        }

     }

	/*

	*	Get the user agent,

	*	Obs.: I can often change this later, that's why the method call aproach

	*	@param (void)

	*	@return (String) userAgent

	*

	*/

	public function getUserAgent(){

		return $_SERVER['HTTP_USER_AGENT'];

	}



	/*

	*	Get the user IP,

	*	Obs.: I can often change this later, that's why the method call aproach

	*	@param (void)

	*	@return (String) userAgent

	*

	*/

	public function getUserIP(){

		return $_SERVER['REMOTE_ADDR'];

	}



    /*------------------------------------- PHP 5.3 VERSION ONLY ----------------------------

     -------------------------------------- DO NOT USE THIS IN PRODUCTION -------------

     --------------------------------------------------------------------------------- */

    /*

	*	Verify two hashed strings

	*	Obs.: I can often change this later, that's why the method call aproach

	*	@param (void)

	*	@return (String) userAgent

	*

	*/

    public function passwordVerify($dbPassword, $passwordInput){

        if (CRYPT_SHA512 != 1) {

            print "Fatal Error! Server Does not Support SHA-512 encyption";

            return false;

        } else {

            if (crypt($passwordInput, $dbPassword) == $dbPassword){

				return true;

            } else {

                return false;

            }

        }

    }

    /*

	*	Encrypt a string using SHA-512

	*	Obs.: I can often change this later, that's why the method call aproach

	*	@param (string) string

	*	@return (String) hashed_password

	*

	*/

    // public function encOneWayString($string){

    //      $salt = substr(str_shuffle("./ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz012346789"), 0, 8);

    //     if (CRYPT_SHA512 != 1) {

    //         print "Fatal Error! Server Does not Support SHA-512 encyption";

    //         return false;

    //     } else {

    //         return crypt($string, '$6$'.$salt);

    //     }

    // }

}

?>