<?php
/*
 * Copyright 2007-2011 Charles du Jeu <contact (at) cdujeu.me>
 * This file is part of AjaXplorer.
 *
 * AjaXplorer is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * AjaXplorer is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with AjaXplorer.  If not, see <http://www.gnu.org/licenses/>.
 *
 * The latest code can be found at <http://www.ajaxplorer.info/>.
 */
defined('AJXP_EXEC') or die( 'Access not allowed');

/**
 * @package info.ajaxplorer.core
 */
/**
 * Credential keeper that can be stored in the session, the credentials are kept crypted.
 */
class AJXP_Safe{
	
	private static $instance;
	
	private $user;
	private $encodedPassword;
	private $secretKey;	
	private $separator = "__SAFE_SEPARATOR__";
	private $forceSessionCredentials = false;
	/**
     * Instance constructor
     */
	public function __construct(){
		if(defined('AJXP_SAFE_SECRET_KEY')){
			$this->secretKey = AJXP_SAFE_SECRET_KEY;
		}else{
			$this->secretKey = "\1CDAFx¨op#";
		}
	} 
	/**
     * Store the user/password pair. Password will be encoded
     * @param string $user
     * @param string $password
     * @return void
     */
	public function setCredentials($user, $password){
		$this->user = $user;
		$this->encodedPassword = $this->_encodePassword($password, $user);
	}
	/**
     * Return the user/password pair, or false if cannot find it.
     * @return array|bool
     */
	public function getCredentials(){
		if(isSet($this->user) && isSet($this->encodedPassword)){
			$decoded = $this->_decodePassword($this->encodedPassword, $this->user);
			return array(
				"user" 		=> $this->user,
				"password"	=> $decoded,
				0			=> $this->user,
				1			=> $decoded
			);
		}else{
			return false;
		}
	}
	/**
     * Use mcrypt function to encode the password
     * @param $password
     * @param $user
     * @return string
     */
	private function _encodePassword($password, $user){
		if (function_exists('mcrypt_encrypt'))
        {
	        // The initialisation vector is only required to avoid a warning, as ECB ignore IV
	        $iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND);
	        // We encode as base64 so if we need to store the result in a database, it can be stored in text column
	        $password = base64_encode(mcrypt_encrypt(MCRYPT_RIJNDAEL_256,  md5($user.$this->secretKey), $password, MCRYPT_MODE_ECB, $iv));
        }
		return $password;
	}
	/**
     * Use mcrypt functions to decode the password
     * @param $encoded
     * @param $user
     * @return string
     */
	private function _decodePassword($encoded, $user){
        if (function_exists('mcrypt_decrypt'))
        {
             // The initialisation vector is only required to avoid a warning, as ECB ignore IV
             $iv = mcrypt_create_iv(mcrypt_get_iv_size(MCRYPT_RIJNDAEL_256, MCRYPT_MODE_ECB), MCRYPT_RAND);
             // We have encoded as base64 so if we need to store the result in a database, it can be stored in text column
             $encoded = trim(mcrypt_decrypt(MCRYPT_RIJNDAEL_256, md5($user.$this->secretKey), base64_decode($encoded), MCRYPT_MODE_ECB, $iv), "\0");
        }
		return $encoded;
	}
	/**
     * Store the password credentials in the session
     * @return void
     */
	public function store(){
		$_SESSION["AJXP_SAFE_CREDENTIALS"] = base64_encode($this->user.$this->separator.$this->encodedPassword);
	}
	/**
     * Load the credentials from session
     * @return
     */
	public function load($encodedString = ""){
        if($encodedString == "" && !empty($_SESSION["AJXP_SAFE_CREDENTIALS"])){
            $encodedString = $_SESSION["AJXP_SAFE_CREDENTIALS"];
        }
		if(empty($encodedString)) return;
		$sessData = base64_decode($encodedString);
		$parts = explode($this->separator, $sessData);
		$this->user = $parts[0];
		$this->encodedPassword = $parts[1];
	}
	/**
     * Remove the credentials from session
     * @return void
     */
	public function clear(){
		unset($_SESSION["AJXP_SAFE_CREDENTIALS"]);
		$this->user = null;
		$this->encodedPassword = null;
	}
	/**
     * For the session credentials to override other credentials set via config
     * @return void
     */
	public function forceSessionCredentialsUsage(){
		$this->forceSessionCredentials = true;
	}
	
		
	
	/**
	 * Creates the singleton instance
	 * @return AJXP_Safe
	 */
	public static function getInstance(){
		if(empty(self::$instance)){
			self::$instance = new AJXP_Safe();
		}
		return self::$instance;
	}
	/**
     * Store the user/pass key pair
     * @static
     * @param string $user
     * @param string $password
     * @return void
     */
	public static function storeCredentials($user, $password){
		$inst = AJXP_Safe::getInstance();
		$inst->setCredentials($user, $password);
		$inst->store();
	}
	/**
     * Remove the user/pass encoded from the session
     * @static
     * @return void
     */
	public static function clearCredentials(){
		$inst = AJXP_Safe::getInstance();
		$inst->clear();
	}
	/**
     * Retrieve the user/pass from the session
     * @static
     * @return array|bool
     */
	public static function loadCredentials(){
		$inst = AJXP_Safe::getInstance();
		$inst->load();
		return $inst->getCredentials();
	}

    public static function getEncodedCredentialString(){
        return $_SESSION["AJXP_SAFE_CREDENTIALS"];
    }

    public static function getCredentialsFromEncodedString($encoded){
        $tmpInstance = new AJXP_Safe();
        $tmpInstance->load($encoded);
        return $tmpInstance->getCredentials();
    }
		
	/**
	 * Will try to get the credentials for a given repository as follow :
     * + Try to get the credentials from the url parsing
     * + Try to get them from the user "Wallet" (personal data)
     * + Try to get them from the repository configuration
     * + Try to get them from the AJXP_Safe.
     * 
	 * @param array $parsedUrl
	 * @param Repository $repository
     * @return array
	 */
	public static function tryLoadingCredentialsFromSources($parsedUrl, $repository){
		$user = $password = "";
		$optionsPrefix = "";
		if($repository->getAccessType() == "ftp"){
			$optionsPrefix = "FTP_";
		}
		// Get USER/PASS
		// 1. Try from URL
		if(isSet($parsedUrl["user"]) && isset($parsedUrl["pass"])){
			$user = rawurldecode($parsedUrl["user"]);
			$password = rawurldecode($parsedUrl["pass"]);
		}
		// 2. Try from user wallet
		if($user==""){
			$loggedUser = AuthService::getLoggedUser();
			if($loggedUser != null){
				$wallet = $loggedUser->getPref("AJXP_WALLET");
				if(is_array($wallet) && isSet($wallet[$repository->getId()][$optionsPrefix."USER"])){
					$user = $wallet[$repository->getId()][$optionsPrefix."USER"];
					$password = $loggedUser->decodeUserPassword($wallet[$repository->getId()][$optionsPrefix."PASS"]);
				}
			}
		}
		// 3. Try from repository config
		if($user==""){
			$user = $repository->getOption($optionsPrefix."USER");
			$password = $repository->getOption($optionsPrefix."PASS");
		}
        // 4. Test if there are encoded credentials available
        if($user == "" && $repository->getOption("ENCODED_CREDENTIALS") != ""){
            list($user, $password) = AJXP_Safe::getCredentialsFromEncodedString($repository->getOption("ENCODED_CREDENTIALS"));
        }
		// 5. Try from session
		if($user=="" && ( $repository->getOption("USE_SESSION_CREDENTIALS") || self::getInstance()->forceSessionCredentials )){
			$safeCred = AJXP_Safe::loadCredentials();
			if($safeCred !== false){			
				$user = $safeCred["user"];
				$password = $safeCred["password"];
			}
		}		
		return array("user" => $user, "password" => $password);
		
	}
	
}

?>
