php – 用于存储/检索PGP私钥和密码的安全方法？

据了解,这条链中最薄弱的环节就是处理私钥和密码.从我下面的代码可以看出,我只是使用file_get_contents从当前Web目录中的文件中检索密钥和密码 – 不好.

我的问题是：什么是安全地检索私钥和密码以用于解密登录信息的好方法？也许我应该通过身份验证的远程文件服务器存储/检索私钥？

我搜索了最佳做法,但是找不到多少.

class DB {

    protected $_config;
    protected $_iUserId;
    protected $_iServerId;
    protected $_dbConn;
    protected $_sPubKey;
    protected $_sPrivKey;


    public function __construct($iUserId,$iServerId) {

        //bring the global config array into local scope
        global $config;
        $this->_config = $config;

        $this->_iUserId = $iUserId;
        $this->_iServerId = $iServerId;

        $this->_sPubKey = file_get_contents("public_key");
        $this->_sPrivKey = file_get_contents("private_key");
        $this->_sPrivKeyPass = trim(file_get_contents("private_key_pass"));

    }

    //connect to the database
    public function connect() {
        try {


            $this->_dbConn = new PDO("pgsql:host=".$this->_config['db_host']." dbname=".$this->_config['db_name'],$this->_config['db_username'],$this->_config['db_password']);

            echo "PDO connection object created";
        } catch(PDOException $e) {

            echo $e->getMessage();

        }

    }

    public function insertServerDef($sHost,$iPort,$sUser,$sPass) {

        //testing
        $iUserId = 1;

        $oStmt = $this->_dbConn->prepare("INSERT INTO upze_server_def (server_id,host_address,ssh_port,username,pass,user_id) VALUES (DEFAULT,:host_address,:ssh_port,:username,pgp_pub_encrypt(:pass,dearmor(:pub_key)),:user_id)");
        $oStmt->bindParam(':host_address',$sHost);
        $oStmt->bindParam(':ssh_port',$iPort);
        $oStmt->bindParam(':username',$sUser);
        $oStmt->bindParam(':pass',$sPass);
        $oStmt->bindParam(':pub_key',$this->_sPubKey);

        $oStmt->bindParam(':user_id',$iUserId);
        $oStmt->execute();

    }

    public function getServerDef($iServerId) {

        $oStmt = $this->_dbConn->prepare("  SELECT server_id,pgp_pub_decrypt(pass,dearmor(:priv_key),:priv_key_pass) As decryptpass 
                                            FROM upze_server_def usd 
                                            WHERE usd.server_id = :server_id
                                        ");

        $oStmt->bindParam(':server_id',$iServerId);
        $oStmt->bindParam(':priv_key',$this->_sPrivKey);
        $oStmt->bindParam(':priv_key_pass',$this->_sPrivKeyPass);
        $oStmt->execute();

        while($row = $oStmt->fetch()) {
            echo "<pre>".print_r($row)."</pre>";
        }

    }

    //close any existing db connection
    public function close() {
        $this->_dbConn = null;
    }


    //close any existing db connections on unload
    public function __destruct() {
        $this->_dbConn = null;
    }

}