Revision as of 08:17, 7 June 2008

Overview

The enormous global increase of information which is to be stored, forces certain approaches of archiving and restoring data, while keeping track of numerous valuable and essential preconditions, e. g. data integrity.

Relational databases are still the common way of accomplishing the storage of masses of information, although its conceptional basics reach back to 1970, where E. F. Codd firstly introduced this method of data handling [Cod70].

As global networking dramatically increased the past decades, the TCP/IP protocol stack has become very popular and nowadays builds the fundamental backbone of the Internet. As conclusion to this tendency, also the way of controlling and operating relational database systems mostly relies on the mentioned protocol suites, with all advantages and disadvantages, inherently given by using them.

Accessability and reliability of information services is often constrained by providing them over the Internet, which should be seen as naturally untrusted and insecure network, since not only permitted persons are able to try to establish connections. With the aspect of Unix-like system environments in mind, I’ll figure out how to secure and harden database systems primarily on Linux, taking MySQL 5 as example, since this software is commonly used and widespread, especially over the Internet, for it is Open Source Software. Except for the description of filesystem encryption, all examples should work also on other POSIX compliant operating systems than Linux.

The language of given sourcecodes should be clear from the context they are mentioned. However, shell scripts are written using the Bourne Again Shell (/bin/bash), and most sources are plain C. When shell command examples are given, every line is prefixed with either # or $. While the hash indicates that the following statement has to be called as root user, the dollarsign commands doesn’t need administrative permissions.

Sectional overview

• Firstly, we will deal about hardening the underlying operating system environment. This is an ultimately essential step towards application layer security, since also the best security mechnism and configuration won't be useful if the whole system is attackable one layer beyond the actual target application. Operating system hardening includes setting right filesystem permissions, the design and implementation of a virtual chroot-jail application executing environment, the use of access control lists as well as a quick introduction about modern virtualization approaches.
• The next topic will be about cryptography, which we will use to aid and secure our database instance at filesystem level and, possibly even more important, the DMBS' communication channels. This will be achieved using either OpenSSL, OpenSSH or OpenVPN. For encrypting the raw database pages themselves, we'll also take a look about filesystem encryption.
• Due to some quite aweful security bugs in the past, we'll discuss how the application's memory area can be protected against stack- and heap-smashing attacks for executing arbitrary code on the machine which actually executes the MySQL database server.
• Then we'll discuss certain security-related MySQL configuration attributes. MySQL is quite straight to configure, but nevertheless there are a few options which inside the configuration files which make life easier - and more secure.
• Finally the access control and privilege management mechanism of the MySQL DBMS itself will be explored and shown in some detail.

Description

References