IBM developerWorks has another new tutorial today with a look at locking down your PHP applications - "four security rules you can't violate".
In this tutorial, you'll learn how to add security to your PHP Web applications. It is assumed that you've been coding PHP Web applications for at least a year, so it won't cover the basics of the language (either conventions or syntax). The goal is to make you more aware of what you should be doing to secure the Web applications you're building.
This tutorial teaches you how to guard against the most common security threats: SQL injections, the manipulation of the GET and POST variables, buffer overflow attacks, cross-site scripting attacks, data manipulation inside the browser, and remote form posting.
You'll need a system already running PHP (at least version 4.x) and MySQL on a web server (Apache or otherwise). They look briefly at some of the common security issues plaguing web applications these days before moving on to the four rules:
- Never trust outside data or input
- Disable PHP settings that make security difficult to enforce
- You can't secure it if you can't understand it
- "Defense in depth" is your new mantra
They take a look at each of these and use the rest of the article (8 more pages) showing you how to keep yourself safe from these issues.