In the April issue of the PHPArch magazine (also published on her blog), Elizabeth Tucker Long wrote a really interesting editorial piece coining a concept she called Security-Driven-Development. She (quite correctly) identified a problem in the current development community where security has become an after-thought (if it’s thought of at all). This isn’t a new concept, in fact it’s a concept that I and many others have been preaching for quite a while now. However I’ve been coming to realize that I’ve had it wrong the whole time. And I think the entire industry is getting it wrong today.

There’s been a bit of noise in the past week about the proper way to prevent Cross-Site-Request-Forgery (CSRF) attacks. It seemed to have started with this post. There’s been discussion in the comments, and on Twitter about it, and there seems to be several opposing viewpoints on the matter. I want to start off by saying that I agree completely with the post in question. But I figured I’d write a post to explain WHY I agree with it.

There are numerous articles on the web about how to properly use bcrypt in PHP. So this time, rather than write yet-another-how-to-use-bcrypt article, I’m going to focus on the mistakes that are commonly made when implementing bcrypt. So, let’s dive right in:

Almost two years ago I had stumbled upon a pretty significant vulnerability in the StackExchange network. I say stumbled, because I wasn’t actually trying to attack the site. Circumstance just showed me a door. The actual attack is pretty interesting, and it holds a lesson for everybody who builds or maintains websites or server infrastructure. So here’s the story on how I hacked StackOverflow…

Every day I come across code that is insecure. Sometimes the code is so hilariously insecure that any 10 year old could break it. I’ve also gotten into discussions with people who should know better about their practices. It’s very, how to put this, disheartening. It’s sad that the average developer knows (and cares) so little about proper security practices. So, I’ve put together a simple pledge (or manifesto, if you’d like).

Yesterday, I read an article about using GPUs to accelerate password hashing: No, Heavy Salting of Passwords Is Not Enough, Use CUDA Accelerated PBKDF2. The article makes some very interesting points about password hashing. But the conclusion of the article really misses a huge point, and get a major point fundamentally wrong (bordering on misunderstanding). Let’s start with the part they got wrong…

The other day I announced the release of my new password hashing library, PasswordLib. As I’ve come to expect, Reddit was full of interesting commentary on the topic. Some was good, some was bad and some surprised me. What surprised me was the insistence on a global salt (otherwise known as a “pepper”). So, I started thinking about it some more, and I figured I’d write a post on why I don’t use peppers in my hashing algorithms (and why you may want to rethink it too).

Today, I’m proud to announce the immediate availability of a new password hashing library for PHP: PasswordLib. The project is a spin-off of another that I started about a year ago, CryptLib. I was unable to find a clean solution to a few problems in CryptLib, so dev work stalled for a while. I realized recently that the password hashing functionality was complete, so if I stripped out the incomplete parts, it would still be a very useful library. And so PasswordLib was born.

Well ok, not really. But you should not be securing hashes against rainbow tables anymore, you need to secure them against brute forcing. Rainbow tables are still very effective for simple hashes (md5($password)), but just because an algorithm is hard to use for a rainbow table doesn’t mean that it is safe, because the rainbow table is dead…

The other day, an article popped up in my feed reader that had a very interesting title (to me at least), Simple and Secure Login Script. As usual, I decided to click the link and give the article a read. Not overly shocking was the fact that I didn’t find the content of the article to be, how shall I say this…, overly factual. It’s not really a “tutorial”, but more of a “here’s some code that’s secure”. A quick review of the code found more than one vulnerability, and some significant things that I would change about it (as well as a few “really bad practices”).

So, rather than write a “rant post” about the code, I’ve decided to take another tactic. In this article, I’m going to walk you through my process for performing a security code review. Inline with the review, we’ll take note of any issues that we do find, and number them. Then at the end of the review, we’ll go over each one and look at potential mediation that we can apply and how to fix the issues.