Mac Reversing

I have decided to re-release my beginners tutorial, this time based on a crackme, so it deserves the upgrade to Universe instead of World. It includes patching, serial fishing and a keygen. I have updated some errors that I found in the original tutorial. Reversing and breaking protections is a great hobby and fantastic knowledge to possess. The problem is that many abuse this and want to profit from it. I really don’t like not sharing knowledge because sharing also allows me to progress, seeking new challenges and learning new things....

I shouldn’t be posting this because the guy doesn’t deserve any traffic he might get by writing this. But it’s so funny that I cannot resist (yes, I’m weak). The blog post is called “I Can Crack Your App With Just A Shell (And How To Stop Me)” and it’s available here. I especially like his advice because it shows he doesn’t know nothing about protecting apps and I have the feeling on that second article he links being a complete ripoff from one or two articles around the web....

This will be a working in progress so this post might be updated a few times. As promised, a reader sent me the Mac App Store (MAS) validation guidelines (thank you again!) and I got curious about one detail, the exit(173). This guides states if application fails to validate the receipt because it’s not present, then it should exit with status 173. This status will be interpreted by the system and it will try to obtain a valid receipt – this is the reason why you see that message asking for Sign in when the receipt isn’t valid and you can see the email address of the guy who released that app to the wild....

The Mac App Store opened yesterday and a few hours after the web is already full of news about the hacking/cracking/defeat/whatever of the store. When I heard about the Mac App Store, I became curious about how it would handle the serial and other protections of normal applications. I had read an article/news that talked about no more serials since the App Store would handle that – this is logical since you pay first to download the application, so the payment problem is solved....

The original method to hijack sysent table was described by Landon Fuller and then Braden Thomas updated it to Snow Leopard due to new location and lack of nsysent symbol. Charlie Miller and Dino Dai Zovi at The Mac Hacker’s Handbook, have some code to try to automate this search for sysent. I never tried it before and today I decided to hack around it. It suffers from the problem of no nsysent symbol (is there a way to fix it?...