Using Radare2 to patch a binary Dec 28 2019

When reversing a binary, sometimes it's useful to modify how the binary behaves. We can accomplish this by changing the binary itself. If we had the source code, it'd be easy, but for us, it'll require looking at the decompiled code and deciding which...

Using LLDB for reverse engineering Dec 20 2019

I've been exploring reverse engineering, and it's a fascinating topic. There are many ways to analyse a binary. Usually, the analysis is divided into two types, static and dynamic. Static analysis is when you decompile the binary and read the assembly...

Let's write some assembly code in macOS for Intel x86_64 Dec 12 2019

This is going to be a small article on the basics of working with Assembly Language. We won't go deep into building extensive programs in assembly. The main idea of this post is to clarify the workflow for creating an assembly program and some key...

Understanding Disk Images by building a macOS Catalina ISO image for VirtualBox [macOS] Dec 4 2019

Having a virtual machine running macOS opens up a lot of opportunities for learning. If you are into security, you can set up a VM for your security lab. Or if you want to learn networking or kernel debugging, it is also helpful to use a VM. The other...

Managing UTI and URL schemes via Launch Services' API from Swift Nov 27 2019

Apple provides the Launch Services API so we can interact with different applications from our current process. We can define URL schemes for our apps, and when that URL is opened, our app gets launched. We can also specify which application to open...

Command-line argument parsing using Swift Package Manager's TSCUtility module Nov 21 2019

If you've used the Swift Package Manager, you have interacted with its handy command-line tool. When creating command-line tools, we strive to provide an easy to use interface. One of the main characteristics of a good CLI tool is how it handles parameters...

Creating a state machine in Swift Nov 13 2019

State machines are used to model systems that can be thought of as a collection of states, and a collection of events that cause state changes. Many of the systems we want to model can be abstracted to a state machine. For example, elements in a Game...

Making a C library available in Swift using the Swift Package Manager Nov 7 2019

System libraries are typically defined using C, that means we need a way to make them available to Swift. In this post, we are going to explore how to use the Swift Package Manager to give us access to C libraries, be it system or user-defined.

Let...

Multithreading with pthreads in Swift Oct 29 2019

Long gone are the days when single process single thread was the norm. We now take multithreading for granted, we expect all our applications not to lockup when we interact with them. We expect them to handle multiple users at the same time, etcetera...

Creating a Launch Agent that provides an XPC service on macOS using Swift Oct 21 2019

Last week we discussed how to build XPC Services(the .xpc bundles) inside your macOS applications. This week we are going to explore how to provide XPC services that can be used from other applications or tools.

To make the XPC service available to...