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I’ve been using GitHub Actions on a few projects now, and I find them like the future of what bash scripting was back in the day. I feel I can do pretty much everything in a quick and concise way. In this post, I’ll show you the setup I use for a simple Build and Deploy GitHub Action.
This post is not an in-depth view on GitHub Actions, but let’s review some basic concepts, so we know what we are talking about.
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Creating a jailed web server is a fun exercise to learn how about jails. If you are reading this post, you are probably already convinced of the benefits of running your services inside jails. A jailed service provides additional security by restricting the jailed environment to access only to its perceived root directory. We can run many services in the same host, and we could isolate them to their own jailed environment. Another useful trait of jails is dependency segregation. We can run different jails that depend on different versions of the same libraries or programs, without causing problems between them. Each jail will have its own userland. In this post, we are going to explore how to run a service inside a jail. We are going to use Nginx as an example, but you can take what you learned in the post and apply it to your specific case.
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Hello, and welcome to issue #26!
Did you manage to see the launch of SpaceX first crew mission? It was a success! There were 10.3 million concurrent watchers on the stream, that’s massive. If you somehow miss it here is the link to space.com article, it includes videos. It was cool to watch. It felt like the beginnings of a sci-fi story.
Anyways, Important news for humanity aside. There was also other important news around. In the previous newsletter (#25), we talked about the new unc0ver jailbreak for iOS. This week Apple released new updates, iOS 13.5.1 and iPadOS 13.5.1, that fix the kernel bug that allowed this exploit. You can read the release notes here. I guess some people won’t be wanting to apply that patch if they’re going to jailbreak their phones.
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Sometimes deciding on a partition schema could be a confusing, here are my notes on partitioning a GPT disk. I hope you find them useful.
I will advice creating a virtual machine using FreeBSD and take it for a spin. It would be nice if we had lots of physical devices we could work with to gain more experience, but a virtual machine will do.
Before we begin, make sure you have a copy of FreeBSD. You can download it from here. My architecture is amd64 so that’s what I’ll use.
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Hello, and welcome to issue #23!
How are things your way? I hope that coping1 well with the changes and keeping safe. Things are quite different from what I expect them to be by this time in the year. I was hoping this year I was going to make a significant career change, but there is no international travel, and things seem to be slowing down. So, who knows what the future might bring.
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I use Parallels on macOS to spin virtual machines for learning purposes. Lately, I’ve been interested in FreeBSD, so I wanted to create a slimmed-down version of the FreeBSD Kernel for my VM. And that is the topic of this post, how to create a custom FreeBSD Kernel for a Parallels virtual machine. It is not limited to Parallels tho. You can easily use the content of this note to build any custom Kernel.
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I use Middleman as my Static Site Generator, I have two “blogs” in my site:
blog - contains more lengthy and detailed articles.til - contains short entries that I use as a reference, and not necessarily a full well-researched article.
When I created the TIL blog I wanted it to be my repository of small notes for things I learned that day (hence the name Today I Learned).
Naming is important, and the TIL has prevented me from posting short pieces on my site because it’s not something I “learned today”. So I decided Notes would be a better name.
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There are many fields in Computer Science, and tech in general, where you’ll want a lab with multiple VMs, containers, or even physical devices running various services. When learning networks, it’s useful to have a local lab. Another example is when doing Reverse Engineering, we sometimes want to work on an ARM processor instead of our desktop x86 processor, so we create a VM.
You get the idea. At some point in your career, you’ll find yourself surrounded by many hosts running services in different ports. Not having a system to reference your host can become a source of confusion. For example, if you stop for the weekend, the following Monday you have to go through your history to figure out if you were using port 2222 or port 2223 to ssh to the VM you were working on last week. In this short post, I’ll show you some techniques I use to keep my lab organised.
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If you want to get into mobile security or reverse engineering, you’ll get to a point when you would like to have access to an ARM processor. There are many devices you could use, but one very cheap (in price not in quality) is the Raspberry pi. You can get one for about 35$, which opens up the doors to a lot of learning. But sometimes you don’t want to carry an additional device, so what to do? Well, you can run a virtual machine that is ARM-based. That is what we are going to explore in this short post, how to install Raspbian OS using QUEMU so you can create your own ARM lab.
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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 option is risk breaking your work machine in your experiments (not fun). To build our VM, we need to use Disk Images, another topic that is useful in other areas.
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