Personal blog where I occasionally post about my projects, programming and security
VyOS is an open-source operating system based on Linux that provides
software-based networking. There’s an official
guide 
for setting up a Site-to-Site VPN between an on-premises VyOS router and AWS,
but it is fairly outdated, as it was written for VyOS 1.3, not for the current
LTS: VyOS 1.4 (sagitta). AWS also has the option to download a sample
configuration for…
A couple of months ago I discovered three issues that allow one to bypass app
lock in Ente Auth. The issues I found aren’t technically interesting and don’t
really deserve a blog post, but since Ente appears to be hesitant to notify
their users about them, off we go. 

 Disclaimer: I’m one of the authors of Aegis Authenticator . 

 Some background:…
We recently added support 
for scanning the new Google Authenticator export QR codes to Aegis
Authenticator. The single token URI format is
 well-documented ,
but the format of the QR codes displayed in the new export feature of Google
Authenticator is not. It’s not immediately obvious how the format works without
doing some reverse engineering, so I figured I’d…
Starting with the release of the Pixel 3, all of Google’s Pixel Android
smartphones come with the Titan M security chip on board. When I realized the
Pixel 3a XL I purchased also had it, I decided to try to take advantage of it in
an app I work on. It turned out that using the Titan M chip through the Android
Keystore API for AES-GCM in a specific way lead to predictable and…
With the release of the Ryzen 3000 series CPUs, I decided it was finally time to
upgrade from my good old Intel i5 2500K. It served me well for nearly 8 years,
but its age was starting to show. While doing the upgrade, I also wanted to
address the other two main pain points I had with my previous setup. Long story
short: I ended up installing NixOS and setting up PCI passthrough.…
I think I experienced a random bit flip while updating Linux on one of my
machines today. My laptop was humming along happily during compilation until GCC
suddenly aborted with an error: invalid preprocessing directive #lefine; did
you mean #define? . 

 

 Huh, #lefine instead of #define ? 

 Now, GCC is known for its cryptic error messages, but this one left…
On the 21th of June 2018, the release of the new wallet applications for Nano
was announced on
Reddit .
Shortly after that, another
announcement 
was made telling users of the Android app to transfer their funds to a wallet
with a seed that was not generated by the app. I quickly looked up the source
code and found that the app was using a random number generator that…