Choosing Your Android-Based Operating System

Android is a secure operating system that has strong app sandboxing, Verified Boot (AVB), and a robust permission control system. When you buy an Android phone, the device’s default operating system often comes with invasive integration with apps and services that are not part of the Android Open-Source Project. An example of such is Google Play Services, which has irrevocable privileges to access your files, contacts storage, call logs, SMS messages, location, camera, microphone, hardware identifiers, and so on....

July 18, 2022 · 9 min · 1724 words · Tommy

Choosing Your Desktop Linux Distribution

Not all Linux distributions are created equal. When choosing a Linux distribution, there are several things you need to keep in mind. Release Cycle You should choose a distribution which stays close to the stable upstream software releases, typically rolling release distributions. This is because frozen release cycle distributions often don’t update package versions and fall behind on security updates. For frozen distributions, package maintainers are expected to backport patches to fix vulnerabilities (Debian is one such example) rather than bump the software to the “next version” released by the upstream developer....

July 17, 2022 · 7 min · 1349 words · Tommy

Docker and OCI Hardening

Containers aren’t that new fancy thing anymore, but they were a big deal. And they still are. They are a concrete solution to the following problem: - Hey, your software doesn’t work… - Sorry, it works on my computer! Can’t help you. Whether we like them or not, containers are here to stay. Their expressiveness and semantics allow for an abstraction of the OS dependencies that a software has, the latter being often dynamically linked against certain libraries....

March 30, 2022 · 19 min · 3924 words · Wonderfall

F-Droid Security Issues

F-Droid is a popular alternative app repository for Android, especially known for its main repository dedicated to free and open-source software. F-Droid is often recommended among security and privacy enthusiasts, but how does it stack up against Play Store in practice? This write-up will attempt to emphasize major security issues with F-Droid that you should consider. Before we start, a few things to keep in mind: The main goal of this write-up was to inform users so they can make responsible choices, not to trash someone else’s work....

January 2, 2022 · 27 min · 5672 words · PrivSec.dev Contributors

FLOSS Security

While source code is critical for user autonomy, it isn’t required to evaluate software security or understand run-time behavior. One of the biggest parts of the Free and Open Source Software definitions is the freedom to study a program and modify it; in other words, access to editable source code. I agree that such access is essential; however, far too many people support source availability for the wrong reasons. One such reason is that source code is necessary to have any degree of transparency into how a piece of software operates, and is therefore necessary to determine if it is at all secure or trustworthy....

February 2, 2022 · 20 min · 4166 words · Rohan Kumar

Linux Insecurities

There is a common misconception among privacy communities that Linux is one of the more secure operating systems, either because it is open-source or because it is widely used in the cloud. However, this is a far cry from reality. There is already a very in-depth technical blog explaining the various security weaknesses of Linux by Madaidan, Whonix’s Security Researcher. This page will attempt to address some of the questions commonly raised in reaction to his blog post....

July 18, 2022 · 6 min · 1160 words · Tommy

Multi-factor Authentication

Multi-factor authentication is a security mechanism that requires additional verification beyond your username (or email) and password. This usually comes in the form of a one-time passcode, a push notification, or plugging in and tapping a hardware security key. Common protocols Email and SMS MFA Email and SMS MFA are examples of the weaker MFA protocols. Email MFA is not great as whoever controls your email account can typically both reset your password and receive your MFA verification....

July 16, 2022 · 6 min · 1219 words · Tommy

Securing OpenSSH with FIDO2

Passwordless authentication with OpenSSH keys has been the de facto security standard for years. SSH keys are more robust since they’re cryptographically sane by default, and are therefore resilient to most bruteforce atacks. They’re also easier to manage while enabling a form of decentralized authentication (it’s easy and painless to revoke them). So, what’s the next step? And more exactly, why would one need something even better? Why? The main problem with SSH keys is that they’re not magic: they consist of a key pair, of which the private key is stored on your disk....

April 9, 2022 · 5 min · 863 words · Wonderfall

Slightly Improving Mailcow Security

Mailcow is a fairly popular self-hosted mail server. If you use it, there are a few ways you can improve its security by following these steps. Postfix Configuration Consider disabling weak ciphers and TLS versions below 1.2 in data/conf/postfix/extra.cf: tls_high_cipherlist = ECDHE-ECDSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-GCM-SHA384:ECDHE-ECDSA-CHACHA20-POLY1305:ECDHE-RSA-CHACHA20-POLY1305:ECDHE-ECDSA-AES128-GCM-SHA256:ECDHE-RSA-AES128-GCM-SHA256 tls_preempt_cipherlist = yes smtp_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1 smtp_tls_ciphers = high smtp_tls_mandatory_ciphers = high smtpd_tls_protocols = !SSLv2, !SSLv3, !TLSv1, !TLSv1.1 smtpd_tls_ciphers = high smtpd_tls_mandatory_ciphers = high NGINX Configuration These security configurations can be added/modified in data/conf/nginx/includes/site-defaults....

July 18, 2022 · 2 min · 364 words · Tommy

Threat Modeling

The first task a person should do when taking steps to protect their privacy and security is to make a threat model. Defining a threat To make a threat model, we must first define a threat. A common mistake made by people who are just getting into the privacy space is to define the threat as “big-tech companies.” There is a fundamental problem with this definition: Why are we not trusting “big-tech companies,” but then shifting our trust to “small-tech companies”?...

July 18, 2022 · 9 min · 1912 words · Tommy