This article introduces the concept of “3TOFU” — a harm-reduction process when downloading software that cannot be verified cryptographically.
⚠ NOTE: This article is about harm reduction.
It is dangerous to download and run binaries (or code) whose authenticity you cannot verify (using a cryptographic signature from a key stored offline). However, sometimes we cannot avoid it. If you’re going to proceed with running untrusted code, then following the steps outlined in this guide may reduce your risk.
TOFU
TOFU stands for Trust On First Use. It’s a (often abused) concept of downloading a person or org’s signing key and just blindly trusting it (instead of verifying it).
3TOFU
3TOFU is a process where a user downloads something three times at three different locations. If-and-only-if all three downloads are identical, then you trust it.
Why 3TOFU?
The EFF’s Deep Crack proved DES to be insecure and pushed a switch to 3DES.
During the Crypto Wars of the 1990s, it was illegal to export cryptography from the United States. In 1996, after intense public pressure and legal challenges, the government officially permitted export with the 56-bit DES cipher — which was a known-vulnerable cipher.
In 2021, I raised $18,507 on CrowdSupply to manufacture and sell the BusKill cable. This article will review my experience working with Crowd Supply.
Introduction
So you have a great idea for a cool product, but you’re not sure how to scrap up the necessary funds to ramp-up production and sell it? If you’re a traditional capitalist then you’d be considering financing your new entrepreneurial venture through loans or venture capital.
But you’re not a capitalist. You want to avoid the fat cats draining equity from your hard labor. Your idea is so cool, why not try your hand at crowdfunding direct from your soon-to-be customers?
Why Crowd Supply?
The first place I looked was Kickstarter. But I did some googling, and I saw so many people complain that they backed a project on kickstarter and never received anything from the creator. In fact, Kickstarter’s own Fulfillment Report says that 9% of all their projects fail to deliver.
And, especially in the computer security department, if anyone with half a brain scans through the projects on kickstarter, even the ones that raise $1 million scream SCAM! Either their promises are unrealistic, they clearly have no idea what they’re talking . . . → Read More: Crowdfunding on Crowd Supply (Review of my experience)
This article will present a few simple website availability monitoring solutions for tor onion services.
Problem
So you’ve just setup an Onion Service for your website, but how often do you actually check that it’s working? Maybe it’s a .onion alias to an existing website, and you usually only check it on the clearnet. What’s to prevent the darknet presence of your website from going down for weeks without you noticing?
Indeed, it’s important to monitor your .onion websites so that you can discover and fix issues before your customers do. But how? Most of the popular uptime monitoring solutions (pingdom, freshping, statuscake, etc) certainly can’t monitor .onion websites.
This guide will enumerate some solutions for monitoring .onion websites, so you get an email alert if your site goes down.
Michael Altfield
Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡
This article will describe how to point a .onion domain at your existing wordpress sites (on wordpress multisite) so that your website will be accessible both on the clearnet and directly on the darknet via a .onion domain.
Intro
There are numerous security benefits for why millions of people use tor every day. Besides the obvious privacy benefits for journalists, activists, cancer patients, etc — Tor has a fundamentally different approach to encryption (read: it’s more secure).
Instead of using the untrustworthy X.509 PKI model, all connections to a v3 .onion address is made to a single pinned certificate that is directly correlated to the domain itself (the domain is just a hash of the public key + some metadata).
Moreover, some of the most secure operating systems send all the user’s Internet traffic through the Tor network — for the ultimate data security & privacy of its users.
In short, your users are much safer communicating to your site using a .onion domain than its clearnet domain.
For all these reasons, I wanted to make all my wordpress sites directly available to tor users. Unfortunately, I found that it’s not especially easy to point a .onion domain at . . . → Read More: WordPress Multisite on the Darknet (Mercator .onion alias)
This website is now accessible on the darknet. And how!
Why
Fun fact: the most popular website on the darknet is facebook. There are hundreds of other popular sites on the darknet, including debian, the CIA, the NYT, the BBC, ProPublica, and–now–michaelaltfield.net.
All of these organizations chose to make their websites available over .onion addresses so their website will be accessible from millions of daily tor users without leaving the darknet. Besides the obvious privacy benefits for journalists, activists, cancer patients, etc — Tor has a fundamentally different approach to encryption (read: it’s more secure).
Instead of using the untrustworthy X.509 PKI model, all connections to a v3 .onion address is made to a single pinned certificate that is directly correlated to the domain itself (the domain is just a hash of the public key + some metadata).
Moreover, some of the most secure operating systems send all the user’s Internet traffic through the Tor network — for the ultimate data security & privacy of its users.
In short, your users are much safer communicating to your site using a .onion domain than its clearnet domain.
This post will outline recommended steps to harden phpList after install to make it reasonably secure.
phpList is the most popular open-source software for managing mailing lists. Like wordpress, they have a phplist.com for paid hosting services and phplist.org for free self-hosting.
Earlier this week, it was announced that phpList had a critical security vulnerability permitting an attacker to bypass authentication and login as an administrator using an incorrect & carefully-crafted password in some cases. This bug is a result of the fact that [a] PHP is a loosely typed language and [b] the phpList team was using the ‘==‘ operator to test for equality of the user’s hashed password against the DB. This security pitfall has been known in PHP since at least 2010 (a decade ago!), but I’m sure the same mistake will be made again..
Indeed, security is porous. There’s no such thing as 100% vulnerability-free code, and phpList is no exception. But if we’re careful in adding layers of security to our infrastructure, then we might be able to protect ourselves from certain 0-days.
That said, here’s my recommended steps to making your phpList install reasonably secure.
This post will introduce a simple udev rule and ~$20 in USB hardware that effectively implements a kill cord Dead Man Switch to trigger your machine to self-destruct in the event that you’re kicked out of the helm position.
Rubber Ducky I <3 you; you make hack time lots of fun!
Let’s consider a scenario: You’re at a public location (let’s say a cafe) while necessarily authenticated into some super important service (let’s say online banking). But what if–after you’ve carefully authenticated–someone snatch-and-runs with your laptop?
Maybe you can call your bank to freeze your accounts before they’ve done significant financial harm. Maybe you can’t.
Or maybe your laptop was connected to your work VPN. In less than 60 seconds and with the help of a rubber ducky, the thief could literally cause millions of dollars in damages to your organization.
Surely there must be some solution to trigger your computer to lock, shutdown, or self-destruct when it’s physically separated from you! There is: I call it BusKill.
Michael Altfield
Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡
This article will describe PGP Certificate Flooding attacks as well as inform the reader
How to detect if you have a poisoned certificate in your keyring, How to identify & clean the poisoned cert, and How to update the configuration to prevent it from importing poisoned certs in the future
Last month, an attacker spammed several high-profile PGP certificates with tens of thousands (or hundreds of thousands) of signatures (CVE-2019-13050) and uploaded these signatures to the SKS keyservers.
Without looking very deep, I quickly stumbled on 4 keys that were attacked last month:
Michael Altfield
Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡
This article is a part 3/3 of a series describing how to setup an Ephemeral Firefox session as a Site-Specific Browser. The ultimate goal is to be able to have a self-destructing browsing session that can only access a single company’s services, such as Google or Facebook.
Part 1/3: Ephemeral Firefox in Ubuntu Part 2/3: Ephemeral Firefox with Extensions Part 3/3: Ephemeral Firefox as a Site-Specific Browser
After setting up the Site-Specific Ephemeral Firefox Browser, you can then blacklist services designated to your Site-Specific browser(s) (such as Google or Facebook) from your main browser. This significantly improves your ability to browse the internet without your activity being tracked by these companies — leaving your sensitive data vulnerable to being stolen by hackers.
Michael Altfield
Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡
I recently posted about how to create a sandboxed firefox profile to compartmentalize (and shred) your firefox browsing history in an Ephemeral Firefox session. But so far I’ve only covered how to create a simple vanilla firefox profile. What if you want your Ephemeral Firefox to include a few basic extensions?
This post will cover how to add extensions to your Ephemeral Firefox profile.
Part 1/3: Ephemeral Firefox in Ubuntu Part 2/3: Ephemeral Firefox with Extensions Part 3/3: Ephemeral Firefox as a Site-Specific Browser Michael Altfield
Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡
