Featured Articles

Nightmare on Lemmy Street (A Fediverse GDPR Horror Story)
Hardening Guide for phpList
WordPress Multisite on the Darknet (Mercator .onion alias)
Trusted Boot (Anti-Evil-Maid, Heads, and PureBoot)
Introducing BusKill: A Kill Cord for your Laptop
Continuous Documentation: Hosting Read the Docs on GitHub Pages (2/2)
Crowdfunding on Crowd Supply (Review of my experience)
WordPress Profiling with XHProf (Debugging & Optimizing Speed)
Detecting (Malicious) Unicode in GitHub PRs
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Introducing BusKill: A Kill Cord for your Laptop

Bus Kill: A USB Kill Cord for your Laptop

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 ➡

About Michael


. . . → Read More: Introducing BusKill: A Kill Cord for your Laptop

Ephemeral Firefox as a Site-Specific Browser (3/3)

Site-Specific Ephemeral Firefox featured image showing a firewall between the facebook and firefox icons

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 ➡

About Michael


. . . → Read More: Ephemeral Firefox as a Site-Specific Browser (3/3)

Detect outgoing port blocking with nmap and portquiz.net

This post will describe how to detect if your network is blocking outgoing ports. In this test, we’ll be using nmap and the fine website portquiz.net

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: Detect outgoing port blocking with nmap and portquiz.net

Detecting Censorship or ISP Network Tampering with OONI

This article will introduce a tool to detect censorship or network tampering using the Open Observatory of Network Interference (OONI) android app, which is part of the Tor Project.

The OONI project’s mission is to collect data on network providers to determine where the Internet is free and where it’s being manipulated. For example, the OONI Explorer displays a world map of such data.

On the OONI explorer, you can drill-down on the world map into a specific country to get a list of websites that were detected as being blocked from within that country.

For example, when I looked at the history of OONI probe runs within the US, I saw a list of the usual suspects: gambling sites, pornography sites, torrenting sites, etc. More surprising (at least to me) was the number of pastebin sites that were banned. And, despicably, there was a network in the US blocking The Internet Archive

When I looked at the data from scans within another great “free country” = India, I saw a lot of cherry-picked censorship on facebook and news articles as it relates to the 2017 genocide of Rohingya Refugees in Burma and various muslim/hindu conflicts.

Anyone
. . . → Read More: Detecting Censorship or ISP Network Tampering with OONI

Bypassing Check Point firewall DPI Tor-blocking

This article will describe how to bypass censorship from within any network that uses firewalls using Deep Packet Inspection (DPI) built by the Israeli software company Check Point Software Technologies Ltd, such as is being used by the Miami-Dade’s Public Library System to censor on their public wifi.

I’ve been very fortunate to live in a country where freedom of speech is a well-protected human right and censorship is generally unaccepted. But, I’ve long been aware that many States prefer to assert their control over their citizens by controlling their available information. One of the shining achievements from the Tor Project is a system that allows these unfortunate souls to be able to bypass these censors and access the unfettered Internet. Indeed, the UN affirmed that a State’s attempt to prevent or disrupt dissemination of information online is a violation of international human rights law, as defined by article 19 of the Universal Declaration of Human Rights.

Of course, many States today continue to ban access to the Tor network. In response, Tor provided hidden entry-points called bridge relays that are harder to block. In response to Tor bridges, States purchased firewalls from companies like Check Point to analyze the
. . . → Read More: Bypassing Check Point firewall DPI Tor-blocking

HPKP Best Practices for Let’s Encrypt

This post describes how to generate a few backup public key hashes to add to your HTTP Public Key Pinning (HPKP) config that might save you from bricking your domain if Let’s Encrypt ever gets untrusted like StartCom did.

If you have a healthy distrust of the X.509 PKI trust model, then you’ve probably heard of HPKP (and probably also HSTS & CAA). Website certificate pinning was a trend first started by google, who hard-coded a pin of their certificates in their Chrome browser. Eventually, google helped build a more standardized pinning method under RFC 7469. And today, it’s supported by Chrome, Firefox, and Opera.

Pinning is a great TOFU improvement to https, but–if misconfigured–you could “brick” your domain–making it so that your client’s browsers will refuse to let them access your site for months or years (interestingly, this has also caused some security experts to think of how HPKP could be abused in ransom-ware). Therefore, it’s a good idea to follow a few HPKP Best Practices.

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael


. . . → Read More: HPKP Best Practices for Let’s Encrypt

Howto Guide: Whole House VPN with Ubiquiti + Cryptostorm (netflix safe!)

This post will describe what hardware to buy & how to configure it so that you have 2 wireless networks in your house: One that seamlessly forces all of the traffic on that network through a VPN–and one that connects to the Internet normally . When finished, the internet activity for any device connected to the first network will be entirely encrypted so that the ISP cannot see which websites are visited*, what software you use, and what information you send & receive on the internet.

* Assuming your config doesn’t leak DNS; see improvements section

Update 2017-08-25: Added “kill switch” firewall rule that prevents LAN traffic from escaping to the ISP unless it passed through the VPN’s vtun0 interface first. Following this change, if the VPN connection is down, the internet will not be accessible (as desired) over the ‘home’ wifi network (without this, the router bypasses the VPN by sending the packets straight to the ISP–giving a false sense of privacy).

Update 2021-02-01: Fixed GitHub URL of cryptostorm’s free OpenVPN configuration file Update 2021-02-14: Fixed GitHub URL of cryptostorm’s paid OpenVPN configuration file

Update: I wrote this guide in 2017. It’s intended for an audience that has
. . . → Read More: Howto Guide: Whole House VPN with Ubiquiti + Cryptostorm (netflix safe!)

Let’s Encrypt!

Finally, this website is (only) accessible over https!

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael

tech.michaelaltfield.net/

UCF Wifi in Ubuntu

This month (September 2011), UCF officially killed the “UCF” SSID to be replaced by “UCF_WPA” and “UCF_WPA2.” Configuring Ubuntu Linux to connect to the UCF WPA2 network is neither trivial nor documented by UCF.

To aid other UCF Ubuntu users, I created a Wireless article on the unofficial UCF wiki. This includes links to the official UCF certificates and instructions on how to connect to the UCF_WPA2 network in Ubuntu.

Michael Altfield

Hi, I’m Michael Altfield. I write articles about opsec, privacy, and devops ➡

About Michael

tech.michaelaltfield.net/

UCF Wifi Rant

While I frustratingly waited to connect to the UCF Wifi after a recent change to their system, I typed up the following email complaint to the UCF DoIT Manager. If *you* have also had issues with unstable/dropped connections, slow bandwidth, latency, or the inability to connect to the UCF Wifi, I urge you to also contact the UCF Department of Information Technology via:

cst@ucf.edu = General bob.yanckello@ucf.edu = Bob Yanckello (UCF Chief Technology Officer) lou.garcia@ucf.edu = Lou Garcia (UCF Network Manager [responsible for wireless services]) chrisv@mail.ucf.edu = Chris Vakhordjian (Information Security Office) tim.larson@ucf.edu = Tim Larson (ERP Consultant) jim.ennis@ucf.edu = Jim Ennis (Enterprise Systems & Operations) andy.hulsey@ucf.edu = Andy Hulsey (Telecommunications [includes Network Services]) aaron.streimish@ucf.edu = Aaron Streimish (Project Performance & Management Office)

Email below

While I understand the benefit of encrypted wireless communications, UCF’s decision to require all student wireless clients to use WPA without preparing to sufficiently upgrade the wireless infrastructure has rendered the UCF Wifi *unusable*.

Allow me to provide a brief log of my Internet Experience this afternoon (2011-09-15).

12:02 – attempt to connect to WiFi – fail for 9 minutes 12:11 – connected 12:11 – google ’email ucf department of information technology’ 12:12 – disconnected
. . . → Read More: UCF Wifi Rant