Featured Articles

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

fix phplist 500 error due to random_compat

So you've just done a fresh install of phplist, but when you attempt to load it in your browser, you get a 500 Internal Server Error. But the error log is empty! It's possible that phplist is suppressing the errors produced by the included library random_compat. This blog post will describe this possible issue, and how to resolve it.

. . . → Read More: fix phplist 500 error due to random_compat

Michael Altfield's gravatar

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

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

Michael Altfield's gravatar

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.

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

Michael Altfield's gravatar

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

Michael Altfield's gravatar

New Thumb Drive Encryption Procedure

In this article, I'll describe a procedure for preparing a brand-new USB flash drive for use. First we'll securely erase all the data on the drive, then we'll encrypt the entire drive, and--finally--we'll check the drive for bad blocks.

Ah, remember the good-ole days of spinning disks? When your OS could tell your hard *disk* to shred a specific sector? Like it or not, those days are gone in the land of USB flash volumes.

There's a lot of great reads on the complications of securely erasing data on a USB thumb drive. Unfortunately, a lot of the techniques are not universal to all technologies or manufacturers. Consequently, my approach is more ignorant, straight-forward, and broad (at the risk of causing these cheap usb drives to fail sooner & the process taking longer):

First, I make sure never to write any unencrytped data to the disk Second, when I want to wipe the disk, I fill it entirely with random data

Below are the commands that I use to prepare a new usb drive for my use immediately after purchase. These commands are presented as a rough guide; they're mostly idempotent, but you probably want to copy & paste them
. . . → Read More: New Thumb Drive Encryption Procedure

Michael Altfield's gravatar

GPG Key Transition Statement

After 8 years, I've decided to transition from my original GPG key and replace it with one that uses a stronger master key that meets NIST guidelines.

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Michael Altfield's gravatar

How to check the Public Key Algorithm used for a given gpg key (ie: RSA vs DSA)

Today I discovered how to validate the Public Key Algorithm that's used for a given gpg key. Unfortunately, it's extremely unintuitive & took quite a bit of digging to figure out how. So I'm leaving this here in hopes it helps someone in their future searches.

. . . → Read More: How to check the Public Key Algorithm used for a given gpg key (ie: RSA vs DSA)

Michael Altfield's gravatar

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.

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

Michael Altfield's gravatar

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!)

Michael Altfield's gravatar

Using uBlock Origin to Whitelist

As some mega websites deploy APIs that are used nearly ubiquitously on most of the Internet's websites (I'm looking at you Facebook & Google), I've begun to compartmentalize my browsers to "jail" specific website usage to a single, sandboxed browser (profile). This is sometimes referred to as a Site-Specific Browser (SSB).

Besides making sure that your SSB is isolated in that it cannot access your regular browser's data (a configuration I plan to document in the future), it's essential to block all network traffic from/to your SSB and all websites, except a whitelist. Unfortunately, getting block-all-then-whitelist functionality in uBlock Origin was annoyingly not documented, so I decided to publish it.

If you want uBlock Origin to block all traffic, add the following line to the textbox in your "My filters" tab of uBlock's Dashboard.

. . . → Read More: Using uBlock Origin to Whitelist