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{ Category Archives } Linux

Linux news and information.

CPU Jitter Entropy for the Linux Kernel

Normally, I keep a sharp eye on all things cryptographic-related with the Linux kernel. However, in 4.2, I missed something fantastic: jitterentropy_rng.ko. This is a Linux kernel module that measures the jitter of the high resolution timing available in modern CPUs, and uses this jitter as a source of true randomness. In fact, using the […]

Weechat Relay With Let's Encrypt Certificates

I've been on IRC for a long time. Not as long as some, granted, but likely longer than most. I've had my hand in a number of IRC clients, mostly terminal-based. Yup, I was (shortly) using the ircII client, then (also shortly) BitchX. Then I found irssi, and stuck with that for a long time. […]

How To Always Encrypt Chromium Saved Passwords On GNU/Linux - No Matter What

One of the things that has always bothered me about the Chromium project (the project the Google Chrome browser is based on) is that passwords are encrypted, if and only if your operating system provides an authentication API through your account login. For example, on Windows, is is accomplished through the "CryptProtectData" function. This function […]

Linux Kernel CSPRNG Performance

I'm hardly the first one to notice this, but I was having a discussion in ##crypto on Freenode about the Linux kernel CSPRNG performance. It was mentioned that the kernelspace CSPRNG was "horrendously slow". Personally, I found the performance sufficient for me needs, but I decided to entertain his definition. I'm glad I did; I […]

Manual Authenticated File Encryption With OpenSSL

One thing that bothers me about OpenSSL is the lack of commandline support for AEAD ciphers, specifically AES in CCM and GCM block modes. Why does this matter? Suppose you want to save an encrypted file to disk, without GnuPG, because you don't want to get into key management. Further, suppose you want to send […]

Using Your Monitors As A Cryptographically Secure Pseudorandom Number Generator

File this under the "I'm bored and have nothing better to do" category. While coming into work this morning, I was curious if I could use my monitors as a cryptographically secure pseudorandom number generator (CSPRNG). I don't know what use this would have, if any, as your GNU/Linux operating system already ships a CSPRNG […]

Encrypted Account Passwords with Vim and GnuPG

Background I've been a long-time KeepassX user, and to be honest, I don't see that changing any time soon. I currently have my password database on an SSH-accessible server, of which I use kpcli as the main client for accessing the db. I use Keepass2Android with SFTP on my phone to get read-only access to […]

Password Generation in the Shell

No doubt, some people use password generators- not many, but some. Unfortunately, this means relying on 3rd party utilities, where the source code may not always be available. Personally, I would rather be in full control of the entire generation stack. I know how to make sure plenty of entropy is available in the generation, […]

The Kidekin TRNG Hardware Random Number Generator

Yesterday, I received my Kidekin TRNG hardware random number generator. I was eager to purchase this, because on the Tindie website, the first 2 people to purchase the RNG would get $50 off, making the device $30 total. I quickly ordered one. Hilariously enough, I received a letter from the supplier that I was their […]

Additional Testing Of The rtl-sdr Dongle As A HWRNG

A couple days ago, I put up a post about using the Realtek SDR dongles as a hardware true random number generator. I only tested the randomness of a 512 MB file. I thought this time, I would but a bit more stock into it. In this case, I let it run for a while, […]

Hardware RNG Through an rtl-sdr Dongle

An rtl-sdr dongle allows you to receive radio frequency signals to your computer through a software interface. You can listen to Amateur Radio, watch analog television, listen to FM radio broadcasts, and a number of other things. I have a friend to uses it to monitor power usage at his house. However, I have a […]

Reasonable SSH Security For OpenSSH 6.0 Or Later

As many of you have probably seen, Stribik AndrĂ¡s wrote a post titled Secure Secure Shell. It's made the wide rounds across the Internet, and has seen a good, positive discussion about OpenSSH security. It's got people thinking about their personal SSH keys, as well as the differences between ECC and RSA, why the /etc/ssh/moduli […]

Super Size The Strength Of Your OpenSSH Private Keys

In a previous post, about 18 months ago, I blogged about how you can increase the strength of your OpenSSH private keys by using openssl(1) to convert them to PKCS#8 format. However, as of OpenSSH verison 6.5, there is a new private key format for private keys, as well as a new key type. The […]

Using The Bitmessage Storage Service

While hanging out on the "privacy" channel on Bitmessage, someone sent the following: "You have no files saved. For instructions please send a message to BM-2cUqBbiJhTCQsTeocfocNP5WCRcH28saPU with the subject 'help'." This is actually pretty cool. No doubt should you call into question a faceless storage provider, but I thought I would play around with it. […]

Cryptographically Secure Pseudorandom Locally Administered Unicast MAC Addresses

Recently, Apple released the ability for iPhone 5c and newer hardware to create a spoofed software MAC address for 2.4 GHz and 5 GHz wireless access points. The MAC address is locally administered, and a unicast address. This has sparked a small discussion in various forums about how to generate valid locally administered unicast MAC […]