Security

Tighten Up SSH

SSH is a Swiss Army knife and Hogwart's magic wand all rolled into one simple command-line tool. As often as we use it, we sometimes forget that even our encrypted friend can be secured more than it is by default. For a full list of options to turn on and off, simply type man sshd_config to read the man page for the configuration file.

Security in Three Ds: Detect, Decide and Deny

Whenever a server is accessible via the Internet, it's a safe bet that hackers will be trying to access it. Just look at the SSH logs for any server you use, and you'll surely find lots of "authentication failure" lines, originating from IPs that have nothing to do with you or your business.

Nmap—Not Just for Evil!

If SSH is the Swiss Army knife of the system administration world, Nmap is a box of dynamite. It's really easy to misuse dynamite and blow your foot off, but it's also a very powerful tool that can do jobs that are impossible without it.

Real-Time Rogue Wireless Access Point Detection with the Raspberry Pi

Years ago, I worked for an automotive IT provider, and occasionally we went out to the plants to search for rogue Wireless Access Points (WAPs). A rogue WAP is one that the company hasn't approved to be there. So if someone were to go and buy a wireless router, and plug it in to the network, that would be a rogue WAP.

Sharing Admin Privileges for Many Hosts Securely

The problem: you have a large team of admins, with a substantial turnover rate. Maybe contractors come and go. Maybe you have tiers of access, due to restrictions based on geography, admin level or even citizenship (as with some US government contracts).

January 2015 Issue of Linux Journal: Security

Security: a Method, Not a Goal The Security issue of Linux Journal always makes me feel a little guilty. It turns out that although I have a fairly wide set of technology skills, I'm not the person you want in charge of securing your network or your systems. By default, Linux is designed with a moderate amount of security in mind. For that, I am incredibly grateful.

The Awesome Program You Never Should Use

I've been hesitating for a couple months about whether to mention sshpass. Conceptually, it's a horrible, horrible program. It basically allows you to enter an SSH user name and password on the command line, so you can create a connection without any interaction. A far better way to accomplish that is with public/private keypairs.

Encrypt Your Dog (Mutt and GPG)

I have been focusing a lot on security and privacy issues in this year's columns so far, but I realize some of you may expect a different kind of topic from me (or maybe are just tired of all this security talk). Well, you are in luck.

Security Hardening with Ansible

Ansible is an open-source automation tool developed and released by Michael DeHaan and others in 2012. DeHaan calls it a "general-purpose automation pipeline" (see Resources for a link to the article "Ansible's Architecture: Beyond Configuration Management").

Linux Security Threats on the Rise

Every year, heck...every month, Linux is adopted by more companies and organizations as an important if not primary component of their enterprise platform. And the more serious the hardware platform, the more likely it is to be running Linux. 60% of servers, 70% of Web servers and 95% of all supercomputers are Linux-based!

Tails above the Rest, Part III

In my first two columns in this series, I gave an overview of Tails, including how to get the distribution securely, and once you have it, how to use some of the basic tools.

Tails above the Rest: the Installation

A few columns ago, I started a series aimed at helping everyone improve their privacy and security on the Internet. The first column in this series was an updated version of a Tor column I wrote a few years ago.

Non-Linux FOSS: My Portable Windows Lab

Portable apps aren't anything new. There are variations of "single executable apps" for most platforms, and some people swear by keeping their own applications with them for use when away from home. I don't usually do that, as most of what I do is on-line, but there is one exception: security.

The Growing Role of UEFI Secure Boot in Linux Distributions

With the increasing prevalence of open-source implementations and the expansion of personal computing device usage to include mobile and non-PC devices as well as traditional desktops and laptops, combating attacks and security obstacles against malware is a growing priority for a broad community of vendors, developers and end users.

Two-Factor Authentication System for Apache and SSH

If you run a publicly accessible Web server for your own use (and let's face it, if you're reading Linux Journal, there's a very good chance you do), how do you go about limiting the risk of someone accessing your site and doing bad things? How about SSH, an even bigger concern?

Quantum Cryptography

Classical cryptography provides security based on unproven mathematical assumptions and depends on the technology available to an eavesdropper. But, these things might not be enough in the near future to guarantee cyber security. We need something that provides unconditional security. We need quantum cryptography.

Encrypting Your Cat Photos

The truth is, I really don't have anything on my hard drive that I would be upset over someone seeing. I have some cat photos. I have a few text files with ideas for future books and/or short stories, and a couple half-written starts to NaNoWriMo novels. It would be easy to say that there's no point encrypting my hard drive, because I have nothing to hide.

More Secure SSH Connections

If you need remote access to a machine, you'll probably use SSH, and for a good reason. The secure shell protocol uses modern cryptography methods to provide privacy and confidentiality, even over an unsecured, unsafe network, such as the Internet.