Matt's Blog

The following instructions show you how to configure Keycloak with Windows AD in order to use Kerberos authentication. Assumptions The Kerberos realm is VIRTUAL.LOCAL The hostname used to access Keycloak is virtual.local. This just means we are running Keycloak on the domain controller. In production virtual.local will be replaced with something like keycloak.dev.virtual.local or something like that, giving you a SPN of  HTTP/keycloak.dev.virtual.local@VIRTUAL.LOCAL Configuration Create a windows domain account called Keycloak. Run the following command to assign a SPN to the user and generate a keytab file: ktpass -out keycloak.keytab -princ HTTP/virtual.local@VIRTUAL.LOCAL -mapUser Keycloak@VIRTUAL.LOCAL -pass password1! -kvno 0 -ptype KRB5_NT_PRINCIPAL -crypto RC4-HMAC-NT Verify the SPN has been assigned to the user with the command: setspn -l Keycloak Configure the LDAP settings in Keycloak like this. Since we are running Keycloak on the domain controller, we...

So it is official. As an internet user in the great country of Australia my actions online are now tracked and recorded by the government. And that doesn't sit so well with me. But rather than complain, I decided to take action and install an Asus RT-N66U router as the gateway on my home network. The router had generally positive reviews online, but I was mostly interested in the fact that it supported third party firmware, like the popular ones provided by a developer calling himself  Merlin . One of the big benefits provided by third party firmware releases is that you get early access to some cool new features. One such feature that caught my eye was the introduction of Tor into the router. I have used Tor sporadically in the past. While I have to commend the Tor developers for making it easy to install Tor and browse anonymously, the reality is that running an additional piece of software was kind of a pain. It was a mental jump to go from "always online" to...

When connecting to a VPN I was constant getting the error Mar  8 09:29:27 openvpn[1696]: Authenticate/Decrypt packet error: cipher final failed I had imported the supplied ovpn file and had followed all the other configuration steps, so this was quite frustrating. Then I saw this in the logs: Mar  8 09:31:07 openvpn[1790]: WARNING: 'cipher' is used inconsistently, local='cipher BF-CBC', remote='cipher AES-256-CBC' Changing my client to use "cipher AES-256-CBC" instead of the default (which apparently was cipher BF-CBC) fixed the issue.

Cross Site Scripting, or XSS, is a fairly common vector used to attack web sites. It involves user generated code being redisplayed by a website with all the privileges and security rights that a browser assigns to code originating from the current host. If the user code is something like <script>doEvil();</script>, then you have a problem. OWASP is an organisation that provides guidance on web security, and they have a page that provides a suggested method for avoiding XSS in JavaEE web app. You can read this document at https://www.owasp.org/index.php/How_to_add_validation_logic_to_HttpServletRequest . The library being demonstrated here is based off the ideas presented in that article, but fleshed out to be more flexible and easy to deploy. We call this library the (unimaginatively named) Parameter Validation Filter, or PVF. PVF is implemented as a Servlet filter that intercepts requests to web pages, runs submitted parameters through a configurable sequence of va...

Three Daily Things is a new, free website that I have put together based on a motivation app that I have had great personal success with. The reason why I wrote this app is best explained with a story about myself. Like most people, I want to be fit an healthy. To achieve this, I sign up to my local gym. But it doesn't take long for the unknowns to start rattling around in my brain. How many reps and set should I do? Should I do cardio before or after resistance training? Should I be taking supplements? Is it best to work out in the morning or afternoon? Which exercises are best? All these unknowns start to weigh heavily in my mind. I begin to wonder if I am wasting my time. I skip a few sessions, and before I know it I haven't visited the gym in weeks. So many beneficial aspirations in my life have followed this path. I like the idea, I try it out, I get overwhelmed by the unknowns and eventually I give up. So I asked myself, what was it that I really w...

If you have tried to used RHEL 7 in VirtualBox, and run into the issue with the guest additions not compiling (see https://www.virtualbox.org/ticket/12638 for details), you can download this tar file , extract it, and run sudo ./install.sh The tar file is just the guest additions pre patched to work with RHEL 7.

We use supervisord on our systems, which has a handy browser based 'tail -f' feature. The problem is that the end of the log file appears off the bottom of the screen, and the browser won't scroll to the bottom automatically. This bookmarklet will keep the end of the page in view. javascript:scroll=function(){setTimeout(function(){window.scrollTo(0,document.body.scrollHeight);scroll();},100);};scroll();