-
Recent Posts
Archives
- September 2021
- May 2019
- January 2019
- November 2017
- July 2017
- March 2017
- August 2016
- May 2015
- January 2015
- October 2014
- June 2014
- December 2013
- September 2013
- August 2013
- July 2013
- May 2013
- March 2013
- February 2013
- January 2013
- October 2012
- August 2012
- June 2012
- February 2012
- January 2011
- October 2010
- December 2009
- July 2009
- January 2009
- October 2008
Me on Twitter
Tweets by lkarsten
Category Archives: stuff
NMEA2000 and CANbus
I’ve been looking at NMEA2000 and CANbus lately. I’m attempting to reverse engineer the binary protocol seen coming out of the USB port on a Garmin GND10 network bridge, and that opens a whole field of new and interesting stuff … Continue reading
What happened to ban.url in Varnish 4.0?
tl;dr; when using Varnish 4 and bans via varnishadm, instead of “ban.url EXPRESSION”, use “ban req.url ~ EXPRESSION”. In Varnish 3.0 we had the ban.url command in the varnishadm CLI. This was a shortcut function expanding to the a bit cryptic (but powerful) … Continue reading
DNS RBL test address for development
If you are writing code that checks a DNS real-time blockhole list (RBL), it looks like 127.0.0.2 is the standard address that is always in the black/white -list. This is probably know for most sysadmins/security people and whatnot, but wasn’t … Continue reading
Varnish and Ghost blogging software
So there is a new shiny blogging platform out called Ghost. Looks pretty good to me. If you want to run it behind Varnish, you’ll soon notice it has the usual problem of setting session cookies everywhere leading to 0% … Continue reading
GSM A5/1 rainbow tables in Oslo, Norway
The A5/1 encryption algorithm used in (traditional) GSM networks were proven to be breakable by brute force back in 2009/2010. This means that GSM calls can be intercepted, decoded and listened to by anyone. (SMS also, but that is a … Continue reading
Posted in stuff
Tagged brute force, encryption algorithm, gsm, gsm networks, hack, rainbowtables, usrp
66 Comments
Building a Varnish VMOD on Debian
From the tutorials department, here are some quick notes on how to install a Varnish VMOD from source. This is slightly complicated because Varnish demands that a VMOD must be built against the same git commit (or release) as the … Continue reading
Setting client.ip in Varnish VCL with libvmod-ipcast
I’ve written a new Varnish 3.0 VMOD called ipcast. It has a single function; ipcast.clientip(ipstring) which sets the internal Varnish variable client.ip to whatever IPv4/IPv6 address you give as the argument. You need this if you want to do ACL checks … Continue reading
Guidelines for ticketing systems (rant)
If you are writing a ticketing/support request system, make sure to remember the following: It is ok to mangle the subject line if you are the ticketing system. Absolutely no UTF8 support. ø Ã¥ ought to do it. Make sure to … Continue reading
Varnish trick: Serve stale content while refetching
Here is a small trick we recently implemented for a customer: The main premise was: No clients should have to wait while the backend works. If a request is a miss, give the client a slightly stale/old page instead, and fetch … Continue reading
Porting GnuRadio USRP examples to USRP2
Most example code in gnuradio-examples/ is written for the USRP. If you are new to this (as I am), it is somewhat tricky to update the USRP1 code into working with the USRP2. This is a short list of what … Continue reading
Blog of Lasse Karstensen 