Archive for the ‘Ubuntu’ Category

Webkitgtk & SSL

April 30, 2013

For a project of mine I created a small app based on webkitgtk that talks to a SSL server.

And I almost forgot about the libsoup default behavior for SSL certificates checking. By default libsoup and therefore webkitgtk will not do any SSL certificate checks. You need to put something like the following snippet into your code (adjust for your language of choice):

from gi.repository import WebKit

session = WebKit.get_default_session()
session.set_property("ssl-use-system-ca-file", True)

If you don’t do this it will accept any certificate (including self-signed ones).

This is documented behavior in libsoup and they don’t want to change it for compatiblity reasons in libsoup. But for webkit its unexpected behavior (at least to me) and I hope the webkitgtk developers will consider changing this default in webkit. I filed a bug about it. So if you use webkitgtk and SSL, remember to set the above property.

PassHash cmdline

April 18, 2013

I use the PassHash firefox extension to generate site-specific strong passwords. The idea behind the extension is that a master password and a siteTag (e.g. the domain name) is used to generate a sha1 hash. This hash is used as the password for the website. In python its essentially this code:

h =, site_tag, hashlib.sha1)

I want a commandline utility that can output me PassHash compatible hashes when I use w3m (or if the extension stops working for some reason).

To my delight I discovered that the upstream git repNice and hard to brute-force.o of PassHash already has a python helper to generate passhash compatible password. I added some tweaks to add pythons argparse [1] and now I’m really happy with it:

$ ./tools/ --hash-size 14
Please enter the master key: 

Hard to brute-force and matches what the extension generates.

squid-deb-proxy for Debian

April 11, 2013

I uploaded squid-deb-proxy into Debian unstable today and its in the NEW queue. I created it back in the days of Ubuntu 10.04 and some people voiced interest in having it in Debian as well so I spend a bit of time to get it customized for Debian.

Squid-deb-proxy uses the well known squid proxy with a custom configuration to cache deb package and Indexfiles (like Packages.gz) that will allow caching from the default archives and mirrors and reject anything else by default.

The basic philosophy is that “it just works”. You run on your server:

root@server# apt-get install squid-deb-proxy

and on your clients:

root@client# apt-get install squid-deb-proxy-client

and that’s it. It does not require any fiddling with configuration (unless you want to 😉 ). The default will let you connect to and nothing else.

The server will announce itself via avahi as _apt_proxy._tcp and the
client will hook into apt to use Acquire::http::ProxyAutoDetect. The
client is useful for other servers that announce themself via avahi.

Packaging was a bit more work than anticipated because there is a bit of setup and teardown work in the initscript. For Debian as sysvinit script was needed, Ubuntu uses upstart so it took a bit of refactoring to extract the code into a common helper.

If you want to try it now, its available via:

$ bzr branch lp:squid-deb-proxy
$ cd squid-deb-proxy
$ bzr-buildpackage

and in unstable once it leaves the NEW queue.

Using gdebi to install build-dependencies

March 22, 2013

I wrote gdebi a long time ago to make it really easy to install .deb package with proper dependency resolution from the commandline and via a gtk (and kde) UI. But another neat (but not very well known) feature of the gdebi-core cli tool is to install the build-dependencies of a debian source package. If you run:

$ gdebi debian/control

in a unpacked debian source package it will check for missing build-dependencies and offer to install them.

mvo at mail not working currently (hopefully back soon)

January 5, 2013

If you tried to reach me via my mail in the last couple of days you got a 550 error. There seems to be some misconfiguration on the mailserver, I hope it gets fixed soon. You can use my mvo at in the meantime.


August 16, 2011

I created a small extension for sqlite3 today to allow order by debian version easily. This allows writing:

.load "./";
SELECT * FROM packages ORDER BY version COLLAT debversion_compare;

And it will do the right ordering. Its available on launchpad.

New apt hits oneiric

August 8, 2011

I just uploaded a new apt to oneiric. Its a ABI break so there will be short time that the archive is in a state of churn while the packages are rebuild against the new ABI. But the good news is that apt finally got dpointers so we will require less ABI breaks in the future. Plus we moved the library into a proper library package making the transitions much easier from now on.


May 7, 2011

In natty we got a new tool called “apt-clone”. Its a commandline application that can be used to clone the packages state of a system and restore it on another system. It will save the full state (sources.list, packages/versions installed, auto-installed inforrmation) and optionally using dpkg-repack in order to save not/no-longer downloadable package (like debs that got installed manually via e.g. gdebi or dpkg -i). The file is pretty small because it just stores references to the files in the archive. One nice feature of the restore is that it can be applied to a different root directory (creating a chroot). I use this to reproduce upgrade issues and its really handy for this. Whats missing currently is modified conffiles detection, but there is some work on this in trunk.

update-manager & unity

May 3, 2011

I merged a branch from Bilal Akhtar for update-manager the other day to add unity quicklist support (thanks Bilal!). While at it I added the updates count to the launcher too. Small change, but I really like it 🙂

Software-center & weblive

March 25, 2011

There is another cool feature in software-center in natty that I would like to show today. If you have the package “qtnx” (in universe) installed you will be able to “test-drive” a lot of the available applications in software-center without having to actually install them. They are run via the NX protocol on a remove server with pretty good speed. Its all possible thanks to Stéphane Grabers Weblive.

This is what it loks like (notice the “Test drive” button below the screenshot):

And here what happens when I press test-drive and its connected (connecting takes about a minute currently).