NOV
17
2012

A trip down memory lane

I was digging through some old backups on Friday looking to see if I had any old versions of the Qt source code lying around after Eirik mentioned during his devdays talk that the release tar balls for lots of the early releases including Qt 1.0 had got lost... I didn't find those, but I found some gems I didn't know I had.

First, there's a presentation on the KDE internals I don't know where I gave, I suspect it was at MANLUG (the Manchester Linux User Group).

MAY
19
2012

An Unexpected Journey

Recently, when building qt5, I'd started noticing some very strange errors from the configure script. The errors seemed to indicate that an awk script was being used as a filename - very strange. Even stranger was that other people weren't hitting this issue - just me. Never a good sign. Today, I finally got around to debugging it and the issue was rather weird.

APR
14
2012

What's New in Qt 5 for SSL?

With the availability of the Qt 5 alpha, I thought I'd try to summarise what's been done in the SSL stack. Most of the changes in Qt 5 for SSL are incremental improvements, or things that will form the basis of future changes. In this post I'll try to highlight the main changes:

  • QSslCertificate::subjectInfo() and QSslCertificate::issuerInfo() now return a QStringList instead of a QString

    It's pretty common for a certificate to contain more than entry of a specific type, but in Qt 4 the API only let you access the first one.

  • JAN
    14
    2012

    Using GnuTLS with QTcpSocket

    It's been quite a while since I last wrote a blog post, but it's not because I haven't been coding, in fact quite the opposite. The Qt opengov project is finally underway and I've been doing quite a lot of work on the various SSL classes. I'm now an official Qt approver, so as you can see the process of getting non-nokia developers the ability to commit to Qt is working.

    NOV
    6
    2011

    Qt SSL Update

    It's been a while since I blogged, so I thought I'd post an update on what I've been up to.

    Along with nearly a thousand other Qt developers, I headed over to Munich for the Qt Dev Days. It was my first time at the event, and I was surprised just how big it was. There were a lot of interesting talks, with highlights including Jens' talks on Qt Quick components for the desktop and using QML for rapid prototyping and Peter's talk on Secure Networking.

    JUL
    3
    2011

    SSL at the Qt Contributor Summit

    I haven't written any posts for a few weeks, so I figure it's time for an update. I, along with a bunch of other people who hack on Qt, attended the Qt Contributor Summit in Berlin. This was a very useful event, since it brought together a good mixture of both Nokia developers and external developers - as I would have hoped, KDE was one of the most common afiliations.

    MAY
    22
    2011

    Improving SSL Security with Certificate Change Notification

    Improving the security of SSL is a hot topic these days, and trust in certifcate authorities is rightly at an all time low. One way of improving the situation that doesn't rely on believing that a 3rd party will actually do their job properly is to notify users when the certificate for a site changes. There are already extensions for some browsers that offer this facility, so I sat down today to write a proof of concept that looked at how this implemented in Qt.

    MAR
    19
    2011

    QPcap - A Qt-Style Wrapper Around libpcap

    I've been working on a new library for the last couple of weeks that provides a Qt style API for libpcap. For those who aren't familiar with it, libpcap is the library used for capturing raw packets used by tools like tcpdump and wireshark. The pcap library has been around for years, and is built in C rather than C++. The API is pretty simple, but it's not one that can be trivially integrated into a gui application. The aim of the library I've been working on is to make using packet capture in Qt programs a simple matter of using a QObject and connecting to its slots.

    JAN
    22
    2011

    Loading and Scaling Images in a Thread

    In a previous blog post, I showed a simple example of using threads to perform complex calculations (SHA hashes) in a worker thread. I used them there because generating the hash of a DVD ISO can take a while, and GUIs that block make everyone cry. In this post, I'll use the same technique to load and scale an image whilst still letting my GUI startup instantly.

    JAN
    9
    2011

    Getting the details of an SSL connection

    SSL is a pretty complex topic, and whilst Qt makes the APIs pretty easy to use, there's a lot going on underneath and it can be hard to debug. In order to make life a bit easier, I've written a simple tool that will connect to an SSL service then dump every piece of information Qt makes available concerning it. Of course the aim here is both that the tool be useful in itself, and also that it provide a good illustration of how to use the APIs concerned.

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