Saturday, February 28, 2009

How much of anonymity is left?

For those that want anonymity is better to turn off computer and do something else.
See information displayed in Google gadget GeoIP on the right side.

That much reveals your IP address, but, beside cookies that everyone knows about, there is actually more information that leaves computer. For instance, HTTP headers that bowser exchange on every contact with any web server. It is not much, but a lot more than people suspect.

Digest answer on question what are the http headers you can see on List of HTTP headers. To see what information comes from server you can use, for instance, DJ Delorie web site HTTP Header Viewer , or to see what your browser is telling to server you can use another HTTP Header Viewer created by Eric Giguere, and finally, if you want to know both at once, try Rex Swain's HTTP Viewer.

You can see all that and much more using program Wireshark. It is serious network analyzer, not only HTTP header viewer. It has it's own training program. Although, if your only need is to see what your computer is talking to Internet reading frequently asked questions should suffice.

It is standard part of Linux, in other words, it is either on installation DVD, or it can be downloaded and installed using distribution specific installation program . For my favorite distribution openSUSE that is Software Management module that can be found in YaST (Yet another Setup Tool) .

There is much more about privacy and anonymity on the web.

Nice texts and tests on privacy and security you can find on Steve Gibson's .

There is also SecurityMetrics portscan that can tell you few more bits.

Friday, February 6, 2009

KDE4 and graphics drivers problems

There is a lot of bugs reported about KDE4, which is natural for system in heavy development. The problem is that many of them are graphic adapter related.

The previous version of KDE was designed few years ago and it used graphic capabilities that were available at that time. That means large part of KDE3 stability on wide variety of hardware platforms can be attributed to well tested hardware drivers.

The desktop, like KDE, GNOME or any other lesser known, is third layer of software, sitting at the top of X server, which is at the top of kernel. The hardware drivers are kernel business, so if they fail all other layers will fail as well. The effects can range from failure to display some element on the screen, that is using missing or buggy feature, to system lockup where only power button can help, with all kinds of weird behavior in between those two.

KDE4 is attempting to use newer features, which has as a consequence that now we can see bugs that are mix of genuine Qt, KDE and X server bugs, and hardware driver bugs that before went unnoticed. That is the worst possible mix for debugging, specially for guys that are not familiar with heavy duty debugging tools and procedures, like me, but there is some help.

People that can use distribution configuration tools, and tell Xorg (X server) what driver to use can use open source driver and eliminate at least that from equation.

I'm using Nvidia legacy graphics, FX 5200 and even older MX 4000.
Consequence is that I have to wait until Nvidia developers find time to fix, or backport fixes, to those drivers, or use the opensource nv driver. The legacy drivers are not top priority at Nvidia, as they want to fix current (recently sold) drivers first.

The other option, nv driver, is halfway help.
It will help to see is it proprietary (commercial) driver at fault, or some other component above in the stack, but you and KDE will miss 3D capabilities of your graphic card.