codeblog code is freedom — patching my itch

September 14, 2005

tivo meets mythtv

Filed under: Multimedia — kees @ 11:50 am

As Bryce has already detailed, a few of us have started examining MythTV. While TiVo has served me pretty well, it sounds like now that the recording restriction flag has been tested it won’t be too long now before the content providers start actually using it. Supposedly the latest alarm is unfounded, in that it was a mistake. Whether it was a test, a mistake, it does show that my TiVo is now prepared to cripple itself.

MythTV has come a long way now. It seems that it’s a viable alternative for a DVR. Within our MythTV Club, we’re each going to have different problems. Doug will be fighting DVD playback via his PVR-350, Bryce will be playing with double recording sources, and I will be fighting with the video library playback capabilities. The EFF has a great write-up on installing MythTV for broadcast HDTV support. I think HD broadcast recording is going to come pretty late in our designs.

My existing video navigator (not the TiVo) is a very simple filesystem browser that just launches “mplayer” or “xmms” on the files it finds. (Holy crap, I set that up in 2002?!) MythTV’s “mythvideo” plugin is a much smarter browser for both video and audio, but its interface is wildly different from my current system. Especially for audio, which is very ID3-tag heavy. Very few of my early CD rips have any ID3 tags at all. The built-in MythTV player is also very very broken for seeking, and for unusual formats. I have a lot of movie trailers in Quicktime that MythTV refuses to play. I suspect that the video library issues will be the easiest to solve, though, since I can select a different viewer, etc. All that I have set up already on my existing navigator.

The nice thing about MythTV’s video/audio browser, though, is all the metadata support. I can pull down DVD and CD covers, etc. It’s way prettier than my existing system too. My goal is to get MythTV set up on my existing TV computer this week. Once it has replaced the filesystem browser, I’ll have the same functionality as the old system, and gain the ability to move on to real DVR activity in the future. I want to match my TiVo’s recording schedule, and then probably run in parallel until TiVo really gets DRM going.

I’m curious to see what the Netflix/TiVo joint venture is going to look like. I suspect the recent DRM testing is for the Netflix offering. If that’s true, I’ll wait until I see it, and then cancel my service. I’d really like to support TiVo, but not if they’re trying to cripple my time-shifting/long-term storage capabilities. I wonder how long it’ll take me to kernel-monte the TiVo into a MythTV frontend. All I really need is a cross-compiler. Sure would be nice to reuse my TiVo as a MythTV frontend if it comes to that.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

September 8, 2005

greasemonkey and fantasy football

Filed under: Web — kees @ 2:01 pm

Fantasy Football isn’t something I have any idea how to play, but I thought I’d join a few friends in their league, since they seemed to have so much fun with it. It’s through Yahoo, and is pretty nifty. I’m slowly learning how to play, but I doubt I’ll ever be any good considering how much I don’t watch football. In the Yahoo interface, however, to evaluate a player’s depth (first string, second string, etc.) I have to click on the player, then the team, then the “Depth chart” link. This was annoying, so it was a perfect opportunity to learn some more javascript, xpath, and DOM manipulation. As a result, I wrote a greasemonkey script to add team links where ever a team abbreviation is seen.

© 2005 – 2006, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 29, 2005

open source disassemblers

Filed under: Reverse Engineering — kees @ 7:57 pm

Not a lot of OSS folks seem to be interested in reverse engineering, so as a result, there isn’t anything like IDA-Pro for the OSS reverse engineer. There is a very excellent disassembling library, but it has no user interface (yet). It used to have Bastard attached, but that’s pretty out of date now. There is also Lida, but it doesn’t even compile. It was based on Bastard, but I can’t get it to work. It seems to be missing some specific version of the opcode map from Bastard.

Bastard and Lida are both static analysis tools, though. What I really want is a dynamic analyzer. I want to be able to trace the call paths during Porrasturvat’s execution, so I can more easily figure out which function is called when I click “Dismount”. That’ll help me find the Force constant. I’m worried I’m going to have to hack together some unholy Perl script to run “stepi” over and over, waiting for each “call” to take place. That. Would. Be. Very. Slow.

Anyway, I was really impressed with libdisasm, so I built an automake/autoconf setup for it. Even if they don’t want it, I like being able to do a “make install” and having the library end up in the right place. :)

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 28, 2005

porrasturvat hacking

Filed under: Reverse Engineering — kees @ 2:14 pm

Three years ago, when I first saw tAAt’s Porrasturvat, I couldn’t stop playing it all day. It’s a really simple game: see how much “damage” you can score to a stick figure that you push down the stairs. It’s basically a physics simulation that tracks force and impact of a body falling down a flight of stairs. So much fun. I hope they make it skinnable. :)

At the time (2002-11-12) I had asked for source code in the hopes of helping to port it to Linux. I got an email yesterday in reply to my request. This sets the record for the longest reply-time on a email, ever. :) Jetro was letting me know it was available for Linux now, so I immediately downloaded it and started playing again. This version is much more stable and lacks any scoring glitches (that I’ve been able to find), so it’s a real challenge to get a high score.

Even in the original game, I had wanted to push the figure backwards off the stairs to see what kind of damage would be done just from having him fall straight down. This time, I’m determined to practice some binary analysis skills and locate the place in memory where the “Force” value is kept so I can tweak it. So far so good, I’ve been able to locate the damage accumulators for the various body parts. Now it’s a matter of just tracing the changes back through the execution paths. Here’s my million-point game:

damage mod

© 2005 – 2015, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

cvs camcorder

Filed under: Multimedia,Reverse Engineering — kees @ 12:43 am

I was able to get my hands on a CVS camcorder this past week. The unit is very cool. It doesn’t have any features of a “real” video camera, but I view it like a super-version of my Digital camera which can take 15 seconds worth of video at a time. This one is only limited by available storage (about 20 minutes). The resolution can be turned up to 640×480, too.

Initially I couldn’t get a cable built for it. I had a spare USB cable and a spare Palm Pilot cable to merge, but after soldering it all together, the device wouldn’t take an address (but my laptop noticed it was getting plugged in). After a hint from Linus (“plug-ins are detected via power-draw, everything else is over the data lines”), I realized that perhaps the USB data wires were reversed (the cable has got to flip them on at least one end of the cable… I just got unlucky).

The software for downloading the videos had been ported to Linux, and I worked on some more code to have a one-shot ability to download all the videos from the camera. Now I’ve got autoconf/automake working for it, and have gotten myself added to the Saturn Tools project where we can all work on the code through SourceForge’s CVS. Much easier than endlessly trading patches. :)

So far, I’ve managed to wreck the splash-screen image during camera bootup. Something is busted with the usb_bulk_write calls, and the device stops taking writes after 4k worth of data. Hopefully I can get that repaired so I can be greeted by the Laughing Man. I’ve also got a JPG all ready to replace the logo screen, “powered by pure digital technology”, with my oh-so-clever “powered by pwnd digital technology”.

© 2005 – 2016, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 25, 2005

playing with cars

Filed under: Vehicles — kees @ 5:54 pm

I ordered a vehicle-bus-to-serial converter last year, but never got around to playing with it. This lets me examine all the sensors on my vehicle’s sensor bus. Stuff like RPM, speed, engine load, etc. It also works as a code-scanner if something bad happens. One harmless example is if the gas cap isn’t tightened all the way, it’ll set a code, and my “check engine” light will come on. With this, I can clear the code, tighten the gas cap, and get on with my life. :)

I was really excited to see that the ScanTool folks released their software under the GPL. Someone else had already gotten it compiled under Linux, but his website is down right now. So, impatient person that I am, I went ahead and installed Allegro and DZComm. DZComm needed a little work to be happy with my USB-to-serial converter, but once that was done, I got to drive around with Bryce reading me my engine load off the laptop. Fun!

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 16, 2005

art thoughts on aug 16, 2005

Filed under: General — kees @ 7:11 pm

I saw a mention of the Portland Time-Based Art festival. Looks to be a pretty wild mix of all kinds of performance art. I’ve got to check it out, but it looks a bit pricey (minimum: $125).

Portland’s 94.7FM “alternative” radio station is great. (They even have live streaming.) I’ve been especially impressed with the 6PM “Cocktail Mix” by Gustav. His personal collection of electronica is very nice. I’ve never heard Messiah played anywhere other than my stereo or very rarely at clubs. A few weeks ago, he played it. So cool. They’re also running a NIN remix contest I’m pondering entering. I’m not really sure what sort of open software I should use to cook it, though.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 15, 2005

1 second film

Filed under: General — kees @ 3:18 pm

I found the 1 Second Film project today while trying to remember the name of the movie I saw this weekend. All I could remember was the dude was from Hackers. His name turns out to be Jesse Bradford. (The movie was Happy Endings, which I thought was pretty fun.) I was surprised to see Jesse Bradford listed as a Producer on another film, so I followed the link only to discover that everyone is a producer for the 1 Second Film.

Anyone can become a Producer (and get listed on IMDB) by sending them money. The film itself is going to be 1 second of 12 doubled frames of animation (which will be auctioned off after the movie opens). The credits will then roll for 60 minutes, playing next to a “The Making Of” movie. The profits are going to charity, and celebrities seem to have started a bidding war. Their credit-purchasing page is linked to PayPal, so it looks super-easy to support them. Crazy.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 7, 2005

quick guide to encryption

Filed under: Networking,Security — kees @ 11:02 pm

I should qualify my comments from my prior blog entry and say that I’m appalled at Service Providers (not users) that continue to offer insecure services to their clients. Users, however, should be asking their Providers for secure services. Most don’t know to ask this, and that’s why I think the responsibility falls on the Provider.

Here’s my crash-course in simple anti-sniffing techniques.

  • Evaluate your network: if you’re on open Wireless, any one interested can see all communications to/from your computer. Be paranoid. If you’re on a wired network, your communications can still be seen, but it tends to be much less likely.
  • Evaluate your services: do you care about your various services? Do you have a different password for each service? Details below…

Evaluating your services requires creating a short list of all the things you send over the network from your computer. For basic anti-sniffing, there are two types of “encryption” available for most services:

  • Authentication: logging into anything. Checking email, logging into IM, logging into websites, etc. Some services offer “encrypted” authentication. Modern AIM clients, “APOP” POP clients, etc. If your authentication is encrypted people can’t just sniff your account/password off the wire.
  • Communication: all the traffic to any site/service. All services have a fully encrypted counterpart. Almost everything uses SSL for encryption, and appends an “S” to the protocol name. HTTP has HTTPS, POP has POPS, IMAP has IMAPS, SMTP has a TLS mode, Jabber has an SSL mode, good IRC networks have an SSL mode, etc. These SSL-protected services encrypt ALL of your communciation, including the username/password authentication.

It’s best to have fully encrypted communications, but if you can’t, just getting some kind of obfuscated authentication mechanism is better than nothing. Just ask yourself any time you type in a username/password, “How is this being sent to the remote server?”

So, here are some specifics to various common services:

  • Receiving email: POP and IMAP have SSL modes that run on different ports. See if your email Provider offers these services and switch your client to using those instead. If that’s not available, see if POP or IMAP support other authentication modes besides the clear-text “Plain” and “Password”. For example CRAM-MD5, Challenge/Response.
  • Sending email: SMTP has an SSL mode too. This is either called “STARTTLS” or “SSL”. A good Provider will offer SMTP on port 587 with STARTTLS. Hopefully your Provider requires you to authenticate before sending email. Instead of SSL, like POP/IMAP above, they may offer CRAM-MD5, etc.
  • Web sites: only use “https://” for logging into websites. If there isn’t a little lock in the corner of your browser, don’t log in. The browser folks have done a lot to help folks with this part. Ecommerce has caused a huge push to avoid in-the-clear authentication on websites. Unfortunately, some sites will still let you log in without SSL. (Like flickr, it seems.)
  • IM: I’m not sure about ICQ, MSN, etc, but Jabber offers a full SSL mode. The “old” style runs on a separate port (5223). The “new” style gets “turned on” during the initial jabber session setup. This would give you fully encrypted communications. I know AIM has both a Challenge/Response and MD5 mechanism for logging in, so at the very least, use those.

If you’re not sure if your communication is being encrypted or not, it’s very easy to install a network sniffer. Ethereal is available for almost every platform around, via the libpcap libraries. Just start it capturing before you use a service, use the service, and then go find the traffic in the capture log. Ethereal will identify almost all services by name (“HTTP”, “POP”, “IRC”, “AIM”, etc.) To see the traffic, click on the “Analyze > Follow TCP Stream”. This will show you all the communication for a given connection. (Click on “Clear” in the Filter bar to see all your traffic again.)

If you want to browse the traffic more easily, you can type in other filter terms. For example, to make sure your POP password isn’t being sent in the clear, enter “pop.request” in the Filter, and click “Apply”. Pick a packet, and select the “Request” section in the Packet Tree. If you see:

Request: USER omfg

Request: PASS intheclear

Then your “omfg” account is showing it’s password to the rest of the network. :)

Another alternative to all this pain is to have a VPN connection to some other network that you trust. This is the easiest to configure on the client side. If that’s not available, you can also tunnel all your traffic through an SSH connection. This is easiest to configure on the server side (no config). Here is an example of tunneling your POP service through SSH:

ssh -L 2110:pop.example.com:110 account@example.com

That’ll set up a local port 2110 that gets forwarded to “pop.example.com” port 110 (POP) after logging you in to some SSH account. This means you have to configure your POP client to use “localhost” port 2110 instead of “pop.example.com” on the regular POP port. And then you can only POP when your SSH connection is up.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

oscon 2005 wireless sniffing

Filed under: Networking,Security — kees @ 9:03 pm

OSCON’s wireless network was okay. It didn’t seem to handle the load very well, but generally you could pick out an Access Point that was still responding to DHCP, and it would work well enough.

I feel like I’m beating a dead horse, but I’m appalled at how many people continue to not use encryption. I spent some time yesterday going through my 4.1G of packet capture logs. Generally, I scanned POP, SMTP, IRC, and HTTP traffic. I should probably find better tools than just ethereal, but after finding 45 different POP accounts that were authenticating in the clear, I stopped counting. That put me half way through Thursday, so that’s only a day and a half of OSCON wireless traffic. No one seems to protect their nick on FreeNode, so at least no one’s nick password was sent in the clear. One person logged into Flickr in the clear. One of the accounts was for the speaker I was listening to at one point. I recognized the POP account because it was up on his slides.

What’s really interesting is the number of people that didn’t authenticate in the clear but ran the rest of their traffic in the clear. For example, many people used various challenge/response systems to authenticate to POP, IMAP, SMTP, and AIM, but then all the traffic continued to stay in the clear. All their email and AIM buddy information was out on the wire.

I know there was at least one other person doing network sniffing, since I saw him running EtherPEG (which makes a live collage of all the incoming HTTP images on the wire). I started up a heavy download of images just for him, but I think he had bored himself with enless slashdot and oreilly GIFs and never looked back to see the fun I had sent over the air for him. :)

(If you don’t have a Mac and you want EtherPEG functionality, there is also DriftNet.)

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 5, 2005

defcon 13 patch round-up

Filed under: Networking — kees @ 7:38 pm

In (useless) preparation for DefCon 13’s CTF this year, I hacked at ettercap and Snort. Since the TTL filtering trick was out of the bag, I figured I’d implement the other idea I had. Since the score bot generally is a short-lived connection to a service in CTF, it would be great if Snort-inline rules could be written to detect how long a conenction had been around for. Initially I hacked at ettercap, but that was mostly so I could build a quick-and-dirty TTL statistics gatherer. In ettercap, I had to add session time tracking, but in Snort, it was actually already there. There just wasn’t anything that could be matched against in the rules section. I lifted the TTL matcher from Snort and just used the existing connection timers to do the work and created the “age” rule. Works like a charm. I hope they take my patches.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 4, 2005

oscon 2005 doppelganger

Filed under: General — kees @ 10:52 am

Wednesday I met my doppelganger. I had people walking up to me all day saying, “Hi Zak!” and I’d look at them and explain that I was someone else less famous, named Kees. Normally I think I’m just being paranoid thinking people are looking at me all the time. However, today, it seemed to be true. People would kind of slowly orbit me, trying to get a look at my face and my name badge. Eventually I started telling people “Hi! I’m not Zak.” By the end of the day, I had finally met him, and we had a good laugh. There is also Dan at the LTC that shares similar features, and all three of us had our picture taken together. (I hope they read this blog and send me photos!)

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 3, 2005

oscon 2005 mid week report

Filed under: General — kees @ 9:33 pm

Day 1 of OSCON was spent recovering from DefCon. I didn’t go to either of my scheduled tutorials. I really wish I could have gotten to see Conway present his Presentation Aikido, since the notes for it are terrific. I also really wish I could have spent some more time with Snort, especially given all the attention I gave to Snort Inline over the last few weeks.

Day 2 of OSCON was spent in the RT and Aterisk tutorials. The RT one was very interesting, but more geared towards people wanting to do something MORE than ticket tracking. I was glad to see that 3+ has a much better commandline query tool. That’ll speed up autokees’s “-rt” responses. (“autokees” is my IRC bot that reports OSDL’s open — and closed — RT tickets for the Core Services group.) The Asterisk presentation was fantastic.

Capouch really knows his stuff, and his Asterisk demo was very impressive. For the last part of his demo his showed off his home X10 turning on a light in his living room that triggered a motion detector running against his webcam, watching his prized Robert Crumb original, which dropped an Asterisk call file into the server and called him. Time between “X10 on” and his phone ringing: 2 seconds, if that. That tutorial was well organized, and detailed. I think I could probably set up an Asterisk server right now if I didn’t need to go to bed so badly.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

August 1, 2005

Plan B sucked!

Filed under: General — kees @ 5:16 pm

Well, our team of 3 didn’t do so well at CTF this year (4th in teams). But, I guess, holding our own against teams with 20+ people on them is kind of good. The game’s network was organized very differently from years past, and we had no way for inline Snort to work. They held the machines locally (in a FreeBSD jail), and we just got a network drop so we could share the network with our server. That was pretty disappointing, but I think it made the game much more pure. This year’s focus was on code auditing and binary analysis.

Both of my basic goals were achieved though:

  • Not come in last
  • Modify the token scoring tool to play victory WAVs any time we scored a point. That worked very well and was a great motivator.

I guess I’m going to have to really get cracking with some gdb programming work. Jesse’s auto-stack-overflow-detector rocks, and I think that can be seriously expanded, if not hooked up to Metasploit directly.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

July 25, 2005

world series of hacking

Filed under: Security — kees @ 9:46 pm

Friday approaches! DefCon is this weekend. I can’t wait. To think I’m going to be hacking so hard this weekend, I won’t see Battlestar Galactica until Monday. *shiver*

So far, I’ve got patches against ettercap, snort, and gdb. This year, I hope to actually do a full write-up of the Capture the Flag game, since no one else ever seems to do it. :)

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

July 22, 2005

open clip art is everywhere

Filed under: Inkscape — kees @ 8:36 am

Although I’m only a user of the Open Clip Art Library, I’m close to the people involved in it since many of them are also involved in Inkscape. As a result, I’m always on the look-out for new places where OCAL is mentioned or OCAL art is used. Today while innocently reading Groklaw‘s response to Dvorak’s misunderstanding of the Creative Commons licenses, I saw OCAL mentioned as the first in a list of examples of useful CC-tagged sites. Very cool. :)

(This post, I think, has my highest ratio of links to words yet.)

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

July 13, 2005

pattern visualization

Filed under: Reverse Engineering — kees @ 7:59 pm

Damn. I just thought up another piece of software (that I’m capable of writing) that I can’t find. This is bad; it means it’s going to haunt me until I code it.

So, frequently, I’m faced with streams of bytes of unknown origin/purpose. (For example, the .TiVo file format, RTMP streams, and most recently, Outlook “NK2” address autocompletion cache files.) I’ve had experience finding patterns, but it’s always so time-consuming. Usually I’m compiling some little C program over and over, slowly tweaking some guessed-at structure. This is basically the advice I got from Andrew Tridgell when I asked how he went about reverse engineering protocols. His methods deal more with sending/receiving, so it’s much more interactive. Most of what I’ve mucked with are just unknown file formats.

What I want is a nice GUI tool that will let me specify a language to describe a data file’s contents. I can see lots of meta-specifications like “repeat this structure until EOF”, and “if byte 5 is 1, read X bytes, otherwise, read X+50 bytes”, etc. Most data formats have pretty simple layouts after you figure them out. As you create the structure for the data to fit into, you can see the data from your example file displayed live. This way you can quickly tweak lengths, offsets, encoding types, endianness, etc, without needing to totally recompile your test harness.

Hell, it could even spit out the C code to process it, too. :)

I’m thinking about using Gtk and Python. We’ll see how rapid that path is for developing a nice GUI. I’ve heard good things. :)

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

June 29, 2005

google maps

Filed under: General — kees @ 9:37 am

Literally an hour after I finished figuring out how to build a Google Maps site (and having Ken help me with CSS hell), Google goes and changes the API and releases documentation. Aagh.

Google retains the right to put advertising on the map in the future.

Like, as a second overlay? Because I can’t see how this would work in the main overlay, considering users can define their own “info” contents for their XSLT. In-map advertising seems like a silly idea. Since everything is currently rendered in the browser, Google is going to have a hard time controlling what people display. I was hoping they’d go the route of making money off this by making people’s sites really really awsome, and then those people would buy advertising from Google directly due to their huge volume of traffic. I guess we’ll see…

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

June 26, 2005

scene diving

Filed under: Blogging — kees @ 6:05 pm

If it hasn’t already got a name, I’m going to coin the phrase “Scene Diving”, because that’s the best way I can describe it. By “scene“, I don’t mean an arrangement of furniture and people on a stage. I mean a group of people interested in a certain common idea, and all the things associated with their communication and productivity. By “diving”, I mean “information diving”, which was probably best outlined in Neuromancer. This is just another “involvement” analogy that uses water (“get your feet wet”, “in over your head”, “jump in at the deep end”, etc). I like this because it makes information a tactile thing that you have to navigate. With all the cyberpunk I’ve read, “diving” into information has such a romantic feel to it. Also, the idea that you’re out of your natural element, and that you’ll have to return to the surface at some point is very apt. It sets this apart from joining a scene.

Scene diving is something I’ve noticed I do a lot of, since there are so many subcultures in the online world. It may just be stating the obvious, but I think it feels like a specific skill. I’ve had people ask me in the past to find things for them, and I tried to show them how I’d go about it, but they weren’t interested in it, or didn’t have the patience. At it’s core, scene diving is just research. It’s really a form a applied research, but it isn’t something that could be done very easily prior to the Internet because of one critical element: communication.

The communication (or rather, language) of a scene is very specific. For example, it’s not immediately obvious to the average person what “BSG” stands for. But if you’re researching the backstory differences between the original and new Battlestar Galactica television series, you’ll find this acronym a lot, and the meaning becomes obvious. If your subculture isn’t online, there is no way for an outsider to observe your language without joining the subculture. This kind of communications research is much more voyeuristic.

Continuing the example, I really like a lot of Science Fiction. I’m a big fan of Star Wars, Star Trek, Doctor Who, BSG, etc. However, I don’t really have a lot of time (or, honestly, interest) to dedicate to these individual subcultures. I’ll watch Star Trek religiously, but I can’t tell you any of the character’s middle names, and I don’t know starship registry numbers off the top of my head. I used to think that meant I didn’t like these shows as much as other people, and that somehow meant I was missing something. It took a while for me to realize that I’m not missing anything, for the very reason that I’m not interested in that level of involvement.

However, there are some things I want to get out of a scene. I have always been fascinated by Star Wars Stormtroopers. Several years ago, I scene-dove and found out how to get myself some white armor. It’s very cool. Recently, I got it into my head that I wanted my very own TARDIS, and scene-dove until I had measurements, parts lists, etc. I still don’t have a TARDIS, but I think that’s because I can’t foresee having the time to build one. I really wanted to see the new Serenity movie from the Firefly series. Again, I scene-dove, and came away with the tickets I needed. My level of involvement in any of these subcultures is rather low, but this kind of diving doesn’t seem to be something a lot of people do. Other people tend to join just a few scenes and maintain a very high level of dedication and time investment. Perhaps I’m just too scattered to stay interested in one thing. Whatever the case, it seems that there is a skill to scene diving, and I enjoy using it. I’ve also met some extremely cool people as a result.

For me, the basic outline for successful scene diving is:

Research the top layer via Google
– “Public information” sites
– Discussion forums
Learn the language
– Abbreviations
– Build your own FAQ — answer any questions you have on your own
Find stuff not out in the open
– Share resources
– Be a useful to other members of the scene

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

June 23, 2005

serenity

Filed under: General — kees @ 8:12 am

We won two tickets to tonight’s screening of Serenity. I’m so excited! I am such a SciFi junkie. So much, in fact, I have to share the SciFi Ship Size Comparison website.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

June 6, 2005

my first podcast

Filed under: Blogging — kees @ 4:55 pm

I got invited to talk about Device::SerialPort on the weekly PerlCast. I discuss a little bit about the purpose and history of Device::SerialPort, as well as some cool things I know it’s been used for. I get to tell my favorite (short) story about the person in the furthest geographical location from me I’ve ever been in contact with. I had a lot of fun making my 4 minute talk. :) It kind of gives me some practice with what I’m going to be doing for OSCON. Except that OSCON will be several orders of magnitude longer, and I won’t be able to edit out my glaring mistakes.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

June 5, 2005

time for some sleep

Filed under: Security — kees @ 8:30 am

That was a seriously challenging prequal and I’m glad it’s over. Our team, Plan B, placed 4th out of 20 or so other teams making it into the top 6 that will move on to DefCon CTF. (Actually, we’re 3rd because one of the teams won’t be playing…)

So far the wittiest motto: “Plan B: we’re not the best, but we’ll damn well stay up all night”.

Night night.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

June 3, 2005

defcon prequal

Filed under: Security — kees @ 11:31 am

Man, I’m so excited! The DefCon Capture the Flag contest prequalification round is starting tonight. There goes my whole weekend! I’m very curious how this is going to turn out. This year I’m part of a much smaller team than the last two years, and the game organizers are new. (Well, they’re new to organizing; they’ve been competitors in CTF before.) The last 3 years CTF was run by the Ghetto Hackers, and the last two years had enough applicants that a prequalification round was needed. The same thing is happening this year.

Two years ago, I joined the Immunix CTF team late (who had played the year prior as well), and heard details about the web-based puzzles used for the CTF prequal. Last year, we got to do active attacks against executables on a provided machine. After overflowing each executable, you gained the group privs to run the next executable. Additionally, there was a text string token that you emailed to the GH to prove that you had gotten through that stage. Each stage was progressively more difficult to exploit.

So far this year the early clues are pretty shallow. They have mentioned “tokens” again, and a contest website. Maybe the website will give instructions on a machine to log into. Maybe it’ll all be web based again. Either way, I’m stocking up on beef jerky and water.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

May 25, 2005

ask a stupid question

Filed under: General — kees @ 7:58 am

Well, it seems that my stupid questions and bad starts have actually been useful.

In learning all the right ways to write patches for the Wine project, I got corrected a lot by the various developers. This is a much better situation to be in than the dreadful dead-air you can sometimes find on other development mailing lists where the more experienced project members just ignore questions and don’t bother to critique patch submissions. That case is so much more frustrating.

On the Wine devel list, there was never a shortage of people trying to show me how to make my patches better. It took me several weeks to get a large chunk of code into the project, but in the end, it was well documented, had a test suite, used the correct debug channels, handled memory management correctly, and generally did everything the right way. On top of that success was the fact that the Wine Wiki FAQ, which is studiously kept up to date, ended up recording a lot of my questions (or more importantly, their answers). You’ll find a lot of “K. Cook” in the Coding Hints section now.

While there may be no such thing as a stupid question, they’re clearly newbie questions if everything you ask ends up in the FAQ. :) Hopefully my bumbling will be useful to other folks in the future.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

May 16, 2005

writing for OSCon

Filed under: General — kees @ 6:56 pm

Aaaagh. I’ve got 30 days to write two full presentations for OSCon! AAaaaaa!

In other news, I got a few crash bug patches accepted into Wine. That was cool.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

May 12, 2005

hey, it’s thursday

Filed under: General — kees @ 4:29 pm

On my way to work
Today the odometer in my car rolled across 223344. That was pretty cool.

RSS for kernel.org
I was bothered that I couldn’t add the kernel.org list of latest Linux kernel versions to my RSS aggregator, so I modified the detection scripts to spit out an RSS feed. Whee!

Bug fixes
I got a small patch against mp3cd yesterday. So I took the moment to release a “stable” version, since I’ve been using the “devel” branch for about 6 months now. That sounds pretty stable to me. :)

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

May 6, 2005

O’Reilly OSCon ’05

Filed under: Blogging — kees @ 7:32 am

I am so excited! I’m going to be a speaker at OSCon this year. I’ve never been a speaker anywhere! I’m gonna be so nervous it’s insane. I really hope it all goes well, but I still think it’s intimidating to be surrounded by so many experts in so many fields. I know I have a lot of email/spam/filtering experience (and a little Python), but there are plenty of other people who have more. I just happen to be talking about it. I hope they don’t beat me up during my talks. :) If I teach one thing to one person, I’ll see it as a success. I’d suspect I’m going to learn a lot too. “Why didn’t you do it this way?” “Uh, because I didn’t think of it! Thanks!”

Oh, so nervous. Yeow.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

May 3, 2005

nice kernel.org write-up

Filed under: kernel.org — kees @ 2:50 pm

As if a blog itself wasn’t enough shameless self-promotion, I’ve just gotta share more! There’s a nice write up at Kernel Trap on how the kernel.org servers work. I’m mentioned in there since I’m one of the guys that helps keep the machine running. Mostly I manage the mirror server validations. I’m the guy that bugs the other mirror admins about falling behind, etc. The real work is done by HPA and Nathan. They’ve got some great gear in place now. I can’t wait until the next Fedora Core release; it really drives the machines hard. I think it’s great to log into a fairly responsive machine, and see a load average over 200. And then realize that that’s normal. I love it!

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

May 2, 2005

I feel dirty

Filed under: Multimedia — kees @ 11:13 pm

I’ve just published srcfilter. It runs under Wine, which is the only reason I kept working on it. Coding in the Windows style has this sickening allure, like an overly sweet smell. I know I don’t want it, but it seems so tasty. (Oh, DWORD, how I hate thee. All your instance names start with “dw”.)

Anyway, srcfilter uses the DirectShow API to initialize a SourceFilter from a DLL you supply. It then pulls a specified source file through the DLL, writing the output to a file. Similiar things can be done with the GraphEdit tool that comes with the DirectX SDK. If you wanted to set up a Graph that uses a SourceFilter to read a file and a Dump sink to write output, you can use srcfilter to do the same thing. And you wouldn’t need Windows to do it.

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

April 28, 2005

video editing with gopchop

Filed under: Multimedia — kees @ 10:16 am

Well, in the last few weeks, after finally getting MPEG2-PS streams out of my series 2 TiVo, I’ve been actively using gopchop again. It had stagnated, but it seems that people with hardware MPEG2 encoders continue to use it. I should have realized sooner that they are gopchop’s audience. It’s traditionally been a rather fragile bit of code for software-generated MPEG2-PS streams, but pretty stable for the more regular hardware-encoder streams. Between my recent increase in its use, and two large patch bundles I was sent, I’m trying to pick up development again.

One thing that has been particularly frustrating when dealing with MPEG2 video has been dealing with the rendering of the pictures. MPEG2 stores its pictures “out of order”. And by “order” I mean display order. They’re in order for decoding, but not for display. libmpeg2 handles all this for me, except for the part where I need to stop on a specific picture. For an accurate GOP splitting UI, I need to display the last picture of a GOP. Depending on the stream, libmpeg2 may not have rendered the last picture, since it’s waiting for more B or P frames before it knows the decoding is done. (For example, B frames depend on frames in the future, so you can’t render them until you see further down the stream, etc.)

My plan to deal with this is to force-feed libmpeg2 with End-Of-Stream packets, and not render stuff until I’m on the picture I want. For example, to display the initial B or P frames from a GOP, I may need to process the entire prior GOP first. For some types of streams, this may end up being very CPU expensive, since they may have hundreds of pictures in each GOP. But, this is why MPEG2 editing is hard. :)

© 2005, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 License.
CC BY-SA 4.0

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