Archive for August, 2009

Rusty Bullet hole

August 29th, 2009 7 comments

The secret phrase, it is!

Categories: Games, Garry's Mod Tags:

Windows 7, TrueCrypt and TrueImage – Take two

August 29th, 2009 No comments

It seems like I have a method now for imaging my encrypted hard-disk without the need of doing a sector-by-sector image of the encrypted partition (which would be as big as my partition – 25 GB – and uncompressable).

I now do it that way: I have Windows 7 installed on my primary partition, 25 GB huge. Then I encrypt only this partition with TrueCrypt using Pre-Boot Authentication (PBA). For PBA, I enabled in the options to cache the password in the driver memory. This allows me to use the password I entered upon boot to mount any other truecrypt device with the same password in windows later.

So do I. After Windows 7’s bootpartition was encrypted I created new encrypted partitions with TrueCrypt. These will be mounted when I login into Windows with the password previously stored in the driver-memory.

To the backup part: I create a hot-image from within Windows using TrueCrypt 2009. Since TrueImage now sees the partition unencrypted, I can create a compressable image (filesize is around a DVD’s size). To restore it, I boot up a BartPE bootable CD and restore the image to the system partition. BUT here, the data is written unencrypted! After image restore, I simply bypass the TrueCrypt bootloader pressing Esc, boot into the now unencrypted Windows and start encrypting the partition again (takes 20 minutes).

This method is not really elegant but it works. I just wish, the TrueCrypt developers finally add a “boot from CD” function into the PBA so I can use dos-backup-tools like NortonGhost 2003 which are able to read and write data then unencrypted. With SafeGuard Easy this works, but SGE only supports Windows 2000/XP.

Windows 7

August 23rd, 2009 3 comments

My University recently released Windows 7 on the MSDN-AA Page and I got excited so I installed it on one of my old harddisks. It is really fast. Compared to Vista, it seems to boot twice as fast and nearly as fast as XP.

One thing I didn’t got used to yet is the new taskbar. I instantly switched it back to the “classic” way and with small icons. Sure, stacking icons saves space but you will need one more click or wait about 300 ms until the preview pops up so you can finally select the wished task.

Then to the hard part: I’m now trying to decrypt the harddisk with TrueCrypt while still being able to make a backup in “unencrypted” mode. I need the encryption for my laptop because I don’t want that anyone is able to see my files if I lose it or someone steals it.

Back to the “make a backup in unencrypted mode”: This means that the harddisk is encrypted but right after the password is entered in the bootmenu, my plan was to start a backup-tool from CD or Floppy which now can read the unencrypted data. This was possible with commercial software such as SafeGuard Easy from Utimaco (It only supports Windows 2000 and XP). But it isn’t for the Open Source software TrueCrypt. I made some good attempts but all failed yet.

Attempt 1:

The encryption works like this: First the TrueCrypt bootloader is ran. After you successfully have entered the password it loads the bootloader of Windows. There is no way around this sadly. So my Idea was to add an entry to Window’s bootloader. Since you can’t boot from CD or Floppy using the Windows bootloader I have chosen to load another bootloader: Grub. Grub is still not capable booting a CD but a Floppy. For CD-Booting I installed one more bootloader loaded by Grub which is called Smart Boot Manager. Now I have been able to boot from CD after TrueCrypt. So I have a real big chain of bootloaders before I achieved my aim: TrueCrypt Bootloader -> Windows Bootloader -> Grub Bootloader -> Smart Boot Manager Bootloader -> CD Boot.

The first tests worked so far. I installed TrueCrypt and selected “encrypt the system partition”. I then cancelled encryption (I only needed the TrueCrypt bootloader for now) and installed all the upper bootloaders. This took me around one whole weekend. Then I tested it and bingo: Booting from CD works! I’ve been so damn happy so I started the final encryption process of TrueCrypt. But now after the system was encrypted my system refused to boot from CD or Floppy. Booting from CD threw an error “Read error:1 Drive:0 Sector:0”. Booting from floppy just made the system hang with no errors. It took me 3 more days to figure out it is an error-message of the TrueCrypt bootloader’s “encryption driver”.

So this method nearly worked but failed on the last steps.

Attempt 2:

This method envolves a BartPE bootcd with TrueCrypt and TrueImage installed on it. This CD is booted BEFORE the TrueCrypt bootloader so this CD just sees the encrypted partitions. This generally is bad but I installed TrueCrypt on this bootcd so I were able to mount the partitions. Then I wanted to make a file-based backup (not partition-based since True Image directly reads from the disk in this mode so it sees the encrypted data only). I started it but hey: Now it fucking hangs on reading the files from the system partition. There are (hidden) Systemfolders on your Windows partition which work like “links”, called junctions. They are installed for backwards compatibility to programs written for older systems such as XP. One folder for example is “Application Data”.

These nasty folders link to other folders on the drive. Sadly, there is an issue with the linking: Some folders link to another folder which contain a folder in it which then once more link to the folder before. Example: A links to B, B has a folder in it which links to A. Now TrueImage tries to read the files. First it finds A, sees it links to B, indexes all files in B and sees it has a folder linking to A. Now it does the same again and again: An infinite loop. In TrueImage you see the currently indexed file: It was something like C:\Application Data\Application Data\Application Data\Application Data\Application Data\…..\Application Data\ and so on. Ughh.

So this method also failed.

Attempt 3:

Now I try another method: I will create a Hot-Image directly under Windows using TrueImage in partition-backup-mode (Here, TrueImage sees the data unencrypted because I already booted with TrueCrypt). Then I boot from a BartPE bootable CD where I will restore the image. This will write the data unencrypted to the partition so I need to reencrypt it later after image-restore. I hope this works. I’ve read about this method on several forums but I did not like it at first since encrypting the disk takes time (25 GB in around 22 min on my current, old and slow, harddisk).

Attempt 3.1 (Plan B – Not started yet):

If even Attempt 3 fails, I will boot from a BartPE CD and create and restore the image using a sector-by-sector image of the encrypted data. This has the big disadvantage that the image file will be as big as the partition: 25 GB. And it can’t be compressed. So instead of having only saved the 8 GB Windows System, compressed down to around 4 GB (fits on a DVD) I would have a huge backupfile, 25 GB big fitting on 4-5 DVDs. SHIT.

Categories: Computer Tags: ,

Q&A: The answers

August 13th, 2009 12 comments

I’ve read through all your comments and I’m now going to answer all questions.

What is your favorite kind of strong alcohol?

I do not really like strong alcoholic drinks. The only one I like from time to time is Caipirinha.

When comes the next revision of the GMod-Stargates/Is it ready for release?

I have no idea when it will come. I know you guys have been waiting for it for so damn long but I have hardly any time to work on it currently. At the current state, nearly everything new is implemented but there is a shitload of bugs to fix before I can release it.

What PHP-Lister do you use on ?

It’s a script I have written myself. First it was based on a lister I have found randomly on the net but it was coded awfully so I completely recoded it from scratch (took me ~2 days to recode, 5 more for finetuning).

Do you ever plan to implement Jinto’s renderx library to the stargates for making clipping eventhorizons?

I’m not sure yet. Of course, I like the idea of having it clipping but I don’t like everyone needing to install a module. It’s not that hard implementing clipping visually but physically.

Why do you update your twitter-page once every two weeks?

Oh, I have a twitter account? Nearly forgot about it Smile

What do you think about RTL2 streaming Stargate Atlantis, Season 5 in Germany?

It was about time. The series ended about last year in the US/UK and now they started it (finally) yesterday. I like SGA but I don’t like it ends with Season 5. Luckily there are direct-to-DVD movies announced.

Why did you choose to study quantum mechanics?

Actually I’m studying physics and quantum mechanics is just a subcategory. If you study general physics you have to take a QM-course. And by now it was the most interesting lecture yet.

But maybe you are satisfied with me answering why I do study physics: I have no real clue. Well, I liked math and that. But only math is quite dry so I have chosen to study physics.

Will you ever add a possibility of using all chevrons on the GMod-stargates?

This is not planned.

Can you make some of the weapons on your GMod-Server downloadable for us?

Sorry, I can’t. E.g. the “Venom” or “Nomad-Blaster” are weapons Jinto has coded. And I can’t give them away without his permission.

Are there any new stuff for the GMod-stargates planned?

Why not. For example, the SGU gate will be added (when finished) and probably new air-vehicles.

How much time do you take for playing GMod or relaxing on your PC?

I hardly “play” GMod anymore. I code more for it. I only play a bit on Fretta-Servers but only because I coded a GMod cheat. The only thing I like on GMod is, it’s so expandable. And coding makes me relax on more than playing. But of course I do play other games such as TF2 or UT3.

How much time can you afford for coding rather than University-work?

I’m at University from Monday to Friday, getting up ad 9am and coming home at 20pm or somtimes 0am. This means, I only have time on weekends and there, I generally do different things than coding. So quite less time.

Categories: Blog Tags:

Questions and Answers

August 4th, 2009 16 comments

Hello.Long time I haven’t posted much. That’s because I’ve been busy (I know, this sentence is getting old). So as excuse I’ll give you the propability to post any questions you have regarding me and/or my work or whatever you want to ask. I’ll try to answer all questions as good and valid I can.

I think I’ll give you around one or two weeks time or about ten to 20 questions. Whatever comes first. So let the asking begin.

Categories: Blog Tags: