I Was Stupid and Need Computer Help


#1

Hey all,

So I encrypted (years back) a Linux volume when I was a lot more security conscious than I am now. I have no idea what the password is. I might be able to guess one or two parts of it… maybe… but I’m basically at a loss.

I know there’s no hope besides a brute force attack, and something like Hashcat would likely work on the thing… except I don’t have the hash. I don’t even remember what the encryption protocol was.

Is there a relatively easy way to throw a dictionary at it? I have a giant 4GB dictionary, and I’m pretty sure I know one word. I’m willing to let the computer go at it for up to a week, before resigning myself to formatting the drive and using it for other things. I don’t want to spend a lot of time on it directly. I just want to run something in the background I won’t have to think about. I know it’s a long shot and so I don’t want to sink a ton of time into this.

So the basic question: How to brute force an encrypted Linux drive (from a few years ago- so it has all the vulnerabilities that have been discovered since then) when you don’t have a hash. I don’t know enough to write a Bash script for it.

Or do I just give up now? Any help is much appreciated.


Data Hygiene Thread
#2

I would start by figuring out the disto and version.

It would give you a subset of encryption options to work with, at least.


#3

Based on what I can see in the boot partition, Fedora. FC15. Kernel version is 2.6.40.6-26… I think. That’s the most recent vmlinuz file anyway.

EDIT: Looks like LUKS, which is what I suspected. I tried using LUKS Crack, but it’s ancient abandonware, and I can’t get the underlying OTFE to run properly on Windows because it doesn’t have a signed driver.


#4

I’m sorry.


#5


#6

A google search turns up this https://github.com/glv2/bruteforce-luks

Haven’t used it, can’t vouch for it. And it seems the only way to help the brute force attack is if you know the beginning or end of the passphrase.

The good news is you are not in a unique situation and I bet there are more things to try. It’s all about how important the data is to you and how much time you are willing to invest.


#7

It’s not impossible, but I don’t have the tools to help.

All my master passwords are recorded in [REDACTED] so when this happens to me, I can ask… A thing… For the list.

We all learn the hard way.


#8

Worth a shot.

Not very important, can’t think of what I would want. I’m mostly curious what was in there. This is @beschizza’s safe all over again.

I wouldn’t like to invest any time in it really. Clock cycles, sure. Time, no.

I can’t do that. I both love my cat, and am extremely forgetful.


#9

Blackmail is a harsh term… And it is a harsh term.


#10

BitDoubloons?


#11

Cursed bitdoubloons, natch.


#12

Actually I’m hoping for a lost photograph of Geraldo Rivera.


#13

Docs suggest there is a step in mounting the volume where you provide a password.

It seems to me If:

  1. This fails quickly with a wrong passphrase
  2. You can determine success/failure via return code or parsing std out

Then you should be able to script a wordlist attack predicated on the mount step where you provide the passphrase, no special tools needed.


#14


#15

Hopefully not of shirtless Geraldo.


#16

Why else would it be encrypted?


#17

Irony of ironies… I randomly just remembered having an ebook of Schnier’s Applied Cryptography in there…


#18

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