How to crack a Binary File Format

[Ktomislav]

Does anyone have any ideas how to crack a binary file format?

By crack i mean to find out how to read it in normal text format.

[StealthArcher]

Theoretically, you already can by specifying read in Turing rather than get. Then read in all of the file as strings. Jut remember, not all files are text, so with things like bmps you'll get weird ****.

[r691175002]

It depends a lot on the format of course. Really it could be as simple as decoding it as a normal string or as complicated as stripping away layers of encryption, compression and sorting through a mess of unintelligible data.

[PaulButler]

Do you know what the data is supposed to be? If it's something simple and uncompressed (image, video, audio, numbers), think of how you would store that data. Then look for signs that they are storing data in a similar way. Unless they are intentionally trying to obfuscate it, chances are they had the same thoughts you do.

If it's a popular file format, try: http://www.wotsit.org/

[Ktomislav]

It's a backup from router and i want to know the password.

[Zeroth]

The password isn't going to be in plaintext if its a decent router. It'll be encrypted, with a key that you won't be able to find. Even D-link routers encrypt the passwords. If you have physical access to the machine... you could always... reset it to factory default.

[Ktomislav]

Quote:

Even D-link routers encrypt the passwords

Do you think D-link is the worst or what?

[Zeroth]

Ktomislav @ Sat Sep 20, 2008 9:19 am wrote:

Quote:

Even D-link routers encrypt the passwords

Do you think D-link is the worst or what?

Yes.

[Insectoid]

Yup, D-link sucks. We had a D-link router and it died within a few months, and while it still worked the signal was inconsistent.

[Dan]

Zeroth @ 20th September 2008, 10:29 am wrote:

The password isn't going to be in plaintext if its a decent router. It'll be encrypted, with a key that you won't be able to find. Even D-link routers encrypt the passwords. If you have physical access to the machine... you could always... reset it to factory default.

My bet is that it hashs the password so there is no key, probably with sha1 or md5. So unless you know the hashing algorithm and have a rainbow table (witch would take up TBs of space and a prity impersive mashen to run) set up for it you probably are not going to crack it and thats only if they did not salt it befor hashing.