Password Spaces Bug

boyska edited this page Nov 2, 2011 · 11 revisions

Tomb 1.0 has a bug. A VERY GRAVE BUG. Passwords containing odd characters where badly interpreted: this means that if you password was I am 12!! perfectly 7^!@^#38123 secure, it could have been understood by tomb as I. yes, it was "splitted" at the first odd character. And yes, you thought to have a really great passphrase. Instead, you were using a single character one. Try it yourself, even with an old release of tomb. You might be able to open your tomb using just I as password. Now, this bug has been fixed. This, however, won't fix the tomb that you created and used. You need to create a new one, move the content, then securely delete the old tomb and the old key.

Is it my case?

There are several ways to check:

askpass

use tomb askpass. Enter your password, and check if it printed what you tiped, or a shorter one

try a shorter password

Suppose your password is a very good password. Try using just a as password. If it correctly opens your password, you are affected by the bug.

If unsure, just do it.

That's my case! what should I do now?

If you still use tomb 1.0, you have to do it the hard way. Otherwise, use tomb passwd (see below)

The hard way

Well, actually not that hard.

  • create a new tomb, and use a password with no spaces
  • move the content from the old to the new one
  • WIPE the old tomb and, most importantly, the old key (actually, wiping the key shoudl be enough). Please note that you shouldn't just delete the file; you have to securely delete it. There are lots of tools that can do it, altough their effectiveness is debated, especially on journaling filesystems, like ext3/ext4. You can check wipe, srm. shred

Note that, if you have copies of your old key, you should wipe them as well

Passwd

We are working on the introduction of a tomb subcommand to change password to your key. It has NOT yet been merged in mainline however. The usage should be tomb passwd $keyfile

And be similar to the traditional passwd unix command: ask the old password, then confirm the new one two times.

Notes

If you really want to use spaces in your password, you have to keep in mind that tomb 1.0 WON'T open your tomb.