[Bug 256486] [NEW] No encrypted keyfile for cryptroot in Hardy

martinp martin.piayda at udo.edu
Sat Aug 9 23:11:21 UTC 2008


Public bug reported:

Binary package hint: initramfs-tools

>From what is currently provided in Hardy there seems to be an
inconsistency between handling a cryptroot and crypted devices via
crypttab.

By using cryptroot I'm referring to a crypted root (/) which is directly mounted after initializing the kernel.
While calling /etc/init.d/cryptdisks it will call /lib/cryptsetup/cryptdisks.functions and map possible non-block device files to a loopX dev and use them as input source for e.g. a key. even more: an encrypted key.

In crypttab you can provide keyfile for a crypted partition which itself
is again crypted. e.g. file file1 is  aes-encrypted and therefore must
be mounted as block-dev beforehand so it can be used as input-key for a
partition.

When using cryptroot while booting the system this does not work. There is no losetup in the cpio-arc and therefore unlocking will fail.
The solution might be something like copying losetup when generating the cpio-arc which is fairly easly:
-> copy_exec /sbin/losetup /sbin

The second thing is to extend the cryptroot script in initramfs with sth like
        loopdev=$(losetup -f 2> /dev/null) || return 1

        losetup "$loopdev" "$src" || return 1
        src="$loopdev"
in case the src is not a block-dev

I have experimented with this but it would be nice to have this
integrated with the stream so any updates to the kernel or initramfs
will have this change. Otherwise if you forget to patch your cpio-arc
your system will be.... errr... b0rked. :)

Thank you

** Affects: initramfs-tools (Ubuntu)
     Importance: Undecided
         Status: New

-- 
No encrypted keyfile for cryptroot in Hardy
https://bugs.launchpad.net/bugs/256486
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