[dm-crypt] Migrating from loop AES to dm-crypt

[Nick Battle <nick.battle@gmail.com>]

I've just upgraded from openSUSE 12.1 to 12.2. I find that the latest version of
mount and losetup do not have the file encryption options they used to, since
everyone should have migrated to dm-crypt. The trouble is, I now have some
encrypted backup volumes that I cannot read!

I used to mount the archives with:

	mount ... -o loop,phash=sha256,encryption=aes128

It looks like I should be using the loopaesOpen option to cryptsetup to mount
these now, but I cannot find a combination of options that works. I'm trying the
following:

cryptsetup loopaesOpen <device> <name> --key-file pp --key-size 128 --hash
sha256 -c aes-cbc-plain

Where the file pp has my passphrase (without a newline) - that I used to enter
at the prompt mount gave when using the "-o loop". This successfully sets up the
mapper, but the result is not recognizable as a filesystem (I think it's ext2).
So I assume the crypto and/or passphrase hash isn't quite right.

I'm afraid the archives are so old that I don't know which options I used to
originally create them, though I almost certainly chose "defaults".

Can anyone help?

-- 
Cheers,
-nick