[dm-crypt] How can I write a passphrase hash to key file for plain dm-crypt ?
dm-crypt at jelmail.com
Fri Nov 7 17:34:39 CET 2014
I'm trying to use plain dm-crypt. I have an example like this
$ cryptsetup open /dev/sda mydisk --type plain --hash sha512
that works fine. I enter 'password' as the pass phrase when requested.
I want to create an equivalent key-file so that I can do
$ cryptsetup open /dev/sda mydisk --type plain --key-file mykey
I couldn't find a cryptsetup command do to this, so I tried these:
$ openssl dgst -sha512 -binary <<< 'password' > mykey
$ sha512sum <<< 'my_passphrase' | head -c 128 > mykey
As I understand it, the key file contains a binary key that is used
as-is, so I would have thought the first try above would have worked. I
even used xxd to check that mykey contained the hash in binary data.
How can I make a key-file that is equivalent to a keyed-in passphrase?
Thanks in advance.
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