Re: [Qemu-devel] Can I mount encrypt qcow2?

[Daniel P. Berrange]

On Thu, Jul 20, 2017 at 10:43:53AM +0800, 陳培泓 wrote:
> Can I mount encrypt qcow2 file through qemu-nbd?

What encryption format are you referring to ?  The old AES encrypt, or the
new LUKS encrypt ? The latter is the only one people should be using, and
you can expose it with

   qemu-nbd --object secret,id=sec0,file=passwd.txt,format=raw \
             --image-opts 
driver=qcow2,file.filename=demo.qcow2,encrypt.format=luks,encrypt.key-secret=sec0

Note that 'passwd.txt' file must *not* contain a newline. eg create it
with   'echo -n 123456 > passwd.txt' - the -n flag to omit the newline

You should only do decrypt in qemu-nbd, if you are trying to interoperate
with non-QEMU tools.  If you are exposing the NBD volume to a QEMU system
emulator, you should make the NBD server expose the file as raw, and let
the  QEMU client do the decryption instead, so data over the NBD socket
is still secure.

Regards,
Daniel
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