Re: [PATCH v1.3 4/4] keys: add new key-type encrypted

From: Mimi Zohar
Date: Sat Nov 13 2010 - 19:48:47 EST


On Fri, 2010-11-12 at 21:23 +0000, David Howells wrote:
> Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> wrote:
>
> > > Why do you allow the master key to be supplied by a user-defined key rather
> > > than requiring a trusted-key unconditionally?
> >
> > This is for systems without a TPM. The logic needs to exist, whether it
> > is here or in EVM. By doing it here, a user could provide a passphrase
> > in the initramfs, which is used to decrypt the encrypted key.
>
> I thought that might be the case. In which case, it might be better to allow
> someone to add a trusted key, supplying both encrypted and unencrypted
> versions of the data so that the TPM need not be consulted. You might want to
> mark such a key so that it can be seen when it is dumped.

At least to me, the name 'trusted' implies some form of HW.

> But if you're going to use a user-defined key, you really need to prefix the
> description with something suitable.
>
> David

Agreed. So instead of:
keyctl add encrypted name "new master-key-name keylen" ring

the description would be prefixed with the key type like:
keyctl add encrypted name "new trusted|user master-key-name keylen" ring

thanks,

Mimi

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