Date: Thu, 1 Nov 2012 13:18:49 +0000
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: joeyli <jlee@suse.com>
Cc: Takashi Iwai <tiwai@suse.de>, Matthew Garrett <mjg59@srcf.ucam.org>,
        Jiri Kosina <jkosina@suse.cz>, linux-kernel@vger.kernel.org,
        linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org
Subject: Re: [RFC] Second attempt at kernel secure boot support
Message-ID: <20121101131849.752df6fd@pyramind.ukuu.org.uk>
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> I think it make sense because the private key is still protected by
> signer. Any hacker who modified firmware is still need use private key
> to generate signature, but hacker's private key is impossible to match
> with the public key that kernel used to verify firmware.
> 
> And, I afraid we have no choice that we need put the firmware signature
> in a separate file. Contacting with those company's legal department
> will be very time-consuming, and I am not sure all company will agree we
> put the signature with firmware then distribute.

Then you'd better stop storing it on disk because your disk drive is FEC
encoding it and adding a CRC 8)

It does want checking with a lawyer but my understanding is that if you
have a file which is a package that contains the firmware and a signature
then there is not generally a problem, any more than putting it in an RPM
file - it's packaging/aggregation. This should be referred to the Linux
Foundation folks perhaps - no point designing something badly to work
around a non existant issue.

Also the interface needs to consider that a lot of device firmware is
already signed. Nobody notices because they don't ever try and do their
own thus many drivers don't need extra signatures in fact.

Alan
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