Re: [RFD] linux-firmware key arrangement for firmware signing

Mimi Zohar
2015-05-21T16:59:42Z

On Thu, 2015-05-21 at 19:43 +0300, Petko Manolov wrote:
> On 15-05-21 16:51:49, David Howells wrote:
> >
> > I do have patches to parse PGP key data and add the public keys found therein
> > onto the kernel keyring, but that would mean adding an extra key data parser.
>
> PGP is widely used so i would gladly have one more parser in the kernel.
>
> > You could probably do this with the integrity functions - but turning them on
> > has a performance cost and you have to load things in the right order as I
> > understand it.
>
> The performance hit is negligible, especially on modern hardware. The problem
> is that Joe user must wrap his head around IMA as a concept and go through the
> pains of doing everything right. Failing to do so will result in a lot of
> frustration, and i speak from experience.
>
> Once you make it run properly it mostly stays out of your way. To put it
> another way: IMA is not for sissies... :)

The main problem today is that software doesn't come and isn't installed
with file signatures. Once file signatures are installed with the
files, then it is just a matter of the machine owner signing the
software's public keys. Dracut (or equivalent) would load the signed
keys onto the trusted IMA keyring.

Mimi