Re: Crypto driver -DCP

[Marek Vasut <marex@denx.de>]

On Monday, June 08, 2015 at 06:52:00 AM, Herbert Xu wrote:
> On Fri, Jun 05, 2015 at 04:38:03PM +0200, Marek Vasut wrote:
> > In general, it would probably make sense to add a flag to .setkey() to
> > store the key in a keyslot. The keyslot allocation would be up to the
> > driver. In case all keyslots would be full, the setkey() with the flag
> > set would simply fail. This would imply you would need to have a
> > counterpart function to .setkey() to free keyslots -- something like
> > .unsetkey() .
> 
> Changing setkey is going to cause too much churn.  In any case
> I don't think these key slots should be written to by the kernel
> since the intention appears to be for entites outside the kernel
> to place secret keys in there that can then be used but not read
> by the kernel.

You mean like bootloader or you mean userspace code ? Maybe Jay
can explain how these slots are intended to be used. I'd like to
know the expected usecase.

> So as far as the kernel is concerned these are constant keys.
> 
> Therefore there should be no need for unsetkey.
> 
> So perhaps just add a new call setkey_slot that is optional and
> only needs to be implemented by drivers such as ccp.

Might work as well ... but let's maybe wait for the usecase.

Best regards,
Marek Vasut