Re: [RFC 6/8] KEYS: PGP data parser

[Roberto Sassu]

On Fri, 2024-02-16 at 16:44 +0000, Matthew Wilcox wrote:
> On Fri, Feb 16, 2024 at 04:24:33PM +0100, Petr Tesarik wrote:
> > From: David Howells <dhowells@xxxxxxxxxx>
> > 
> > Implement a PGP data parser for the crypto key type to use when
> > instantiating a key.
> > 
> > This parser attempts to parse the instantiation data as a PGP packet
> > sequence (RFC 4880) and if it parses okay, attempts to extract a public-key
> > algorithm key or subkey from it.
> 
> I don't understand why we want to do this in-kernel instead of in
> userspace and then pass in the actual key.

Sigh, this is a long discussion.

PGP keys would be used as a system-wide trust anchor to verify RPM
package headers, which already contain file digests that can be used as
reference values for kernel-enforced integrity appraisal.

With the assumptions that:

- In a locked-down system the kernel has more privileges than root
- The kernel cannot offload this task to an user space process due to
  insufficient isolation

the only available option is to do it in the kernel (that is what I got
as suggestion).

Roberto