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:

quoted

From: David Howells <dhowells@redhat.com>

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