Re: Module signing and post-quantum crypto public key algorithms

David Howells
2025-11-08T07:47:11Z

Elliott, Robert (Servers) <elliott@hpe.com> wrote:

> The traditional signature would use whatever algorithm is used today.
> Legacy verifiers would only check that.

Would there be any legacy verifiers? Kernel modules are generally tied to the
kernel version for which they were compiled. Granted there are things like
the wifi regulatory stuff that are also signed.

But note also, PKCS#7 supports multiple independent signatures in a single
object. The kernel will handle this already. At least one signature must be
verifiable and none must be blacklisted.

I assume that the main aim of using a composite algorithm is to share the
result of the content hash - but in this case only the authenticatedAttributes
are going to be hashed for the signature, and that's relatively small.

David