Re: [RFC PATCH v15 18/21] ipe: enable support for fs-verity as a trust provider

Roberto Sassu
2024-03-18T08:08:43Z

On Sun, 2024-03-17 at 22:17 -0700, Eric Biggers wrote:
> On Fri, Mar 15, 2024 at 08:35:48PM -0700, Fan Wu wrote:
> > +config IPE_PROP_FS_VERITY
> > + bool "Enable property for fs-verity files"
> > + depends on FS_VERITY && FS_VERITY_BUILTIN_SIGNATURES
> > + help
> > + This option enables the usage of properties "fsverity_signature"
> > + and "fsverity_digest". These properties evaluate to TRUE when
> > + a file is fsverity enabled and with a signed digest
>
> Again: why would anyone care if there is a signature, if that signature is not
> checked.
>
> I think you meant to write something like: "when a file is fsverity enabled and
> has a valid builtin signature whose signing cert is in the .fs-verity keyring".

I was also thinking the same. I didn't follow the recent development
closely, but unless IPE locks somehow the .fs-verity keyring, the
property you suggested would not be immutable. Meaning that someone can
add/remove a key in that keyring, making the property true or false.

Roberto