Re: How to add additional blacklist entries?

[David Howells]

Mimi Zohar <zohar@xxxxxxxxxxxxxxxxxx> wrote:

> > You can link from any key you have LINK permission on.  Further, add_key()
> > can add directly.
> 
> Oh, for some reason I thought the system blacklist keyring was limited
> to the new key type with just a description.   I was able to add, but
> also remove a key from the system blacklist.   I guess the KEY_FLAG_KEEP
> is not set on the system blacklist.

With patch 18 you can.  Prior to that it's not possible to modify it from
userspace at all.

> The keys being added to the IMA keyring are signed x509 certs (eg.
> openssl ca -ss_cert).  It would be nice to be able to include the skid
> in the description, without a payload, and sign that.  I have no idea if
> that Is possible or if it makes sense.  I'm open to suggestions.

I think we need a new keyctl or syscall for this.

We need to run through the X.509 parser, but we don't actually want to keep
any of the payload - and, in fact, we don't even necessarily want to create an
asymmetric-type key, though it's not a complete loss if we do that and create
one with a blacklist subtype.  The blacklist subtype would just return an
error from all operation points, but would otherwise be handled as normal.

David