Re: Migration to trusted keys: sealing user-provided key?

Jan Lübbe [off-list ref] wrote:

quoted

quoted

... But at this point, you can still do 'keyctl read' on that key, exposing
the key material to user space.

I wonder if it would help to provide a keyctl function to mark a key as being
permanently unreadable - so that it overrides the READ permission bit.

Alternatively, you can disable READ and SETATTR permission - but that then
prevents you from removing other perms if you want to :-/

That would mean using user type keys, right? Then we'd still have the core
problem how a master key can be protected against simply reading it from
flash/disk, as it would be unencrypted in this scenario.

It would apply to any type of key or keyring on which it was set.  It would
cause keyctl_read() on a flagged key to return EPERM.

David