Messages in this thread | | | Subject | Re: [PATCH 3/4] KEYS: validate key trust only with selected owner key | From | Mimi Zohar <> | Date | Thu, 12 Jun 2014 13:37:37 -0400 |
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On Thu, 2014-06-12 at 13:32 -0400, Vivek Goyal wrote: > On Thu, Jun 12, 2014 at 08:23:57PM +0300, Dmitry Kasatkin wrote: > > On 12/06/14 19:03, Vivek Goyal wrote: > > > On Tue, Jun 10, 2014 at 11:48:17AM +0300, Dmitry Kasatkin wrote: > > >> This patch provides kernel parameter to specify owner's key id which > > >> must be used for trust validate of keys. Keys signed with other keys > > >> are not trusted. > > >> > > >> Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> > > > Hi, > > > > > > I am continuing to work on verifying kernel signature for kexec/kdump. I > > > am planning to take david howell's patches for pkcs7 signature > > > verification and verify bzImage signature. > > > > > > Part of that process will boil down to verifying a certificate in > > > pkcs7 x509 cert chain using a key in system_trusted_keyring. > > > > > > I think the OS vendor key which signs the kernel signing key propagates to > > > system_trusted_keyring. (shim has that and I am not sure how shim makes > > > it propogate all they way to system_trusted_keyring). > > > > > > So I was planning to use same functionality where I look for any key > > > which can verify the signing cert of kernel. As OS vendor key will be > > > in system_trusted_keyring, it should work. > > > > > > Now with this change where you will trust only one selected owner key. > > > That means you will not even trust the OS vendor key which signs kernel > > > signing key. I think this will stop working with keys_ownerid=<....> > > > > > > As I am doing that work in parallel and I saw these patches, I thought > > > I will bring it up. > > > > Hi Vivek, > > > > All keys stays in the keyring. Usage of owner_keyid is limited to > > validate the trust of the loaded keys. > > Hi Dmitry, > > If owner_keyid scope is just limited to loading extra keys, then it > should be fine as I don't want to load extra keys. I just want to > verify already signed image whose key is supposed to be in > system_trusted_keyring.
Yes, sorry my mistake.
Mimi
> > > > > > Do you really see OS verndor key (Fedora) on the system keyring? > > shim is UEFI binary and can add it to the MOK database.. > > I have been told that mechanism to propagate they key in shim which is > used to verify kernel signature is in place and that key should show > up in system_trusted_keyring. I have never verified it though. I will > check it out. > > Thanks > Vivek >
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