Messages in this thread | | | Date | Thu, 12 Jun 2014 15:01:54 -0400 | From | Vivek Goyal <> | Subject | Re: [PATCH 3/4] KEYS: validate key trust only with selected owner key |
| |
On Thu, Jun 12, 2014 at 09:36:46PM +0300, Dmitry Kasatkin wrote: > On 12 June 2014 20:32, Vivek Goyal <vgoyal@redhat.com> 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. > > > >> > >> > >> 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 > > > Hi Vivek, > > The easiest way to get OS Vendor ker/certificate is just embed it into > the kernel along with > ephemeral (or not) module signing key... They all appears on .system keyring...
I think it will be tricky as in current setup, signing happens on a different server and build server does not have access to keys.
Thanks Vivek
| |