On Sat, Jan 15, 2022 at 09:55:47PM -0500, Mimi Zohar wrote: > On Sat, 2022-01-15 at 21:15 +0200, Jarkko Sakkinen wrote: > > On Sat, Jan 15, 2022 at 09:14:45PM +0200, Jarkko Sakkinen wrote: > > > On Sat, Jan 15, 2022 at 07:12:35PM +0000, Eric Snowberg wrote: > > > > > > > > > > > > > On Jan 15, 2022, at 10:11 AM, Jarkko Sakkinen <jarkko@xxxxxxxxxx> wrote: > > > > > > > > > > On Wed, Jan 12, 2022 at 02:41:47PM -0500, Mimi Zohar wrote: > > > > >> On Tue, 2022-01-11 at 20:14 -0500, Mimi Zohar wrote: > > > > >>> On Tue, 2022-01-11 at 21:26 +0000, Eric Snowberg wrote: > > > > >>>> > > > > >>>>> On Jan 11, 2022, at 11:16 AM, Mimi Zohar <zohar@xxxxxxxxxxxxx> wrote: > > > > >>>>> > > > > >>>>> On Mon, 2022-01-10 at 23:25 +0000, Eric Snowberg wrote: > > > > >>>>>>> Jarkko, my concern is that once this version of the patch set is > > > > >>>>>>> upstreamed, would limiting which keys may be loaded onto the .machine > > > > >>>>>>> keyring be considered a regression? > > > > >>>>>> > > > > >>>>>> > > > > >>>>>> Currently certificates built into the kernel do not have a CA restriction on them. > > > > >>>>>> IMA will trust anything in this keyring even if the CA bit is not set. While it would > > > > >>>>>> be advisable for a kernel to be built with a CA, nothing currently enforces it. > > > > >>>>>> > > > > >>>>>> My thinking for the dropped CA restriction patches was to introduce a new Kconfig. > > > > >>>>>> This Kconfig would do the CA enforcement on the machine keyring. However if the > > > > >>>>>> Kconfig option was not set for enforcement, it would work as it does in this series, > > > > >>>>>> plus it would allow IMA to work with non-CA keys. This would be done by removing > > > > >>>>>> the restriction placed in this patch. Let me know your thoughts on whether this would > > > > >>>>>> be an appropriate solution. I believe this would get around what you are identifying as > > > > >>>>>> a possible regression. > > > > >>>>> > > > > >>>>> True the problem currently exists with the builtin keys, but there's a > > > > >>>>> major difference between trusting the builtin keys and those being > > > > >>>>> loading via MOK. This is an integrity gap that needs to be closed and > > > > >>>>> shouldn't be expanded to keys on the .machine keyring. > > > > >>>>> > > > > >>>>> "plus it would allow IMA to work with non-CA keys" is unacceptable. > > > > >>>> > > > > >>>> Ok, I’ll leave that part out. Could you clarify the wording I should include in the future > > > > >>>> cover letter, which adds IMA support, on why it is unacceptable for the end-user to > > > > >>>> make this decision? > > > > >>> > > > > >>> The Kconfig IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY > > > > >>> "help" is very clear: > > > > >> > > > > >> [Reposting the text due to email formatting issues.] > > > > >> > > > > >> help > > > > >> Keys may be added to the IMA or IMA blacklist keyrings, if the > > > > >> key is validly signed by a CA cert in the system built-in or > > > > >> secondary trusted keyrings. > > > > >> > > > > >> Intermediate keys between those the kernel has compiled in and the > > > > >> IMA keys to be added may be added to the system secondary keyring, > > > > >> provided they are validly signed by a key already resident in the > > > > >> built-in or secondary trusted keyrings. > > > > >> > > > > >> > > > > >> The first paragraph requires "validly signed by a CA cert in the system > > > > >> built-in or secondary trusted keyrings" for keys to be loaded onto the > > > > >> IMA keyring. This Kconfig is limited to just the builtin and secondary > > > > >> keyrings. Changing this silently to include the ".machine" keyring > > > > >> introduces integrity risks that previously did not exist. A new IMA > > > > >> Kconfig needs to be defined to allow all three keyrings - builtin, > > > > >> machine, and secondary. > > > > >> > > > > >> The second paragraph implies that only CA and intermediate CA keys are > > > > >> on secondary keyring, or as in our case the ".machine" keyring linked > > > > >> to the secondary keyring. > > > > >> > > > > >> Mimi > > > > >> > > > > > I have also now test environment for this patch set but if there are > > > > > any possible changes, I'm waiting for a new version, as it is anyway > > > > > for 5.18 cycle earliest. > > > > > > > > Other than the two sentence changes, I have not seen anything identified > > > > code wise requiring a change. If you’d like me to respin a v10 with the sentence > > > > changes let me know. Or if you want to remove the ima reference, that works > > > > too. Just let me know how you want to handle this. Thanks. > > > > > > I'm basically waiting also Mimi to test this as I do not have IMA test > > > environment. > > > > > > From my side: > > > > > > Tested-by: Jarkko Sakkinen <jarkko@xxxxxxxxxx> > > > > I can pick the whole thing at the time when I get green light. > > The MOK keys are not loaded onto the .machine keyring if > CONFIG_IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY is enabled. > From an IMA perspective nothing has changed. > > After the IMA references in the patch descriptions are removed, feel > free to add Tested-by: Mimi Zohar <zohar@xxxxxxxxxxxxx> on patches 1 - > 5. > > thanks, > > Mimi Eric, for me it would be at least a convenience, and overally it would make sure that I pick the right thing if you would fix the typos (and you can add all the tested-by tags of course as no functional changes). There's been times when I've manually "just fixed typos", and failed in a way or another because of human error. Just want to make sure that we have exactly the right content applied, I hope you understand my point of view. And we are early for the 5.18 release cycle anyway. BR, Jarkko
