On 10/21/2022 7:53 AM, Dr. Greg wrote: > On Wed, Oct 19, 2022 at 11:59:40AM -0700, Kees Cook wrote: > > Good morning, I hope the week is ending well for everyone. > >> On Wed, Oct 19, 2022 at 10:34:48AM -0400, Mimi Zohar wrote: >>> The only thing trivial about making IMA and EVM LSMs is moving >>> them to LSM hooks. Although static files may be signed and the >>> signatures distributed with the file data through the normal >>> distribution mechanisms (e.g. RPM), other files cannot be signed >>> remotely (e.g. configuration files). For these files, both IMA >>> and EVM may be configured to maintain persistent file state stored >>> as security xattrs in the form of security.ima file hashes or >>> security.evm HMACs. The LSM flexibility of enabling/disabling IMA >>> or EVM on a per boot basis breaks this usage, potentially >>> preventing subsequent boots. >> I'm not suggesting IMA and EVM don't have specific behaviors that >> need to be correctly integrated into the LSM infrastructure. In >> fact, I spent a lot of time designing that infrastructure to be >> flexible enough to deal with these kinds of things. (e.g. plumbing >> "enablement", etc.) As I mentioned, this was more of trying to >> provide a head-start on the conversion. I don't intend to drive this >> -- please take whatever is useful from this example and use it. :) >> I'm happy to help construct any missing infrastructure needed >> (e.g. LSM_ORDER_LAST, etc). > We are 2-3 weeks out from submitting for review and inclusion in the > kernel, a new LSM, and an associated userspace stack, that will have a > high degree of significance with respect to these conversations. Oh, come on, No one likes a teaser trailer. ;) > >> Kees Cook > Best wishes for a pleasant fall weekend. > > As always, > > Dr. Greg > The Quixote Project - Flailing at the Travails of Cybersecurity
