On Mon, 2022-02-07 at 21:50 -0800, Eric Biggers wrote: > On Mon, Feb 07, 2022 at 08:41:32PM -0500, Mimi Zohar wrote: > > Support for including fs-verity file digests and signatures in the IMA > > measurement list as well as verifying the fs-verity file digest based > > signatures, both based on IMA policy rules, was discussed prior to > > fs-verity being upstreamed[1,2]. > > > > Support for including fs-verity file digests in the 'd-ng' template field > > is based on a new policy rule option named 'digest_type=verity'. A new > > template field named 'd-type' as well as a new template named 'ima-ngv2' > > are defined to differentiate between the regular IMA file hashes from the > > fs-verity file digests (tree-hash based file hashes) stored in the 'd-ng' > > template field. > > > > Support for verifying fs-verity based file signatures stored in the > > 'security.ima' xattr is similarly based on the policy rule option > > 'digest_type=verity'. > > > > To differentiate IMA from fs-verity file signatures a new xattr_type > > named IMA_VERITY_DIGSIG is defined. Signature version 3, which is a hash > > of the ima_file_id struct, disambiguates the signatures stored as > > 'security.ima' xattr. fs-verity only supports the new signature format > > (version 3). To prevent abuse of the different signature formats, policy > > rules must be limited to a specific signature version. > > > > [1] https://events19.linuxfoundation.org/wp-content/uploads/2017/11/fs-verify_Mike-Halcrow_Eric-Biggers.pdf > > [2] Documentation/filesystems/fsverity.rst > > What does this patchset apply to? I'm no longer able to apply it. I tried > both v5.17-rc3, and the next-integrity branch of > https://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity.git. Just refreshed 'next-integrity' now. -- thanks, Mimi
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