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, all based on IMA policy rules, was discussed from the
beginning, prior to fs-verity being upstreamed[1,2].
Support including fs-verity file digests in the 'd-ng' template field
based on a new policy rule option named 'digest_type=hash|verity'.
Also support verifying fs-verity file digest based signatures based on
policy.
A new template field named 'd-type' as well as a new template named
'ima-ngv2' are defined to differentiate betweeen file hashes and fs-verity
file digests, when file signatures are not included in the IMA measurement
list.
[1] https://events19.linuxfoundation.org/wp-content/uploads/2017/11/fs-verify_Mike-Halcrow_Eric-Biggers.pdf
[2] Documentation/filesystems/fsverity.rst
Changelog v2:
- Addressed Eric Bigger's comments: sign the hash of fsverity's digest
and the digest's metadata, use match_string, use preferred function
name fsverity_get_digest(), support including unsigned fs-verity's
digests in the IMA measurement list.
- Remove signatures requirement for including fs-verity's file digests in
the 'd-ng' field of the measurement list.
Changelog v1:
- Updated both fsverity and IMA documentation.
- Addressed both Eric Bigger's and Lakshmi's comments.
Mimi Zohar (6):
ima: rename IMA_ACTION_FLAGS to IMA_NONACTION_FLAGS
fs-verity: define a function to return the integrity protected file
digest
ima: define a new template field 'd-type' and a new template
'ima-ngv2'
ima: include fsverity's file digests in the IMA measurement list
ima: support fs-verity file digest based signatures
fsverity: update the documentation
Documentation/ABI/testing/ima_policy | 17 +++++
Documentation/filesystems/fsverity.rst | 22 +++---
Documentation/security/IMA-templates.rst | 10 ++-
fs/verity/Kconfig | 1 +
fs/verity/fsverity_private.h | 7 --
fs/verity/measure.c | 40 +++++++++++
include/linux/fsverity.h | 18 +++++
include/uapi/linux/ima.h | 26 ++++++++
security/integrity/ima/ima_api.c | 29 +++++++-
security/integrity/ima/ima_appraise.c | 81 +++++++++++++++++++++++
security/integrity/ima/ima_main.c | 2 +-
security/integrity/ima/ima_policy.c | 40 ++++++++++-
security/integrity/ima/ima_template.c | 3 +
security/integrity/ima/ima_template_lib.c | 23 ++++++-
security/integrity/ima/ima_template_lib.h | 2 +
security/integrity/integrity.h | 7 +-
16 files changed, 302 insertions(+), 26 deletions(-)
create mode 100644 include/uapi/linux/ima.h
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2.27.0
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