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| author | Mimi Zohar <zohar@linux.ibm.com> | 2021-12-02 13:13:51 -0500 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.ibm.com> | 2022-05-12 18:38:27 -0400 |
| commit | 02ee2316b93569a26a0f9ccc8679c1066ea76047 (patch) | |
| tree | 470eec6fc892c75dc48a544f4d3d6e5514f46f45 /Documentation/filesystems | |
| parent | 398c42e2c46c88b186ec29097a05b7a8d93b7ce5 (diff) | |
| download | linux-02ee2316b93569a26a0f9ccc8679c1066ea76047.tar.bz2 | |
fsverity: update the documentation
Update the fsverity documentation related to IMA signature support.
Acked-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/fsverity.rst | 35 |
1 files changed, 23 insertions, 12 deletions
diff --git a/Documentation/filesystems/fsverity.rst b/Documentation/filesystems/fsverity.rst index 8cc536d08f51..b7d42fd65e9d 100644 --- a/Documentation/filesystems/fsverity.rst +++ b/Documentation/filesystems/fsverity.rst @@ -70,12 +70,23 @@ must live on a read-write filesystem because they are independently updated and potentially user-installed, so dm-verity cannot be used. The base fs-verity feature is a hashing mechanism only; actually -authenticating the files is up to userspace. However, to meet some -users' needs, fs-verity optionally supports a simple signature -verification mechanism where users can configure the kernel to require -that all fs-verity files be signed by a key loaded into a keyring; see -`Built-in signature verification`_. Support for fs-verity file hashes -in IMA (Integrity Measurement Architecture) policies is also planned. +authenticating the files may be done by: + +* Userspace-only + +* Builtin signature verification + userspace policy + + fs-verity optionally supports a simple signature verification + mechanism where users can configure the kernel to require that + all fs-verity files be signed by a key loaded into a keyring; + see `Built-in signature verification`_. + +* Integrity Measurement Architecture (IMA) + + IMA supports including fs-verity file digests and signatures in the + IMA measurement list and verifying fs-verity based file signatures + stored as security.ima xattrs, based on policy. + User API ======== @@ -653,12 +664,12 @@ weren't already directly answered in other parts of this document. hashed and what to do with those hashes, such as log them, authenticate them, or add them to a measurement list. - IMA is planned to support the fs-verity hashing mechanism as an - alternative to doing full file hashes, for people who want the - performance and security benefits of the Merkle tree based hash. - But it doesn't make sense to force all uses of fs-verity to be - through IMA. As a standalone filesystem feature, fs-verity - already meets many users' needs, and it's testable like other + IMA supports the fs-verity hashing mechanism as an alternative + to full file hashes, for those who want the performance and + security benefits of the Merkle tree based hash. However, it + doesn't make sense to force all uses of fs-verity to be through + IMA. fs-verity already meets many users' needs even as a + standalone filesystem feature, and it's testable like other filesystem features e.g. with xfstests. :Q: Isn't fs-verity useless because the attacker can just modify the |