In preparation for allowing the Merkle tree block size to differ from
PAGE_SIZE, replace fsverity_hash_page() with fsverity_hash_block(). The
new function is similar to the old one, but it operates on the block at
the given offset in the page instead of on the full page.
(For now, all callers still pass a full page.)
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Andrey Albershteyn <aalbersh@redhat.com>
Tested-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
Link: https://lore.kernel.org/r/20221223203638.41293-6-ebiggers@kernel.org
Instead of looking up the algorithm by name in hash_algo_name[] to get
its hash_algo ID, just store the hash_algo ID in the fsverity_hash_alg
struct. Verify at boot time that every fsverity_hash_alg has a valid
hash_algo ID with matching digest size.
Remove an unnecessary memset() of the whole digest array to 0 before the
digest is copied into it.
Finally, remove the pr_debug statement. There is already a pr_debug for
the fsverity digest when the file is opened.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Link: https://lore.kernel.org/r/20221129045139.69803-1-ebiggers@kernel.org
Embedding the file path inside kernel source code files isn't
particularly useful as often files are moved around and the paths become
incorrect. checkpatch.pl warns about this since v5.10-rc1.
Acked-by: Luca Boccassi <luca.boccassi@microsoft.com>
Link: https://lore.kernel.org/r/20201113211918.71883-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
When initializing an fs-verity hash algorithm, also initialize a mempool
that contains a single preallocated hash request object. Then replace
the direct calls to ahash_request_alloc() and ahash_request_free() with
allocating and freeing from this mempool.
This eliminates the possibility of the allocation failing, which is
desirable for the I/O path.
This doesn't cause deadlocks because there's no case where multiple hash
requests are needed at a time to make forward progress.
Link: https://lore.kernel.org/r/20191231175545.20709-1-ebiggers@kernel.org
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add SHA-512 support to fs-verity. This is primarily a demonstration of
the trivial changes needed to support a new hash algorithm in fs-verity;
most users will still use SHA-256, due to the smaller space required to
store the hashes. But some users may prefer SHA-512.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Add the beginnings of the fs/verity/ support layer, including the
Kconfig option and various helper functions for hashing. To start, only
SHA-256 is supported, but other hash algorithms can easily be added.
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Eric Biggers <ebiggers@google.com>
