diff options
author | Eric Biggers <ebiggers@google.com> | 2023-10-08 19:31:16 -0700 |
---|---|---|
committer | Herbert Xu <herbert@gondor.apana.org.au> | 2023-10-20 13:39:25 +0800 |
commit | 7612222ba4d506b41beb8f40abaa206942a4109a (patch) | |
tree | 7fd0ef22043abd48d21bfa11d7485f46c53f055b /crypto/sha256_generic.c | |
parent | 61685126cb52dd3820d10f236f3fec30698de786 (diff) | |
download | linux-crypto-7612222ba4d506b41beb8f40abaa206942a4109a.tar.gz linux-crypto-7612222ba4d506b41beb8f40abaa206942a4109a.zip |
crypto: xts - use 'spawn' for underlying single-block cipher
Since commit f91796cf71a5 ("crypto: api - Fix built-in testing
dependency failures"), the following warning appears when booting an
x86_64 kernel that is configured with
CONFIG_CRYPTO_MANAGER_EXTRA_TESTS=y and CONFIG_CRYPTO_AES_NI_INTEL=y,
even when CONFIG_CRYPTO_XTS=y and CONFIG_CRYPTO_AES=y:
alg: skcipher: skipping comparison tests for xts-aes-aesni because xts(ecb(aes-generic)) is unavailable
This is caused by an issue in the xts template where it allocates an
"aes" single-block cipher without declaring a dependency on it via the
crypto_spawn mechanism. This issue was exposed by the above commit
because it reversed the order that the algorithms are tested in.
Specifically, when "xts(ecb(aes-generic))" is instantiated and tested
during the comparison tests for "xts-aes-aesni", the "xts" template
allocates an "aes" crypto_cipher for encrypting tweaks. This resolves
to "aes-aesni". (Getting "aes-aesni" instead of "aes-generic" here is a
bit weird, but it's apparently intended.) Due to the above-mentioned
commit, the testing of "aes-aesni", and the finalization of its
registration, now happens at this point instead of before. At the end
of that, crypto_remove_spawns() unregisters all algorithm instances that
depend on a lower-priority "aes" implementation such as "aes-generic"
but that do not depend on "aes-aesni". However, because "xts" does not
use the crypto_spawn mechanism for its "aes", its dependency on
"aes-aesni" is not recognized by crypto_remove_spawns(). Thus,
crypto_remove_spawns() unexpectedly unregisters "xts(ecb(aes-generic))".
Fix this issue by making the "xts" template use the crypto_spawn
mechanism for its "aes" dependency, like what other templates do.
Note, this fix could be applied as far back as commit 6c1314f521f2
("crypto: xts - Convert to skcipher"). However, the issue only got
exposed by the much more recent changes to how the crypto API runs the
self-tests, so there should be no need to backport this to very old
kernels. Also, an alternative fix would be to flip the list iteration
order in crypto_start_tests() to restore the original testing order.
I'm thinking we should do that too, since the original order seems more
natural, but it shouldn't be relied on for correctness.
Fixes: f91796cf71a5 ("crypto: api - Fix built-in testing dependency failures")
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'crypto/sha256_generic.c')
0 files changed, 0 insertions, 0 deletions