[PATCH v2 1/4] crypto: drbg - ensure most preferred type is FIPS health checked

From: Dimitri John Ledkov
Date: Mon Oct 30 2023 - 08:05:54 EST


drbg supports multiple types of drbg, and multiple parameters of
each. Health check sanity only checks one drbg of a single type. One
can enable all three types of drbg. And instead of checking the most
preferred algorithm (last one wins), it is currently checking first
one instead.

Update ifdef to ensure that healthcheck prefers HMAC, over HASH, over
CTR, last one wins, like all other code and functions.

This patch updates code from 541af946fe ("crypto: drbg - SP800-90A
Deterministic Random Bit Generator"), but is not interesting to
cherry-pick for stable updates, because it doesn't affect regular
builds, nor has any tangible effect on FIPS certifcation.

Signed-off-by: Dimitri John Ledkov <dimitri.ledkov@xxxxxxxxxxxxx>
Reviewed-by: Stephan Mueller <smueller@xxxxxxxxxx>
---
crypto/drbg.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/crypto/drbg.c b/crypto/drbg.c
index ff4ebbc68e..2cce18dcfc 100644
--- a/crypto/drbg.c
+++ b/crypto/drbg.c
@@ -2018,9 +2018,11 @@ static inline int __init drbg_healthcheck_sanity(void)

#ifdef CONFIG_CRYPTO_DRBG_CTR
drbg_convert_tfm_core("drbg_nopr_ctr_aes128", &coreref, &pr);
-#elif defined CONFIG_CRYPTO_DRBG_HASH
+#endif
+#ifdef CONFIG_CRYPTO_DRBG_HASH
drbg_convert_tfm_core("drbg_nopr_sha256", &coreref, &pr);
-#else
+#endif
+#ifdef CONFIG_CRYPTO_DRBG_HMAC
drbg_convert_tfm_core("drbg_nopr_hmac_sha256", &coreref, &pr);
#endif

--
2.34.1