[PATCH v5 3/3] nvme-auth: allow mixing of secret and hash lengths

From: Mark O'Donovan
Date: Tue Oct 17 2023 - 13:09:56 EST


We can now use any of the secret transformation hashes with a
secret, regardless of the secret size.
e.g. a 32 byte key with the SHA-512(64 byte) hash.

The example secret from the spec should now be permitted with
any of the following:
DHHC-1:00:ia6zGodOr4SEG0Zzaw398rpY0wqipUWj4jWjUh4HWUz6aQ2n:
DHHC-1:01:ia6zGodOr4SEG0Zzaw398rpY0wqipUWj4jWjUh4HWUz6aQ2n:
DHHC-1:02:ia6zGodOr4SEG0Zzaw398rpY0wqipUWj4jWjUh4HWUz6aQ2n:
DHHC-1:03:ia6zGodOr4SEG0Zzaw398rpY0wqipUWj4jWjUh4HWUz6aQ2n:

Note: Secrets are still restricted to 32,48 or 64 bits.

Co-developed-by: Akash Appaiah <Akash.Appaiah@xxxxxxxx>
Signed-off-by: Akash Appaiah <Akash.Appaiah@xxxxxxxx>
Signed-off-by: Mark O'Donovan <shiftee@xxxxxxxxxx>
Reviewed-by: Hannes Reinecke <hare@xxxxxxx>
---
drivers/nvme/common/auth.c | 8 --------
1 file changed, 8 deletions(-)

diff --git a/drivers/nvme/common/auth.c b/drivers/nvme/common/auth.c
index f954aeb647a5..a8e87dfbeab2 100644
--- a/drivers/nvme/common/auth.c
+++ b/drivers/nvme/common/auth.c
@@ -190,14 +190,6 @@ struct nvme_dhchap_key *nvme_auth_extract_key(unsigned char *secret,
goto out_free_secret;
}

- if (key_hash > 0 &&
- (key_len - 4) != nvme_auth_hmac_hash_len(key_hash)) {
- pr_err("Mismatched key len %d for %s\n", key_len,
- nvme_auth_hmac_name(key_hash));
- ret = -EINVAL;
- goto out_free_secret;
- }
-
/* The last four bytes is the CRC in little-endian format */
key_len -= 4;
/*
--
2.39.2