nvme-auth: allow mixing of secret and hash lengths

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@dell.com>
Signed-off-by: Akash Appaiah <Akash.Appaiah@dell.com>
Signed-off-by: Mark O'Donovan <shiftee@posteo.net>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

diff --git a/drivers/nvme/common/auth.c b/drivers/nvme/common/auth.c
index f954aeb647a57efd17114f85856afdd91df8aa5c..a8e87dfbeab2a41a9c73f8c880f709fc0fc830fb 100644 (file)
--- 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;
        /*