[PATCH v2] nvme-auth: Include SC_C in RVAL controller hash

[alistair23]

From: Alistair Francis <alistair.francis@xxxxxxx>

Section 8.3.4.5.5 of the NVMe Base Specification 2.1 describes what is
included in the Response Value (RVAL) hash and SC_C should be included.
Currently we are hardcoding 0 instead of using the correct SC_C value.

Update the host and target code to use the SC_C when calculating the
RVAL instead of using 0.

Fixes: f50fff73d620 ("nvme: implement In-Band authentication")
Signed-off-by: Alistair Francis <alistair.francis@xxxxxxx>
---
v2:
 - Rebase using new nvme_auth_hmac_update() functions

 drivers/nvme/host/auth.c   | 3 ++-
 drivers/nvme/target/auth.c | 3 ++-
 2 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
index bbedbe181c8a6..63f543e809985 100644
--- a/drivers/nvme/host/auth.c
+++ b/drivers/nvme/host/auth.c
@@ -535,11 +535,12 @@ static int nvme_auth_dhchap_setup_ctrl_response(struct nvme_ctrl *ctrl,
 	put_unaligned_le16(chap->transaction, buf);
 	nvme_auth_hmac_update(&hmac, buf, 2);
 
-	memset(buf, 0, 4);
+	*buf = chap->sc_c;
 	nvme_auth_hmac_update(&hmac, buf, 1);
 	nvme_auth_hmac_update(&hmac, "Controller", 10);
 	nvme_auth_hmac_update(&hmac, ctrl->opts->subsysnqn,
 			      strlen(ctrl->opts->subsysnqn));
+	memset(buf, 0, 4);
 	nvme_auth_hmac_update(&hmac, buf, 1);
 	nvme_auth_hmac_update(&hmac, ctrl->opts->host->nqn,
 			      strlen(ctrl->opts->host->nqn));
diff --git a/drivers/nvme/target/auth.c b/drivers/nvme/target/auth.c
index b34610e2f19d4..f032855b21477 100644
--- a/drivers/nvme/target/auth.c
+++ b/drivers/nvme/target/auth.c
@@ -402,11 +402,12 @@ int nvmet_auth_ctrl_hash(struct nvmet_req *req, u8 *response,
 	put_unaligned_le16(req->sq->dhchap_tid, buf);
 	nvme_auth_hmac_update(&hmac, buf, 2);
 
-	memset(buf, 0, 4);
+	*buf = req->sq->sc_c;
 	nvme_auth_hmac_update(&hmac, buf, 1);
 	nvme_auth_hmac_update(&hmac, "Controller", 10);
 	nvme_auth_hmac_update(&hmac, ctrl->subsys->subsysnqn,
 			      strlen(ctrl->subsys->subsysnqn));
+	memset(buf, 0, 4);
 	nvme_auth_hmac_update(&hmac, buf, 1);
 	nvme_auth_hmac_update(&hmac, ctrl->hostnqn, strlen(ctrl->hostnqn));
 	nvme_auth_hmac_final(&hmac, response);
-- 
2.53.0