nvmet-auth: update sc_c in host response

The target code should set the sc_c bit in calculating the host response
based on the status of the 'concat' setting, otherwise we'll get an
authentication mismatch for hosts setting that bit correctly.

Fixes: 7e091ad ("nvme-auth: update sc_c in host response")
Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Author: hreinecke

drivers/nvme/target/auth.c

@@ -298,7 +298,7 @@ int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response,
 	const char *hash_name;
 	u8 *challenge = req->sq->dhchap_c1;
 	struct nvme_dhchap_key *transformed_key;
-	u8 buf[4];
+	u8 buf[4], sc_c = ctrl->concat ? 1 : 0;
 	int ret;
 
 	hash_name = nvme_auth_hmac_name(ctrl->shash_id);
@@ -367,13 +367,14 @@ int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response,
 	ret = crypto_shash_update(shash, buf, 2);
 	if (ret)
 		goto out;
-	memset(buf, 0, 4);
+	*buf = sc_c;
 	ret = crypto_shash_update(shash, buf, 1);
 	if (ret)
 		goto out;
 	ret = crypto_shash_update(shash, "HostHost", 8);
 	if (ret)
 		goto out;
+	memset(buf, 0, 4);
 	ret = crypto_shash_update(shash, ctrl->hostnqn, strlen(ctrl->hostnqn));
 	if (ret)
 		goto out;