From: Eric Biggers <ebiggers@kernel.org>
Date: Mon, 2 Mar 2026 07:59:39 +0000 (-0800)
Subject: nvme-auth: add NVME_AUTH_MAX_DIGEST_SIZE constant
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9100a28c8bb4270744942cf834efcd80f1acda7d;p=thirdparty%2Fkernel%2Flinux.git

nvme-auth: add NVME_AUTH_MAX_DIGEST_SIZE constant

Define a NVME_AUTH_MAX_DIGEST_SIZE constant and use it in the
appropriate places.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Keith Busch <kbusch@kernel.org>
---

diff --git a/drivers/nvme/common/auth.c b/drivers/nvme/common/auth.c
index e07e7d4bf8b68..78d751481fe31 100644
--- a/drivers/nvme/common/auth.c
+++ b/drivers/nvme/common/auth.c
@@ -15,8 +15,6 @@
 #include <linux/nvme.h>
 #include <linux/nvme-auth.h>
 
-#define HKDF_MAX_HASHLEN 64
-
 static u32 nvme_dhchap_seqnum;
 static DEFINE_MUTEX(nvme_dhchap_mutex);
 
@@ -769,7 +767,7 @@ int nvme_auth_derive_tls_psk(int hmac_id, u8 *psk, size_t psk_len,
 	struct crypto_shash *hmac_tfm;
 	const char *hmac_name;
 	const char *label = "nvme-tls-psk";
-	static const char default_salt[HKDF_MAX_HASHLEN];
+	static const char default_salt[NVME_AUTH_MAX_DIGEST_SIZE];
 	size_t prk_len;
 	const char *ctx;
 	unsigned char *prk, *tls_key;
@@ -798,7 +796,7 @@ int nvme_auth_derive_tls_psk(int hmac_id, u8 *psk, size_t psk_len,
 		goto out_free_shash;
 	}
 
-	if (WARN_ON(prk_len > HKDF_MAX_HASHLEN)) {
+	if (WARN_ON(prk_len > NVME_AUTH_MAX_DIGEST_SIZE)) {
 		ret = -EINVAL;
 		goto out_free_prk;
 	}
diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
index 405e7c03b1cfe..301c858b7c577 100644
--- a/drivers/nvme/host/auth.c
+++ b/drivers/nvme/host/auth.c
@@ -38,9 +38,9 @@ struct nvme_dhchap_queue_context {
 	u8 hash_id;
 	u8 sc_c;
 	size_t hash_len;
-	u8 c1[64];
-	u8 c2[64];
-	u8 response[64];
+	u8 c1[NVME_AUTH_MAX_DIGEST_SIZE];
+	u8 c2[NVME_AUTH_MAX_DIGEST_SIZE];
+	u8 response[NVME_AUTH_MAX_DIGEST_SIZE];
 	u8 *ctrl_key;
 	u8 *host_key;
 	u8 *sess_key;
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 655d194f8e722..edfebbce67453 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -1837,6 +1837,11 @@ enum {
 	NVME_AUTH_HASH_INVALID	= 0xff,
 };
 
+/* Maximum digest size for any NVME_AUTH_HASH_* value */
+enum {
+	NVME_AUTH_MAX_DIGEST_SIZE = 64,
+};
+
 /* Defined Diffie-Hellman group identifiers for DH-HMAC-CHAP authentication */
 enum {
 	NVME_AUTH_DHGROUP_NULL		= 0x00,