[PATCH 01/21] nvme-auth: add NVME_AUTH_MAX_DIGEST_SIZE constant

Eric Biggers
2026-03-02T08:01:34Z

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

Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
drivers/nvme/common/auth.c | 6 ++----
drivers/nvme/host/auth.c | 6 +++---
include/linux/nvme.h | 5 +++++
3 files changed, 10 insertions(+), 7 deletions(-)

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
@@ -13,12 +13,10 @@
#include <crypto/dh.h>
#include <crypto/hkdf.h>
#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);

u32 nvme_auth_get_seqnum(void)
{
@@ -767,11 +765,11 @@ int nvme_auth_derive_tls_psk(int hmac_id, u8 *psk, size_t psk_len,
u8 *psk_digest, u8 **ret_psk)
{
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;
int ret;

@@ -796,11 +794,11 @@ int nvme_auth_derive_tls_psk(int hmac_id, u8 *psk, size_t psk_len,
if (!prk) {
ret = -ENOMEM;
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;
}
ret = hkdf_extract(hmac_tfm, psk, psk_len,
default_salt, prk_len, 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
@@ -36,13 +36,13 @@ struct nvme_dhchap_queue_context {
u8 status;
u8 dhgroup_id;
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;
int ctrl_key_len;
int host_key_len;
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
@@ -1835,10 +1835,15 @@ enum {
NVME_AUTH_HASH_SHA384 = 0x02,
NVME_AUTH_HASH_SHA512 = 0x03,
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,
NVME_AUTH_DHGROUP_2048 = 0x01,
NVME_AUTH_DHGROUP_3072 = 0x02,
--
2.53.0