[PATCH 09/10] nvmet-tcp: support secure channel concatenation

Hannes Reinecke
2024-12-03T11:15:06Z

Evaluate the SC_C flag during DH-CHAP-HMAC negotiation and insert
the generated PSK once negotiation has finished.

Signed-off-by: Hannes Reinecke <hare@kernel.org>
---
drivers/nvme/target/auth.c | 72 +++++++++++++++++++++++++-
drivers/nvme/target/fabrics-cmd-auth.c | 49 +++++++++++++++---
drivers/nvme/target/fabrics-cmd.c | 33 +++++++++---
drivers/nvme/target/nvmet.h | 38 +++++++++++---
drivers/nvme/target/tcp.c | 23 +++++++-
5 files changed, 192 insertions(+), 23 deletions(-)

diff --git a/drivers/nvme/target/auth.c b/drivers/nvme/target/auth.c
index 7897d02c681d..7470ac020db6 100644
--- a/drivers/nvme/target/auth.c
+++ b/drivers/nvme/target/auth.c
@@ -15,6 +15,7 @@
#include <linux/ctype.h>
#include <linux/random.h>
#include <linux/nvme-auth.h>
+#include <linux/nvme-keyring.h>
#include <asm/unaligned.h>

#include "nvmet.h"
@@ -138,7 +139,7 @@ int nvmet_setup_dhgroup(struct nvmet_ctrl *ctrl, u8 dhgroup_id)
return ret;
}

-u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl)
+u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl, struct nvmet_req *req)
{
int ret = 0;
struct nvmet_host_link *p;
@@ -164,6 +165,11 @@ u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl)
goto out_unlock;
}

+ if (nvmet_queue_tls_keyid(req->sq)) {
+ pr_debug("host %s tls enabled\n", ctrl->hostnqn);
+ goto out_unlock;
+ }
+
ret = nvmet_setup_dhgroup(ctrl, host->dhchap_dhgroup_id);
if (ret < 0) {
pr_warn("Failed to setup DH group");
@@ -232,6 +238,9 @@ u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl)
void nvmet_auth_sq_free(struct nvmet_sq *sq)
{
cancel_delayed_work(&sq->auth_expired_work);
+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+ sq->tls_key = 0;
+#endif
kfree(sq->dhchap_c1);
sq->dhchap_c1 = NULL;
kfree(sq->dhchap_c2);
@@ -260,6 +269,12 @@ void nvmet_destroy_auth(struct nvmet_ctrl *ctrl)
nvme_auth_free_key(ctrl->ctrl_key);
ctrl->ctrl_key = NULL;
}
+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+ if (ctrl->tls_key) {
+ key_put(ctrl->tls_key);
+ ctrl->tls_key = NULL;
+ }
+#endif
}

bool nvmet_check_auth_status(struct nvmet_req *req)
@@ -541,3 +556,58 @@ int nvmet_auth_ctrl_sesskey(struct nvmet_req *req,

return ret;
}
+
+void nvmet_auth_insert_psk(struct nvmet_sq *sq)
+{
+ int hash_len = nvme_auth_hmac_hash_len(sq->ctrl->shash_id);
+ u8 *psk, *digest, *tls_psk;
+ size_t psk_len;
+ int ret;
+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+ struct key *tls_key = NULL;
+#endif
+
+ ret = nvme_auth_generate_psk(sq->ctrl->shash_id,
+ sq->dhchap_skey,
+ sq->dhchap_skey_len,
+ sq->dhchap_c1, sq->dhchap_c2,
+ hash_len, &psk, &psk_len);
+ if (ret) {
+ pr_warn("%s: ctrl %d qid %d failed to generate PSK, error %d\n",
+ __func__, sq->ctrl->cntlid, sq->qid, ret);
+ return;
+ }
+ ret = nvme_auth_generate_digest(sq->ctrl->shash_id, psk, psk_len,
+ sq->ctrl->subsysnqn,
+ sq->ctrl->hostnqn, &digest);
+ if (ret) {
+ pr_warn("%s: ctrl %d qid %d failed to generate digest, error %d\n",
+ __func__, sq->ctrl->cntlid, sq->qid, ret);
+ goto out_free_psk;
+ }
+ ret = nvme_auth_derive_tls_psk(sq->ctrl->shash_id, psk, psk_len,
+ digest, &tls_psk);
+ if (ret) {
+ pr_warn("%s: ctrl %d qid %d failed to derive TLS PSK, error %d\n",
+ __func__, sq->ctrl->cntlid, sq->qid, ret);
+ goto out_free_digest;
+ }
+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+ tls_key = nvme_tls_psk_refresh(NULL, sq->ctrl->hostnqn, sq->ctrl->subsysnqn,
+ sq->ctrl->shash_id, tls_psk, psk_len, digest);
+ if (IS_ERR(tls_key)) {
+ pr_warn("%s: ctrl %d qid %d failed to refresh key, error %ld\n",
+ __func__, sq->ctrl->cntlid, sq->qid, PTR_ERR(tls_key));
+ tls_key = NULL;
+ kfree_sensitive(tls_psk);
+ }
+ if (sq->ctrl->tls_key)
+ key_put(sq->ctrl->tls_key);
+ sq->ctrl->tls_key = tls_key;
+#endif
+
+out_free_digest:
+ kfree_sensitive(digest);
+out_free_psk:
+ kfree_sensitive(psk);
+}
diff --git a/drivers/nvme/target/fabrics-cmd-auth.c b/drivers/nvme/target/fabrics-cmd-auth.c
index 3f2857c17d95..cf4b38c0e7bd 100644
--- a/drivers/nvme/target/fabrics-cmd-auth.c
+++ b/drivers/nvme/target/fabrics-cmd-auth.c
@@ -43,8 +43,26 @@ static u8 nvmet_auth_negotiate(struct nvmet_req *req, void *d)
data->auth_protocol[0].dhchap.halen,
data->auth_protocol[0].dhchap.dhlen);
req->sq->dhchap_tid = le16_to_cpu(data->t_id);
- if (data->sc_c)
- return NVME_AUTH_DHCHAP_FAILURE_CONCAT_MISMATCH;
+ if (data->sc_c != NVME_AUTH_SECP_NOSC) {
+ if (!IS_ENABLED(CONFIG_NVME_TARGET_TCP_TLS))
+ return NVME_AUTH_DHCHAP_FAILURE_CONCAT_MISMATCH;
+ /* Secure concatenation can only be enabled on the admin queue */
+ if (req->sq->qid)
+ return NVME_AUTH_DHCHAP_FAILURE_CONCAT_MISMATCH;
+ switch (data->sc_c) {
+ case NVME_AUTH_SECP_NEWTLSPSK:
+ if (nvmet_queue_tls_keyid(req->sq))
+ return NVME_AUTH_DHCHAP_FAILURE_CONCAT_MISMATCH;
+ break;
+ case NVME_AUTH_SECP_REPLACETLSPSK:
+ if (!nvmet_queue_tls_keyid(req->sq))
+ return NVME_AUTH_DHCHAP_FAILURE_CONCAT_MISMATCH;
+ break;
+ default:
+ return NVME_AUTH_DHCHAP_FAILURE_CONCAT_MISMATCH;
+ }
+ ctrl->concat = true;
+ }

if (data->napd != 1)
return NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
@@ -103,6 +121,13 @@ static u8 nvmet_auth_negotiate(struct nvmet_req *req, void *d)
nvme_auth_dhgroup_name(fallback_dhgid));
ctrl->dh_gid = fallback_dhgid;
}
+ if (ctrl->dh_gid == NVME_AUTH_DHGROUP_NULL &&
+ ctrl->concat) {
+ pr_debug("%s: ctrl %d qid %d: NULL DH group invalid "
+ "for secure channel concatenation\n", __func__,
+ ctrl->cntlid, req->sq->qid);
+ return NVME_AUTH_DHCHAP_FAILURE_CONCAT_MISMATCH;
+ }
pr_debug("%s: ctrl %d qid %d: selected DH group %s (%d)\n",
__func__, ctrl->cntlid, req->sq->qid,
nvme_auth_dhgroup_name(ctrl->dh_gid), ctrl->dh_gid);
@@ -154,6 +179,12 @@ static u8 nvmet_auth_reply(struct nvmet_req *req, void *d)
kfree(response);
pr_debug("%s: ctrl %d qid %d host authenticated\n",
__func__, ctrl->cntlid, req->sq->qid);
+ if (!data->cvalid && ctrl->concat) {
+ pr_debug("%s: ctrl %d qid %d invalid challenge\n",
+ __func__, ctrl->cntlid, req->sq->qid);
+ return NVME_AUTH_DHCHAP_FAILURE_FAILED;
+ }
+ req->sq->dhchap_s2 = le32_to_cpu(data->seqnum);
if (data->cvalid) {
req->sq->dhchap_c2 = kmemdup(data->rval + data->hl, data->hl,
GFP_KERNEL);
@@ -163,11 +194,15 @@ static u8 nvmet_auth_reply(struct nvmet_req *req, void *d)
pr_debug("%s: ctrl %d qid %d challenge %*ph\n",
__func__, ctrl->cntlid, req->sq->qid, data->hl,
req->sq->dhchap_c2);
- } else {
+ }
+ if (req->sq->dhchap_s2 == 0) {
+ if (ctrl->concat)
+ nvmet_auth_insert_psk(req->sq);
req->sq->authenticated = true;
+ kfree(req->sq->dhchap_c2);
req->sq->dhchap_c2 = NULL;
- }
- req->sq->dhchap_s2 = le32_to_cpu(data->seqnum);
+ } else if (!data->cvalid)
+ req->sq->authenticated = true;

return 0;
}
@@ -241,7 +276,7 @@ void nvmet_execute_auth_send(struct nvmet_req *req)
pr_debug("%s: ctrl %d qid %d reset negotiation\n",
__func__, ctrl->cntlid, req->sq->qid);
if (!req->sq->qid) {
- dhchap_status = nvmet_setup_auth(ctrl);
+ dhchap_status = nvmet_setup_auth(ctrl, req);
if (dhchap_status) {
pr_err("ctrl %d qid 0 failed to setup re-authentication\n",
ctrl->cntlid);
@@ -298,6 +333,8 @@ void nvmet_execute_auth_send(struct nvmet_req *req)
}
goto done_kfree;
case NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2:
+ if (ctrl->concat)
+ nvmet_auth_insert_psk(req->sq);
req->sq->authenticated = true;
pr_debug("%s: ctrl %d qid %d ctrl authenticated\n",
__func__, ctrl->cntlid, req->sq->qid);
diff --git a/drivers/nvme/target/fabrics-cmd.c b/drivers/nvme/target/fabrics-cmd.c
index c4b2eddd5666..9a1256deee51 100644
--- a/drivers/nvme/target/fabrics-cmd.c
+++ b/drivers/nvme/target/fabrics-cmd.c
@@ -199,10 +199,26 @@ static u16 nvmet_install_queue(struct nvmet_ctrl *ctrl, struct nvmet_req *req)
return ret;
}

-static u32 nvmet_connect_result(struct nvmet_ctrl *ctrl)
+static u32 nvmet_connect_result(struct nvmet_ctrl *ctrl, struct nvmet_req *req)
{
+ bool needs_auth = nvmet_has_auth(ctrl, req);
+ key_serial_t keyid = nvmet_queue_tls_keyid(req->sq);
+
+ /* Do not authenticate I/O queues for secure concatenation */
+ if (ctrl->concat && req->sq->qid)
+ needs_auth = false;
+
+ if (keyid)
+ pr_debug("%s: ctrl %d qid %d should %sauthenticate, tls psk %08x\n",
+ __func__, ctrl->cntlid, req->sq->qid,
+ needs_auth ? "" : "not ", keyid);
+ else
+ pr_debug("%s: ctrl %d qid %d should %sauthenticate%s\n",
+ __func__, ctrl->cntlid, req->sq->qid,
+ needs_auth ? "" : "not ",
+ ctrl->concat ? ", secure concatenation" : "");
return (u32)ctrl->cntlid |
- (nvmet_has_auth(ctrl) ? NVME_CONNECT_AUTHREQ_ATR : 0);
+ (needs_auth ? NVME_CONNECT_AUTHREQ_ATR : 0);
}

static void nvmet_execute_admin_connect(struct nvmet_req *req)
@@ -251,7 +267,7 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)

uuid_copy(&ctrl->hostid, &d->hostid);

- dhchap_status = nvmet_setup_auth(ctrl);
+ dhchap_status = nvmet_setup_auth(ctrl, req);
if (dhchap_status) {
pr_err("Failed to setup authentication, dhchap status %u\n",
dhchap_status);
@@ -269,12 +285,13 @@ static void nvmet_execute_admin_connect(struct nvmet_req *req)
goto out;
}

- pr_info("creating %s controller %d for subsystem %s for NQN %s%s%s.\n",
+ pr_info("creating %s controller %d for subsystem %s for NQN %s%s%s%s.\n",
nvmet_is_disc_subsys(ctrl->subsys) ? "discovery" : "nvm",
ctrl->cntlid, ctrl->subsys->subsysnqn, ctrl->hostnqn,
- ctrl->pi_support ? " T10-PI is enabled" : "",
- nvmet_has_auth(ctrl) ? " with DH-HMAC-CHAP" : "");
- req->cqe->result.u32 = cpu_to_le32(nvmet_connect_result(ctrl));
+ ctrl->pi_support ? ", T10-PI" : "",
+ nvmet_has_auth(ctrl, req) ? ", DH-HMAC-CHAP" : "",
+ nvmet_queue_tls_keyid(req->sq) ? ", TLS" : "");
+ req->cqe->result.u32 = cpu_to_le32(nvmet_connect_result(ctrl, req));
out:
kfree(d);
complete:
@@ -330,7 +347,7 @@ static void nvmet_execute_io_connect(struct nvmet_req *req)
goto out_ctrl_put;

pr_debug("adding queue %d to ctrl %d.\n", qid, ctrl->cntlid);
- req->cqe->result.u32 = cpu_to_le32(nvmet_connect_result(ctrl));
+ req->cqe->result.u32 = cpu_to_le32(nvmet_connect_result(ctrl, req));
out:
kfree(d);
complete:
diff --git a/drivers/nvme/target/nvmet.h b/drivers/nvme/target/nvmet.h
index 190f55e6d753..c2e17201c757 100644
--- a/drivers/nvme/target/nvmet.h
+++ b/drivers/nvme/target/nvmet.h
@@ -121,6 +121,9 @@ struct nvmet_sq {
u32 dhchap_s2;
u8 *dhchap_skey;
int dhchap_skey_len;
+#endif
+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+ struct key *tls_key;
#endif
struct completion free_done;
struct completion confirm_done;
@@ -237,6 +240,7 @@ struct nvmet_ctrl {
u64 err_counter;
struct nvme_error_slot slots[NVMET_ERROR_LOG_SLOTS];
bool pi_support;
+ bool concat;
#ifdef CONFIG_NVME_TARGET_AUTH
struct nvme_dhchap_key *host_key;
struct nvme_dhchap_key *ctrl_key;
@@ -246,6 +250,9 @@ struct nvmet_ctrl {
u8 *dh_key;
size_t dh_keysize;
#endif
+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+ struct key *tls_key;
+#endif
};

struct nvmet_subsys {
@@ -716,13 +723,29 @@ static inline void nvmet_req_bio_put(struct nvmet_req *req, struct bio *bio)
bio_put(bio);
}

+#ifdef CONFIG_NVME_TARGET_TCP_TLS
+static inline key_serial_t nvmet_queue_tls_keyid(struct nvmet_sq *sq)
+{
+ return sq->tls_key ? key_serial(sq->tls_key) : 0;
+}
+static inline void nvmet_sq_put_tls_key(struct nvmet_sq *sq)
+{
+ if (sq->tls_key) {
+ key_put(sq->tls_key);
+ sq->tls_key = NULL;
+ }
+}
+#else
+static inline key_serial_t nvmet_queue_tls_keyid(struct nvmet_sq *sq) { return 0; }
+static inline void nvmet_sq_put_tls_key(struct nvmet_sq *sq) {}
+#endif
#ifdef CONFIG_NVME_TARGET_AUTH
void nvmet_execute_auth_send(struct nvmet_req *req);
void nvmet_execute_auth_receive(struct nvmet_req *req);
int nvmet_auth_set_key(struct nvmet_host *host, const char *secret,
bool set_ctrl);
int nvmet_auth_set_host_hash(struct nvmet_host *host, const char *hash);
-u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl);
+u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl, struct nvmet_req *req);
void nvmet_auth_sq_init(struct nvmet_sq *sq);
void nvmet_destroy_auth(struct nvmet_ctrl *ctrl);
void nvmet_auth_sq_free(struct nvmet_sq *sq);
@@ -732,16 +755,18 @@ int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response,
unsigned int hash_len);
int nvmet_auth_ctrl_hash(struct nvmet_req *req, u8 *response,
unsigned int hash_len);
-static inline bool nvmet_has_auth(struct nvmet_ctrl *ctrl)
+static inline bool nvmet_has_auth(struct nvmet_ctrl *ctrl, struct nvmet_req *req)
{
- return ctrl->host_key != NULL;
+ return ctrl->host_key != NULL && !nvmet_queue_tls_keyid(req->sq);
}
int nvmet_auth_ctrl_exponential(struct nvmet_req *req,
u8 *buf, int buf_size);
int nvmet_auth_ctrl_sesskey(struct nvmet_req *req,
u8 *buf, int buf_size);
+void nvmet_auth_insert_psk(struct nvmet_sq *sq);
#else
-static inline u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl)
+static inline u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl,
+ struct nvmet_req *req)
{
return 0;
}
@@ -754,11 +779,12 @@ static inline bool nvmet_check_auth_status(struct nvmet_req *req)
{
return true;
}
-static inline bool nvmet_has_auth(struct nvmet_ctrl *ctrl)
+static inline bool nvmet_has_auth(struct nvmet_ctrl *ctrl,
+ struct nvmet_req *req)
{
return false;
}
static inline const char *nvmet_dhchap_dhgroup_name(u8 dhgid) { return NULL; }
+static inline void nvmet_auth_insert_psk(struct nvmet_sq *sq) {};
#endif
-
#endif /* _NVMET_H */
diff --git a/drivers/nvme/target/tcp.c b/drivers/nvme/target/tcp.c
index fa59a7996efa..6d8d150a75c6 100644
--- a/drivers/nvme/target/tcp.c
+++ b/drivers/nvme/target/tcp.c
@@ -1072,10 +1072,11 @@ static int nvmet_tcp_done_recv_pdu(struct nvmet_tcp_queue *queue)

if (unlikely(!nvmet_req_init(req, &queue->nvme_cq,
&queue->nvme_sq, &nvmet_tcp_ops))) {
- pr_err("failed cmd %p id %d opcode %d, data_len: %d\n",
+ pr_err("failed cmd %p id %d opcode %d, data_len: %d, status: %04x\n",
req->cmd, req->cmd->common.command_id,
req->cmd->common.opcode,
- le32_to_cpu(req->cmd->common.dptr.sgl.length));
+ le32_to_cpu(req->cmd->common.dptr.sgl.length),
+ le16_to_cpu(req->cqe->status));

nvmet_tcp_handle_req_failure(queue, queue->cmd, req);
return 0;
@@ -1601,6 +1602,7 @@ static void nvmet_tcp_release_queue_work(struct work_struct *w)
/* stop accepting incoming data */
queue->rcv_state = NVMET_TCP_RECV_ERR;

+ nvmet_sq_put_tls_key(&queue->nvme_sq);
nvmet_tcp_uninit_data_in_cmds(queue);
nvmet_sq_destroy(&queue->nvme_sq);
cancel_work_sync(&queue->io_work);
@@ -1806,6 +1808,23 @@ static void nvmet_tcp_tls_handshake_done(void *data, int status,
spin_unlock_bh(&queue->state_lock);

cancel_delayed_work_sync(&queue->tls_handshake_tmo_work);
+
+ if (!status) {
+ struct key *tls_key = nvme_tls_key_lookup(peerid);
+
+ if (IS_ERR(tls_key)) {
+ pr_warn("%s: queue %d failed to lookup key %x\n",
+ __func__, queue->idx, peerid);
+ spin_lock_bh(&queue->state_lock);
+ queue->state = NVMET_TCP_Q_FAILED;
+ spin_unlock_bh(&queue->state_lock);
+ status = PTR_ERR(tls_key);
+ } else {
+ pr_debug("%s: queue %d using TLS PSK %x\n",
+ __func__, queue->idx, peerid);
+ queue->nvme_sq.tls_key = tls_key;
+ }
+ }
if (status)
nvmet_tcp_schedule_release_queue(queue);
else
--
2.35.3