nvme: implement In-Band authentication

Implement NVMe-oF In-Band authentication according to NVMe TPAR 8006.
This patch adds two new fabric options 'dhchap_secret' to specify the
pre-shared key (in ASCII respresentation according to NVMe 2.0 section
8.13.5.8 'Secret representation') and 'dhchap_ctrl_secret' to specify
the pre-shared controller key for bi-directional authentication of both
the host and the controller.
Re-authentication can be triggered by writing the PSK into the new
controller sysfs attribute 'dhchap_secret' or 'dhchap_ctrl_secret'.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: Christoph Hellwig <hch@lst.de>
[axboe: fold in clang build fix]
Signed-off-by: Jens Axboe <axboe@kernel.dk>

1 files changed, 828 insertions, 0 deletions

diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
new file mode 100644
index 000000000000..9766bfffecac
--- /dev/null
+++ b/drivers/nvme/host/auth.c
@@ -0,0 +1,828 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020 Hannes Reinecke, SUSE Linux
+ */
+
+#include <linux/crc32.h>
+#include <linux/base64.h>
+#include <linux/prandom.h>
+#include <asm/unaligned.h>
+#include <crypto/hash.h>
+#include <crypto/dh.h>
+#include "nvme.h"
+#include "fabrics.h"
+#include <linux/nvme-auth.h>
+
+struct nvme_dhchap_queue_context {
+	struct list_head entry;
+	struct work_struct auth_work;
+	struct nvme_ctrl *ctrl;
+	struct crypto_shash *shash_tfm;
+	void *buf;
+	size_t buf_size;
+	int qid;
+	int error;
+	u32 s1;
+	u32 s2;
+	u16 transaction;
+	u8 status;
+	u8 hash_id;
+	size_t hash_len;
+	u8 dhgroup_id;
+	u8 c1[64];
+	u8 c2[64];
+	u8 response[64];
+	u8 *host_response;
+};
+
+#define nvme_auth_flags_from_qid(qid) \
+	(qid == 0) ? 0 : BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED
+#define nvme_auth_queue_from_qid(ctrl, qid) \
+	(qid == 0) ? (ctrl)->fabrics_q : (ctrl)->connect_q
+
+static int nvme_auth_submit(struct nvme_ctrl *ctrl, int qid,
+			    void *data, size_t data_len, bool auth_send)
+{
+	struct nvme_command cmd = {};
+	blk_mq_req_flags_t flags = nvme_auth_flags_from_qid(qid);
+	struct request_queue *q = nvme_auth_queue_from_qid(ctrl, qid);
+	int ret;
+
+	cmd.auth_common.opcode = nvme_fabrics_command;
+	cmd.auth_common.secp = NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER;
+	cmd.auth_common.spsp0 = 0x01;
+	cmd.auth_common.spsp1 = 0x01;
+	if (auth_send) {
+		cmd.auth_send.fctype = nvme_fabrics_type_auth_send;
+		cmd.auth_send.tl = cpu_to_le32(data_len);
+	} else {
+		cmd.auth_receive.fctype = nvme_fabrics_type_auth_receive;
+		cmd.auth_receive.al = cpu_to_le32(data_len);
+	}
+
+	ret = __nvme_submit_sync_cmd(q, &cmd, NULL, data, data_len,
+				     qid == 0 ? NVME_QID_ANY : qid,
+				     0, flags);
+	if (ret > 0)
+		dev_warn(ctrl->device,
+			"qid %d auth_send failed with status %d\n", qid, ret);
+	else if (ret < 0)
+		dev_err(ctrl->device,
+			"qid %d auth_send failed with error %d\n", qid, ret);
+	return ret;
+}
+
+static int nvme_auth_receive_validate(struct nvme_ctrl *ctrl, int qid,
+		struct nvmf_auth_dhchap_failure_data *data,
+		u16 transaction, u8 expected_msg)
+{
+	dev_dbg(ctrl->device, "%s: qid %d auth_type %d auth_id %x\n",
+		__func__, qid, data->auth_type, data->auth_id);
+
+	if (data->auth_type == NVME_AUTH_COMMON_MESSAGES &&
+	    data->auth_id == NVME_AUTH_DHCHAP_MESSAGE_FAILURE1) {
+		return data->rescode_exp;
+	}
+	if (data->auth_type != NVME_AUTH_DHCHAP_MESSAGES ||
+	    data->auth_id != expected_msg) {
+		dev_warn(ctrl->device,
+			 "qid %d invalid message %02x/%02x\n",
+			 qid, data->auth_type, data->auth_id);
+		return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_MESSAGE;
+	}
+	if (le16_to_cpu(data->t_id) != transaction) {
+		dev_warn(ctrl->device,
+			 "qid %d invalid transaction ID %d\n",
+			 qid, le16_to_cpu(data->t_id));
+		return NVME_AUTH_DHCHAP_FAILURE_INCORRECT_MESSAGE;
+	}
+	return 0;
+}
+
+static int nvme_auth_set_dhchap_negotiate_data(struct nvme_ctrl *ctrl,
+		struct nvme_dhchap_queue_context *chap)
+{
+	struct nvmf_auth_dhchap_negotiate_data *data = chap->buf;
+	size_t size = sizeof(*data) + sizeof(union nvmf_auth_protocol);
+
+	if (chap->buf_size < size) {
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+		return -EINVAL;
+	}
+	memset((u8 *)chap->buf, 0, size);
+	data->auth_type = NVME_AUTH_COMMON_MESSAGES;
+	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_NEGOTIATE;
+	data->t_id = cpu_to_le16(chap->transaction);
+	data->sc_c = 0; /* No secure channel concatenation */
+	data->napd = 1;
+	data->auth_protocol[0].dhchap.authid = NVME_AUTH_DHCHAP_AUTH_ID;
+	data->auth_protocol[0].dhchap.halen = 3;
+	data->auth_protocol[0].dhchap.dhlen = 6;
+	data->auth_protocol[0].dhchap.idlist[0] = NVME_AUTH_HASH_SHA256;
+	data->auth_protocol[0].dhchap.idlist[1] = NVME_AUTH_HASH_SHA384;
+	data->auth_protocol[0].dhchap.idlist[2] = NVME_AUTH_HASH_SHA512;
+	data->auth_protocol[0].dhchap.idlist[30] = NVME_AUTH_DHGROUP_NULL;
+	data->auth_protocol[0].dhchap.idlist[31] = NVME_AUTH_DHGROUP_2048;
+	data->auth_protocol[0].dhchap.idlist[32] = NVME_AUTH_DHGROUP_3072;
+	data->auth_protocol[0].dhchap.idlist[33] = NVME_AUTH_DHGROUP_4096;
+	data->auth_protocol[0].dhchap.idlist[34] = NVME_AUTH_DHGROUP_6144;
+	data->auth_protocol[0].dhchap.idlist[35] = NVME_AUTH_DHGROUP_8192;
+
+	return size;
+}
+
+static int nvme_auth_process_dhchap_challenge(struct nvme_ctrl *ctrl,
+		struct nvme_dhchap_queue_context *chap)
+{
+	struct nvmf_auth_dhchap_challenge_data *data = chap->buf;
+	u16 dhvlen = le16_to_cpu(data->dhvlen);
+	size_t size = sizeof(*data) + data->hl + dhvlen;
+	const char *hmac_name, *kpp_name;
+
+	if (chap->buf_size < size) {
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+		return NVME_SC_INVALID_FIELD;
+	}
+
+	hmac_name = nvme_auth_hmac_name(data->hashid);
+	if (!hmac_name) {
+		dev_warn(ctrl->device,
+			 "qid %d: invalid HASH ID %d\n",
+			 chap->qid, data->hashid);
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
+		return NVME_SC_INVALID_FIELD;
+	}
+
+	if (chap->hash_id == data->hashid && chap->shash_tfm &&
+	    !strcmp(crypto_shash_alg_name(chap->shash_tfm), hmac_name) &&
+	    crypto_shash_digestsize(chap->shash_tfm) == data->hl) {
+		dev_dbg(ctrl->device,
+			"qid %d: reuse existing hash %s\n",
+			chap->qid, hmac_name);
+		goto select_kpp;
+	}
+
+	/* Reset if hash cannot be reused */
+	if (chap->shash_tfm) {
+		crypto_free_shash(chap->shash_tfm);
+		chap->hash_id = 0;
+		chap->hash_len = 0;
+	}
+	chap->shash_tfm = crypto_alloc_shash(hmac_name, 0,
+					     CRYPTO_ALG_ALLOCATES_MEMORY);
+	if (IS_ERR(chap->shash_tfm)) {
+		dev_warn(ctrl->device,
+			 "qid %d: failed to allocate hash %s, error %ld\n",
+			 chap->qid, hmac_name, PTR_ERR(chap->shash_tfm));
+		chap->shash_tfm = NULL;
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
+		return NVME_SC_AUTH_REQUIRED;
+	}
+
+	if (crypto_shash_digestsize(chap->shash_tfm) != data->hl) {
+		dev_warn(ctrl->device,
+			 "qid %d: invalid hash length %d\n",
+			 chap->qid, data->hl);
+		crypto_free_shash(chap->shash_tfm);
+		chap->shash_tfm = NULL;
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
+		return NVME_SC_AUTH_REQUIRED;
+	}
+
+	/* Reset host response if the hash had been changed */
+	if (chap->hash_id != data->hashid) {
+		kfree(chap->host_response);
+		chap->host_response = NULL;
+	}
+
+	chap->hash_id = data->hashid;
+	chap->hash_len = data->hl;
+	dev_dbg(ctrl->device, "qid %d: selected hash %s\n",
+		chap->qid, hmac_name);
+
+select_kpp:
+	kpp_name = nvme_auth_dhgroup_kpp(data->dhgid);
+	if (!kpp_name) {
+		dev_warn(ctrl->device,
+			 "qid %d: invalid DH group id %d\n",
+			 chap->qid, data->dhgid);
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
+		return NVME_SC_AUTH_REQUIRED;
+	}
+
+	if (data->dhgid != NVME_AUTH_DHGROUP_NULL) {
+		dev_warn(ctrl->device,
+			 "qid %d: unsupported DH group %s\n",
+			 chap->qid, kpp_name);
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
+		return NVME_SC_AUTH_REQUIRED;
+	} else if (dhvlen != 0) {
+		dev_warn(ctrl->device,
+			 "qid %d: invalid DH value for NULL DH\n",
+			 chap->qid);
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+		return NVME_SC_INVALID_FIELD;
+	}
+	chap->dhgroup_id = data->dhgid;
+
+	chap->s1 = le32_to_cpu(data->seqnum);
+	memcpy(chap->c1, data->cval, chap->hash_len);
+
+	return 0;
+}
+
+static int nvme_auth_set_dhchap_reply_data(struct nvme_ctrl *ctrl,
+		struct nvme_dhchap_queue_context *chap)
+{
+	struct nvmf_auth_dhchap_reply_data *data = chap->buf;
+	size_t size = sizeof(*data);
+
+	size += 2 * chap->hash_len;
+
+	if (chap->buf_size < size) {
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+		return -EINVAL;
+	}
+
+	memset(chap->buf, 0, size);
+	data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
+	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_REPLY;
+	data->t_id = cpu_to_le16(chap->transaction);
+	data->hl = chap->hash_len;
+	data->dhvlen = 0;
+	memcpy(data->rval, chap->response, chap->hash_len);
+	if (ctrl->ctrl_key) {
+		get_random_bytes(chap->c2, chap->hash_len);
+		data->cvalid = 1;
+		chap->s2 = nvme_auth_get_seqnum();
+		memcpy(data->rval + chap->hash_len, chap->c2,
+		       chap->hash_len);
+		dev_dbg(ctrl->device, "%s: qid %d ctrl challenge %*ph\n",
+			__func__, chap->qid, (int)chap->hash_len, chap->c2);
+	} else {
+		memset(chap->c2, 0, chap->hash_len);
+		chap->s2 = 0;
+	}
+	data->seqnum = cpu_to_le32(chap->s2);
+	return size;
+}
+
+static int nvme_auth_process_dhchap_success1(struct nvme_ctrl *ctrl,
+		struct nvme_dhchap_queue_context *chap)
+{
+	struct nvmf_auth_dhchap_success1_data *data = chap->buf;
+	size_t size = sizeof(*data);
+
+	if (ctrl->ctrl_key)
+		size += chap->hash_len;
+
+	if (chap->buf_size < size) {
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_INCORRECT_PAYLOAD;
+		return NVME_SC_INVALID_FIELD;
+	}
+
+	if (data->hl != chap->hash_len) {
+		dev_warn(ctrl->device,
+			 "qid %d: invalid hash length %u\n",
+			 chap->qid, data->hl);
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
+		return NVME_SC_INVALID_FIELD;
+	}
+
+	/* Just print out information for the admin queue */
+	if (chap->qid == 0)
+		dev_info(ctrl->device,
+			 "qid 0: authenticated with hash %s dhgroup %s\n",
+			 nvme_auth_hmac_name(chap->hash_id),
+			 nvme_auth_dhgroup_name(chap->dhgroup_id));
+
+	if (!data->rvalid)
+		return 0;
+
+	/* Validate controller response */
+	if (memcmp(chap->response, data->rval, data->hl)) {
+		dev_dbg(ctrl->device, "%s: qid %d ctrl response %*ph\n",
+			__func__, chap->qid, (int)chap->hash_len, data->rval);
+		dev_dbg(ctrl->device, "%s: qid %d host response %*ph\n",
+			__func__, chap->qid, (int)chap->hash_len,
+			chap->response);
+		dev_warn(ctrl->device,
+			 "qid %d: controller authentication failed\n",
+			 chap->qid);
+		chap->status = NVME_AUTH_DHCHAP_FAILURE_FAILED;
+		return NVME_SC_AUTH_REQUIRED;
+	}
+
+	/* Just print out information for the admin queue */
+	if (chap->qid == 0)
+		dev_info(ctrl->device,
+			 "qid 0: controller authenticated\n");
+	return 0;
+}
+
+static int nvme_auth_set_dhchap_success2_data(struct nvme_ctrl *ctrl,
+		struct nvme_dhchap_queue_context *chap)
+{
+	struct nvmf_auth_dhchap_success2_data *data = chap->buf;
+	size_t size = sizeof(*data);
+
+	memset(chap->buf, 0, size);
+	data->auth_type = NVME_AUTH_DHCHAP_MESSAGES;
+	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_SUCCESS2;
+	data->t_id = cpu_to_le16(chap->transaction);
+
+	return size;
+}
+
+static int nvme_auth_set_dhchap_failure2_data(struct nvme_ctrl *ctrl,
+		struct nvme_dhchap_queue_context *chap)
+{
+	struct nvmf_auth_dhchap_failure_data *data = chap->buf;
+	size_t size = sizeof(*data);
+
+	memset(chap->buf, 0, size);
+	data->auth_type = NVME_AUTH_COMMON_MESSAGES;
+	data->auth_id = NVME_AUTH_DHCHAP_MESSAGE_FAILURE2;
+	data->t_id = cpu_to_le16(chap->transaction);
+	data->rescode = NVME_AUTH_DHCHAP_FAILURE_REASON_FAILED;
+	data->rescode_exp = chap->status;
+
+	return size;
+}
+
+static int nvme_auth_dhchap_setup_host_response(struct nvme_ctrl *ctrl,
+		struct nvme_dhchap_queue_context *chap)
+{
+	SHASH_DESC_ON_STACK(shash, chap->shash_tfm);
+	u8 buf[4], *challenge = chap->c1;
+	int ret;
+
+	dev_dbg(ctrl->device, "%s: qid %d host response seq %u transaction %d\n",
+		__func__, chap->qid, chap->s1, chap->transaction);
+
+	if (!chap->host_response) {
+		chap->host_response = nvme_auth_transform_key(ctrl->host_key,
+						ctrl->opts->host->nqn);
+		if (IS_ERR(chap->host_response)) {
+			ret = PTR_ERR(chap->host_response);
+			chap->host_response = NULL;
+			return ret;
+		}
+	} else {
+		dev_dbg(ctrl->device, "%s: qid %d re-using host response\n",
+			__func__, chap->qid);
+	}
+
+	ret = crypto_shash_setkey(chap->shash_tfm,
+			chap->host_response, ctrl->host_key->len);
+	if (ret) {
+		dev_warn(ctrl->device, "qid %d: failed to set key, error %d\n",
+			 chap->qid, ret);
+		goto out;
+	}
+
+	shash->tfm = chap->shash_tfm;
+	ret = crypto_shash_init(shash);
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, challenge, chap->hash_len);
+	if (ret)
+		goto out;
+	put_unaligned_le32(chap->s1, buf);
+	ret = crypto_shash_update(shash, buf, 4);
+	if (ret)
+		goto out;
+	put_unaligned_le16(chap->transaction, buf);
+	ret = crypto_shash_update(shash, buf, 2);
+	if (ret)
+		goto out;
+	memset(buf, 0, sizeof(buf));
+	ret = crypto_shash_update(shash, buf, 1);
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, "HostHost", 8);
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, ctrl->opts->host->nqn,
+				  strlen(ctrl->opts->host->nqn));
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, buf, 1);
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, ctrl->opts->subsysnqn,
+			    strlen(ctrl->opts->subsysnqn));
+	if (ret)
+		goto out;
+	ret = crypto_shash_final(shash, chap->response);
+out:
+	if (challenge != chap->c1)
+		kfree(challenge);
+	return ret;
+}
+
+static int nvme_auth_dhchap_setup_ctrl_response(struct nvme_ctrl *ctrl,
+		struct nvme_dhchap_queue_context *chap)
+{
+	SHASH_DESC_ON_STACK(shash, chap->shash_tfm);
+	u8 *ctrl_response;
+	u8 buf[4], *challenge = chap->c2;
+	int ret;
+
+	ctrl_response = nvme_auth_transform_key(ctrl->ctrl_key,
+				ctrl->opts->subsysnqn);
+	if (IS_ERR(ctrl_response)) {
+		ret = PTR_ERR(ctrl_response);
+		return ret;
+	}
+	ret = crypto_shash_setkey(chap->shash_tfm,
+			ctrl_response, ctrl->ctrl_key->len);
+	if (ret) {
+		dev_warn(ctrl->device, "qid %d: failed to set key, error %d\n",
+			 chap->qid, ret);
+		goto out;
+	}
+
+	dev_dbg(ctrl->device, "%s: qid %d ctrl response seq %u transaction %d\n",
+		__func__, chap->qid, chap->s2, chap->transaction);
+	dev_dbg(ctrl->device, "%s: qid %d challenge %*ph\n",
+		__func__, chap->qid, (int)chap->hash_len, challenge);
+	dev_dbg(ctrl->device, "%s: qid %d subsysnqn %s\n",
+		__func__, chap->qid, ctrl->opts->subsysnqn);
+	dev_dbg(ctrl->device, "%s: qid %d hostnqn %s\n",
+		__func__, chap->qid, ctrl->opts->host->nqn);
+	shash->tfm = chap->shash_tfm;
+	ret = crypto_shash_init(shash);
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, challenge, chap->hash_len);
+	if (ret)
+		goto out;
+	put_unaligned_le32(chap->s2, buf);
+	ret = crypto_shash_update(shash, buf, 4);
+	if (ret)
+		goto out;
+	put_unaligned_le16(chap->transaction, buf);
+	ret = crypto_shash_update(shash, buf, 2);
+	if (ret)
+		goto out;
+	memset(buf, 0, 4);
+	ret = crypto_shash_update(shash, buf, 1);
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, "Controller", 10);
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, ctrl->opts->subsysnqn,
+				  strlen(ctrl->opts->subsysnqn));
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, buf, 1);
+	if (ret)
+		goto out;
+	ret = crypto_shash_update(shash, ctrl->opts->host->nqn,
+				  strlen(ctrl->opts->host->nqn));
+	if (ret)
+		goto out;
+	ret = crypto_shash_final(shash, chap->response);
+out:
+	if (challenge != chap->c2)
+		kfree(challenge);
+	kfree(ctrl_response);
+	return ret;
+}
+
+static void __nvme_auth_reset(struct nvme_dhchap_queue_context *chap)
+{
+	chap->status = 0;
+	chap->error = 0;
+	chap->s1 = 0;
+	chap->s2 = 0;
+	chap->transaction = 0;
+	memset(chap->c1, 0, sizeof(chap->c1));
+	memset(chap->c2, 0, sizeof(chap->c2));
+}
+
+static void __nvme_auth_free(struct nvme_dhchap_queue_context *chap)
+{
+	__nvme_auth_reset(chap);
+	if (chap->shash_tfm)
+		crypto_free_shash(chap->shash_tfm);
+	kfree_sensitive(chap->host_response);
+	kfree(chap->buf);
+	kfree(chap);
+}
+
+static void __nvme_auth_work(struct work_struct *work)
+{
+	struct nvme_dhchap_queue_context *chap =
+		container_of(work, struct nvme_dhchap_queue_context, auth_work);
+	struct nvme_ctrl *ctrl = chap->ctrl;
+	size_t tl;
+	int ret = 0;
+
+	chap->transaction = ctrl->transaction++;
+
+	/* DH-HMAC-CHAP Step 1: send negotiate */
+	dev_dbg(ctrl->device, "%s: qid %d send negotiate\n",
+		__func__, chap->qid);
+	ret = nvme_auth_set_dhchap_negotiate_data(ctrl, chap);
+	if (ret < 0) {
+		chap->error = ret;
+		return;
+	}
+	tl = ret;
+	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
+	if (ret) {
+		chap->error = ret;
+		return;
+	}
+
+	/* DH-HMAC-CHAP Step 2: receive challenge */
+	dev_dbg(ctrl->device, "%s: qid %d receive challenge\n",
+		__func__, chap->qid);
+
+	memset(chap->buf, 0, chap->buf_size);
+	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, chap->buf_size, false);
+	if (ret) {
+		dev_warn(ctrl->device,
+			 "qid %d failed to receive challenge, %s %d\n",
+			 chap->qid, ret < 0 ? "error" : "nvme status", ret);
+		chap->error = ret;
+		return;
+	}
+	ret = nvme_auth_receive_validate(ctrl, chap->qid, chap->buf, chap->transaction,
+					 NVME_AUTH_DHCHAP_MESSAGE_CHALLENGE);
+	if (ret) {
+		chap->status = ret;
+		chap->error = NVME_SC_AUTH_REQUIRED;
+		return;
+	}
+
+	ret = nvme_auth_process_dhchap_challenge(ctrl, chap);
+	if (ret) {
+		/* Invalid challenge parameters */
+		chap->error = ret;
+		goto fail2;
+	}
+
+	dev_dbg(ctrl->device, "%s: qid %d host response\n",
+		__func__, chap->qid);
+	ret = nvme_auth_dhchap_setup_host_response(ctrl, chap);
+	if (ret) {
+		chap->error = ret;
+		goto fail2;
+	}
+
+	/* DH-HMAC-CHAP Step 3: send reply */
+	dev_dbg(ctrl->device, "%s: qid %d send reply\n",
+		__func__, chap->qid);
+	ret = nvme_auth_set_dhchap_reply_data(ctrl, chap);
+	if (ret < 0) {
+		chap->error = ret;
+		goto fail2;
+	}
+
+	tl = ret;
+	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
+	if (ret) {
+		chap->error = ret;
+		goto fail2;
+	}
+
+	/* DH-HMAC-CHAP Step 4: receive success1 */
+	dev_dbg(ctrl->device, "%s: qid %d receive success1\n",
+		__func__, chap->qid);
+
+	memset(chap->buf, 0, chap->buf_size);
+	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, chap->buf_size, false);
+	if (ret) {
+		dev_warn(ctrl->device,
+			 "qid %d failed to receive success1, %s %d\n",
+			 chap->qid, ret < 0 ? "error" : "nvme status", ret);
+		chap->error = ret;
+		return;
+	}
+	ret = nvme_auth_receive_validate(ctrl, chap->qid,
+					 chap->buf, chap->transaction,
+					 NVME_AUTH_DHCHAP_MESSAGE_SUCCESS1);
+	if (ret) {
+		chap->status = ret;
+		chap->error = NVME_SC_AUTH_REQUIRED;
+		return;
+	}
+
+	if (ctrl->ctrl_key) {
+		dev_dbg(ctrl->device,
+			"%s: qid %d controller response\n",
+			__func__, chap->qid);
+		ret = nvme_auth_dhchap_setup_ctrl_response(ctrl, chap);
+		if (ret) {
+			chap->error = ret;
+			goto fail2;
+		}
+	}
+
+	ret = nvme_auth_process_dhchap_success1(ctrl, chap);
+	if (ret) {
+		/* Controller authentication failed */
+		chap->error = NVME_SC_AUTH_REQUIRED;
+		goto fail2;
+	}
+
+	if (ctrl->ctrl_key) {
+		/* DH-HMAC-CHAP Step 5: send success2 */
+		dev_dbg(ctrl->device, "%s: qid %d send success2\n",
+			__func__, chap->qid);
+		tl = nvme_auth_set_dhchap_success2_data(ctrl, chap);
+		ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
+		if (ret)
+			chap->error = ret;
+	}
+	if (!ret) {
+		chap->error = 0;
+		return;
+	}
+
+fail2:
+	dev_dbg(ctrl->device, "%s: qid %d send failure2, status %x\n",
+		__func__, chap->qid, chap->status);
+	tl = nvme_auth_set_dhchap_failure2_data(ctrl, chap);
+	ret = nvme_auth_submit(ctrl, chap->qid, chap->buf, tl, true);
+	/*
+	 * only update error if send failure2 failed and no other
+	 * error had been set during authentication.
+	 */
+	if (ret && !chap->error)
+		chap->error = ret;
+}
+
+int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
+{
+	struct nvme_dhchap_queue_context *chap;
+
+	if (!ctrl->host_key) {
+		dev_warn(ctrl->device, "qid %d: no key\n", qid);
+		return -ENOKEY;
+	}
+
+	if (ctrl->opts->dhchap_ctrl_secret && !ctrl->ctrl_key) {
+		dev_warn(ctrl->device, "qid %d: invalid ctrl key\n", qid);
+		return -ENOKEY;
+	}
+
+	mutex_lock(&ctrl->dhchap_auth_mutex);
+	/* Check if the context is already queued */
+	list_for_each_entry(chap, &ctrl->dhchap_auth_list, entry) {
+		WARN_ON(!chap->buf);
+		if (chap->qid == qid) {
+			dev_dbg(ctrl->device, "qid %d: re-using context\n", qid);
+			mutex_unlock(&ctrl->dhchap_auth_mutex);
+			flush_work(&chap->auth_work);
+			__nvme_auth_reset(chap);
+			queue_work(nvme_wq, &chap->auth_work);
+			return 0;
+		}
+	}
+	chap = kzalloc(sizeof(*chap), GFP_KERNEL);
+	if (!chap) {
+		mutex_unlock(&ctrl->dhchap_auth_mutex);
+		return -ENOMEM;
+	}
+	chap->qid = (qid == NVME_QID_ANY) ? 0 : qid;
+	chap->ctrl = ctrl;
+
+	/*
+	 * Allocate a large enough buffer for the entire negotiation:
+	 * 4k should be enough to ffdhe8192.
+	 */
+	chap->buf_size = 4096;
+	chap->buf = kzalloc(chap->buf_size, GFP_KERNEL);
+	if (!chap->buf) {
+		mutex_unlock(&ctrl->dhchap_auth_mutex);
+		kfree(chap);
+		return -ENOMEM;
+	}
+
+	INIT_WORK(&chap->auth_work, __nvme_auth_work);
+	list_add(&chap->entry, &ctrl->dhchap_auth_list);
+	mutex_unlock(&ctrl->dhchap_auth_mutex);
+	queue_work(nvme_wq, &chap->auth_work);
+	return 0;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_negotiate);
+
+int nvme_auth_wait(struct nvme_ctrl *ctrl, int qid)
+{
+	struct nvme_dhchap_queue_context *chap;
+	int ret;
+
+	mutex_lock(&ctrl->dhchap_auth_mutex);
+	list_for_each_entry(chap, &ctrl->dhchap_auth_list, entry) {
+		if (chap->qid != qid)
+			continue;
+		mutex_unlock(&ctrl->dhchap_auth_mutex);
+		flush_work(&chap->auth_work);
+		ret = chap->error;
+		return ret;
+	}
+	mutex_unlock(&ctrl->dhchap_auth_mutex);
+	return -ENXIO;
+}
+EXPORT_SYMBOL_GPL(nvme_auth_wait);
+
+void nvme_auth_reset(struct nvme_ctrl *ctrl)
+{
+	struct nvme_dhchap_queue_context *chap;
+
+	mutex_lock(&ctrl->dhchap_auth_mutex);
+	list_for_each_entry(chap, &ctrl->dhchap_auth_list, entry) {
+		mutex_unlock(&ctrl->dhchap_auth_mutex);
+		flush_work(&chap->auth_work);
+		__nvme_auth_reset(chap);
+	}
+	mutex_unlock(&ctrl->dhchap_auth_mutex);
+}
+EXPORT_SYMBOL_GPL(nvme_auth_reset);
+
+static void nvme_dhchap_auth_work(struct work_struct *work)
+{
+	struct nvme_ctrl *ctrl =
+		container_of(work, struct nvme_ctrl, dhchap_auth_work);
+	int ret, q;
+
+	/* Authenticate admin queue first */
+	ret = nvme_auth_negotiate(ctrl, 0);
+	if (ret) {
+		dev_warn(ctrl->device,
+			 "qid 0: error %d setting up authentication\n", ret);
+		return;
+	}
+	ret = nvme_auth_wait(ctrl, 0);
+	if (ret) {
+		dev_warn(ctrl->device,
+			 "qid 0: authentication failed\n");
+		return;
+	}
+
+	for (q = 1; q < ctrl->queue_count; q++) {
+		ret = nvme_auth_negotiate(ctrl, q);
+		if (ret) {
+			dev_warn(ctrl->device,
+				 "qid %d: error %d setting up authentication\n",
+				 q, ret);
+			break;
+		}
+	}
+
+	/*
+	 * Failure is a soft-state; credentials remain valid until
+	 * the controller terminates the connection.
+	 */
+}
+
+void nvme_auth_init_ctrl(struct nvme_ctrl *ctrl)
+{
+	INIT_LIST_HEAD(&ctrl->dhchap_auth_list);
+	INIT_WORK(&ctrl->dhchap_auth_work, nvme_dhchap_auth_work);
+	mutex_init(&ctrl->dhchap_auth_mutex);
+	if (!ctrl->opts)
+		return;
+	nvme_auth_generate_key(ctrl->opts->dhchap_secret, &ctrl->host_key);
+	nvme_auth_generate_key(ctrl->opts->dhchap_ctrl_secret, &ctrl->ctrl_key);
+}
+EXPORT_SYMBOL_GPL(nvme_auth_init_ctrl);
+
+void nvme_auth_stop(struct nvme_ctrl *ctrl)
+{
+	struct nvme_dhchap_queue_context *chap = NULL, *tmp;
+
+	cancel_work_sync(&ctrl->dhchap_auth_work);
+	mutex_lock(&ctrl->dhchap_auth_mutex);
+	list_for_each_entry_safe(chap, tmp, &ctrl->dhchap_auth_list, entry)
+		cancel_work_sync(&chap->auth_work);
+	mutex_unlock(&ctrl->dhchap_auth_mutex);
+}
+EXPORT_SYMBOL_GPL(nvme_auth_stop);
+
+void nvme_auth_free(struct nvme_ctrl *ctrl)
+{
+	struct nvme_dhchap_queue_context *chap = NULL, *tmp;
+
+	mutex_lock(&ctrl->dhchap_auth_mutex);
+	list_for_each_entry_safe(chap, tmp, &ctrl->dhchap_auth_list, entry) {
+		list_del_init(&chap->entry);
+		flush_work(&chap->auth_work);
+		__nvme_auth_free(chap);
+	}
+	mutex_unlock(&ctrl->dhchap_auth_mutex);
+	if (ctrl->host_key) {
+		nvme_auth_free_key(ctrl->host_key);
+		ctrl->host_key = NULL;
+	}
+	if (ctrl->ctrl_key) {
+		nvme_auth_free_key(ctrl->ctrl_key);
+		ctrl->ctrl_key = NULL;
+	}
+}
+EXPORT_SYMBOL_GPL(nvme_auth_free);