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Subject: Re: [PATCH 07/12] nvme: Implement In-Band authentication
To:     Hannes Reinecke <hare@suse.de>, Christoph Hellwig <hch@lst.de>
Cc:     Keith Busch <keith.busch@wdc.com>,
        Herbert Xu <herbert@gondor.apana.org.au>,
        "David S . Miller" <davem@davemloft.net>,
        linux-nvme@lists.infradead.org, linux-crypto@vger.kernel.org
References: <20210910064322.67705-1-hare@suse.de>
 <20210910064322.67705-8-hare@suse.de>
From:   Sagi Grimberg <sagi@grimberg.me>
Message-ID: <99cbf790-c276-b3d0-6140-1f5bfa8665eb@grimberg.me>
Date:   Mon, 13 Sep 2021 16:55:28 +0300
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On 9/10/21 9:43 AM, Hannes Reinecke wrote:
> 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_bidi' to request 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'.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
>   drivers/nvme/host/Kconfig   |   12 +
>   drivers/nvme/host/Makefile  |    1 +
>   drivers/nvme/host/auth.c    | 1285 +++++++++++++++++++++++++++++++++++
>   drivers/nvme/host/auth.h    |   25 +
>   drivers/nvme/host/core.c    |   79 ++-
>   drivers/nvme/host/fabrics.c |   73 +-
>   drivers/nvme/host/fabrics.h |    6 +
>   drivers/nvme/host/nvme.h    |   30 +
>   drivers/nvme/host/trace.c   |   32 +
>   9 files changed, 1537 insertions(+), 6 deletions(-)
>   create mode 100644 drivers/nvme/host/auth.c
>   create mode 100644 drivers/nvme/host/auth.h
> 
> diff --git a/drivers/nvme/host/Kconfig b/drivers/nvme/host/Kconfig
> index dc0450ca23a3..97e8412dc42d 100644
> --- a/drivers/nvme/host/Kconfig
> +++ b/drivers/nvme/host/Kconfig
> @@ -83,3 +83,15 @@ config NVME_TCP
>   	  from https://github.com/linux-nvme/nvme-cli.
>   
>   	  If unsure, say N.
> +
> +config NVME_AUTH
> +	bool "NVM Express over Fabrics In-Band Authentication"
> +	depends on NVME_CORE
> +	select CRYPTO_HMAC
> +	select CRYPTO_SHA256
> +	select CRYPTO_SHA512
> +	help
> +	  This provides support for NVMe over Fabrics In-Band Authentication
> +	  for the NVMe over TCP transport.

Not tcp specific...

> diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
> new file mode 100644
> index 000000000000..5393ac16a002
> --- /dev/null
> +++ b/drivers/nvme/host/auth.c
> @@ -0,0 +1,1285 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Copyright (c) 2020 Hannes Reinecke, SUSE Linux
> + */
> +
> +#include <linux/crc32.h>
> +#include <linux/base64.h>
> +#include <asm/unaligned.h>
> +#include <crypto/hash.h>
> +#include <crypto/dh.h>
> +#include <crypto/ffdhe.h>
> +#include "nvme.h"
> +#include "fabrics.h"
> +#include "auth.h"
> +
> +static u32 nvme_dhchap_seqnum;
> +
> +struct nvme_dhchap_queue_context {
> +	struct list_head entry;
> +	struct work_struct auth_work;
> +	struct nvme_ctrl *ctrl;
> +	struct crypto_shash *shash_tfm;
> +	struct crypto_kpp *dh_tfm;
> +	void *buf;
> +	size_t buf_size;
> +	int qid;
> +	int error;
> +	u32 s1;
> +	u32 s2;
> +	u16 transaction;
> +	u8 status;
> +	u8 hash_id;
> +	u8 hash_len;
> +	u8 dhgroup_id;
> +	u8 c1[64];
> +	u8 c2[64];
> +	u8 response[64];
> +	u8 *host_response;
> +};
> +
> +static struct nvme_auth_dhgroup_map {
> +	int id;
> +	const char name[16];
> +	const char kpp[16];
> +	int privkey_size;
> +	int pubkey_size;
> +} dhgroup_map[] = {
> +	{ .id = NVME_AUTH_DHCHAP_DHGROUP_NULL,
> +	  .name = "NULL", .kpp = "NULL",

Nit, no need for all-caps, can do "null"

> +	  .privkey_size = 0, .pubkey_size = 0 },
> +	{ .id = NVME_AUTH_DHCHAP_DHGROUP_2048,
> +	  .name = "ffdhe2048", .kpp = "dh",
> +	  .privkey_size = 256, .pubkey_size = 256 },
> +	{ .id = NVME_AUTH_DHCHAP_DHGROUP_3072,
> +	  .name = "ffdhe3072", .kpp = "dh",
> +	  .privkey_size = 384, .pubkey_size = 384 },
> +	{ .id = NVME_AUTH_DHCHAP_DHGROUP_4096,
> +	  .name = "ffdhe4096", .kpp = "dh",
> +	  .privkey_size = 512, .pubkey_size = 512 },
> +	{ .id = NVME_AUTH_DHCHAP_DHGROUP_6144,
> +	  .name = "ffdhe6144", .kpp = "dh",
> +	  .privkey_size = 768, .pubkey_size = 768 },
> +	{ .id = NVME_AUTH_DHCHAP_DHGROUP_8192,
> +	  .name = "ffdhe8192", .kpp = "dh",
> +	  .privkey_size = 1024, .pubkey_size = 1024 },
> +};
> +
> +const char *nvme_auth_dhgroup_name(int dhgroup_id)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
> +		if (dhgroup_map[i].id == dhgroup_id)
> +			return dhgroup_map[i].name;
> +	}
> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_name);
> +
> +int nvme_auth_dhgroup_pubkey_size(int dhgroup_id)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
> +		if (dhgroup_map[i].id == dhgroup_id)
> +			return dhgroup_map[i].pubkey_size;
> +	}
> +	return -1;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_pubkey_size);
> +
> +int nvme_auth_dhgroup_privkey_size(int dhgroup_id)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
> +		if (dhgroup_map[i].id == dhgroup_id)
> +			return dhgroup_map[i].privkey_size;
> +	}
> +	return -1;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_privkey_size);
> +
> +const char *nvme_auth_dhgroup_kpp(int dhgroup_id)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
> +		if (dhgroup_map[i].id == dhgroup_id)
> +			return dhgroup_map[i].kpp;
> +	}
> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_kpp);
> +
> +int nvme_auth_dhgroup_id(const char *dhgroup_name)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) {
> +		if (!strncmp(dhgroup_map[i].name, dhgroup_name,
> +			     strlen(dhgroup_map[i].name)))
> +			return dhgroup_map[i].id;
> +	}
> +	return -1;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_id);
> +
> +static struct nvme_dhchap_hash_map {
> +	int id;
> +	const char hmac[15];
> +	const char digest[15];
> +} hash_map[] = {
> +	{.id = NVME_AUTH_DHCHAP_SHA256,
> +	 .hmac = "hmac(sha256)", .digest = "sha256" },
> +	{.id = NVME_AUTH_DHCHAP_SHA384,
> +	 .hmac = "hmac(sha384)", .digest = "sha384" },
> +	{.id = NVME_AUTH_DHCHAP_SHA512,
> +	 .hmac = "hmac(sha512)", .digest = "sha512" },
> +};
> +
> +const char *nvme_auth_hmac_name(int hmac_id)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(hash_map); i++) {
> +		if (hash_map[i].id == hmac_id)
> +			return hash_map[i].hmac;
> +	}
> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_hmac_name);
> +
> +const char *nvme_auth_digest_name(int hmac_id)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(hash_map); i++) {
> +		if (hash_map[i].id == hmac_id)
> +			return hash_map[i].digest;
> +	}
> +	return NULL;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_digest_name);
> +
> +int nvme_auth_hmac_id(const char *hmac_name)
> +{
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(hash_map); i++) {
> +		if (!strncmp(hash_map[i].hmac, hmac_name,
> +			     strlen(hash_map[i].hmac)))
> +			return hash_map[i].id;
> +	}
> +	return -1;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_hmac_id);
> +
> +unsigned char *nvme_auth_extract_secret(unsigned char *secret, size_t *out_len)
> +{
> +	unsigned char *key;
> +	u32 crc;
> +	int key_len;
> +	size_t allocated_len;
> +
> +	allocated_len = strlen(secret);

Can move to declaration initializer.

> +	key = kzalloc(allocated_len, GFP_KERNEL);
> +	if (!key)
> +		return ERR_PTR(-ENOMEM);
> +
> +	key_len = base64_decode(secret, allocated_len, key);
> +	if (key_len != 36 && key_len != 52 &&
> +	    key_len != 68) {
> +		pr_debug("Invalid DH-HMAC-CHAP key len %d\n",
> +			 key_len);
> +		kfree_sensitive(key);
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	/* The last four bytes is the CRC in little-endian format */
> +	key_len -= 4;
> +	/*
> +	 * The linux implementation doesn't do pre- and post-increments,
> +	 * so we have to do it manually.
> +	 */
> +	crc = ~crc32(~0, key, key_len);
> +
> +	if (get_unaligned_le32(key + key_len) != crc) {
> +		pr_debug("DH-HMAC-CHAP key crc mismatch (key %08x, crc %08x)\n",
> +		       get_unaligned_le32(key + key_len), crc);
> +		kfree_sensitive(key);
> +		return ERR_PTR(-EKEYREJECTED);
> +	}
> +	*out_len = key_len;
> +	return key;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_extract_secret);
> +
> +u8 *nvme_auth_transform_key(u8 *key, size_t key_len, u8 key_hash, char *nqn)
> +{
> +	const char *hmac_name = nvme_auth_hmac_name(key_hash);
> +	struct crypto_shash *key_tfm;
> +	struct shash_desc *shash;
> +	u8 *transformed_key;
> +	int ret;
> +
> +	/* No key transformation required */
> +	if (key_hash == 0)
> +		return 0;
> +
> +	hmac_name = nvme_auth_hmac_name(key_hash);
> +	if (!hmac_name) {
> +		pr_warn("Invalid key hash id %d\n", key_hash);
> +		return ERR_PTR(-EKEYREJECTED);
> +	}

newline here.

> +	key_tfm = crypto_alloc_shash(hmac_name, 0, 0);
> +	if (IS_ERR(key_tfm))
> +		return (u8 *)key_tfm;
> +
> +	shash = kmalloc(sizeof(struct shash_desc) +
> +			crypto_shash_descsize(key_tfm),
> +			GFP_KERNEL);
> +	if (!shash) {
> +		crypto_free_shash(key_tfm);
> +		return ERR_PTR(-ENOMEM);
> +	}

newline here.

> +	transformed_key = kzalloc(crypto_shash_digestsize(key_tfm), GFP_KERNEL);
> +	if (!transformed_key) {
> +		ret = -ENOMEM;
> +		goto out_free_shash;
> +	}
> +
> +	shash->tfm = key_tfm;
> +	ret = crypto_shash_setkey(key_tfm, key, key_len);
> +	if (ret < 0)
> +		goto out_free_shash;
> +	ret = crypto_shash_init(shash);
> +	if (ret < 0)
> +		goto out_free_shash;
> +	ret = crypto_shash_update(shash, nqn, strlen(nqn));
> +	if (ret < 0)
> +		goto out_free_shash;
> +	ret = crypto_shash_update(shash, "NVMe-over-Fabrics", 17);
> +	if (ret < 0)
> +		goto out_free_shash;
> +	ret = crypto_shash_final(shash, transformed_key);
> +out_free_shash:
> +	kfree(shash);
> +	crypto_free_shash(key_tfm);
> +	if (ret < 0) {
> +		kfree_sensitive(transformed_key);
> +		return ERR_PTR(ret);
> +	}

Any reason why this is not a reverse cleanup with goto call-sites
standard style?

> +	return transformed_key;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_transform_key);
> +
> +static int nvme_auth_hash_skey(int hmac_id, u8 *skey, size_t skey_len, u8 *hkey)
> +{
> +	const char *digest_name;
> +	struct crypto_shash *tfm;
> +	int ret;
> +
> +	digest_name = nvme_auth_digest_name(hmac_id);
> +	if (!digest_name) {
> +		pr_debug("%s: failed to get digest for %d\n", __func__,
> +			 hmac_id);
> +		return -EINVAL;
> +	}
> +	tfm = crypto_alloc_shash(digest_name, 0, 0);
> +	if (IS_ERR(tfm))
> +		return -ENOMEM;
> +
> +	ret = crypto_shash_tfm_digest(tfm, skey, skey_len, hkey);
> +	if (ret < 0)
> +		pr_debug("%s: Failed to hash digest len %zu\n", __func__,
> +			 skey_len);
> +
> +	crypto_free_shash(tfm);
> +	return ret;
> +}
> +
> +int nvme_auth_augmented_challenge(u8 hmac_id, u8 *skey, size_t skey_len,
> +		u8 *challenge, u8 *aug, size_t hlen)
> +{
> +	struct crypto_shash *tfm;
> +	struct shash_desc *desc;
> +	u8 *hashed_key;
> +	const char *hmac_name;
> +	int ret;
> +
> +	hashed_key = kmalloc(hlen, GFP_KERNEL);
> +	if (!hashed_key)
> +		return -ENOMEM;
> +
> +	ret = nvme_auth_hash_skey(hmac_id, skey,
> +				  skey_len, hashed_key);
> +	if (ret < 0)
> +		goto out_free_key;
> +
> +	hmac_name = nvme_auth_hmac_name(hmac_id);
> +	if (!hmac_name) {
> +		pr_warn("%s: invalid hash algoritm %d\n",
> +			__func__, hmac_id);
> +		ret = -EINVAL;
> +		goto out_free_key;
> +	}

newline.

> +	tfm = crypto_alloc_shash(hmac_name, 0, 0);
> +	if (IS_ERR(tfm)) {
> +		ret = PTR_ERR(tfm);
> +		goto out_free_key;
> +	}

newline

> +	desc = kmalloc(sizeof(struct shash_desc) + crypto_shash_descsize(tfm),
> +		       GFP_KERNEL);
> +	if (!desc) {
> +		ret = -ENOMEM;
> +		goto out_free_hash;
> +	}
> +	desc->tfm = tfm;
> +
> +	ret = crypto_shash_setkey(tfm, hashed_key, hlen);
> +	if (ret)
> +		goto out_free_desc;
> +
> +	ret = crypto_shash_init(desc);
> +	if (ret)
> +		goto out_free_desc;
> +
> +	ret = crypto_shash_update(desc, challenge, hlen);
> +	if (ret)
> +		goto out_free_desc;
> +
> +	ret = crypto_shash_final(desc, aug);
> +out_free_desc:
> +	kfree_sensitive(desc);
> +out_free_hash:
> +	crypto_free_shash(tfm);
> +out_free_key:
> +	kfree_sensitive(hashed_key);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_augmented_challenge);
> +
> +int nvme_auth_gen_privkey(struct crypto_kpp *dh_tfm, int dh_gid)
> +{
> +	char *pkey;
> +	int ret, pkey_len;
> +
> +	if (dh_gid == NVME_AUTH_DHCHAP_DHGROUP_2048 ||
> +	    dh_gid == NVME_AUTH_DHCHAP_DHGROUP_3072 ||
> +	    dh_gid == NVME_AUTH_DHCHAP_DHGROUP_4096 ||
> +	    dh_gid == NVME_AUTH_DHCHAP_DHGROUP_6144 ||
> +	    dh_gid == NVME_AUTH_DHCHAP_DHGROUP_8192) {
> +		struct dh p = {0};
> +		int bits = nvme_auth_dhgroup_pubkey_size(dh_gid) << 3;
> +		int dh_secret_len = 64;
> +		u8 *dh_secret = kzalloc(dh_secret_len, GFP_KERNEL);
> +
> +		if (!dh_secret)
> +			return -ENOMEM;
> +
> +		/*
> +		 * NVMe base spec v2.0: The DH value shall be set to the value
> +		 * of g^x mod p, where 'x' is a random number selected by the
> +		 * host that shall be at least 256 bits long.
> +		 *
> +		 * We will be using a 512 bit random number as private key.
> +		 * This is large enough to provide adequate security, but
> +		 * small enough such that we can trivially conform to
> +		 * NIST SB800-56A section 5.6.1.1.4 if
> +		 * we guarantee that the random number is not either
> +		 * all 0xff or all 0x00. But that should be guaranteed
> +		 * by the in-kernel RNG anyway.
> +		 */
> +		get_random_bytes(dh_secret, dh_secret_len);
> +
> +		ret = crypto_ffdhe_params(&p, bits);
> +		if (ret) {
> +			kfree_sensitive(dh_secret);
> +			return ret;
> +		}
> +
> +		p.key = dh_secret;
> +		p.key_size = dh_secret_len;
> +
> +		pkey_len = crypto_dh_key_len(&p);
> +		pkey = kmalloc(pkey_len, GFP_KERNEL);
> +		if (!pkey) {
> +			kfree_sensitive(dh_secret);
> +			return -ENOMEM;
> +		}
> +
> +		get_random_bytes(pkey, pkey_len);
> +		ret = crypto_dh_encode_key(pkey, pkey_len, &p);
> +		if (ret) {
> +			pr_debug("failed to encode private key, error %d\n",
> +				 ret);
> +			kfree_sensitive(dh_secret);
> +			goto out;
> +		}
> +	} else {
> +		pr_warn("invalid dh group %d\n", dh_gid);
> +		return -EINVAL;
> +	}
> +	ret = crypto_kpp_set_secret(dh_tfm, pkey, pkey_len);
> +	if (ret)
> +		pr_debug("failed to set private key, error %d\n", ret);
> +out:
> +	kfree_sensitive(pkey);

pkey can be unset here.

> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_gen_privkey);
> +
> +int nvme_auth_gen_pubkey(struct crypto_kpp *dh_tfm,
> +		u8 *host_key, size_t host_key_len)
> +{
> +	struct kpp_request *req;
> +	struct crypto_wait wait;
> +	struct scatterlist dst;
> +	int ret;
> +
> +	req = kpp_request_alloc(dh_tfm, GFP_KERNEL);
> +	if (!req)
> +		return -ENOMEM;
> +
> +	crypto_init_wait(&wait);
> +	kpp_request_set_input(req, NULL, 0);
> +	sg_init_one(&dst, host_key, host_key_len);
> +	kpp_request_set_output(req, &dst, host_key_len);
> +	kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
> +				 crypto_req_done, &wait);
> +
> +	ret = crypto_wait_req(crypto_kpp_generate_public_key(req), &wait);
> +

no need for this newline

> +	kpp_request_free(req);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_gen_pubkey);
> +
> +int nvme_auth_gen_shared_secret(struct crypto_kpp *dh_tfm,
> +		u8 *ctrl_key, size_t ctrl_key_len,
> +		u8 *sess_key, size_t sess_key_len)
> +{
> +	struct kpp_request *req;
> +	struct crypto_wait wait;
> +	struct scatterlist src, dst;
> +	int ret;
> +
> +	req = kpp_request_alloc(dh_tfm, GFP_KERNEL);
> +	if (!req)
> +		return -ENOMEM;
> +
> +	crypto_init_wait(&wait);
> +	sg_init_one(&src, ctrl_key, ctrl_key_len);
> +	kpp_request_set_input(req, &src, ctrl_key_len);
> +	sg_init_one(&dst, sess_key, sess_key_len);
> +	kpp_request_set_output(req, &dst, sess_key_len);
> +	kpp_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG,
> +				 crypto_req_done, &wait);
> +
> +	ret = crypto_wait_req(crypto_kpp_compute_shared_secret(req), &wait);
> +
> +	kpp_request_free(req);
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_gen_shared_secret);
> +
> +static int nvme_auth_send(struct nvme_ctrl *ctrl, int qid,
> +		void *data, size_t tl)
> +{
> +	struct nvme_command cmd = {};
> +	blk_mq_req_flags_t flags = qid == NVME_QID_ANY ?
> +		0 : BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED;
> +	struct request_queue *q = qid == NVME_QID_ANY ?
> +		ctrl->fabrics_q : ctrl->connect_q;
> +	int ret;
> +
> +	cmd.auth_send.opcode = nvme_fabrics_command;
> +	cmd.auth_send.fctype = nvme_fabrics_type_auth_send;
> +	cmd.auth_send.secp = NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER;
> +	cmd.auth_send.spsp0 = 0x01;
> +	cmd.auth_send.spsp1 = 0x01;
> +	cmd.auth_send.tl = tl;
> +
> +	ret = __nvme_submit_sync_cmd(q, &cmd, NULL, data, tl, 0, qid,
> +				     0, flags);
> +	if (ret > 0)
> +		dev_dbg(ctrl->device,
> +			"%s: qid %d nvme status %d\n", __func__, qid, ret);
> +	else if (ret < 0)
> +		dev_dbg(ctrl->device,
> +			"%s: qid %d error %d\n", __func__, qid, ret);
> +	return ret;
> +}
> +
> +static int nvme_auth_receive(struct nvme_ctrl *ctrl, int qid,
> +		void *buf, size_t al)
> +{
> +	struct nvme_command cmd = {};
> +	blk_mq_req_flags_t flags = qid == NVME_QID_ANY ?
> +		0 : BLK_MQ_REQ_NOWAIT | BLK_MQ_REQ_RESERVED;
> +	struct request_queue *q = qid == NVME_QID_ANY ?
> +		ctrl->fabrics_q : ctrl->connect_q;
> +	int ret;
> +
> +	cmd.auth_receive.opcode = nvme_fabrics_command;
> +	cmd.auth_receive.fctype = nvme_fabrics_type_auth_receive;
> +	cmd.auth_receive.secp = NVME_AUTH_DHCHAP_PROTOCOL_IDENTIFIER;
> +	cmd.auth_receive.spsp0 = 0x01;
> +	cmd.auth_receive.spsp1 = 0x01;
> +	cmd.auth_receive.al = al;
> +
> +	ret = __nvme_submit_sync_cmd(q, &cmd, NULL, buf, al, 0, qid,
> +				     0, flags);
> +	if (ret > 0) {
> +		dev_dbg(ctrl->device, "%s: qid %d nvme status %x\n",
> +			__func__, qid, ret);
> +		ret = -EIO;

Why EIO?

> +	}
> +	if (ret < 0) {
> +		dev_dbg(ctrl->device, "%s: qid %d error %d\n",
> +			__func__, qid, ret);
> +		return ret;
> +	}

Why did you choose to do these error conditionals differently for the
send and receive functions?

> +
> +	return 0;
> +}
> +
> +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;

Is this an internal error? not sure I understand setting of this status

> +		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_DHCHAP_SHA256;
> +	data->auth_protocol[0].dhchap.idlist[1] = NVME_AUTH_DHCHAP_SHA384;
> +	data->auth_protocol[0].dhchap.idlist[2] = NVME_AUTH_DHCHAP_SHA512;
> +	data->auth_protocol[0].dhchap.idlist[3] = NVME_AUTH_DHCHAP_DHGROUP_NULL;
> +	data->auth_protocol[0].dhchap.idlist[4] = NVME_AUTH_DHCHAP_DHGROUP_2048;
> +	data->auth_protocol[0].dhchap.idlist[5] = NVME_AUTH_DHCHAP_DHGROUP_3072;
> +	data->auth_protocol[0].dhchap.idlist[6] = NVME_AUTH_DHCHAP_DHGROUP_4096;
> +	data->auth_protocol[0].dhchap.idlist[7] = NVME_AUTH_DHCHAP_DHGROUP_6144;
> +	data->auth_protocol[0].dhchap.idlist[8] = NVME_AUTH_DHCHAP_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;
> +	size_t size = sizeof(*data) + data->hl + data->dhvlen;
> +	const char *hmac_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 -EPROTO;
> +	}
> +	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;
> +	}

newline

> +	if (chap->shash_tfm) {
> +		crypto_free_shash(chap->shash_tfm);
> +		chap->hash_id = 0;
> +		chap->hash_len = 0;
> +	}

newline

> +	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;
> +	}

newline

> +	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;
> +	}

newline

> +	if (chap->hash_id != data->hashid) {
> +		kfree(chap->host_response);

kfree_sensitive? also why is is freed here? where was it allocated?

> +		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);
> +
> +	gid_name = nvme_auth_dhgroup_kpp(data->dhgid);
> +	if (!gid_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 -EPROTO;

No need for all the previous frees?
Maybe we can rework these such that we first do all the checks and then
go and allocate stuff?

> +	}
> +
> +	if (data->dhgid != NVME_AUTH_DHCHAP_DHGROUP_NULL) {
> +		if (data->dhvlen == 0) {
> +			dev_warn(ctrl->device,
> +				 "qid %d: empty DH value\n",
> +				 chap->qid);
> +			chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
> +			return -EPROTO;
> +		}
> +		chap->dh_tfm = crypto_alloc_kpp(gid_name, 0, 0);
> +		if (IS_ERR(chap->dh_tfm)) {
> +			int ret = PTR_ERR(chap->dh_tfm);
> +
> +			dev_warn(ctrl->device,
> +				 "qid %d: failed to initialize %s\n",
> +				 chap->qid, gid_name);
> +			chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
> +			chap->dh_tfm = NULL;
> +			return ret;
> +		}
> +		chap->dhgroup_id = data->dhgid;
> +	} else if (data->dhvlen != 0) {
> +		dev_warn(ctrl->device,
> +			 "qid %d: invalid DH value for NULL DH\n",
> +			chap->qid);
> +		chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
> +		return -EPROTO;
> +	}
> +	dev_dbg(ctrl->device, "qid %d: selected DH group %s\n",
> +		chap->qid, gid_name);
> +
> +select_kpp:
> +	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 (ctrl->opts->dhchap_bidi) {
> +		get_random_bytes(chap->c2, chap->hash_len);
> +		chap->s2 = nvme_dhchap_seqnum++;

Any serialization needed on nvme_dhchap_seqnum?

> +	} else
> +		memset(chap->c2, 0, 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;
> +	data->seqnum = cpu_to_le32(chap->s2);
> +	memcpy(data->rval, chap->response, chap->hash_len);
> +	if (ctrl->opts->dhchap_bidi) {

Can we unite the "if (ctrl->opts->dhchap_bidi)"
conditionals?

> +		dev_dbg(ctrl->device, "%s: qid %d ctrl challenge %*ph\n",
> +			__func__, chap->qid,
> +			chap->hash_len, chap->c2);
> +		data->cvalid = 1;
> +		memcpy(data->rval + chap->hash_len, chap->c2,
> +		       chap->hash_len);
> +	}
> +	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->opts->dhchap_bidi)
> +		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 %d\n",
> +			 chap->qid, data->hl);
> +		chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
> +		return NVME_SC_INVALID_FIELD;
> +	}
> +
> +	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, chap->hash_len, data->rval);
> +		dev_dbg(ctrl->device, "%s: qid %d host response %*ph\n",
> +			__func__, chap->qid, 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;
> +	}
> +	dev_info(ctrl->device,
> +		 "qid %d: controller authenticated\n",
> +		chap->qid);
> +	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_DHCHAP_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_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 %d transaction %d\n",
> +		__func__, chap->qid, chap->s1, chap->transaction);
> +	if (chap->dh_tfm) {
> +		challenge = kmalloc(chap->hash_len, GFP_KERNEL);
> +		if (!challenge) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
> +		ret = nvme_auth_augmented_challenge(chap->hash_id,
> +						    chap->sess_key,
> +						    chap->sess_key_len,
> +						    chap->c1, challenge,
> +						    chap->hash_len);
> +		if (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_ctrl_response(struct nvme_ctrl *ctrl,
> +		struct nvme_dhchap_queue_context *chap)
> +{
> +	SHASH_DESC_ON_STACK(shash, chap->shash_tfm);
> +	u8 buf[4], *challenge = chap->c2;
> +	int ret;
> +
> +	if (chap->dh_tfm) {
> +		challenge = kmalloc(chap->hash_len, GFP_KERNEL);
> +		if (!challenge) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
> +		ret = nvme_auth_augmented_challenge(chap->hash_id,
> +						    chap->sess_key,
> +						    chap->sess_key_len,
> +						    chap->c2, challenge,
> +						    chap->hash_len);
> +		if (ret)
> +			goto out;
> +	}
> +	dev_dbg(ctrl->device, "%s: qid %d host response seq %d transaction %d\n",
> +		__func__, chap->qid, chap->s2, chap->transaction);
> +	dev_dbg(ctrl->device, "%s: qid %d challenge %*ph\n",
> +		__func__, chap->qid, 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);
> +	return ret;
> +}
> +
> +int nvme_auth_generate_key(struct nvme_ctrl *ctrl)
> +{
> +	int ret;
> +	u8 key_hash;
> +
> +	if (!ctrl->opts->dhchap_secret)
> +		return 0;
> +
> +	if (ctrl->dhchap_key && ctrl->dhchap_key_len)
> +		/* Key already set */
> +		return 0;
> +
> +	if (sscanf(ctrl->opts->dhchap_secret, "DHHC-1:%hhd:%*s:",
> +		   &key_hash) != 1)
> +		return -EINVAL;
> +
> +	/* Pass in the secret without the 'DHHC-1:XX:' prefix */
> +	ctrl->dhchap_key = nvme_auth_extract_secret(ctrl->opts->dhchap_secret + 10,
> +					     &ctrl->dhchap_key_len);
> +	if (IS_ERR(ctrl->dhchap_key)) {
> +		ret = PTR_ERR(ctrl->dhchap_key);
> +		ctrl->dhchap_key = NULL;
> +		return ret;
> +	}
> +	return ret;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_generate_key);
> +
> +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)
> +{
> +	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_send(ctrl, chap->qid, chap->buf, tl);
> +	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_receive(ctrl, chap->qid, chap->buf, chap->buf_size);
> +	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 */
> +		goto fail2;
> +	}
> +
> +	if (chap->ctrl_key_len) {
> +		dev_dbg(ctrl->device,
> +			"%s: qid %d DH exponential\n",
> +			__func__, chap->qid);
> +		ret = nvme_auth_dhchap_exponential(ctrl, chap);
> +		if (ret)
> +			goto fail2;
> +	}
> +
> +	dev_dbg(ctrl->device, "%s: qid %d host response\n",
> +		__func__, chap->qid);
> +	ret = nvme_auth_dhchap_host_response(ctrl, chap);
> +	if (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)
> +		goto fail2;
> +
> +	tl = ret;
> +	ret = nvme_auth_send(ctrl, chap->qid, chap->buf, tl);
> +	if (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_receive(ctrl, chap->qid, chap->buf, chap->buf_size);
> +	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->opts->dhchap_bidi) {
> +		dev_dbg(ctrl->device,
> +			"%s: qid %d controller response\n",
> +			__func__, chap->qid);
> +		ret = nvme_auth_dhchap_ctrl_response(ctrl, chap);
> +		if (ret)
> +			goto fail2;
> +	}
> +
> +	ret = nvme_auth_process_dhchap_success1(ctrl, chap);
> +	if (ret < 0) {
> +		/* Controller authentication failed */
> +		goto fail2;
> +	}
> +
> +	/* 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_send(ctrl, chap->qid, chap->buf, tl);
> +	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_send(ctrl, chap->qid, chap->buf, tl);
> +	if (!ret)
> +		ret = -EPROTO;
> +	chap->error = ret;
> +}
> +
> +int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
> +{
> +	struct nvme_dhchap_queue_context *chap;
> +
> +	if (!ctrl->dhchap_key || !ctrl->dhchap_key_len) {
> +		dev_warn(ctrl->device, "qid %d: no 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) {
> +		if (chap->qid == qid) {
> +			mutex_unlock(&ctrl->dhchap_auth_mutex);
> +			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;
> +	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);

Why is the auth in a work? e.g. it won't fail the connect?

> +	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;
> +		nvme_auth_reset(chap);
> +		return ret;
> +	}
> +	mutex_unlock(&ctrl->dhchap_auth_mutex);
> +	return -ENXIO;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_wait);
> +
> +/* Assumes that the controller is in state RESETTING */
> +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;
> +
> +	nvme_stop_queues(ctrl);
> +	/* Authenticate admin queue first */
> +	ret = nvme_auth_negotiate(ctrl, NVME_QID_ANY);
> +	if (ret) {
> +		dev_warn(ctrl->device,
> +			 "qid 0: error %d setting up authentication\n", ret);
> +		goto out;
> +	}
> +	ret = nvme_auth_wait(ctrl, NVME_QID_ANY);
> +	if (ret) {
> +		dev_warn(ctrl->device,
> +			 "qid 0: authentication failed\n");
> +		goto out;
> +	}
> +	dev_info(ctrl->device, "qid 0: authenticated\n");
> +
> +	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);
> +			goto out;
> +		}
> +	}
> +out:
> +	/*
> +	 * Failure is a soft-state; credentials remain valid until
> +	 * the controller terminates the connection.
> +	 */
> +	if (nvme_change_ctrl_state(ctrl, NVME_CTRL_LIVE))
> +		nvme_start_queues(ctrl);
> +}
> +
> +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);
> +	nvme_auth_generate_key(ctrl);
> +}
> +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);
> +	kfree(ctrl->dhchap_key);
> +	ctrl->dhchap_key = NULL;
> +	ctrl->dhchap_key_len = 0;
> +}
> +EXPORT_SYMBOL_GPL(nvme_auth_free);
> diff --git a/drivers/nvme/host/auth.h b/drivers/nvme/host/auth.h
> new file mode 100644
> index 000000000000..cf1255f9db6d
> --- /dev/null
> +++ b/drivers/nvme/host/auth.h
> @@ -0,0 +1,25 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * Copyright (c) 2021 Hannes Reinecke, SUSE Software Solutions
> + */
> +
> +#ifndef _NVME_AUTH_H
> +#define _NVME_AUTH_H
> +
> +#include <crypto/kpp.h>
> +
> +const char *nvme_auth_dhgroup_name(int dhgroup_id);
> +int nvme_auth_dhgroup_pubkey_size(int dhgroup_id);
> +int nvme_auth_dhgroup_privkey_size(int dhgroup_id);
> +const char *nvme_auth_dhgroup_kpp(int dhgroup_id);
> +int nvme_auth_dhgroup_id(const char *dhgroup_name);
> +
> +const char *nvme_auth_hmac_name(int hmac_id);
> +const char *nvme_auth_digest_name(int hmac_id);
> +int nvme_auth_hmac_id(const char *hmac_name);
> +
> +unsigned char *nvme_auth_extract_secret(unsigned char *dhchap_secret,
> +					size_t *dhchap_key_len);
> +u8 *nvme_auth_transform_key(u8 *key, size_t key_len, u8 key_hash, char *nqn);
> +
> +#endif /* _NVME_AUTH_H */
> diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
> index 7efb31b87f37..f669b054790b 100644
> --- a/drivers/nvme/host/core.c
> +++ b/drivers/nvme/host/core.c
> @@ -24,6 +24,7 @@
>   
>   #include "nvme.h"
>   #include "fabrics.h"
> +#include "auth.h"
>   
>   #define CREATE_TRACE_POINTS
>   #include "trace.h"
> @@ -322,6 +323,7 @@ enum nvme_disposition {
>   	COMPLETE,
>   	RETRY,
>   	FAILOVER,
> +	AUTHENTICATE,
>   };
>   
>   static inline enum nvme_disposition nvme_decide_disposition(struct request *req)
> @@ -329,6 +331,9 @@ static inline enum nvme_disposition nvme_decide_disposition(struct request *req)
>   	if (likely(nvme_req(req)->status == 0))
>   		return COMPLETE;
>   
> +	if ((nvme_req(req)->status & 0x7ff) == NVME_SC_AUTH_REQUIRED)
> +		return AUTHENTICATE;
> +
>   	if (blk_noretry_request(req) ||
>   	    (nvme_req(req)->status & NVME_SC_DNR) ||
>   	    nvme_req(req)->retries >= nvme_max_retries)
> @@ -361,11 +366,13 @@ static inline void nvme_end_req(struct request *req)
>   
>   void nvme_complete_rq(struct request *req)
>   {
> +	struct nvme_ctrl *ctrl = nvme_req(req)->ctrl;
> +
>   	trace_nvme_complete_rq(req);
>   	nvme_cleanup_cmd(req);
>   
> -	if (nvme_req(req)->ctrl->kas)
> -		nvme_req(req)->ctrl->comp_seen = true;
> +	if (ctrl->kas)
> +		ctrl->comp_seen = true;
>   
>   	switch (nvme_decide_disposition(req)) {
>   	case COMPLETE:
> @@ -377,6 +384,15 @@ void nvme_complete_rq(struct request *req)
>   	case FAILOVER:
>   		nvme_failover_req(req);
>   		return;
> +	case AUTHENTICATE:
> +#ifdef CONFIG_NVME_AUTH
> +		if (nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING))
> +			queue_work(nvme_wq, &ctrl->dhchap_auth_work);

Why is the state change here and not in nvme_dhchap_auth_work?

> +		nvme_retry_req(req);
> +#else
> +		nvme_end_req(req);
> +#endif
> +		return;
>   	}
>   }
>   EXPORT_SYMBOL_GPL(nvme_complete_rq);
> @@ -707,7 +723,9 @@ bool __nvme_check_ready(struct nvme_ctrl *ctrl, struct request *rq,
>   		switch (ctrl->state) {
>   		case NVME_CTRL_CONNECTING:
>   			if (blk_rq_is_passthrough(rq) && nvme_is_fabrics(req->cmd) &&
> -			    req->cmd->fabrics.fctype == nvme_fabrics_type_connect)
> +			    (req->cmd->fabrics.fctype == nvme_fabrics_type_connect ||
> +			     req->cmd->fabrics.fctype == nvme_fabrics_type_auth_send ||
> +			     req->cmd->fabrics.fctype == nvme_fabrics_type_auth_receive))

What happens if the auth command comes before the connect (say in case 
of ctrl reset when auth was already queued but not yet executed?

>   				return true;
>   			break;
>   		default:
> @@ -3458,6 +3476,51 @@ static ssize_t nvme_ctrl_fast_io_fail_tmo_store(struct device *dev,
>   static DEVICE_ATTR(fast_io_fail_tmo, S_IRUGO | S_IWUSR,
>   	nvme_ctrl_fast_io_fail_tmo_show, nvme_ctrl_fast_io_fail_tmo_store);
>   
> +#ifdef CONFIG_NVME_AUTH
> +static ssize_t nvme_ctrl_dhchap_secret_show(struct device *dev,
> +		struct device_attribute *attr, char *buf)
> +{
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +	struct nvmf_ctrl_options *opts = ctrl->opts;
> +
> +	if (!opts->dhchap_secret)
> +		return sysfs_emit(buf, "none\n");
> +	return sysfs_emit(buf, "%s\n", opts->dhchap_secret);

Should we actually show this? don't know enough how much the secret
should be kept a secret...

> +}
> +
> +static ssize_t nvme_ctrl_dhchap_secret_store(struct device *dev,
> +		struct device_attribute *attr, const char *buf, size_t count)
> +{
> +	struct nvme_ctrl *ctrl = dev_get_drvdata(dev);
> +	struct nvmf_ctrl_options *opts = ctrl->opts;
> +	char *dhchap_secret;
> +
> +	if (!ctrl->opts->dhchap_secret)
> +		return -EINVAL;
> +	if (count < 7)
> +		return -EINVAL;
> +	if (memcmp(buf, "DHHC-1:", 7))
> +		return -EINVAL;
> +
> +	dhchap_secret = kzalloc(count + 1, GFP_KERNEL);
> +	if (!dhchap_secret)
> +		return -ENOMEM;
> +	memcpy(dhchap_secret, buf, count);
> +	if (strcmp(dhchap_secret, opts->dhchap_secret)) {
> +		kfree(opts->dhchap_secret);
> +		opts->dhchap_secret = dhchap_secret;
> +		/* Key has changed; reset authentication data */
> +		nvme_auth_free(ctrl);
> +		nvme_auth_generate_key(ctrl);
> +	}

Nice, worth a comment "/* Re-authentication with new secret */"

> +	if (nvme_change_ctrl_state(ctrl, NVME_CTRL_RESETTING))
> +		queue_work(nvme_wq, &ctrl->dhchap_auth_work);
> +	return count;
> +}
> +DEVICE_ATTR(dhchap_secret, S_IRUGO | S_IWUSR,
> +	nvme_ctrl_dhchap_secret_show, nvme_ctrl_dhchap_secret_store);
> +#endif
> +
>   static struct attribute *nvme_dev_attrs[] = {
>   	&dev_attr_reset_controller.attr,
>   	&dev_attr_rescan_controller.attr,
> @@ -3479,6 +3542,9 @@ static struct attribute *nvme_dev_attrs[] = {
>   	&dev_attr_reconnect_delay.attr,
>   	&dev_attr_fast_io_fail_tmo.attr,
>   	&dev_attr_kato.attr,
> +#ifdef CONFIG_NVME_AUTH
> +	&dev_attr_dhchap_secret.attr,
> +#endif
>   	NULL
>   };
>   
> @@ -3502,6 +3568,10 @@ static umode_t nvme_dev_attrs_are_visible(struct kobject *kobj,
>   		return 0;
>   	if (a == &dev_attr_fast_io_fail_tmo.attr && !ctrl->opts)
>   		return 0;
> +#ifdef CONFIG_NVME_AUTH
> +	if (a == &dev_attr_dhchap_secret.attr && !ctrl->opts)
> +		return 0;
> +#endif
>   
>   	return a->mode;
>   }
> @@ -4312,6 +4382,7 @@ EXPORT_SYMBOL_GPL(nvme_complete_async_event);
>   void nvme_stop_ctrl(struct nvme_ctrl *ctrl)
>   {
>   	nvme_mpath_stop(ctrl);
> +	nvme_auth_stop(ctrl);
>   	nvme_stop_keep_alive(ctrl);
>   	nvme_stop_failfast_work(ctrl);
>   	flush_work(&ctrl->async_event_work);
> @@ -4366,6 +4437,7 @@ static void nvme_free_ctrl(struct device *dev)
>   
>   	nvme_free_cels(ctrl);
>   	nvme_mpath_uninit(ctrl);
> +	nvme_auth_free(ctrl);
>   	__free_page(ctrl->discard_page);
>   
>   	if (subsys) {
> @@ -4456,6 +4528,7 @@ int nvme_init_ctrl(struct nvme_ctrl *ctrl, struct device *dev,
>   
>   	nvme_fault_inject_init(&ctrl->fault_inject, dev_name(ctrl->device));
>   	nvme_mpath_init_ctrl(ctrl);
> +	nvme_auth_init_ctrl(ctrl);
>   
>   	return 0;
>   out_free_name:
> diff --git a/drivers/nvme/host/fabrics.c b/drivers/nvme/host/fabrics.c
> index 9a8eade7cd23..ee6058c24743 100644
> --- a/drivers/nvme/host/fabrics.c
> +++ b/drivers/nvme/host/fabrics.c
> @@ -370,6 +370,7 @@ int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl)
>   	union nvme_result res;
>   	struct nvmf_connect_data *data;
>   	int ret;
> +	u32 result;
>   
>   	cmd.connect.opcode = nvme_fabrics_command;
>   	cmd.connect.fctype = nvme_fabrics_type_connect;
> @@ -402,8 +403,25 @@ int nvmf_connect_admin_queue(struct nvme_ctrl *ctrl)
>   		goto out_free_data;
>   	}
>   
> -	ctrl->cntlid = le16_to_cpu(res.u16);
> -
> +	result = le32_to_cpu(res.u32);
> +	ctrl->cntlid = result & 0xFFFF;
> +	if ((result >> 16) & 2) {
> +		/* Authentication required */
> +		ret = nvme_auth_negotiate(ctrl, NVME_QID_ANY);
> +		if (ret) {
> +			dev_warn(ctrl->device,
> +				 "qid 0: failed to setup authentication\n");
> +			ret = NVME_SC_AUTH_REQUIRED;
> +			goto out_free_data;
> +		}
> +		ret = nvme_auth_wait(ctrl, NVME_QID_ANY);
> +		if (ret)
> +			dev_warn(ctrl->device,
> +				 "qid 0: authentication failed\n");
> +		else
> +			dev_info(ctrl->device,
> +				 "qid 0: authenticated\n");

OK, so the auth work is serialized via nvme_auth_wait here... got it..

> +	}
>   out_free_data:
>   	kfree(data);
>   	return ret;
> @@ -436,6 +454,7 @@ int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid)
>   	struct nvmf_connect_data *data;
>   	union nvme_result res;
>   	int ret;
> +	u32 result;
>   
>   	cmd.connect.opcode = nvme_fabrics_command;
>   	cmd.connect.fctype = nvme_fabrics_type_connect;
> @@ -461,6 +480,24 @@ int nvmf_connect_io_queue(struct nvme_ctrl *ctrl, u16 qid)
>   		nvmf_log_connect_error(ctrl, ret, le32_to_cpu(res.u32),
>   				       &cmd, data);
>   	}
> +	result = le32_to_cpu(res.u32);
> +	if ((result >> 16) & 2) {
> +		/* Authentication required */
> +		ret = nvme_auth_negotiate(ctrl, qid);
> +		if (ret) {
> +			dev_warn(ctrl->device,
> +				 "qid %d: failed to setup authentication\n", qid);
> +			ret = NVME_SC_AUTH_REQUIRED;
> +		} else {
> +			ret = nvme_auth_wait(ctrl, qid);
> +			if (ret)
> +				dev_warn(ctrl->device,
> +					 "qid %u: authentication failed\n", qid);
> +			else
> +				dev_info(ctrl->device,
> +					 "qid %u: authenticated\n", qid);
> +		}
> +	}
>   	kfree(data);
>   	return ret;
>   }
> @@ -552,6 +589,8 @@ static const match_table_t opt_tokens = {
>   	{ NVMF_OPT_NR_POLL_QUEUES,	"nr_poll_queues=%d"	},
>   	{ NVMF_OPT_TOS,			"tos=%d"		},
>   	{ NVMF_OPT_FAIL_FAST_TMO,	"fast_io_fail_tmo=%d"	},
> +	{ NVMF_OPT_DHCHAP_SECRET,	"dhchap_secret=%s"	},
> +	{ NVMF_OPT_DHCHAP_BIDI,		"dhchap_bidi"		},
>   	{ NVMF_OPT_ERR,			NULL			}
>   };
>   
> @@ -827,6 +866,23 @@ static int nvmf_parse_options(struct nvmf_ctrl_options *opts,
>   			}
>   			opts->tos = token;
>   			break;
> +		case NVMF_OPT_DHCHAP_SECRET:
> +			p = match_strdup(args);
> +			if (!p) {
> +				ret = -ENOMEM;
> +				goto out;
> +			}
> +			if (strlen(p) < 11 || strncmp(p, "DHHC-1:", 7)) {
> +				pr_err("Invalid DH-CHAP secret %s\n", p);
> +				ret = -EINVAL;
> +				goto out;
> +			}
> +			kfree(opts->dhchap_secret);
> +			opts->dhchap_secret = p;
> +			break;
> +		case NVMF_OPT_DHCHAP_BIDI:
> +			opts->dhchap_bidi = true;
> +			break;
>   		default:
>   			pr_warn("unknown parameter or missing value '%s' in ctrl creation request\n",
>   				p);
> @@ -945,6 +1001,7 @@ void nvmf_free_options(struct nvmf_ctrl_options *opts)
>   	kfree(opts->subsysnqn);
>   	kfree(opts->host_traddr);
>   	kfree(opts->host_iface);
> +	kfree(opts->dhchap_secret);
>   	kfree(opts);
>   }
>   EXPORT_SYMBOL_GPL(nvmf_free_options);
> @@ -954,7 +1011,10 @@ EXPORT_SYMBOL_GPL(nvmf_free_options);
>   				 NVMF_OPT_KATO | NVMF_OPT_HOSTNQN | \
>   				 NVMF_OPT_HOST_ID | NVMF_OPT_DUP_CONNECT |\
>   				 NVMF_OPT_DISABLE_SQFLOW |\
> -				 NVMF_OPT_FAIL_FAST_TMO)
> +				 NVMF_OPT_CTRL_LOSS_TMO |\
> +				 NVMF_OPT_FAIL_FAST_TMO |\
> +				 NVMF_OPT_DHCHAP_SECRET |\
> +				 NVMF_OPT_DHCHAP_BIDI)
>   
>   static struct nvme_ctrl *
>   nvmf_create_ctrl(struct device *dev, const char *buf)
> @@ -1171,7 +1231,14 @@ static void __exit nvmf_exit(void)
>   	BUILD_BUG_ON(sizeof(struct nvmf_connect_command) != 64);
>   	BUILD_BUG_ON(sizeof(struct nvmf_property_get_command) != 64);
>   	BUILD_BUG_ON(sizeof(struct nvmf_property_set_command) != 64);
> +	BUILD_BUG_ON(sizeof(struct nvmf_auth_send_command) != 64);
> +	BUILD_BUG_ON(sizeof(struct nvmf_auth_receive_command) != 64);
>   	BUILD_BUG_ON(sizeof(struct nvmf_connect_data) != 1024);
> +	BUILD_BUG_ON(sizeof(struct nvmf_auth_dhchap_negotiate_data) != 8);
> +	BUILD_BUG_ON(sizeof(struct nvmf_auth_dhchap_challenge_data) != 16);
> +	BUILD_BUG_ON(sizeof(struct nvmf_auth_dhchap_reply_data) != 16);
> +	BUILD_BUG_ON(sizeof(struct nvmf_auth_dhchap_success1_data) != 16);
> +	BUILD_BUG_ON(sizeof(struct nvmf_auth_dhchap_success2_data) != 16);
>   }
>   
>   MODULE_LICENSE("GPL v2");
> diff --git a/drivers/nvme/host/fabrics.h b/drivers/nvme/host/fabrics.h
> index a146cb903869..27df1aac5736 100644
> --- a/drivers/nvme/host/fabrics.h
> +++ b/drivers/nvme/host/fabrics.h
> @@ -67,6 +67,8 @@ enum {
>   	NVMF_OPT_TOS		= 1 << 19,
>   	NVMF_OPT_FAIL_FAST_TMO	= 1 << 20,
>   	NVMF_OPT_HOST_IFACE	= 1 << 21,
> +	NVMF_OPT_DHCHAP_SECRET	= 1 << 22,
> +	NVMF_OPT_DHCHAP_BIDI	= 1 << 23,
>   };
>   
>   /**
> @@ -96,6 +98,8 @@ enum {
>    * @max_reconnects: maximum number of allowed reconnect attempts before removing
>    *              the controller, (-1) means reconnect forever, zero means remove
>    *              immediately;
> + * @dhchap_secret: DH-HMAC-CHAP secret
> + * @dhchap_bidi: enable DH-HMAC-CHAP bi-directional authentication
>    * @disable_sqflow: disable controller sq flow control
>    * @hdr_digest: generate/verify header digest (TCP)
>    * @data_digest: generate/verify data digest (TCP)
> @@ -120,6 +124,8 @@ struct nvmf_ctrl_options {
>   	unsigned int		kato;
>   	struct nvmf_host	*host;
>   	int			max_reconnects;
> +	char			*dhchap_secret;
> +	bool			dhchap_bidi;
>   	bool			disable_sqflow;
>   	bool			hdr_digest;
>   	bool			data_digest;
> diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
> index 9871c0c9374c..b0dcb7d79b9e 100644
> --- a/drivers/nvme/host/nvme.h
> +++ b/drivers/nvme/host/nvme.h
> @@ -318,6 +318,15 @@ struct nvme_ctrl {
>   	struct work_struct ana_work;
>   #endif
>   
> +#ifdef CONFIG_NVME_AUTH
> +	struct work_struct dhchap_auth_work;
> +	struct list_head dhchap_auth_list;
> +	struct mutex dhchap_auth_mutex;
> +	unsigned char *dhchap_key;
> +	size_t dhchap_key_len;
> +	u16 transaction;
> +#endif
> +
>   	/* Power saving configuration */
>   	u64 ps_max_latency_us;
>   	bool apst_enabled;
> @@ -885,6 +894,27 @@ static inline bool nvme_ctrl_sgl_supported(struct nvme_ctrl *ctrl)
>   	return ctrl->sgls & ((1 << 0) | (1 << 1));
>   }
>   
> +#ifdef CONFIG_NVME_AUTH
> +void nvme_auth_init_ctrl(struct nvme_ctrl *ctrl);
> +void nvme_auth_stop(struct nvme_ctrl *ctrl);
> +int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid);
> +int nvme_auth_wait(struct nvme_ctrl *ctrl, int qid);
> +void nvme_auth_free(struct nvme_ctrl *ctrl);
> +int nvme_auth_generate_key(struct nvme_ctrl *ctrl);
> +#else
> +static inline void nvme_auth_init_ctrl(struct nvme_ctrl *ctrl) {};
> +static inline void nvme_auth_stop(struct nvme_ctrl *ctrl) {};
> +static inline int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int qid)
> +{
> +	return -EPROTONOSUPPORT;
> +}
> +static inline int nvme_auth_wait(struct nvme_ctrl *ctrl, int qid)
> +{
> +	return NVME_SC_AUTH_REQUIRED;
> +}
> +static inline void nvme_auth_free(struct nvme_ctrl *ctrl) {};
> +#endif
> +
>   u32 nvme_command_effects(struct nvme_ctrl *ctrl, struct nvme_ns *ns,
>   			 u8 opcode);
>   int nvme_execute_passthru_rq(struct request *rq);
> diff --git a/drivers/nvme/host/trace.c b/drivers/nvme/host/trace.c
> index 2a89c5aa0790..1c36fcedea20 100644
> --- a/drivers/nvme/host/trace.c
> +++ b/drivers/nvme/host/trace.c
> @@ -287,6 +287,34 @@ static const char *nvme_trace_fabrics_property_get(struct trace_seq *p, u8 *spc)
>   	return ret;
>   }
>   
> +static const char *nvme_trace_fabrics_auth_send(struct trace_seq *p, u8 *spc)
> +{
> +	const char *ret = trace_seq_buffer_ptr(p);
> +	u8 spsp0 = spc[1];
> +	u8 spsp1 = spc[2];
> +	u8 secp = spc[3];
> +	u32 tl = get_unaligned_le32(spc + 4);
> +
> +	trace_seq_printf(p, "spsp0=%02x, spsp1=%02x, secp=%02x, tl=%u",
> +			 spsp0, spsp1, secp, tl);
> +	trace_seq_putc(p, 0);
> +	return ret;
> +}
> +
> +static const char *nvme_trace_fabrics_auth_receive(struct trace_seq *p, u8 *spc)
> +{
> +	const char *ret = trace_seq_buffer_ptr(p);
> +	u8 spsp0 = spc[1];
> +	u8 spsp1 = spc[2];
> +	u8 secp = spc[3];
> +	u32 al = get_unaligned_le32(spc + 4);
> +
> +	trace_seq_printf(p, "spsp0=%02x, spsp1=%02x, secp=%02x, al=%u",
> +			 spsp0, spsp1, secp, al);
> +	trace_seq_putc(p, 0);
> +	return ret;
> +}
> +
>   static const char *nvme_trace_fabrics_common(struct trace_seq *p, u8 *spc)
>   {
>   	const char *ret = trace_seq_buffer_ptr(p);
> @@ -306,6 +334,10 @@ const char *nvme_trace_parse_fabrics_cmd(struct trace_seq *p,
>   		return nvme_trace_fabrics_connect(p, spc);
>   	case nvme_fabrics_type_property_get:
>   		return nvme_trace_fabrics_property_get(p, spc);
> +	case nvme_fabrics_type_auth_send:
> +		return nvme_trace_fabrics_auth_send(p, spc);
> +	case nvme_fabrics_type_auth_receive:
> +		return nvme_trace_fabrics_auth_receive(p, spc);
>   	default:
>   		return nvme_trace_fabrics_common(p, spc);
>   	}
>