Re: [PATCH 07/11] nvme-auth: augmented challenge support

["Stephan Müller" <smueller@chronox.de>]

Am Freitag, 16. Juli 2021, 13:04:24 CEST schrieb Hannes Reinecke:

Hi Hannes,

> Implement support for augmented challenge using FFDHE groups.
> 
> Signed-off-by: Hannes Reinecke <hare@suse.de>
> ---
>  drivers/nvme/host/auth.c | 403 +++++++++++++++++++++++++++++++++++----
>  1 file changed, 371 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/nvme/host/auth.c b/drivers/nvme/host/auth.c
> index 448a3adebea6..754343aced19 100644
> --- a/drivers/nvme/host/auth.c
> +++ b/drivers/nvme/host/auth.c
> @@ -8,6 +8,8 @@
>  #include <asm/unaligned.h>
>  #include <crypto/hash.h>
>  #include <crypto/kpp.h>
> +#include <crypto/dh.h>
> +#include <crypto/ffdhe.h>
>  #include "nvme.h"
>  #include "fabrics.h"
>  #include "auth.h"
> @@ -16,6 +18,8 @@ static u32 nvme_dhchap_seqnum;
> 
>  struct nvme_dhchap_context {
>  	struct crypto_shash *shash_tfm;
> +	struct crypto_shash *digest_tfm;
> +	struct crypto_kpp *dh_tfm;
>  	unsigned char *key;
>  	size_t key_len;
>  	int qid;
> @@ -25,6 +29,8 @@ struct nvme_dhchap_context {
>  	u8 status;
>  	u8 hash_id;
>  	u8 hash_len;
> +	u8 dhgroup_id;
> +	u16 dhgroup_size;
>  	u8 c1[64];
>  	u8 c2[64];
>  	u8 response[64];
> @@ -36,6 +42,94 @@ struct nvme_dhchap_context {
>  	int sess_key_len;
>  };
> 
> +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",
> +	  .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);
> +
>  struct nvmet_dhchap_hash_map {
>  	int id;
>  	int hash_len;
> @@ -243,11 +337,16 @@ static int nvme_auth_dhchap_negotiate(struct nvme_ctrl
> *ctrl, 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 = 1;
> +	data->auth_protocol[0].dhchap.dhlen = 6;
>  	data->auth_protocol[0].dhchap.idlist[0] = NVME_AUTH_DHCHAP_HASH_SHA256;
>  	data->auth_protocol[0].dhchap.idlist[1] = NVME_AUTH_DHCHAP_HASH_SHA384;
>  	data->auth_protocol[0].dhchap.idlist[2] = NVME_AUTH_DHCHAP_HASH_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;
>  }
> @@ -274,14 +373,7 @@ static int nvme_auth_dhchap_challenge(struct nvme_ctrl
> *ctrl, chap->status = NVME_AUTH_DHCHAP_FAILURE_HASH_UNUSABLE;
>  		return -EPROTO;
>  	}
> -	switch (data->dhgid) {
> -	case NVME_AUTH_DHCHAP_DHGROUP_NULL:
> -		gid_name = "null";
> -		break;
> -	default:
> -		gid_name = NULL;
> -		break;
> -	}
> +	gid_name = nvme_auth_dhgroup_kpp(data->dhgid);
>  	if (!gid_name) {
>  		dev_warn(ctrl->device,
>  			 "qid %d: DH-HMAC-CHAP: invalid DH group id %d\n",
> @@ -290,10 +382,24 @@ static int nvme_auth_dhchap_challenge(struct nvme_ctrl
> *ctrl, return -EPROTO;
>  	}
>  	if (data->dhgid != NVME_AUTH_DHCHAP_DHGROUP_NULL) {
> -		chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
> -		return -EPROTO;
> -	}
> -	if (data->dhgid == NVME_AUTH_DHCHAP_DHGROUP_NULL && data->dhvlen != 0) {
> +		if (data->dhvlen == 0) {
> +			dev_warn(ctrl->device,
> +				 "qid %d: DH-HMAC-CHAP: 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)) {
> +			dev_warn(ctrl->device,
> +				 "qid %d: DH-HMAC-CHAP: failed to initialize %s\n",
> +				 chap->qid, gid_name);
> +			chap->status = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
> +			chap->dh_tfm = NULL;
> +			return -EPROTO;
> +		}
> +		chap->dhgroup_id = data->dhgid;
> +	} else if (data->dhvlen != 0) {
>  		dev_warn(ctrl->device,
>  			 "qid %d: DH-HMAC-CHAP: invalid DH value for NULL DH\n",
>  			chap->qid);
> @@ -313,6 +419,16 @@ static int nvme_auth_dhchap_challenge(struct nvme_ctrl
> *ctrl, chap->hash_len = data->hl;
>  	chap->s1 = le32_to_cpu(data->seqnum);
>  	memcpy(chap->c1, data->cval, chap->hash_len);
> +	if (data->dhvlen) {
> +		chap->ctrl_key = kmalloc(data->dhvlen, GFP_KERNEL);
> +		if (!chap->ctrl_key)
> +			return -ENOMEM;
> +		chap->ctrl_key_len = data->dhvlen;
> +		memcpy(chap->ctrl_key, data->cval + chap->hash_len,
> +		       data->dhvlen);
> +		dev_dbg(ctrl->device, "ctrl public key %*ph\n",
> +			 (int)chap->ctrl_key_len, chap->ctrl_key);
> +	}
> 
>  	return 0;
>  }
> @@ -353,10 +469,13 @@ static int nvme_auth_dhchap_reply(struct nvme_ctrl
> *ctrl, memcpy(data->rval + chap->hash_len, chap->c2,
>  		       chap->hash_len);
>  	}
> -	if (chap->host_key_len)
> +	if (chap->host_key_len) {
> +		dev_dbg(ctrl->device, "%s: qid %d host public key %*ph\n",
> +			__func__, chap->qid,
> +			chap->host_key_len, chap->host_key);
>  		memcpy(data->rval + 2 * chap->hash_len, chap->host_key,
>  		       chap->host_key_len);
> -
> +	}
>  	return size;
>  }
> 
> @@ -440,23 +559,10 @@ static int nvme_auth_dhchap_failure2(struct nvme_ctrl
> *ctrl, int nvme_auth_select_hash(struct nvme_ctrl *ctrl,
>  			  struct nvme_dhchap_context *chap)
>  {
> -	char *hash_name;
> +	const char *hash_name, *digest_name;
>  	int ret;
> 
> -	switch (chap->hash_id) {
> -	case NVME_AUTH_DHCHAP_HASH_SHA256:
> -		hash_name = "hmac(sha256)";
> -		break;
> -	case NVME_AUTH_DHCHAP_HASH_SHA384:
> -		hash_name = "hmac(sha384)";
> -		break;
> -	case NVME_AUTH_DHCHAP_HASH_SHA512:
> -		hash_name = "hmac(sha512)";
> -		break;
> -	default:
> -		hash_name = NULL;
> -		break;
> -	}
> +	hash_name = nvme_auth_hmac_name(chap->hash_id);
>  	if (!hash_name) {
>  		chap->status = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
>  		return -EPROTO;
> @@ -468,26 +574,100 @@ int nvme_auth_select_hash(struct nvme_ctrl *ctrl,
>  		chap->shash_tfm = NULL;
>  		return -EPROTO;
>  	}
> +	digest_name = nvme_auth_digest_name(chap->hash_id);
> +	if (!digest_name) {
> +		crypto_free_shash(chap->shash_tfm);
> +		chap->shash_tfm = NULL;
> +		return -EPROTO;
> +	}
> +	chap->digest_tfm = crypto_alloc_shash(digest_name, 0, 0);
> +	if (IS_ERR(chap->digest_tfm)) {
> +		chap->status = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
> +		crypto_free_shash(chap->shash_tfm);
> +		chap->shash_tfm = NULL;
> +		chap->digest_tfm = NULL;
> +		return -EPROTO;
> +	}
>  	if (!chap->key) {
>  		dev_warn(ctrl->device, "qid %d: cannot select hash, no key\n",
>  			 chap->qid);
>  		chap->status = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
> +		crypto_free_shash(chap->digest_tfm);
>  		crypto_free_shash(chap->shash_tfm);
>  		chap->shash_tfm = NULL;
> +		chap->digest_tfm = NULL;
>  		return -EINVAL;
>  	}
>  	ret = crypto_shash_setkey(chap->shash_tfm, chap->key, chap->key_len);
>  	if (ret) {
>  		chap->status = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
> +		crypto_free_shash(chap->digest_tfm);
>  		crypto_free_shash(chap->shash_tfm);
>  		chap->shash_tfm = NULL;
> +		chap->digest_tfm = NULL;
>  		return ret;
>  	}
> -	dev_info(ctrl->device, "qid %d: DH-HMAC_CHAP: selected hash %s\n",
> -		 chap->qid, hash_name);
> +	dev_dbg(ctrl->device, "qid %d: DH-HMAC_CHAP: selected hash %s\n",
> +		chap->qid, hash_name);
>  	return 0;
>  }
> 
> +static int nvme_auth_augmented_challenge(struct nvme_dhchap_context *chap,
> +					 u8 *challenge, u8 *aug)
> +{
> +	struct crypto_shash *tfm;
> +	struct shash_desc *desc;
> +	u8 *hashed_key;
> +	const char *hash_name;
> +	int ret;
> +
> +	hashed_key = kmalloc(chap->hash_len, GFP_KERNEL);
> +	if (!hashed_key)
> +		return -ENOMEM;
> +
> +	ret = crypto_shash_tfm_digest(chap->digest_tfm, chap->sess_key,
> +				      chap->sess_key_len, hashed_key);
> +	if (ret < 0) {
> +		pr_debug("failed to hash session key, err %d\n", ret);
> +		kfree(hashed_key);
> +		return ret;
> +	}
> +	hash_name = crypto_shash_alg_name(chap->shash_tfm);
> +	if (!hash_name) {
> +		pr_debug("Invalid hash algoritm\n");
> +		return -EINVAL;
> +	}
> +	tfm = crypto_alloc_shash(hash_name, 0, 0);
> +	if (IS_ERR(tfm)) {
> +		ret = PTR_ERR(tfm);
> +		goto out_free_key;
> +	}
> +	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, chap->hash_len);
> +	if (ret)
> +		goto out_free_desc;
> +	ret = crypto_shash_init(desc);
> +	if (ret)
> +		goto out_free_desc;
> +	crypto_shash_update(desc, challenge, chap->hash_len);
> +	crypto_shash_final(desc, aug);
> +
> +out_free_desc:
> +	kfree_sensitive(desc);
> +out_free_hash:
> +	crypto_free_shash(tfm);
> +out_free_key:
> +	kfree(hashed_key);
> +	return ret;
> +}
> +
>  static int nvme_auth_dhchap_host_response(struct nvme_ctrl *ctrl,
>  					  struct nvme_dhchap_context *chap)
>  {
> @@ -497,6 +677,16 @@ static int nvme_auth_dhchap_host_response(struct
> nvme_ctrl *ctrl,
> 
>  	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);

Again, alignment?

> +		if (!challenge) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
> +		ret = nvme_auth_augmented_challenge(chap, chap->c1, challenge);
> +		if (ret)
> +			goto out;
> +	}
>  	shash->tfm = chap->shash_tfm;
>  	ret = crypto_shash_init(shash);
>  	if (ret)
> @@ -532,6 +722,8 @@ static int nvme_auth_dhchap_host_response(struct
> nvme_ctrl *ctrl, goto out;
>  	ret = crypto_shash_final(shash, chap->response);
>  out:
> +	if (challenge != chap->c1)
> +		kfree(challenge);
>  	return ret;
>  }
> 
> @@ -542,6 +734,17 @@ static int nvme_auth_dhchap_ctrl_response(struct
> nvme_ctrl *ctrl, u8 buf[4], *challenge = chap->c2;
>  	int ret;
> 
> +	if (chap->dh_tfm) {
> +		challenge = kmalloc(chap->hash_len, GFP_KERNEL);

dto.

> +		if (!challenge) {
> +			ret = -ENOMEM;
> +			goto out;
> +		}
> +		ret = nvme_auth_augmented_challenge(chap, chap->c2,
> +						    challenge);
> +		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",
> @@ -585,6 +788,8 @@ static int nvme_auth_dhchap_ctrl_response(struct
> nvme_ctrl *ctrl, goto out;
>  	ret = crypto_shash_final(shash, chap->response);
>  out:
> +	if (challenge != chap->c2)
> +		kfree(challenge);
>  	return ret;
>  }
> 
> @@ -644,10 +849,134 @@ int nvme_auth_generate_key(struct nvme_ctrl *ctrl,
>  	return 0;
>  }
> 
> +static int nvme_auth_dhchap_exponential(struct nvme_ctrl *ctrl,
> +					struct nvme_dhchap_context *chap)
> +{
> +	struct kpp_request *req;
> +	struct crypto_wait wait;
> +	struct scatterlist src, dst;
> +	u8 *pkey;
> +	int ret, pkey_len;
> +
> +	if (chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_2048 ||
> +	    chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_3072 ||
> +	    chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_4096 ||
> +	    chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_6144 ||
> +	    chap->dhgroup_id == NVME_AUTH_DHCHAP_DHGROUP_8192) {
> +		struct dh p = {0};
> +		int pubkey_size = nvme_auth_dhgroup_pubkey_size(chap->dhgroup_id);
> +
> +		ret = crypto_ffdhe_params(&p, pubkey_size << 3);
> +		if (ret) {
> +			dev_dbg(ctrl->device,
> +				"failed to generate ffdhe params, error %d\n",
> +				ret);
> +			return ret;
> +		}
> +		p.key = chap->key;
> +		p.key_size = chap->key_len;
> +
> +		pkey_len = crypto_dh_key_len(&p);
> +		pkey = kzalloc(pkey_len, GFP_KERNEL);
> +
> +		get_random_bytes(pkey, pkey_len);
> +		ret = crypto_dh_encode_key(pkey, pkey_len, &p);
> +		if (ret) {
> +			dev_dbg(ctrl->device,
> +				"failed to encode pkey, error %d\n", ret);
> +			kfree(pkey);
> +			return ret;
> +		}
> +		chap->host_key_len = pubkey_size;
> +		chap->sess_key_len = pubkey_size;
> +	} else {
> +		dev_warn(ctrl->device, "Invalid DH group id %d\n",
> +			 chap->dhgroup_id);
> +		chap->status = NVME_AUTH_DHCHAP_FAILURE_INVALID_PAYLOAD;
> +		return -EINVAL;
> +	}
> +
> +	ret = crypto_kpp_set_secret(chap->dh_tfm, pkey, pkey_len);
> +	if (ret) {
> +		dev_dbg(ctrl->dev, "failed to set secret, error %d\n", ret);
> +		kfree(pkey);
> +		return ret;
> +	}
> +	req = kpp_request_alloc(chap->dh_tfm, GFP_KERNEL);
> +	if (!req) {
> +		ret = -ENOMEM;
> +		goto out_free_exp;
> +	}
> +
> +	chap->host_key = kzalloc(chap->host_key_len, GFP_KERNEL);
> +	if (!chap->host_key) {
> +		ret = -ENOMEM;
> +		goto out_free_req;
> +	}
> +	crypto_init_wait(&wait);
> +	kpp_request_set_input(req, NULL, 0);
> +	sg_init_one(&dst, chap->host_key, chap->host_key_len);
> +	kpp_request_set_output(req, &dst, chap->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);
> +	if (ret == -EOVERFLOW) {
> +		dev_dbg(ctrl->dev,
> +			"public key buffer too small, wants %d is %d\n",
> +			crypto_kpp_maxsize(chap->dh_tfm), chap->host_key_len);
> +		goto out_free_host;
> +	} else if (ret) {
> +		dev_dbg(ctrl->dev,
> +			"failed to generate public key, error %d\n", ret);
> +		goto out_free_host;
> +	}
> +
> +	chap->sess_key = kmalloc(chap->sess_key_len, GFP_KERNEL);
> +	if (!chap->sess_key)
> +		goto out_free_host;
> +
> +	crypto_init_wait(&wait);
> +	sg_init_one(&src, chap->ctrl_key, chap->ctrl_key_len);
> +	kpp_request_set_input(req, &src, chap->ctrl_key_len);
> +	sg_init_one(&dst, chap->sess_key, chap->sess_key_len);
> +	kpp_request_set_output(req, &dst, chap->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);
> +	if (ret) {
> +		dev_dbg(ctrl->dev,
> +			"failed to generate shared secret, error %d\n", ret);
> +		kfree_sensitive(chap->sess_key);
> +		chap->sess_key = NULL;
> +		chap->sess_key_len = 0;
> +	} else
> +		dev_dbg(ctrl->dev, "shared secret %*ph\n",
> +			 (int)chap->sess_key_len, chap->sess_key);
> +out_free_host:
> +	if (ret) {
> +		kfree(chap->host_key);
> +		chap->host_key = NULL;
> +		chap->host_key_len = 0;
> +	}
> +out_free_req:
> +	kpp_request_free(req);
> +out_free_exp:
> +	kfree_sensitive(pkey);
> +	if (ret)
> +		chap->status = NVME_AUTH_DHCHAP_FAILURE_INVALID_PAYLOAD;
> +	return ret;
> +}
> +
>  void nvme_auth_free(struct nvme_dhchap_context *chap)
>  {
>  	if (chap->shash_tfm)
>  		crypto_free_shash(chap->shash_tfm);
> +	if (chap->digest_tfm)
> +		crypto_free_shash(chap->digest_tfm);
> +	if (chap->dh_tfm)
> +		crypto_free_kpp(chap->dh_tfm);
>  	if (chap->key)
>  		kfree(chap->key);
>  	if (chap->ctrl_key)
> @@ -732,6 +1061,15 @@ int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int
> qid) if (ret)
>  		goto fail2;
> 
> +	if (chap->ctrl_key_len) {
> +		dev_dbg(ctrl->device,
> +			"%s: qid %d DH-HMAC-DHAP DH exponential\n",
> +			__func__, qid);
> +		ret = nvme_auth_dhchap_exponential(ctrl, chap);
> +		if (ret)
> +			goto fail2;
> +	}
> +
>  	dev_dbg(ctrl->device, "%s: qid %d DH-HMAC-CHAP host response\n",
>  		__func__, qid);
>  	ret = nvme_auth_dhchap_host_response(ctrl, chap);
> @@ -806,6 +1144,7 @@ int nvme_auth_negotiate(struct nvme_ctrl *ctrl, int
> qid) ret = -EPROTO;
>  	if (!ret) {
>  		ctrl->dhchap_hash = chap->hash_id;
> +		ctrl->dhchap_dhgroup = chap->dhgroup_id;
>  	}
>  	kfree(buf);
>  	nvme_auth_free(chap);


Ciao
Stephan