#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/module.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <crypto/hash.h>
#include <linux/crc32.h>
#include <linux/base64.h>
#include <linux/ctype.h>
#include <linux/random.h>
#include <linux/nvme-auth.h>
#include <linux/nvme-keyring.h>
#include <linux/unaligned.h>
#include "nvmet.h"
int nvmet_auth_set_key(struct nvmet_host *host, const char *secret,
bool set_ctrl)
{
unsigned char key_hash;
char *dhchap_secret;
if (!strlen(secret)) {
if (set_ctrl) {
kfree(host->dhchap_ctrl_secret);
host->dhchap_ctrl_secret = NULL;
host->dhchap_ctrl_key_hash = 0;
} else {
kfree(host->dhchap_secret);
host->dhchap_secret = NULL;
host->dhchap_key_hash = 0;
}
return 0;
}
if (sscanf(secret, "DHHC-1:%hhd:%*s", &key_hash) != 1)
return -EINVAL;
if (key_hash > 3) {
pr_warn("Invalid DH-HMAC-CHAP hash id %d\n",
key_hash);
return -EINVAL;
}
if (key_hash > 0) {
const char *hmac = nvme_auth_hmac_name(key_hash);
if (!crypto_has_shash(hmac, 0, 0)) {
pr_err("DH-HMAC-CHAP hash %s unsupported\n", hmac);
return -ENOTSUPP;
}
}
dhchap_secret = kstrdup(secret, GFP_KERNEL);
if (!dhchap_secret)
return -ENOMEM;
down_write(&nvmet_config_sem);
if (set_ctrl) {
kfree(host->dhchap_ctrl_secret);
host->dhchap_ctrl_secret = strim(dhchap_secret);
host->dhchap_ctrl_key_hash = key_hash;
} else {
kfree(host->dhchap_secret);
host->dhchap_secret = strim(dhchap_secret);
host->dhchap_key_hash = key_hash;
}
up_write(&nvmet_config_sem);
return 0;
}
int nvmet_setup_dhgroup(struct nvmet_ctrl *ctrl, u8 dhgroup_id)
{
const char *dhgroup_kpp;
int ret = 0;
pr_debug("%s: ctrl %d selecting dhgroup %d\n",
__func__, ctrl->cntlid, dhgroup_id);
if (ctrl->dh_tfm) {
if (ctrl->dh_gid == dhgroup_id) {
pr_debug("%s: ctrl %d reuse existing DH group %d\n",
__func__, ctrl->cntlid, dhgroup_id);
return 0;
}
crypto_free_kpp(ctrl->dh_tfm);
ctrl->dh_tfm = NULL;
ctrl->dh_gid = 0;
}
if (dhgroup_id == NVME_AUTH_DHGROUP_NULL)
return 0;
dhgroup_kpp = nvme_auth_dhgroup_kpp(dhgroup_id);
if (!dhgroup_kpp) {
pr_debug("%s: ctrl %d invalid DH group %d\n",
__func__, ctrl->cntlid, dhgroup_id);
return -EINVAL;
}
ctrl->dh_tfm = crypto_alloc_kpp(dhgroup_kpp, 0, 0);
if (IS_ERR(ctrl->dh_tfm)) {
pr_debug("%s: ctrl %d failed to setup DH group %d, err %ld\n",
__func__, ctrl->cntlid, dhgroup_id,
PTR_ERR(ctrl->dh_tfm));
ret = PTR_ERR(ctrl->dh_tfm);
ctrl->dh_tfm = NULL;
ctrl->dh_gid = 0;
} else {
ctrl->dh_gid = dhgroup_id;
pr_debug("%s: ctrl %d setup DH group %d\n",
__func__, ctrl->cntlid, ctrl->dh_gid);
ret = nvme_auth_gen_privkey(ctrl->dh_tfm, ctrl->dh_gid);
if (ret < 0) {
pr_debug("%s: ctrl %d failed to generate private key, err %d\n",
__func__, ctrl->cntlid, ret);
kfree_sensitive(ctrl->dh_key);
ctrl->dh_key = NULL;
return ret;
}
ctrl->dh_keysize = crypto_kpp_maxsize(ctrl->dh_tfm);
kfree_sensitive(ctrl->dh_key);
ctrl->dh_key = kzalloc(ctrl->dh_keysize, GFP_KERNEL);
if (!ctrl->dh_key) {
pr_warn("ctrl %d failed to allocate public key\n",
ctrl->cntlid);
return -ENOMEM;
}
ret = nvme_auth_gen_pubkey(ctrl->dh_tfm, ctrl->dh_key,
ctrl->dh_keysize);
if (ret < 0) {
pr_warn("ctrl %d failed to generate public key\n",
ctrl->cntlid);
kfree(ctrl->dh_key);
ctrl->dh_key = NULL;
}
}
return ret;
}
u8 nvmet_setup_auth(struct nvmet_ctrl *ctrl, struct nvmet_sq *sq)
{
int ret = 0;
struct nvmet_host_link *p;
struct nvmet_host *host = NULL;
down_read(&nvmet_config_sem);
if (nvmet_is_disc_subsys(ctrl->subsys))
goto out_unlock;
if (ctrl->subsys->allow_any_host)
goto out_unlock;
list_for_each_entry(p, &ctrl->subsys->hosts, entry) {
pr_debug("check %s\n", nvmet_host_name(p->host));
if (strcmp(nvmet_host_name(p->host), ctrl->hostnqn))
continue;
host = p->host;
break;
}
if (!host) {
pr_debug("host %s not found\n", ctrl->hostnqn);
ret = NVME_AUTH_DHCHAP_FAILURE_FAILED;
goto out_unlock;
}
if (nvmet_queue_tls_keyid(sq)) {
pr_debug("host %s tls enabled\n", ctrl->hostnqn);
goto out_unlock;
}
ret = nvmet_setup_dhgroup(ctrl, host->dhchap_dhgroup_id);
if (ret < 0) {
pr_warn("Failed to setup DH group");
ret = NVME_AUTH_DHCHAP_FAILURE_DHGROUP_UNUSABLE;
goto out_unlock;
}
if (!host->dhchap_secret) {
pr_debug("No authentication provided\n");
goto out_unlock;
}
if (host->dhchap_hash_id == ctrl->shash_id) {
pr_debug("Re-use existing hash ID %d\n",
ctrl->shash_id);
} else {
ctrl->shash_id = host->dhchap_hash_id;
}
nvme_auth_free_key(ctrl->host_key);
ctrl->host_key = nvme_auth_extract_key(host->dhchap_secret + 10,
host->dhchap_key_hash);
if (IS_ERR(ctrl->host_key)) {
ret = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
ctrl->host_key = NULL;
goto out_free_hash;
}
pr_debug("%s: using hash %s key %*ph\n", __func__,
ctrl->host_key->hash > 0 ?
nvme_auth_hmac_name(ctrl->host_key->hash) : "none",
(int)ctrl->host_key->len, ctrl->host_key->key);
nvme_auth_free_key(ctrl->ctrl_key);
if (!host->dhchap_ctrl_secret) {
ctrl->ctrl_key = NULL;
goto out_unlock;
}
ctrl->ctrl_key = nvme_auth_extract_key(host->dhchap_ctrl_secret + 10,
host->dhchap_ctrl_key_hash);
if (IS_ERR(ctrl->ctrl_key)) {
ret = NVME_AUTH_DHCHAP_FAILURE_NOT_USABLE;
ctrl->ctrl_key = NULL;
goto out_free_hash;
}
pr_debug("%s: using ctrl hash %s key %*ph\n", __func__,
ctrl->ctrl_key->hash > 0 ?
nvme_auth_hmac_name(ctrl->ctrl_key->hash) : "none",
(int)ctrl->ctrl_key->len, ctrl->ctrl_key->key);
out_free_hash:
if (ret) {
if (ctrl->host_key) {
nvme_auth_free_key(ctrl->host_key);
ctrl->host_key = NULL;
}
ctrl->shash_id = 0;
}
out_unlock:
up_read(&nvmet_config_sem);
return ret;
}
void nvmet_auth_sq_free(struct nvmet_sq *sq)
{
cancel_delayed_work(&sq->auth_expired_work);
#ifdef CONFIG_NVME_TARGET_TCP_TLS
sq->tls_key = NULL;
#endif
kfree(sq->dhchap_c1);
sq->dhchap_c1 = NULL;
kfree(sq->dhchap_c2);
sq->dhchap_c2 = NULL;
kfree(sq->dhchap_skey);
sq->dhchap_skey = NULL;
}
void nvmet_destroy_auth(struct nvmet_ctrl *ctrl)
{
ctrl->shash_id = 0;
if (ctrl->dh_tfm) {
crypto_free_kpp(ctrl->dh_tfm);
ctrl->dh_tfm = NULL;
ctrl->dh_gid = 0;
}
kfree_sensitive(ctrl->dh_key);
ctrl->dh_key = NULL;
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;
}
#ifdef CONFIG_NVME_TARGET_TCP_TLS
if (ctrl->tls_key) {
key_put(ctrl->tls_key);
ctrl->tls_key = NULL;
}
#endif
}
bool nvmet_check_auth_status(struct nvmet_req *req)
{
if (req->sq->ctrl->host_key) {
if (req->sq->qid > 0)
return true;
if (!req->sq->authenticated)
return false;
}
return true;
}
int nvmet_auth_host_hash(struct nvmet_req *req, u8 *response,
unsigned int shash_len)
{
struct crypto_shash *shash_tfm;
SHASH_DESC_ON_STACK(shash, shash_tfm);
struct nvmet_ctrl *ctrl = req->sq->ctrl;
const char *hash_name;
u8 *challenge = req->sq->dhchap_c1;
struct nvme_dhchap_key *transformed_key;
u8 buf[4];
int ret;
hash_name = nvme_auth_hmac_name(ctrl->shash_id);
if (!hash_name) {
pr_warn("Hash ID %d invalid\n", ctrl->shash_id);
return -EINVAL;
}
shash_tfm = crypto_alloc_shash(hash_name, 0, 0);
if (IS_ERR(shash_tfm)) {
pr_err("failed to allocate shash %s\n", hash_name);
return PTR_ERR(shash_tfm);
}
if (shash_len != crypto_shash_digestsize(shash_tfm)) {
pr_err("%s: hash len mismatch (len %d digest %d)\n",
__func__, shash_len,
crypto_shash_digestsize(shash_tfm));
ret = -EINVAL;
goto out_free_tfm;
}
transformed_key = nvme_auth_transform_key(ctrl->host_key,
ctrl->hostnqn);
if (IS_ERR(transformed_key)) {
ret = PTR_ERR(transformed_key);
goto out_free_tfm;
}
ret = crypto_shash_setkey(shash_tfm, transformed_key->key,
transformed_key->len);
if (ret)
goto out_free_response;
if (ctrl->dh_gid != NVME_AUTH_DHGROUP_NULL) {
challenge = kmalloc(shash_len, GFP_KERNEL);
if (!challenge) {
ret = -ENOMEM;
goto out_free_response;
}
ret = nvme_auth_augmented_challenge(ctrl->shash_id,
req->sq->dhchap_skey,
req->sq->dhchap_skey_len,
req->sq->dhchap_c1,
challenge, shash_len);
if (ret)
goto out;
}
pr_debug("ctrl %d qid %d host response seq %u transaction %d\n",
ctrl->cntlid, req->sq->qid, req->sq->dhchap_s1,
req->sq->dhchap_tid);
shash->tfm = shash_tfm;
ret = crypto_shash_init(shash);
if (ret)
goto out;
ret = crypto_shash_update(shash, challenge, shash_len);
if (ret)
goto out;
put_unaligned_le32(req->sq->dhchap_s1, buf);
ret = crypto_shash_update(shash, buf, 4);
if (ret)
goto out;
put_unaligned_le16(req->sq->dhchap_tid, buf);
ret = crypto_shash_update(shash, buf, 2);
if (ret)
goto out;
*buf = req->sq->sc_c;
ret = crypto_shash_update(shash, buf, 1);
if (ret)
goto out;
ret = crypto_shash_update(shash, "HostHost", 8);
if (ret)
goto out;
memset(buf, 0, 4);
ret = crypto_shash_update(shash, ctrl->hostnqn, strlen(ctrl->hostnqn));
if (ret)
goto out;
ret = crypto_shash_update(shash, buf, 1);
if (ret)
goto out;
ret = crypto_shash_update(shash, ctrl->subsys->subsysnqn,
strlen(ctrl->subsys->subsysnqn));
if (ret)
goto out;
ret = crypto_shash_final(shash, response);
out:
if (challenge != req->sq->dhchap_c1)
kfree(challenge);
out_free_response:
nvme_auth_free_key(transformed_key);
out_free_tfm:
crypto_free_shash(shash_tfm);
return ret;
}
int nvmet_auth_ctrl_hash(struct nvmet_req *req, u8 *response,
unsigned int shash_len)
{
struct crypto_shash *shash_tfm;
struct shash_desc *shash;
struct nvmet_ctrl *ctrl = req->sq->ctrl;
const char *hash_name;
u8 *challenge = req->sq->dhchap_c2;
struct nvme_dhchap_key *transformed_key;
u8 buf[4];
int ret;
hash_name = nvme_auth_hmac_name(ctrl->shash_id);
if (!hash_name) {
pr_warn("Hash ID %d invalid\n", ctrl->shash_id);
return -EINVAL;
}
shash_tfm = crypto_alloc_shash(hash_name, 0, 0);
if (IS_ERR(shash_tfm)) {
pr_err("failed to allocate shash %s\n", hash_name);
return PTR_ERR(shash_tfm);
}
if (shash_len != crypto_shash_digestsize(shash_tfm)) {
pr_debug("%s: hash len mismatch (len %d digest %d)\n",
__func__, shash_len,
crypto_shash_digestsize(shash_tfm));
ret = -EINVAL;
goto out_free_tfm;
}
transformed_key = nvme_auth_transform_key(ctrl->ctrl_key,
ctrl->subsys->subsysnqn);
if (IS_ERR(transformed_key)) {
ret = PTR_ERR(transformed_key);
goto out_free_tfm;
}
ret = crypto_shash_setkey(shash_tfm, transformed_key->key,
transformed_key->len);
if (ret)
goto out_free_response;
if (ctrl->dh_gid != NVME_AUTH_DHGROUP_NULL) {
challenge = kmalloc(shash_len, GFP_KERNEL);
if (!challenge) {
ret = -ENOMEM;
goto out_free_response;
}
ret = nvme_auth_augmented_challenge(ctrl->shash_id,
req->sq->dhchap_skey,
req->sq->dhchap_skey_len,
req->sq->dhchap_c2,
challenge, shash_len);
if (ret)
goto out_free_challenge;
}
shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(shash_tfm),
GFP_KERNEL);
if (!shash) {
ret = -ENOMEM;
goto out_free_challenge;
}
shash->tfm = shash_tfm;
ret = crypto_shash_init(shash);
if (ret)
goto out;
ret = crypto_shash_update(shash, challenge, shash_len);
if (ret)
goto out;
put_unaligned_le32(req->sq->dhchap_s2, buf);
ret = crypto_shash_update(shash, buf, 4);
if (ret)
goto out;
put_unaligned_le16(req->sq->dhchap_tid, 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->subsys->subsysnqn,
strlen(ctrl->subsys->subsysnqn));
if (ret)
goto out;
ret = crypto_shash_update(shash, buf, 1);
if (ret)
goto out;
ret = crypto_shash_update(shash, ctrl->hostnqn, strlen(ctrl->hostnqn));
if (ret)
goto out;
ret = crypto_shash_final(shash, response);
out:
kfree(shash);
out_free_challenge:
if (challenge != req->sq->dhchap_c2)
kfree(challenge);
out_free_response:
nvme_auth_free_key(transformed_key);
out_free_tfm:
crypto_free_shash(shash_tfm);
return ret;
}
int nvmet_auth_ctrl_exponential(struct nvmet_req *req,
u8 *buf, int buf_size)
{
struct nvmet_ctrl *ctrl = req->sq->ctrl;
int ret = 0;
if (!ctrl->dh_key) {
pr_warn("ctrl %d no DH public key!\n", ctrl->cntlid);
return -ENOKEY;
}
if (buf_size != ctrl->dh_keysize) {
pr_warn("ctrl %d DH public key size mismatch, need %zu is %d\n",
ctrl->cntlid, ctrl->dh_keysize, buf_size);
ret = -EINVAL;
} else {
memcpy(buf, ctrl->dh_key, buf_size);
pr_debug("%s: ctrl %d public key %*ph\n", __func__,
ctrl->cntlid, (int)buf_size, buf);
}
return ret;
}
int nvmet_auth_ctrl_sesskey(struct nvmet_req *req,
u8 *pkey, int pkey_size)
{
struct nvmet_ctrl *ctrl = req->sq->ctrl;
int ret;
req->sq->dhchap_skey_len = ctrl->dh_keysize;
req->sq->dhchap_skey = kzalloc(req->sq->dhchap_skey_len, GFP_KERNEL);
if (!req->sq->dhchap_skey)
return -ENOMEM;
ret = nvme_auth_gen_shared_secret(ctrl->dh_tfm,
pkey, pkey_size,
req->sq->dhchap_skey,
req->sq->dhchap_skey_len);
if (ret)
pr_debug("failed to compute shared secret, err %d\n", ret);
else
pr_debug("%s: shared secret %*ph\n", __func__,
(int)req->sq->dhchap_skey_len,
req->sq->dhchap_skey);
return ret;
}
void nvmet_auth_insert_psk(struct nvmet_sq *sq)
{
int hash_len = nvme_auth_hmac_hash_len(sq->ctrl->shash_id);
u8 *psk, *digest, *tls_psk;
size_t psk_len;
int ret;
#ifdef CONFIG_NVME_TARGET_TCP_TLS
struct key *tls_key = NULL;
#endif
ret = nvme_auth_generate_psk(sq->ctrl->shash_id,
sq->dhchap_skey,
sq->dhchap_skey_len,
sq->dhchap_c1, sq->dhchap_c2,
hash_len, &psk, &psk_len);
if (ret) {
pr_warn("%s: ctrl %d qid %d failed to generate PSK, error %d\n",
__func__, sq->ctrl->cntlid, sq->qid, ret);
return;
}
ret = nvme_auth_generate_digest(sq->ctrl->shash_id, psk, psk_len,
sq->ctrl->subsys->subsysnqn,
sq->ctrl->hostnqn, &digest);
if (ret) {
pr_warn("%s: ctrl %d qid %d failed to generate digest, error %d\n",
__func__, sq->ctrl->cntlid, sq->qid, ret);
goto out_free_psk;
}
ret = nvme_auth_derive_tls_psk(sq->ctrl->shash_id, psk, psk_len,
digest, &tls_psk);
if (ret) {
pr_warn("%s: ctrl %d qid %d failed to derive TLS PSK, error %d\n",
__func__, sq->ctrl->cntlid, sq->qid, ret);
goto out_free_digest;
}
#ifdef CONFIG_NVME_TARGET_TCP_TLS
tls_key = nvme_tls_psk_refresh(NULL, sq->ctrl->hostnqn,
sq->ctrl->subsys->subsysnqn,
sq->ctrl->shash_id, tls_psk, psk_len,
digest);
if (IS_ERR(tls_key)) {
pr_warn("%s: ctrl %d qid %d failed to refresh key, error %ld\n",
__func__, sq->ctrl->cntlid, sq->qid, PTR_ERR(tls_key));
tls_key = NULL;
}
if (sq->ctrl->tls_key)
key_put(sq->ctrl->tls_key);
sq->ctrl->tls_key = tls_key;
#endif
kfree_sensitive(tls_psk);
out_free_digest:
kfree_sensitive(digest);
out_free_psk:
kfree_sensitive(psk);
}
