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|
// SPDX-License-Identifier: GPL-2.0
/*
* NVMe over Fabrics DH-HMAC-CHAP authentication.
* Copyright (c) 2020 Hannes Reinecke, SUSE Software Solutions.
* All rights reserved.
*/
#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 <asm/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 (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) {
/* Validate selected hash algorithm */
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;
if (set_ctrl) {
host->dhchap_ctrl_secret = strim(dhchap_secret);
host->dhchap_ctrl_key_hash = key_hash;
} else {
host->dhchap_secret = strim(dhchap_secret);
host->dhchap_key_hash = key_hash;
}
return 0;
}
int nvmet_setup_auth(struct nvmet_ctrl *ctrl)
{
int ret = 0;
struct nvmet_host_link *p;
struct nvmet_host *host = NULL;
const char *hash_name;
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 = -EPERM;
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 {
hash_name = nvme_auth_hmac_name(host->dhchap_hash_id);
if (!hash_name) {
pr_warn("Hash ID %d invalid\n", host->dhchap_hash_id);
ret = -EINVAL;
goto out_unlock;
}
ctrl->shash_id = host->dhchap_hash_id;
}
/* Skip the 'DHHC-1:XX:' prefix */
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 = PTR_ERR(ctrl->host_key);
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 = PTR_ERR(ctrl->ctrl_key);
ctrl->ctrl_key = NULL;
}
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)
{
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->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;
}
}
bool nvmet_check_auth_status(struct nvmet_req *req)
{
if (req->sq->ctrl->host_key &&
!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;
struct shash_desc *shash;
struct nvmet_ctrl *ctrl = req->sq->ctrl;
const char *hash_name;
u8 *challenge = req->sq->dhchap_c1, *host_response;
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;
}
host_response = nvme_auth_transform_key(ctrl->host_key, ctrl->hostnqn);
if (IS_ERR(host_response)) {
ret = PTR_ERR(host_response);
goto out_free_tfm;
}
ret = crypto_shash_setkey(shash_tfm, host_response,
ctrl->host_key->len);
if (ret)
goto out_free_response;
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 = kzalloc(sizeof(*shash) + crypto_shash_descsize(shash_tfm),
GFP_KERNEL);
if (!shash) {
ret = -ENOMEM;
goto out_free_response;
}
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;
memset(buf, 0, 4);
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->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->subsysnqn,
strlen(ctrl->subsysnqn));
if (ret)
goto out;
ret = crypto_shash_final(shash, response);
out:
if (challenge != req->sq->dhchap_c1)
kfree(challenge);
kfree(shash);
out_free_response:
kfree_sensitive(host_response);
out_free_tfm:
crypto_free_shash(shash_tfm);
return 0;
}
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, *ctrl_response;
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;
}
ctrl_response = nvme_auth_transform_key(ctrl->ctrl_key,
ctrl->subsysnqn);
if (IS_ERR(ctrl_response)) {
ret = PTR_ERR(ctrl_response);
goto out_free_tfm;
}
ret = crypto_shash_setkey(shash_tfm, ctrl_response,
ctrl->ctrl_key->len);
if (ret)
goto out_free_response;
shash = kzalloc(sizeof(*shash) + crypto_shash_descsize(shash_tfm),
GFP_KERNEL);
if (!shash) {
ret = -ENOMEM;
goto out_free_response;
}
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->subsysnqn,
strlen(ctrl->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:
if (challenge != req->sq->dhchap_c2)
kfree(challenge);
kfree(shash);
out_free_response:
kfree_sensitive(ctrl_response);
out_free_tfm:
crypto_free_shash(shash_tfm);
return 0;
}
|
