diff options
Diffstat (limited to 'drivers/nvme/target/auth.c')
| -rw-r--r-- | drivers/nvme/target/auth.c | 528 |
1 files changed, 528 insertions, 0 deletions
diff --git a/drivers/nvme/target/auth.c b/drivers/nvme/target/auth.c new file mode 100644 index 000000000..4dcddcf95 --- /dev/null +++ b/drivers/nvme/target/auth.c @@ -0,0 +1,528 @@ +// 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) { + 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; + } + 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); + 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; +} + +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; + } + + ret = nvmet_setup_dhgroup(ctrl, host->dhchap_dhgroup_id); + if (ret < 0) + pr_warn("Failed to setup DH group"); + + 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; + 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); + 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; + } +} + +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; + + 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_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; + + 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_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; +} + +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; +} |