diff options
Diffstat (limited to 'drivers/nvme/common/auth.c')
| -rw-r--r-- | drivers/nvme/common/auth.c | 483 |
1 files changed, 483 insertions, 0 deletions
diff --git a/drivers/nvme/common/auth.c b/drivers/nvme/common/auth.c new file mode 100644 index 000000000..d90e4f0c0 --- /dev/null +++ b/drivers/nvme/common/auth.c @@ -0,0 +1,483 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (c) 2020 Hannes Reinecke, SUSE Linux + */ + +#include <linux/module.h> +#include <linux/crc32.h> +#include <linux/base64.h> +#include <linux/prandom.h> +#include <linux/scatterlist.h> +#include <asm/unaligned.h> +#include <crypto/hash.h> +#include <crypto/dh.h> +#include <linux/nvme.h> +#include <linux/nvme-auth.h> + +static u32 nvme_dhchap_seqnum; +static DEFINE_MUTEX(nvme_dhchap_mutex); + +u32 nvme_auth_get_seqnum(void) +{ + u32 seqnum; + + mutex_lock(&nvme_dhchap_mutex); + if (!nvme_dhchap_seqnum) + nvme_dhchap_seqnum = get_random_u32(); + else { + nvme_dhchap_seqnum++; + if (!nvme_dhchap_seqnum) + nvme_dhchap_seqnum++; + } + seqnum = nvme_dhchap_seqnum; + mutex_unlock(&nvme_dhchap_mutex); + return seqnum; +} +EXPORT_SYMBOL_GPL(nvme_auth_get_seqnum); + +static struct nvme_auth_dhgroup_map { + const char name[16]; + const char kpp[16]; +} dhgroup_map[] = { + [NVME_AUTH_DHGROUP_NULL] = { + .name = "null", .kpp = "null" }, + [NVME_AUTH_DHGROUP_2048] = { + .name = "ffdhe2048", .kpp = "ffdhe2048(dh)" }, + [NVME_AUTH_DHGROUP_3072] = { + .name = "ffdhe3072", .kpp = "ffdhe3072(dh)" }, + [NVME_AUTH_DHGROUP_4096] = { + .name = "ffdhe4096", .kpp = "ffdhe4096(dh)" }, + [NVME_AUTH_DHGROUP_6144] = { + .name = "ffdhe6144", .kpp = "ffdhe6144(dh)" }, + [NVME_AUTH_DHGROUP_8192] = { + .name = "ffdhe8192", .kpp = "ffdhe8192(dh)" }, +}; + +const char *nvme_auth_dhgroup_name(u8 dhgroup_id) +{ + if (dhgroup_id >= ARRAY_SIZE(dhgroup_map)) + return NULL; + return dhgroup_map[dhgroup_id].name; +} +EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_name); + +const char *nvme_auth_dhgroup_kpp(u8 dhgroup_id) +{ + if (dhgroup_id >= ARRAY_SIZE(dhgroup_map)) + return NULL; + return dhgroup_map[dhgroup_id].kpp; +} +EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_kpp); + +u8 nvme_auth_dhgroup_id(const char *dhgroup_name) +{ + int i; + + if (!dhgroup_name || !strlen(dhgroup_name)) + return NVME_AUTH_DHGROUP_INVALID; + for (i = 0; i < ARRAY_SIZE(dhgroup_map); i++) { + if (!strlen(dhgroup_map[i].name)) + continue; + if (!strncmp(dhgroup_map[i].name, dhgroup_name, + strlen(dhgroup_map[i].name))) + return i; + } + return NVME_AUTH_DHGROUP_INVALID; +} +EXPORT_SYMBOL_GPL(nvme_auth_dhgroup_id); + +static struct nvme_dhchap_hash_map { + int len; + const char hmac[15]; + const char digest[8]; +} hash_map[] = { + [NVME_AUTH_HASH_SHA256] = { + .len = 32, + .hmac = "hmac(sha256)", + .digest = "sha256", + }, + [NVME_AUTH_HASH_SHA384] = { + .len = 48, + .hmac = "hmac(sha384)", + .digest = "sha384", + }, + [NVME_AUTH_HASH_SHA512] = { + .len = 64, + .hmac = "hmac(sha512)", + .digest = "sha512", + }, +}; + +const char *nvme_auth_hmac_name(u8 hmac_id) +{ + if (hmac_id >= ARRAY_SIZE(hash_map)) + return NULL; + return hash_map[hmac_id].hmac; +} +EXPORT_SYMBOL_GPL(nvme_auth_hmac_name); + +const char *nvme_auth_digest_name(u8 hmac_id) +{ + if (hmac_id >= ARRAY_SIZE(hash_map)) + return NULL; + return hash_map[hmac_id].digest; +} +EXPORT_SYMBOL_GPL(nvme_auth_digest_name); + +u8 nvme_auth_hmac_id(const char *hmac_name) +{ + int i; + + if (!hmac_name || !strlen(hmac_name)) + return NVME_AUTH_HASH_INVALID; + + for (i = 0; i < ARRAY_SIZE(hash_map); i++) { + if (!strlen(hash_map[i].hmac)) + continue; + if (!strncmp(hash_map[i].hmac, hmac_name, + strlen(hash_map[i].hmac))) + return i; + } + return NVME_AUTH_HASH_INVALID; +} +EXPORT_SYMBOL_GPL(nvme_auth_hmac_id); + +size_t nvme_auth_hmac_hash_len(u8 hmac_id) +{ + if (hmac_id >= ARRAY_SIZE(hash_map)) + return 0; + return hash_map[hmac_id].len; +} +EXPORT_SYMBOL_GPL(nvme_auth_hmac_hash_len); + +struct nvme_dhchap_key *nvme_auth_extract_key(unsigned char *secret, + u8 key_hash) +{ + struct nvme_dhchap_key *key; + unsigned char *p; + u32 crc; + int ret, key_len; + size_t allocated_len = strlen(secret); + + /* Secret might be affixed with a ':' */ + p = strrchr(secret, ':'); + if (p) + allocated_len = p - secret; + key = kzalloc(sizeof(*key), GFP_KERNEL); + if (!key) + return ERR_PTR(-ENOMEM); + key->key = kzalloc(allocated_len, GFP_KERNEL); + if (!key->key) { + ret = -ENOMEM; + goto out_free_key; + } + + key_len = base64_decode(secret, allocated_len, key->key); + if (key_len < 0) { + pr_debug("base64 key decoding error %d\n", + key_len); + ret = key_len; + goto out_free_secret; + } + + if (key_len != 36 && key_len != 52 && + key_len != 68) { + pr_err("Invalid key len %d\n", key_len); + ret = -EINVAL; + goto out_free_secret; + } + + if (key_hash > 0 && + (key_len - 4) != nvme_auth_hmac_hash_len(key_hash)) { + pr_err("Mismatched key len %d for %s\n", key_len, + nvme_auth_hmac_name(key_hash)); + ret = -EINVAL; + goto out_free_secret; + } + + /* 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, key_len); + + if (get_unaligned_le32(key->key + key_len) != crc) { + pr_err("key crc mismatch (key %08x, crc %08x)\n", + get_unaligned_le32(key->key + key_len), crc); + ret = -EKEYREJECTED; + goto out_free_secret; + } + key->len = key_len; + key->hash = key_hash; + return key; +out_free_secret: + kfree_sensitive(key->key); +out_free_key: + kfree(key); + return ERR_PTR(ret); +} +EXPORT_SYMBOL_GPL(nvme_auth_extract_key); + +void nvme_auth_free_key(struct nvme_dhchap_key *key) +{ + if (!key) + return; + kfree_sensitive(key->key); + kfree(key); +} +EXPORT_SYMBOL_GPL(nvme_auth_free_key); + +u8 *nvme_auth_transform_key(struct nvme_dhchap_key *key, char *nqn) +{ + const char *hmac_name; + struct crypto_shash *key_tfm; + struct shash_desc *shash; + u8 *transformed_key; + int ret; + + if (!key || !key->key) { + pr_warn("No key specified\n"); + return ERR_PTR(-ENOKEY); + } + if (key->hash == 0) { + transformed_key = kmemdup(key->key, key->len, GFP_KERNEL); + return transformed_key ? transformed_key : ERR_PTR(-ENOMEM); + } + hmac_name = nvme_auth_hmac_name(key->hash); + if (!hmac_name) { + pr_warn("Invalid key hash id %d\n", key->hash); + return ERR_PTR(-EINVAL); + } + + 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) { + ret = -ENOMEM; + goto out_free_key; + } + + 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, key->len); + if (ret < 0) + goto out_free_transformed_key; + ret = crypto_shash_init(shash); + if (ret < 0) + goto out_free_transformed_key; + ret = crypto_shash_update(shash, nqn, strlen(nqn)); + if (ret < 0) + goto out_free_transformed_key; + ret = crypto_shash_update(shash, "NVMe-over-Fabrics", 17); + if (ret < 0) + goto out_free_transformed_key; + ret = crypto_shash_final(shash, transformed_key); + if (ret < 0) + goto out_free_transformed_key; + + kfree(shash); + crypto_free_shash(key_tfm); + + return transformed_key; + +out_free_transformed_key: + kfree_sensitive(transformed_key); +out_free_shash: + kfree(shash); +out_free_key: + crypto_free_shash(key_tfm); + + return ERR_PTR(ret); +} +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 algorithm %d\n", + __func__, hmac_id); + ret = -EINVAL; + goto out_free_key; + } + + tfm = crypto_alloc_shash(hmac_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, 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, u8 dh_gid) +{ + int ret; + + ret = crypto_kpp_set_secret(dh_tfm, NULL, 0); + if (ret) + pr_debug("failed to set private key, error %d\n", ret); + + 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); + 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); + +int nvme_auth_generate_key(u8 *secret, struct nvme_dhchap_key **ret_key) +{ + struct nvme_dhchap_key *key; + u8 key_hash; + + if (!secret) { + *ret_key = NULL; + return 0; + } + + if (sscanf(secret, "DHHC-1:%hhd:%*s:", &key_hash) != 1) + return -EINVAL; + + /* Pass in the secret without the 'DHHC-1:XX:' prefix */ + key = nvme_auth_extract_key(secret + 10, key_hash); + if (IS_ERR(key)) { + *ret_key = NULL; + return PTR_ERR(key); + } + + *ret_key = key; + return 0; +} +EXPORT_SYMBOL_GPL(nvme_auth_generate_key); + +MODULE_LICENSE("GPL v2"); |