blob: d90e4f0c08b7b90201e745663d658afd61b21d57 [file] [log] [blame]
// 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");