diff options
Diffstat (limited to 'drivers/nvme/common')
| -rw-r--r-- | drivers/nvme/common/Kconfig | 1 | ||||
| -rw-r--r-- | drivers/nvme/common/auth.c | 337 | ||||
| -rw-r--r-- | drivers/nvme/common/keyring.c | 65 |
3 files changed, 402 insertions, 1 deletions
diff --git a/drivers/nvme/common/Kconfig b/drivers/nvme/common/Kconfig index 244432e0b73d..da963e4f3f1f 100644 --- a/drivers/nvme/common/Kconfig +++ b/drivers/nvme/common/Kconfig @@ -12,3 +12,4 @@ config NVME_AUTH select CRYPTO_SHA512 select CRYPTO_DH select CRYPTO_DH_RFC7919_GROUPS + select CRYPTO_HKDF diff --git a/drivers/nvme/common/auth.c b/drivers/nvme/common/auth.c index 9b7126e1a19d..2c092ec8c0a9 100644 --- a/drivers/nvme/common/auth.c +++ b/drivers/nvme/common/auth.c @@ -11,9 +11,12 @@ #include <linux/unaligned.h> #include <crypto/hash.h> #include <crypto/dh.h> +#include <crypto/hkdf.h> #include <linux/nvme.h> #include <linux/nvme-auth.h> +#define HKDF_MAX_HASHLEN 64 + static u32 nvme_dhchap_seqnum; static DEFINE_MUTEX(nvme_dhchap_mutex); @@ -471,5 +474,339 @@ int nvme_auth_generate_key(u8 *secret, struct nvme_dhchap_key **ret_key) } EXPORT_SYMBOL_GPL(nvme_auth_generate_key); +/** + * nvme_auth_generate_psk - Generate a PSK for TLS + * @hmac_id: Hash function identifier + * @skey: Session key + * @skey_len: Length of @skey + * @c1: Value of challenge C1 + * @c2: Value of challenge C2 + * @hash_len: Hash length of the hash algorithm + * @ret_psk: Pointer too the resulting generated PSK + * @ret_len: length of @ret_psk + * + * Generate a PSK for TLS as specified in NVMe base specification, section + * 8.13.5.9: Generated PSK for TLS + * + * The generated PSK for TLS shall be computed applying the HMAC function + * using the hash function H( ) selected by the HashID parameter in the + * DH-HMAC-CHAP_Challenge message with the session key KS as key to the + * concatenation of the two challenges C1 and C2 (i.e., generated + * PSK = HMAC(KS, C1 || C2)). + * + * Returns 0 on success with a valid generated PSK pointer in @ret_psk and + * the length of @ret_psk in @ret_len, or a negative error number otherwise. + */ +int nvme_auth_generate_psk(u8 hmac_id, u8 *skey, size_t skey_len, + u8 *c1, u8 *c2, size_t hash_len, u8 **ret_psk, size_t *ret_len) +{ + struct crypto_shash *tfm; + SHASH_DESC_ON_STACK(shash, tfm); + u8 *psk; + const char *hmac_name; + int ret, psk_len; + + if (!c1 || !c2) + return -EINVAL; + + hmac_name = nvme_auth_hmac_name(hmac_id); + if (!hmac_name) { + pr_warn("%s: invalid hash algorithm %d\n", + __func__, hmac_id); + return -EINVAL; + } + + tfm = crypto_alloc_shash(hmac_name, 0, 0); + if (IS_ERR(tfm)) + return PTR_ERR(tfm); + + psk_len = crypto_shash_digestsize(tfm); + psk = kzalloc(psk_len, GFP_KERNEL); + if (!psk) { + ret = -ENOMEM; + goto out_free_tfm; + } + + shash->tfm = tfm; + ret = crypto_shash_setkey(tfm, skey, skey_len); + if (ret) + goto out_free_psk; + + ret = crypto_shash_init(shash); + if (ret) + goto out_free_psk; + + ret = crypto_shash_update(shash, c1, hash_len); + if (ret) + goto out_free_psk; + + ret = crypto_shash_update(shash, c2, hash_len); + if (ret) + goto out_free_psk; + + ret = crypto_shash_final(shash, psk); + if (!ret) { + *ret_psk = psk; + *ret_len = psk_len; + } + +out_free_psk: + if (ret) + kfree_sensitive(psk); +out_free_tfm: + crypto_free_shash(tfm); + + return ret; +} +EXPORT_SYMBOL_GPL(nvme_auth_generate_psk); + +/** + * nvme_auth_generate_digest - Generate TLS PSK digest + * @hmac_id: Hash function identifier + * @psk: Generated input PSK + * @psk_len: Length of @psk + * @subsysnqn: NQN of the subsystem + * @hostnqn: NQN of the host + * @ret_digest: Pointer to the returned digest + * + * Generate a TLS PSK digest as specified in TP8018 Section 3.6.1.3: + * TLS PSK and PSK identity Derivation + * + * The PSK digest shall be computed by encoding in Base64 (refer to RFC + * 4648) the result of the application of the HMAC function using the hash + * function specified in item 4 above (ie the hash function of the cipher + * suite associated with the PSK identity) with the PSK as HMAC key to the + * concatenation of: + * - the NQN of the host (i.e., NQNh) not including the null terminator; + * - a space character; + * - the NQN of the NVM subsystem (i.e., NQNc) not including the null + * terminator; + * - a space character; and + * - the seventeen ASCII characters "NVMe-over-Fabrics" + * (i.e., <PSK digest> = Base64(HMAC(PSK, NQNh || " " || NQNc || " " || + * "NVMe-over-Fabrics"))). + * The length of the PSK digest depends on the hash function used to compute + * it as follows: + * - If the SHA-256 hash function is used, the resulting PSK digest is 44 + * characters long; or + * - If the SHA-384 hash function is used, the resulting PSK digest is 64 + * characters long. + * + * Returns 0 on success with a valid digest pointer in @ret_digest, or a + * negative error number on failure. + */ +int nvme_auth_generate_digest(u8 hmac_id, u8 *psk, size_t psk_len, + char *subsysnqn, char *hostnqn, u8 **ret_digest) +{ + struct crypto_shash *tfm; + SHASH_DESC_ON_STACK(shash, tfm); + u8 *digest, *enc; + const char *hmac_name; + size_t digest_len, hmac_len; + int ret; + + if (WARN_ON(!subsysnqn || !hostnqn)) + return -EINVAL; + + hmac_name = nvme_auth_hmac_name(hmac_id); + if (!hmac_name) { + pr_warn("%s: invalid hash algorithm %d\n", + __func__, hmac_id); + return -EINVAL; + } + + switch (nvme_auth_hmac_hash_len(hmac_id)) { + case 32: + hmac_len = 44; + break; + case 48: + hmac_len = 64; + break; + default: + pr_warn("%s: invalid hash algorithm '%s'\n", + __func__, hmac_name); + return -EINVAL; + } + + enc = kzalloc(hmac_len + 1, GFP_KERNEL); + if (!enc) + return -ENOMEM; + + tfm = crypto_alloc_shash(hmac_name, 0, 0); + if (IS_ERR(tfm)) { + ret = PTR_ERR(tfm); + goto out_free_enc; + } + + digest_len = crypto_shash_digestsize(tfm); + digest = kzalloc(digest_len, GFP_KERNEL); + if (!digest) { + ret = -ENOMEM; + goto out_free_tfm; + } + + shash->tfm = tfm; + ret = crypto_shash_setkey(tfm, psk, psk_len); + if (ret) + goto out_free_digest; + + ret = crypto_shash_init(shash); + if (ret) + goto out_free_digest; + + ret = crypto_shash_update(shash, hostnqn, strlen(hostnqn)); + if (ret) + goto out_free_digest; + + ret = crypto_shash_update(shash, " ", 1); + if (ret) + goto out_free_digest; + + ret = crypto_shash_update(shash, subsysnqn, strlen(subsysnqn)); + if (ret) + goto out_free_digest; + + ret = crypto_shash_update(shash, " NVMe-over-Fabrics", 18); + if (ret) + goto out_free_digest; + + ret = crypto_shash_final(shash, digest); + if (ret) + goto out_free_digest; + + ret = base64_encode(digest, digest_len, enc); + if (ret < hmac_len) { + ret = -ENOKEY; + goto out_free_digest; + } + *ret_digest = enc; + ret = 0; + +out_free_digest: + kfree_sensitive(digest); +out_free_tfm: + crypto_free_shash(tfm); +out_free_enc: + if (ret) + kfree_sensitive(enc); + + return ret; +} +EXPORT_SYMBOL_GPL(nvme_auth_generate_digest); + +/** + * nvme_auth_derive_tls_psk - Derive TLS PSK + * @hmac_id: Hash function identifier + * @psk: generated input PSK + * @psk_len: size of @psk + * @psk_digest: TLS PSK digest + * @ret_psk: Pointer to the resulting TLS PSK + * + * Derive a TLS PSK as specified in TP8018 Section 3.6.1.3: + * TLS PSK and PSK identity Derivation + * + * The TLS PSK shall be derived as follows from an input PSK + * (i.e., either a retained PSK or a generated PSK) and a PSK + * identity using the HKDF-Extract and HKDF-Expand-Label operations + * (refer to RFC 5869 and RFC 8446) where the hash function is the + * one specified by the hash specifier of the PSK identity: + * 1. PRK = HKDF-Extract(0, Input PSK); and + * 2. TLS PSK = HKDF-Expand-Label(PRK, "nvme-tls-psk", PskIdentityContext, L), + * where PskIdentityContext is the hash identifier indicated in + * the PSK identity concatenated to a space character and to the + * Base64 PSK digest (i.e., "<hash> <PSK digest>") and L is the + * output size in bytes of the hash function (i.e., 32 for SHA-256 + * and 48 for SHA-384). + * + * Returns 0 on success with a valid psk pointer in @ret_psk or a negative + * error number otherwise. + */ +int nvme_auth_derive_tls_psk(int hmac_id, u8 *psk, size_t psk_len, + u8 *psk_digest, u8 **ret_psk) +{ + struct crypto_shash *hmac_tfm; + const char *hmac_name; + const char *psk_prefix = "tls13 nvme-tls-psk"; + static const char default_salt[HKDF_MAX_HASHLEN]; + size_t info_len, prk_len; + char *info; + unsigned char *prk, *tls_key; + int ret; + + hmac_name = nvme_auth_hmac_name(hmac_id); + if (!hmac_name) { + pr_warn("%s: invalid hash algorithm %d\n", + __func__, hmac_id); + return -EINVAL; + } + if (hmac_id == NVME_AUTH_HASH_SHA512) { + pr_warn("%s: unsupported hash algorithm %s\n", + __func__, hmac_name); + return -EINVAL; + } + + hmac_tfm = crypto_alloc_shash(hmac_name, 0, 0); + if (IS_ERR(hmac_tfm)) + return PTR_ERR(hmac_tfm); + + prk_len = crypto_shash_digestsize(hmac_tfm); + prk = kzalloc(prk_len, GFP_KERNEL); + if (!prk) { + ret = -ENOMEM; + goto out_free_shash; + } + + if (WARN_ON(prk_len > HKDF_MAX_HASHLEN)) { + ret = -EINVAL; + goto out_free_prk; + } + ret = hkdf_extract(hmac_tfm, psk, psk_len, + default_salt, prk_len, prk); + if (ret) + goto out_free_prk; + + ret = crypto_shash_setkey(hmac_tfm, prk, prk_len); + if (ret) + goto out_free_prk; + + /* + * 2 addtional bytes for the length field from HDKF-Expand-Label, + * 2 addtional bytes for the HMAC ID, and one byte for the space + * separator. + */ + info_len = strlen(psk_digest) + strlen(psk_prefix) + 5; + info = kzalloc(info_len + 1, GFP_KERNEL); + if (!info) { + ret = -ENOMEM; + goto out_free_prk; + } + + put_unaligned_be16(psk_len, info); + memcpy(info + 2, psk_prefix, strlen(psk_prefix)); + sprintf(info + 2 + strlen(psk_prefix), "%02d %s", hmac_id, psk_digest); + + tls_key = kzalloc(psk_len, GFP_KERNEL); + if (!tls_key) { + ret = -ENOMEM; + goto out_free_info; + } + ret = hkdf_expand(hmac_tfm, info, info_len, tls_key, psk_len); + if (ret) { + kfree(tls_key); + goto out_free_info; + } + *ret_psk = tls_key; + +out_free_info: + kfree(info); +out_free_prk: + kfree(prk); +out_free_shash: + crypto_free_shash(hmac_tfm); + + return ret; +} +EXPORT_SYMBOL_GPL(nvme_auth_derive_tls_psk); + MODULE_DESCRIPTION("NVMe Authentication framework"); MODULE_LICENSE("GPL v2"); diff --git a/drivers/nvme/common/keyring.c b/drivers/nvme/common/keyring.c index ed5167f942d8..32d16c53133b 100644 --- a/drivers/nvme/common/keyring.c +++ b/drivers/nvme/common/keyring.c @@ -5,7 +5,6 @@ #include <linux/module.h> #include <linux/seq_file.h> -#include <linux/key.h> #include <linux/key-type.h> #include <keys/user-type.h> #include <linux/nvme.h> @@ -124,6 +123,70 @@ static struct key *nvme_tls_psk_lookup(struct key *keyring, return key_ref_to_ptr(keyref); } +/** + * nvme_tls_psk_refresh - Refresh TLS PSK + * @keyring: Keyring holding the TLS PSK + * @hostnqn: Host NQN to use + * @subnqn: Subsystem NQN to use + * @hmac_id: Hash function identifier + * @data: TLS PSK key material + * @data_len: Length of @data + * @digest: TLS PSK digest + * + * Refresh a generated version 1 TLS PSK with the identity generated + * from @hmac_id, @hostnqn, @subnqn, and @digest in the keyring given + * by @keyring. + * + * Returns the updated key success or an error pointer otherwise. + */ +struct key *nvme_tls_psk_refresh(struct key *keyring, + const char *hostnqn, const char *subnqn, u8 hmac_id, + u8 *data, size_t data_len, const char *digest) +{ + key_perm_t keyperm = + KEY_POS_SEARCH | KEY_POS_VIEW | KEY_POS_READ | + KEY_POS_WRITE | KEY_POS_LINK | KEY_POS_SETATTR | + KEY_USR_SEARCH | KEY_USR_VIEW | KEY_USR_READ; + char *identity; + key_ref_t keyref; + key_serial_t keyring_id; + struct key *key; + + if (!hostnqn || !subnqn || !data || !data_len) + return ERR_PTR(-EINVAL); + + identity = kasprintf(GFP_KERNEL, "NVMe1G%02d %s %s %s", + hmac_id, hostnqn, subnqn, digest); + if (!identity) + return ERR_PTR(-ENOMEM); + + if (!keyring) + keyring = nvme_keyring; + keyring_id = key_serial(keyring); + pr_debug("keyring %x refresh tls psk '%s'\n", + keyring_id, identity); + keyref = key_create_or_update(make_key_ref(keyring, true), + "psk", identity, data, data_len, + keyperm, KEY_ALLOC_NOT_IN_QUOTA | + KEY_ALLOC_BUILT_IN | + KEY_ALLOC_BYPASS_RESTRICTION); + if (IS_ERR(keyref)) { + pr_debug("refresh tls psk '%s' failed, error %ld\n", + identity, PTR_ERR(keyref)); + kfree(identity); + return ERR_PTR(-ENOKEY); + } + kfree(identity); + /* + * Set the default timeout to 1 hour + * as suggested in TP8018. + */ + key = key_ref_to_ptr(keyref); + key_set_timeout(key, 3600); + return key; +} +EXPORT_SYMBOL_GPL(nvme_tls_psk_refresh); + /* * NVMe PSK priority list * |