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zfs-builds-mm/zfs-2.0.0/module/os/freebsd/zfs/zio_crypt.c

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add_2.0.0
2020-12-02 17:25:31 +01:00
/*
* CDDL HEADER START
*
* This file and its contents are supplied under the terms of the
* Common Development and Distribution License ("CDDL"), version 1.0.
* You may only use this file in accordance with the terms of version
* 1.0 of the CDDL.
*
* A full copy of the text of the CDDL should have accompanied this
* source. A copy of the CDDL is also available via the Internet at
* http://www.illumos.org/license/CDDL.
*
* CDDL HEADER END
*/
/*
* Copyright (c) 2017, Datto, Inc. All rights reserved.
*/
#include <sys/zio_crypt.h>
#include <sys/dmu.h>
#include <sys/dmu_objset.h>
#include <sys/dnode.h>
#include <sys/fs/zfs.h>
#include <sys/zio.h>
#include <sys/zil.h>
#include <sys/sha2.h>
#include <sys/hkdf.h>
/*
* This file is responsible for handling all of the details of generating
* encryption parameters and performing encryption and authentication.
*
* BLOCK ENCRYPTION PARAMETERS:
* Encryption /Authentication Algorithm Suite (crypt):
* The encryption algorithm, mode, and key length we are going to use. We
* currently support AES in either GCM or CCM modes with 128, 192, and 256 bit
* keys. All authentication is currently done with SHA512-HMAC.
*
* Plaintext:
* The unencrypted data that we want to encrypt.
*
* Initialization Vector (IV):
* An initialization vector for the encryption algorithms. This is used to
* "tweak" the encryption algorithms so that two blocks of the same data are
* encrypted into different ciphertext outputs, thus obfuscating block patterns.
* The supported encryption modes (AES-GCM and AES-CCM) require that an IV is
* never reused with the same encryption key. This value is stored unencrypted
* and must simply be provided to the decryption function. We use a 96 bit IV
* (as recommended by NIST) for all block encryption. For non-dedup blocks we
* derive the IV randomly. The first 64 bits of the IV are stored in the second
* word of DVA[2] and the remaining 32 bits are stored in the upper 32 bits of
* blk_fill. This is safe because encrypted blocks can't use the upper 32 bits
* of blk_fill. We only encrypt level 0 blocks, which normally have a fill count
* of 1. The only exception is for DMU_OT_DNODE objects, where the fill count of
* level 0 blocks is the number of allocated dnodes in that block. The on-disk
* format supports at most 2^15 slots per L0 dnode block, because the maximum
* block size is 16MB (2^24). In either case, for level 0 blocks this number
* will still be smaller than UINT32_MAX so it is safe to store the IV in the
* top 32 bits of blk_fill, while leaving the bottom 32 bits of the fill count
* for the dnode code.
*
* Master key:
* This is the most important secret data of an encrypted dataset. It is used
* along with the salt to generate that actual encryption keys via HKDF. We
* do not use the master key to directly encrypt any data because there are
* theoretical limits on how much data can actually be safely encrypted with
* any encryption mode. The master key is stored encrypted on disk with the
* user's wrapping key. Its length is determined by the encryption algorithm.
* For details on how this is stored see the block comment in dsl_crypt.c
*
* Salt:
* Used as an input to the HKDF function, along with the master key. We use a
* 64 bit salt, stored unencrypted in the first word of DVA[2]. Any given salt
* can be used for encrypting many blocks, so we cache the current salt and the
* associated derived key in zio_crypt_t so we do not need to derive it again
* needlessly.
*
* Encryption Key:
* A secret binary key, generated from an HKDF function used to encrypt and
* decrypt data.
*
* Message Authentication Code (MAC)
* The MAC is an output of authenticated encryption modes such as AES-GCM and
* AES-CCM. Its purpose is to ensure that an attacker cannot modify encrypted
* data on disk and return garbage to the application. Effectively, it is a
* checksum that can not be reproduced by an attacker. We store the MAC in the
* second 128 bits of blk_cksum, leaving the first 128 bits for a truncated
* regular checksum of the ciphertext which can be used for scrubbing.
*
* OBJECT AUTHENTICATION:
* Some object types, such as DMU_OT_MASTER_NODE cannot be encrypted because
* they contain some info that always needs to be readable. To prevent this
* data from being altered, we authenticate this data using SHA512-HMAC. This
* will produce a MAC (similar to the one produced via encryption) which can
* be used to verify the object was not modified. HMACs do not require key
* rotation or IVs, so we can keep up to the full 3 copies of authenticated
* data.
*
* ZIL ENCRYPTION:
* ZIL blocks have their bp written to disk ahead of the associated data, so we
* cannot store the MAC there as we normally do. For these blocks the MAC is
* stored in the embedded checksum within the zil_chain_t header. The salt and
* IV are generated for the block on bp allocation instead of at encryption
* time. In addition, ZIL blocks have some pieces that must be left in plaintext
* for claiming even though all of the sensitive user data still needs to be
* encrypted. The function zio_crypt_init_uios_zil() handles parsing which
* pieces of the block need to be encrypted. All data that is not encrypted is
* authenticated using the AAD mechanisms that the supported encryption modes
* provide for. In order to preserve the semantics of the ZIL for encrypted
* datasets, the ZIL is not protected at the objset level as described below.
*
* DNODE ENCRYPTION:
* Similarly to ZIL blocks, the core part of each dnode_phys_t needs to be left
* in plaintext for scrubbing and claiming, but the bonus buffers might contain
* sensitive user data. The function zio_crypt_init_uios_dnode() handles parsing
* which which pieces of the block need to be encrypted. For more details about
* dnode authentication and encryption, see zio_crypt_init_uios_dnode().
*
* OBJECT SET AUTHENTICATION:
* Up to this point, everything we have encrypted and authenticated has been
* at level 0 (or -2 for the ZIL). If we did not do any further work the
* on-disk format would be susceptible to attacks that deleted or rearranged
* the order of level 0 blocks. Ideally, the cleanest solution would be to
* maintain a tree of authentication MACs going up the bp tree. However, this
* presents a problem for raw sends. Send files do not send information about
* indirect blocks so there would be no convenient way to transfer the MACs and
* they cannot be recalculated on the receive side without the master key which
* would defeat one of the purposes of raw sends in the first place. Instead,
* for the indirect levels of the bp tree, we use a regular SHA512 of the MACs
* from the level below. We also include some portable fields from blk_prop such
* as the lsize and compression algorithm to prevent the data from being
* misinterpreted.
*
* At the objset level, we maintain 2 separate 256 bit MACs in the
* objset_phys_t. The first one is "portable" and is the logical root of the
* MAC tree maintained in the metadnode's bps. The second, is "local" and is
* used as the root MAC for the user accounting objects, which are also not
* transferred via "zfs send". The portable MAC is sent in the DRR_BEGIN payload
* of the send file. The useraccounting code ensures that the useraccounting
* info is not present upon a receive, so the local MAC can simply be cleared
* out at that time. For more info about objset_phys_t authentication, see
* zio_crypt_do_objset_hmacs().
*
* CONSIDERATIONS FOR DEDUP:
* In order for dedup to work, blocks that we want to dedup with one another
* need to use the same IV and encryption key, so that they will have the same
* ciphertext. Normally, one should never reuse an IV with the same encryption
* key or else AES-GCM and AES-CCM can both actually leak the plaintext of both
* blocks. In this case, however, since we are using the same plaintext as
* well all that we end up with is a duplicate of the original ciphertext we
* already had. As a result, an attacker with read access to the raw disk will
* be able to tell which blocks are the same but this information is given away
* by dedup anyway. In order to get the same IVs and encryption keys for
* equivalent blocks of data we use an HMAC of the plaintext. We use an HMAC
* here so that a reproducible checksum of the plaintext is never available to
* the attacker. The HMAC key is kept alongside the master key, encrypted on
* disk. The first 64 bits of the HMAC are used in place of the random salt, and
* the next 96 bits are used as the IV. As a result of this mechanism, dedup
* will only work within a clone family since encrypted dedup requires use of
* the same master and HMAC keys.
*/
/*
* After encrypting many blocks with the same key we may start to run up
* against the theoretical limits of how much data can securely be encrypted
* with a single key using the supported encryption modes. The most obvious
* limitation is that our risk of generating 2 equivalent 96 bit IVs increases
* the more IVs we generate (which both GCM and CCM modes strictly forbid).
* This risk actually grows surprisingly quickly over time according to the
* Birthday Problem. With a total IV space of 2^(96 bits), and assuming we have
* generated n IVs with a cryptographically secure RNG, the approximate
* probability p(n) of a collision is given as:
*
* p(n) ~= e^(-n*(n-1)/(2*(2^96)))
*
* [http://www.math.cornell.edu/~mec/2008-2009/TianyiZheng/Birthday.html]
*
* Assuming that we want to ensure that p(n) never goes over 1 / 1 trillion
* we must not write more than 398,065,730 blocks with the same encryption key.
* Therefore, we rotate our keys after 400,000,000 blocks have been written by
* generating a new random 64 bit salt for our HKDF encryption key generation
* function.
*/
#define ZFS_KEY_MAX_SALT_USES_DEFAULT 400000000
#define ZFS_CURRENT_MAX_SALT_USES \
(MIN(zfs_key_max_salt_uses, ZFS_KEY_MAX_SALT_USES_DEFAULT))
unsigned long zfs_key_max_salt_uses = ZFS_KEY_MAX_SALT_USES_DEFAULT;
/*
* Set to a nonzero value to cause zio_do_crypt_uio() to fail 1/this many
* calls, to test decryption error handling code paths.
*/
uint64_t zio_decrypt_fail_fraction = 0;
typedef struct blkptr_auth_buf {
uint64_t bab_prop; /* blk_prop - portable mask */
uint8_t bab_mac[ZIO_DATA_MAC_LEN]; /* MAC from blk_cksum */
uint64_t bab_pad; /* reserved for future use */
} blkptr_auth_buf_t;
zio_crypt_info_t zio_crypt_table[ZIO_CRYPT_FUNCTIONS] = {
{"", ZC_TYPE_NONE, 0, "inherit"},
{"", ZC_TYPE_NONE, 0, "on"},
{"", ZC_TYPE_NONE, 0, "off"},
{SUN_CKM_AES_CCM, ZC_TYPE_CCM, 16, "aes-128-ccm"},
{SUN_CKM_AES_CCM, ZC_TYPE_CCM, 24, "aes-192-ccm"},
{SUN_CKM_AES_CCM, ZC_TYPE_CCM, 32, "aes-256-ccm"},
{SUN_CKM_AES_GCM, ZC_TYPE_GCM, 16, "aes-128-gcm"},
{SUN_CKM_AES_GCM, ZC_TYPE_GCM, 24, "aes-192-gcm"},
{SUN_CKM_AES_GCM, ZC_TYPE_GCM, 32, "aes-256-gcm"}
};
static void
zio_crypt_key_destroy_early(zio_crypt_key_t *key)
{
rw_destroy(&key->zk_salt_lock);
/* free crypto templates */
bzero(&key->zk_session, sizeof (key->zk_session));
/* zero out sensitive data */
bzero(key, sizeof (zio_crypt_key_t));
}
void
zio_crypt_key_destroy(zio_crypt_key_t *key)
{
freebsd_crypt_freesession(&key->zk_session);
zio_crypt_key_destroy_early(key);
}
int
zio_crypt_key_init(uint64_t crypt, zio_crypt_key_t *key)
{
int ret;
crypto_mechanism_t mech __unused;
uint_t keydata_len;
zio_crypt_info_t *ci = NULL;
ASSERT(key != NULL);
ASSERT3U(crypt, <, ZIO_CRYPT_FUNCTIONS);
ci = &zio_crypt_table[crypt];
if (ci->ci_crypt_type != ZC_TYPE_GCM &&
ci->ci_crypt_type != ZC_TYPE_CCM)
return (ENOTSUP);
keydata_len = zio_crypt_table[crypt].ci_keylen;
bzero(key, sizeof (zio_crypt_key_t));
rw_init(&key->zk_salt_lock, NULL, RW_DEFAULT, NULL);
/* fill keydata buffers and salt with random data */
ret = random_get_bytes((uint8_t *)&key->zk_guid, sizeof (uint64_t));
if (ret != 0)
goto error;
ret = random_get_bytes(key->zk_master_keydata, keydata_len);
if (ret != 0)
goto error;
ret = random_get_bytes(key->zk_hmac_keydata, SHA512_HMAC_KEYLEN);
if (ret != 0)
goto error;
ret = random_get_bytes(key->zk_salt, ZIO_DATA_SALT_LEN);
if (ret != 0)
goto error;
/* derive the current key from the master key */
ret = hkdf_sha512(key->zk_master_keydata, keydata_len, NULL, 0,
key->zk_salt, ZIO_DATA_SALT_LEN, key->zk_current_keydata,
keydata_len);
if (ret != 0)
goto error;
/* initialize keys for the ICP */
key->zk_current_key.ck_format = CRYPTO_KEY_RAW;
key->zk_current_key.ck_data = key->zk_current_keydata;
key->zk_current_key.ck_length = CRYPTO_BYTES2BITS(keydata_len);
key->zk_hmac_key.ck_format = CRYPTO_KEY_RAW;
key->zk_hmac_key.ck_data = &key->zk_hmac_key;
key->zk_hmac_key.ck_length = CRYPTO_BYTES2BITS(SHA512_HMAC_KEYLEN);
ci = &zio_crypt_table[crypt];
if (ci->ci_crypt_type != ZC_TYPE_GCM &&
ci->ci_crypt_type != ZC_TYPE_CCM)
return (ENOTSUP);
ret = freebsd_crypt_newsession(&key->zk_session, ci,
&key->zk_current_key);
if (ret)
goto error;
key->zk_crypt = crypt;
key->zk_version = ZIO_CRYPT_KEY_CURRENT_VERSION;
key->zk_salt_count = 0;
return (0);
error:
zio_crypt_key_destroy_early(key);
return (ret);
}
static int
zio_crypt_key_change_salt(zio_crypt_key_t *key)
{
int ret = 0;
uint8_t salt[ZIO_DATA_SALT_LEN];
crypto_mechanism_t mech __unused;
uint_t keydata_len = zio_crypt_table[key->zk_crypt].ci_keylen;
/* generate a new salt */
ret = random_get_bytes(salt, ZIO_DATA_SALT_LEN);
if (ret != 0)
goto error;
rw_enter(&key->zk_salt_lock, RW_WRITER);
/* someone beat us to the salt rotation, just unlock and return */
if (key->zk_salt_count < ZFS_CURRENT_MAX_SALT_USES)
goto out_unlock;
/* derive the current key from the master key and the new salt */
ret = hkdf_sha512(key->zk_master_keydata, keydata_len, NULL, 0,
salt, ZIO_DATA_SALT_LEN, key->zk_current_keydata, keydata_len);
if (ret != 0)
goto out_unlock;
/* assign the salt and reset the usage count */
bcopy(salt, key->zk_salt, ZIO_DATA_SALT_LEN);
key->zk_salt_count = 0;
freebsd_crypt_freesession(&key->zk_session);
ret = freebsd_crypt_newsession(&key->zk_session,
&zio_crypt_table[key->zk_crypt], &key->zk_current_key);
if (ret != 0)
goto out_unlock;
rw_exit(&key->zk_salt_lock);
return (0);
out_unlock:
rw_exit(&key->zk_salt_lock);
error:
return (ret);
}
/* See comment above zfs_key_max_salt_uses definition for details */
int
zio_crypt_key_get_salt(zio_crypt_key_t *key, uint8_t *salt)
{
int ret;
boolean_t salt_change;
rw_enter(&key->zk_salt_lock, RW_READER);
bcopy(key->zk_salt, salt, ZIO_DATA_SALT_LEN);
salt_change = (atomic_inc_64_nv(&key->zk_salt_count) >=
ZFS_CURRENT_MAX_SALT_USES);
rw_exit(&key->zk_salt_lock);
if (salt_change) {
ret = zio_crypt_key_change_salt(key);
if (ret != 0)
goto error;
}
return (0);
error:
return (ret);
}
void *failed_decrypt_buf;
int failed_decrypt_size;
/*
* This function handles all encryption and decryption in zfs. When
* encrypting it expects puio to reference the plaintext and cuio to
* reference the ciphertext. cuio must have enough space for the
* ciphertext + room for a MAC. datalen should be the length of the
* plaintext / ciphertext alone.
*/
/*
* The implementation for FreeBSD's OpenCrypto.
*
* The big difference between ICP and FOC is that FOC uses a single
* buffer for input and output. This means that (for AES-GCM, the
* only one supported right now) the source must be copied into the
* destination, and the destination must have the AAD, and the tag/MAC,
* already associated with it. (Both implementations can use a uio.)
*
* Since the auth data is part of the iovec array, all we need to know
* is the length: 0 means there's no AAD.
*
*/
static int
zio_do_crypt_uio_opencrypto(boolean_t encrypt, freebsd_crypt_session_t *sess,
uint64_t crypt, crypto_key_t *key, uint8_t *ivbuf, uint_t datalen,
uio_t *uio, uint_t auth_len)
{
zio_crypt_info_t *ci;
int ret;
ci = &zio_crypt_table[crypt];
if (ci->ci_crypt_type != ZC_TYPE_GCM &&
ci->ci_crypt_type != ZC_TYPE_CCM)
return (ENOTSUP);
ret = freebsd_crypt_uio(encrypt, sess, ci, uio, key, ivbuf,
datalen, auth_len);
if (ret != 0) {
#ifdef FCRYPTO_DEBUG
printf("%s(%d): Returning error %s\n",
__FUNCTION__, __LINE__, encrypt ? "EIO" : "ECKSUM");
#endif
ret = SET_ERROR(encrypt ? EIO : ECKSUM);
}
return (ret);
}
int
zio_crypt_key_wrap(crypto_key_t *cwkey, zio_crypt_key_t *key, uint8_t *iv,
uint8_t *mac, uint8_t *keydata_out, uint8_t *hmac_keydata_out)
{
int ret;
uint64_t aad[3];
/*
* With OpenCrypto in FreeBSD, the same buffer is used for
* input and output. Also, the AAD (for AES-GMC at least)
* needs to logically go in front.
*/
uio_t cuio;
iovec_t iovecs[4];
uint64_t crypt = key->zk_crypt;
uint_t enc_len, keydata_len, aad_len;
ASSERT3U(crypt, <, ZIO_CRYPT_FUNCTIONS);
ASSERT3U(cwkey->ck_format, ==, CRYPTO_KEY_RAW);
keydata_len = zio_crypt_table[crypt].ci_keylen;
/* generate iv for wrapping the master and hmac key */
ret = random_get_pseudo_bytes(iv, WRAPPING_IV_LEN);
if (ret != 0)
goto error;
/*
* Since we only support one buffer, we need to copy
* the plain text (source) to the cipher buffer (dest).
* We set iovecs[0] -- the authentication data -- below.
*/
bcopy((void*)key->zk_master_keydata, keydata_out, keydata_len);
bcopy((void*)key->zk_hmac_keydata, hmac_keydata_out,
SHA512_HMAC_KEYLEN);
iovecs[1].iov_base = keydata_out;
iovecs[1].iov_len = keydata_len;
iovecs[2].iov_base = hmac_keydata_out;
iovecs[2].iov_len = SHA512_HMAC_KEYLEN;
iovecs[3].iov_base = mac;
iovecs[3].iov_len = WRAPPING_MAC_LEN;
/*
* Although we don't support writing to the old format, we do
* support rewrapping the key so that the user can move and
* quarantine datasets on the old format.
*/
if (key->zk_version == 0) {
aad_len = sizeof (uint64_t);
aad[0] = LE_64(key->zk_guid);
} else {
ASSERT3U(key->zk_version, ==, ZIO_CRYPT_KEY_CURRENT_VERSION);
aad_len = sizeof (uint64_t) * 3;
aad[0] = LE_64(key->zk_guid);
aad[1] = LE_64(crypt);
aad[2] = LE_64(key->zk_version);
}
iovecs[0].iov_base = aad;
iovecs[0].iov_len = aad_len;
enc_len = zio_crypt_table[crypt].ci_keylen + SHA512_HMAC_KEYLEN;
cuio.uio_iov = iovecs;
cuio.uio_iovcnt = 4;
cuio.uio_segflg = UIO_SYSSPACE;
/* encrypt the keys and store the resulting ciphertext and mac */
ret = zio_do_crypt_uio_opencrypto(B_TRUE, NULL, crypt, cwkey,
iv, enc_len, &cuio, aad_len);
if (ret != 0)
goto error;
return (0);
error:
return (ret);
}
int
zio_crypt_key_unwrap(crypto_key_t *cwkey, uint64_t crypt, uint64_t version,
uint64_t guid, uint8_t *keydata, uint8_t *hmac_keydata, uint8_t *iv,
uint8_t *mac, zio_crypt_key_t *key)
{
int ret;
uint64_t aad[3];
/*
* With OpenCrypto in FreeBSD, the same buffer is used for
* input and output. Also, the AAD (for AES-GMC at least)
* needs to logically go in front.
*/
uio_t cuio;
iovec_t iovecs[4];
void *src, *dst;
uint_t enc_len, keydata_len, aad_len;
ASSERT3U(crypt, <, ZIO_CRYPT_FUNCTIONS);
ASSERT3U(cwkey->ck_format, ==, CRYPTO_KEY_RAW);
keydata_len = zio_crypt_table[crypt].ci_keylen;
rw_init(&key->zk_salt_lock, NULL, RW_DEFAULT, NULL);
/*
* Since we only support one buffer, we need to copy
* the encrypted buffer (source) to the plain buffer
* (dest). We set iovecs[0] -- the authentication data --
* below.
*/
dst = key->zk_master_keydata;
src = keydata;
bcopy(src, dst, keydata_len);
dst = key->zk_hmac_keydata;
src = hmac_keydata;
bcopy(src, dst, SHA512_HMAC_KEYLEN);
iovecs[1].iov_base = key->zk_master_keydata;
iovecs[1].iov_len = keydata_len;
iovecs[2].iov_base = key->zk_hmac_keydata;
iovecs[2].iov_len = SHA512_HMAC_KEYLEN;
iovecs[3].iov_base = mac;
iovecs[3].iov_len = WRAPPING_MAC_LEN;
if (version == 0) {
aad_len = sizeof (uint64_t);
aad[0] = LE_64(guid);
} else {
ASSERT3U(version, ==, ZIO_CRYPT_KEY_CURRENT_VERSION);
aad_len = sizeof (uint64_t) * 3;
aad[0] = LE_64(guid);
aad[1] = LE_64(crypt);
aad[2] = LE_64(version);
}
enc_len = keydata_len + SHA512_HMAC_KEYLEN;
iovecs[0].iov_base = aad;
iovecs[0].iov_len = aad_len;
cuio.uio_iov = iovecs;
cuio.uio_iovcnt = 4;
cuio.uio_segflg = UIO_SYSSPACE;
/* decrypt the keys and store the result in the output buffers */
ret = zio_do_crypt_uio_opencrypto(B_FALSE, NULL, crypt, cwkey,
iv, enc_len, &cuio, aad_len);
if (ret != 0)
goto error;
/* generate a fresh salt */
ret = random_get_bytes(key->zk_salt, ZIO_DATA_SALT_LEN);
if (ret != 0)
goto error;
/* derive the current key from the master key */
ret = hkdf_sha512(key->zk_master_keydata, keydata_len, NULL, 0,
key->zk_salt, ZIO_DATA_SALT_LEN, key->zk_current_keydata,
keydata_len);
if (ret != 0)
goto error;
/* initialize keys for ICP */
key->zk_current_key.ck_format = CRYPTO_KEY_RAW;
key->zk_current_key.ck_data = key->zk_current_keydata;
key->zk_current_key.ck_length = CRYPTO_BYTES2BITS(keydata_len);
key->zk_hmac_key.ck_format = CRYPTO_KEY_RAW;
key->zk_hmac_key.ck_data = key->zk_hmac_keydata;
key->zk_hmac_key.ck_length = CRYPTO_BYTES2BITS(SHA512_HMAC_KEYLEN);
ret = freebsd_crypt_newsession(&key->zk_session,
&zio_crypt_table[crypt], &key->zk_current_key);
if (ret != 0)
goto error;
key->zk_crypt = crypt;
key->zk_version = version;
key->zk_guid = guid;
key->zk_salt_count = 0;
return (0);
error:
zio_crypt_key_destroy_early(key);
return (ret);
}
int
zio_crypt_generate_iv(uint8_t *ivbuf)
{
int ret;
/* randomly generate the IV */
ret = random_get_pseudo_bytes(ivbuf, ZIO_DATA_IV_LEN);
if (ret != 0)
goto error;
return (0);
error:
bzero(ivbuf, ZIO_DATA_IV_LEN);
return (ret);
}
int
zio_crypt_do_hmac(zio_crypt_key_t *key, uint8_t *data, uint_t datalen,
uint8_t *digestbuf, uint_t digestlen)
{
uint8_t raw_digestbuf[SHA512_DIGEST_LENGTH];
ASSERT3U(digestlen, <=, SHA512_DIGEST_LENGTH);
crypto_mac(&key->zk_hmac_key, data, datalen,
raw_digestbuf, SHA512_DIGEST_LENGTH);
bcopy(raw_digestbuf, digestbuf, digestlen);
return (0);
}
int
zio_crypt_generate_iv_salt_dedup(zio_crypt_key_t *key, uint8_t *data,
uint_t datalen, uint8_t *ivbuf, uint8_t *salt)
{
int ret;
uint8_t digestbuf[SHA512_DIGEST_LENGTH];
ret = zio_crypt_do_hmac(key, data, datalen,
digestbuf, SHA512_DIGEST_LENGTH);
if (ret != 0)
return (ret);
bcopy(digestbuf, salt, ZIO_DATA_SALT_LEN);
bcopy(digestbuf + ZIO_DATA_SALT_LEN, ivbuf, ZIO_DATA_IV_LEN);
return (0);
}
/*
* The following functions are used to encode and decode encryption parameters
* into blkptr_t and zil_header_t. The ICP wants to use these parameters as
* byte strings, which normally means that these strings would not need to deal
* with byteswapping at all. However, both blkptr_t and zil_header_t may be
* byteswapped by lower layers and so we must "undo" that byteswap here upon
* decoding and encoding in a non-native byteorder. These functions require
* that the byteorder bit is correct before being called.
*/
void
zio_crypt_encode_params_bp(blkptr_t *bp, uint8_t *salt, uint8_t *iv)
{
uint64_t val64;
uint32_t val32;
ASSERT(BP_IS_ENCRYPTED(bp));
if (!BP_SHOULD_BYTESWAP(bp)) {
bcopy(salt, &bp->blk_dva[2].dva_word[0], sizeof (uint64_t));
bcopy(iv, &bp->blk_dva[2].dva_word[1], sizeof (uint64_t));
bcopy(iv + sizeof (uint64_t), &val32, sizeof (uint32_t));
BP_SET_IV2(bp, val32);
} else {
bcopy(salt, &val64, sizeof (uint64_t));
bp->blk_dva[2].dva_word[0] = BSWAP_64(val64);
bcopy(iv, &val64, sizeof (uint64_t));
bp->blk_dva[2].dva_word[1] = BSWAP_64(val64);
bcopy(iv + sizeof (uint64_t), &val32, sizeof (uint32_t));
BP_SET_IV2(bp, BSWAP_32(val32));
}
}
void
zio_crypt_decode_params_bp(const blkptr_t *bp, uint8_t *salt, uint8_t *iv)
{
uint64_t val64;
uint32_t val32;
ASSERT(BP_IS_PROTECTED(bp));
/* for convenience, so callers don't need to check */
if (BP_IS_AUTHENTICATED(bp)) {
bzero(salt, ZIO_DATA_SALT_LEN);
bzero(iv, ZIO_DATA_IV_LEN);
return;
}
if (!BP_SHOULD_BYTESWAP(bp)) {
bcopy(&bp->blk_dva[2].dva_word[0], salt, sizeof (uint64_t));
bcopy(&bp->blk_dva[2].dva_word[1], iv, sizeof (uint64_t));
val32 = (uint32_t)BP_GET_IV2(bp);
bcopy(&val32, iv + sizeof (uint64_t), sizeof (uint32_t));
} else {
val64 = BSWAP_64(bp->blk_dva[2].dva_word[0]);
bcopy(&val64, salt, sizeof (uint64_t));
val64 = BSWAP_64(bp->blk_dva[2].dva_word[1]);
bcopy(&val64, iv, sizeof (uint64_t));
val32 = BSWAP_32((uint32_t)BP_GET_IV2(bp));
bcopy(&val32, iv + sizeof (uint64_t), sizeof (uint32_t));
}
}
void
zio_crypt_encode_mac_bp(blkptr_t *bp, uint8_t *mac)
{
uint64_t val64;
ASSERT(BP_USES_CRYPT(bp));
ASSERT3U(BP_GET_TYPE(bp), !=, DMU_OT_OBJSET);
if (!BP_SHOULD_BYTESWAP(bp)) {
bcopy(mac, &bp->blk_cksum.zc_word[2], sizeof (uint64_t));
bcopy(mac + sizeof (uint64_t), &bp->blk_cksum.zc_word[3],
sizeof (uint64_t));
} else {
bcopy(mac, &val64, sizeof (uint64_t));
bp->blk_cksum.zc_word[2] = BSWAP_64(val64);
bcopy(mac + sizeof (uint64_t), &val64, sizeof (uint64_t));
bp->blk_cksum.zc_word[3] = BSWAP_64(val64);
}
}
void
zio_crypt_decode_mac_bp(const blkptr_t *bp, uint8_t *mac)
{
uint64_t val64;
ASSERT(BP_USES_CRYPT(bp) || BP_IS_HOLE(bp));
/* for convenience, so callers don't need to check */
if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
bzero(mac, ZIO_DATA_MAC_LEN);
return;
}
if (!BP_SHOULD_BYTESWAP(bp)) {
bcopy(&bp->blk_cksum.zc_word[2], mac, sizeof (uint64_t));
bcopy(&bp->blk_cksum.zc_word[3], mac + sizeof (uint64_t),
sizeof (uint64_t));
} else {
val64 = BSWAP_64(bp->blk_cksum.zc_word[2]);
bcopy(&val64, mac, sizeof (uint64_t));
val64 = BSWAP_64(bp->blk_cksum.zc_word[3]);
bcopy(&val64, mac + sizeof (uint64_t), sizeof (uint64_t));
}
}
void
zio_crypt_encode_mac_zil(void *data, uint8_t *mac)
{
zil_chain_t *zilc = data;
bcopy(mac, &zilc->zc_eck.zec_cksum.zc_word[2], sizeof (uint64_t));
bcopy(mac + sizeof (uint64_t), &zilc->zc_eck.zec_cksum.zc_word[3],
sizeof (uint64_t));
}
void
zio_crypt_decode_mac_zil(const void *data, uint8_t *mac)
{
/*
* The ZIL MAC is embedded in the block it protects, which will
* not have been byteswapped by the time this function has been called.
* As a result, we don't need to worry about byteswapping the MAC.
*/
const zil_chain_t *zilc = data;
bcopy(&zilc->zc_eck.zec_cksum.zc_word[2], mac, sizeof (uint64_t));
bcopy(&zilc->zc_eck.zec_cksum.zc_word[3], mac + sizeof (uint64_t),
sizeof (uint64_t));
}
/*
* This routine takes a block of dnodes (src_abd) and copies only the bonus
* buffers to the same offsets in the dst buffer. datalen should be the size
* of both the src_abd and the dst buffer (not just the length of the bonus
* buffers).
*/
void
zio_crypt_copy_dnode_bonus(abd_t *src_abd, uint8_t *dst, uint_t datalen)
{
uint_t i, max_dnp = datalen >> DNODE_SHIFT;
uint8_t *src;
dnode_phys_t *dnp, *sdnp, *ddnp;
src = abd_borrow_buf_copy(src_abd, datalen);
sdnp = (dnode_phys_t *)src;
ddnp = (dnode_phys_t *)dst;
for (i = 0; i < max_dnp; i += sdnp[i].dn_extra_slots + 1) {
dnp = &sdnp[i];
if (dnp->dn_type != DMU_OT_NONE &&
DMU_OT_IS_ENCRYPTED(dnp->dn_bonustype) &&
dnp->dn_bonuslen != 0) {
bcopy(DN_BONUS(dnp), DN_BONUS(&ddnp[i]),
DN_MAX_BONUS_LEN(dnp));
}
}
abd_return_buf(src_abd, src, datalen);
}
/*
* This function decides what fields from blk_prop are included in
* the on-disk various MAC algorithms.
*/
static void
zio_crypt_bp_zero_nonportable_blkprop(blkptr_t *bp, uint64_t version)
{
int avoidlint = SPA_MINBLOCKSIZE;
/*
* Version 0 did not properly zero out all non-portable fields
* as it should have done. We maintain this code so that we can
* do read-only imports of pools on this version.
*/
if (version == 0) {
BP_SET_DEDUP(bp, 0);
BP_SET_CHECKSUM(bp, 0);
BP_SET_PSIZE(bp, avoidlint);
return;
}
ASSERT3U(version, ==, ZIO_CRYPT_KEY_CURRENT_VERSION);
/*
* The hole_birth feature might set these fields even if this bp
* is a hole. We zero them out here to guarantee that raw sends
* will function with or without the feature.
*/
if (BP_IS_HOLE(bp)) {
bp->blk_prop = 0ULL;
return;
}
/*
* At L0 we want to verify these fields to ensure that data blocks
* can not be reinterpreted. For instance, we do not want an attacker
* to trick us into returning raw lz4 compressed data to the user
* by modifying the compression bits. At higher levels, we cannot
* enforce this policy since raw sends do not convey any information
* about indirect blocks, so these values might be different on the
* receive side. Fortunately, this does not open any new attack
* vectors, since any alterations that can be made to a higher level
* bp must still verify the correct order of the layer below it.
*/
if (BP_GET_LEVEL(bp) != 0) {
BP_SET_BYTEORDER(bp, 0);
BP_SET_COMPRESS(bp, 0);
/*
* psize cannot be set to zero or it will trigger
* asserts, but the value doesn't really matter as
* long as it is constant.
*/
BP_SET_PSIZE(bp, avoidlint);
}
BP_SET_DEDUP(bp, 0);
BP_SET_CHECKSUM(bp, 0);
}
static void
zio_crypt_bp_auth_init(uint64_t version, boolean_t should_bswap, blkptr_t *bp,
blkptr_auth_buf_t *bab, uint_t *bab_len)
{
blkptr_t tmpbp = *bp;
if (should_bswap)
byteswap_uint64_array(&tmpbp, sizeof (blkptr_t));
ASSERT(BP_USES_CRYPT(&tmpbp) || BP_IS_HOLE(&tmpbp));
ASSERT0(BP_IS_EMBEDDED(&tmpbp));
zio_crypt_decode_mac_bp(&tmpbp, bab->bab_mac);
/*
* We always MAC blk_prop in LE to ensure portability. This
* must be done after decoding the mac, since the endianness
* will get zero'd out here.
*/
zio_crypt_bp_zero_nonportable_blkprop(&tmpbp, version);
bab->bab_prop = LE_64(tmpbp.blk_prop);
bab->bab_pad = 0ULL;
/* version 0 did not include the padding */
*bab_len = sizeof (blkptr_auth_buf_t);
if (version == 0)
*bab_len -= sizeof (uint64_t);
}
static int
zio_crypt_bp_do_hmac_updates(crypto_context_t ctx, uint64_t version,
boolean_t should_bswap, blkptr_t *bp)
{
uint_t bab_len;
blkptr_auth_buf_t bab;
zio_crypt_bp_auth_init(version, should_bswap, bp, &bab, &bab_len);
crypto_mac_update(ctx, &bab, bab_len);
return (0);
}
static void
zio_crypt_bp_do_indrect_checksum_updates(SHA2_CTX *ctx, uint64_t version,
boolean_t should_bswap, blkptr_t *bp)
{
uint_t bab_len;
blkptr_auth_buf_t bab;
zio_crypt_bp_auth_init(version, should_bswap, bp, &bab, &bab_len);
SHA2Update(ctx, &bab, bab_len);
}
static void
zio_crypt_bp_do_aad_updates(uint8_t **aadp, uint_t *aad_len, uint64_t version,
boolean_t should_bswap, blkptr_t *bp)
{
uint_t bab_len;
blkptr_auth_buf_t bab;
zio_crypt_bp_auth_init(version, should_bswap, bp, &bab, &bab_len);
bcopy(&bab, *aadp, bab_len);
*aadp += bab_len;
*aad_len += bab_len;
}
static int
zio_crypt_do_dnode_hmac_updates(crypto_context_t ctx, uint64_t version,
boolean_t should_bswap, dnode_phys_t *dnp)
{
int ret, i;
dnode_phys_t *adnp;
boolean_t le_bswap = (should_bswap == ZFS_HOST_BYTEORDER);
uint8_t tmp_dncore[offsetof(dnode_phys_t, dn_blkptr)];
/* authenticate the core dnode (masking out non-portable bits) */
bcopy(dnp, tmp_dncore, sizeof (tmp_dncore));
adnp = (dnode_phys_t *)tmp_dncore;
if (le_bswap) {
adnp->dn_datablkszsec = BSWAP_16(adnp->dn_datablkszsec);
adnp->dn_bonuslen = BSWAP_16(adnp->dn_bonuslen);
adnp->dn_maxblkid = BSWAP_64(adnp->dn_maxblkid);
adnp->dn_used = BSWAP_64(adnp->dn_used);
}
adnp->dn_flags &= DNODE_CRYPT_PORTABLE_FLAGS_MASK;
adnp->dn_used = 0;
crypto_mac_update(ctx, adnp, sizeof (tmp_dncore));
for (i = 0; i < dnp->dn_nblkptr; i++) {
ret = zio_crypt_bp_do_hmac_updates(ctx, version,
should_bswap, &dnp->dn_blkptr[i]);
if (ret != 0)
goto error;
}
if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
ret = zio_crypt_bp_do_hmac_updates(ctx, version,
should_bswap, DN_SPILL_BLKPTR(dnp));
if (ret != 0)
goto error;
}
return (0);
error:
return (ret);
}
/*
* objset_phys_t blocks introduce a number of exceptions to the normal
* authentication process. objset_phys_t's contain 2 separate HMACS for
* protecting the integrity of their data. The portable_mac protects the
* metadnode. This MAC can be sent with a raw send and protects against
* reordering of data within the metadnode. The local_mac protects the user
* accounting objects which are not sent from one system to another.
*
* In addition, objset blocks are the only blocks that can be modified and
* written to disk without the key loaded under certain circumstances. During
* zil_claim() we need to be able to update the zil_header_t to complete
* claiming log blocks and during raw receives we need to write out the
* portable_mac from the send file. Both of these actions are possible
* because these fields are not protected by either MAC so neither one will
* need to modify the MACs without the key. However, when the modified blocks
* are written out they will be byteswapped into the host machine's native
* endianness which will modify fields protected by the MAC. As a result, MAC
* calculation for objset blocks works slightly differently from other block
* types. Where other block types MAC the data in whatever endianness is
* written to disk, objset blocks always MAC little endian version of their
* values. In the code, should_bswap is the value from BP_SHOULD_BYTESWAP()
* and le_bswap indicates whether a byteswap is needed to get this block
* into little endian format.
*/
/* ARGSUSED */
int
zio_crypt_do_objset_hmacs(zio_crypt_key_t *key, void *data, uint_t datalen,
boolean_t should_bswap, uint8_t *portable_mac, uint8_t *local_mac)
{
int ret;
struct hmac_ctx hash_ctx;
struct hmac_ctx *ctx = &hash_ctx;
objset_phys_t *osp = data;
uint64_t intval;
boolean_t le_bswap = (should_bswap == ZFS_HOST_BYTEORDER);
uint8_t raw_portable_mac[SHA512_DIGEST_LENGTH];
uint8_t raw_local_mac[SHA512_DIGEST_LENGTH];
/* calculate the portable MAC from the portable fields and metadnode */
crypto_mac_init(ctx, &key->zk_hmac_key);
/* add in the os_type */
intval = (le_bswap) ? osp->os_type : BSWAP_64(osp->os_type);
crypto_mac_update(ctx, &intval, sizeof (uint64_t));
/* add in the portable os_flags */
intval = osp->os_flags;
if (should_bswap)
intval = BSWAP_64(intval);
intval &= OBJSET_CRYPT_PORTABLE_FLAGS_MASK;
/* CONSTCOND */
if (!ZFS_HOST_BYTEORDER)
intval = BSWAP_64(intval);
crypto_mac_update(ctx, &intval, sizeof (uint64_t));
/* add in fields from the metadnode */
ret = zio_crypt_do_dnode_hmac_updates(ctx, key->zk_version,
should_bswap, &osp->os_meta_dnode);
if (ret)
goto error;
crypto_mac_final(ctx, raw_portable_mac, SHA512_DIGEST_LENGTH);
bcopy(raw_portable_mac, portable_mac, ZIO_OBJSET_MAC_LEN);
/*
* The local MAC protects the user, group and project accounting.
* If these objects are not present, the local MAC is zeroed out.
*/
if ((datalen >= OBJSET_PHYS_SIZE_V3 &&
osp->os_userused_dnode.dn_type == DMU_OT_NONE &&
osp->os_groupused_dnode.dn_type == DMU_OT_NONE &&
osp->os_projectused_dnode.dn_type == DMU_OT_NONE) ||
(datalen >= OBJSET_PHYS_SIZE_V2 &&
osp->os_userused_dnode.dn_type == DMU_OT_NONE &&
osp->os_groupused_dnode.dn_type == DMU_OT_NONE) ||
(datalen <= OBJSET_PHYS_SIZE_V1)) {
bzero(local_mac, ZIO_OBJSET_MAC_LEN);
return (0);
}
/* calculate the local MAC from the userused and groupused dnodes */
crypto_mac_init(ctx, &key->zk_hmac_key);
/* add in the non-portable os_flags */
intval = osp->os_flags;
if (should_bswap)
intval = BSWAP_64(intval);
intval &= ~OBJSET_CRYPT_PORTABLE_FLAGS_MASK;
/* CONSTCOND */
if (!ZFS_HOST_BYTEORDER)
intval = BSWAP_64(intval);
crypto_mac_update(ctx, &intval, sizeof (uint64_t));
/* XXX check dnode type ... */
/* add in fields from the user accounting dnodes */
if (osp->os_userused_dnode.dn_type != DMU_OT_NONE) {
ret = zio_crypt_do_dnode_hmac_updates(ctx, key->zk_version,
should_bswap, &osp->os_userused_dnode);
if (ret)
goto error;
}
if (osp->os_groupused_dnode.dn_type != DMU_OT_NONE) {
ret = zio_crypt_do_dnode_hmac_updates(ctx, key->zk_version,
should_bswap, &osp->os_groupused_dnode);
if (ret)
goto error;
}
if (osp->os_projectused_dnode.dn_type != DMU_OT_NONE &&
datalen >= OBJSET_PHYS_SIZE_V3) {
ret = zio_crypt_do_dnode_hmac_updates(ctx, key->zk_version,
should_bswap, &osp->os_projectused_dnode);
if (ret)
goto error;
}
crypto_mac_final(ctx, raw_local_mac, SHA512_DIGEST_LENGTH);
bcopy(raw_local_mac, local_mac, ZIO_OBJSET_MAC_LEN);
return (0);
error:
bzero(portable_mac, ZIO_OBJSET_MAC_LEN);
bzero(local_mac, ZIO_OBJSET_MAC_LEN);
return (ret);
}
static void
zio_crypt_destroy_uio(uio_t *uio)
{
if (uio->uio_iov)
kmem_free(uio->uio_iov, uio->uio_iovcnt * sizeof (iovec_t));
}
/*
* This function parses an uncompressed indirect block and returns a checksum
* of all the portable fields from all of the contained bps. The portable
* fields are the MAC and all of the fields from blk_prop except for the dedup,
* checksum, and psize bits. For an explanation of the purpose of this, see
* the comment block on object set authentication.
*/
static int
zio_crypt_do_indirect_mac_checksum_impl(boolean_t generate, void *buf,
uint_t datalen, uint64_t version, boolean_t byteswap, uint8_t *cksum)
{
blkptr_t *bp;
int i, epb = datalen >> SPA_BLKPTRSHIFT;
SHA2_CTX ctx;
uint8_t digestbuf[SHA512_DIGEST_LENGTH];
/* checksum all of the MACs from the layer below */
SHA2Init(SHA512, &ctx);
for (i = 0, bp = buf; i < epb; i++, bp++) {
zio_crypt_bp_do_indrect_checksum_updates(&ctx, version,
byteswap, bp);
}
SHA2Final(digestbuf, &ctx);
if (generate) {
bcopy(digestbuf, cksum, ZIO_DATA_MAC_LEN);
return (0);
}
if (bcmp(digestbuf, cksum, ZIO_DATA_MAC_LEN) != 0) {
#ifdef FCRYPTO_DEBUG
printf("%s(%d): Setting ECKSUM\n", __FUNCTION__, __LINE__);
#endif
return (SET_ERROR(ECKSUM));
}
return (0);
}
int
zio_crypt_do_indirect_mac_checksum(boolean_t generate, void *buf,
uint_t datalen, boolean_t byteswap, uint8_t *cksum)
{
int ret;
/*
* Unfortunately, callers of this function will not always have
* easy access to the on-disk format version. This info is
* normally found in the DSL Crypto Key, but the checksum-of-MACs
* is expected to be verifiable even when the key isn't loaded.
* Here, instead of doing a ZAP lookup for the version for each
* zio, we simply try both existing formats.
*/
ret = zio_crypt_do_indirect_mac_checksum_impl(generate, buf,
datalen, ZIO_CRYPT_KEY_CURRENT_VERSION, byteswap, cksum);
if (ret == ECKSUM) {
ASSERT(!generate);
ret = zio_crypt_do_indirect_mac_checksum_impl(generate,
buf, datalen, 0, byteswap, cksum);
}
return (ret);
}
int
zio_crypt_do_indirect_mac_checksum_abd(boolean_t generate, abd_t *abd,
uint_t datalen, boolean_t byteswap, uint8_t *cksum)
{
int ret;
void *buf;
buf = abd_borrow_buf_copy(abd, datalen);
ret = zio_crypt_do_indirect_mac_checksum(generate, buf, datalen,
byteswap, cksum);
abd_return_buf(abd, buf, datalen);
return (ret);
}
/*
* Special case handling routine for encrypting / decrypting ZIL blocks.
* We do not check for the older ZIL chain because the encryption feature
* was not available before the newer ZIL chain was introduced. The goal
* here is to encrypt everything except the blkptr_t of a lr_write_t and
* the zil_chain_t header. Everything that is not encrypted is authenticated.
*/
/*
* The OpenCrypto used in FreeBSD does not use separate source and
* destination buffers; instead, the same buffer is used. Further, to
* accommodate some of the drivers, the authbuf needs to be logically before
* the data. This means that we need to copy the source to the destination,
* and set up an extra iovec_t at the beginning to handle the authbuf.
* It also means we'll only return one uio_t.
*/
/* ARGSUSED */
static int
zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
uint8_t *cipherbuf, uint_t datalen, boolean_t byteswap, uio_t *puio,
uio_t *out_uio, uint_t *enc_len, uint8_t **authbuf, uint_t *auth_len,
boolean_t *no_crypt)
{
uint8_t *aadbuf = zio_buf_alloc(datalen);
uint8_t *src, *dst, *slrp, *dlrp, *blkend, *aadp;
iovec_t *dst_iovecs;
zil_chain_t *zilc;
lr_t *lr;
uint64_t txtype, lr_len;
uint_t crypt_len, nr_iovecs, vec;
uint_t aad_len = 0, total_len = 0;
if (encrypt) {
src = plainbuf;
dst = cipherbuf;
} else {
src = cipherbuf;
dst = plainbuf;
}
bcopy(src, dst, datalen);
/* Find the start and end record of the log block. */
zilc = (zil_chain_t *)src;
slrp = src + sizeof (zil_chain_t);
aadp = aadbuf;
blkend = src + ((byteswap) ? BSWAP_64(zilc->zc_nused) : zilc->zc_nused);
/*
* Calculate the number of encrypted iovecs we will need.
*/
/* We need at least two iovecs -- one for the AAD, one for the MAC. */
nr_iovecs = 2;
for (; slrp < blkend; slrp += lr_len) {
lr = (lr_t *)slrp;
if (byteswap) {
txtype = BSWAP_64(lr->lrc_txtype);
lr_len = BSWAP_64(lr->lrc_reclen);
} else {
txtype = lr->lrc_txtype;
lr_len = lr->lrc_reclen;
}
nr_iovecs++;
if (txtype == TX_WRITE && lr_len != sizeof (lr_write_t))
nr_iovecs++;
}
dst_iovecs = kmem_alloc(nr_iovecs * sizeof (iovec_t), KM_SLEEP);
/*
* Copy the plain zil header over and authenticate everything except
* the checksum that will store our MAC. If we are writing the data
* the embedded checksum will not have been calculated yet, so we don't
* authenticate that.
*/
bcopy(src, aadp, sizeof (zil_chain_t) - sizeof (zio_eck_t));
aadp += sizeof (zil_chain_t) - sizeof (zio_eck_t);
aad_len += sizeof (zil_chain_t) - sizeof (zio_eck_t);
slrp = src + sizeof (zil_chain_t);
dlrp = dst + sizeof (zil_chain_t);
/*
* Loop over records again, filling in iovecs.
*/
/* The first iovec will contain the authbuf. */
vec = 1;
for (; slrp < blkend; slrp += lr_len, dlrp += lr_len) {
lr = (lr_t *)slrp;
if (!byteswap) {
txtype = lr->lrc_txtype;
lr_len = lr->lrc_reclen;
} else {
txtype = BSWAP_64(lr->lrc_txtype);
lr_len = BSWAP_64(lr->lrc_reclen);
}
/* copy the common lr_t */
bcopy(slrp, dlrp, sizeof (lr_t));
bcopy(slrp, aadp, sizeof (lr_t));
aadp += sizeof (lr_t);
aad_len += sizeof (lr_t);
/*
* If this is a TX_WRITE record we want to encrypt everything
* except the bp if exists. If the bp does exist we want to
* authenticate it.
*/
if (txtype == TX_WRITE) {
crypt_len = sizeof (lr_write_t) -
sizeof (lr_t) - sizeof (blkptr_t);
dst_iovecs[vec].iov_base = (char *)dlrp +
sizeof (lr_t);
dst_iovecs[vec].iov_len = crypt_len;
/* copy the bp now since it will not be encrypted */
bcopy(slrp + sizeof (lr_write_t) - sizeof (blkptr_t),
dlrp + sizeof (lr_write_t) - sizeof (blkptr_t),
sizeof (blkptr_t));
bcopy(slrp + sizeof (lr_write_t) - sizeof (blkptr_t),
aadp, sizeof (blkptr_t));
aadp += sizeof (blkptr_t);
aad_len += sizeof (blkptr_t);
vec++;
total_len += crypt_len;
if (lr_len != sizeof (lr_write_t)) {
crypt_len = lr_len - sizeof (lr_write_t);
dst_iovecs[vec].iov_base = (char *)
dlrp + sizeof (lr_write_t);
dst_iovecs[vec].iov_len = crypt_len;
vec++;
total_len += crypt_len;
}
} else {
crypt_len = lr_len - sizeof (lr_t);
dst_iovecs[vec].iov_base = (char *)dlrp +
sizeof (lr_t);
dst_iovecs[vec].iov_len = crypt_len;
vec++;
total_len += crypt_len;
}
}
/* The last iovec will contain the MAC. */
ASSERT3U(vec, ==, nr_iovecs - 1);
/* AAD */
dst_iovecs[0].iov_base = aadbuf;
dst_iovecs[0].iov_len = aad_len;
/* MAC */
dst_iovecs[vec].iov_base = 0;
dst_iovecs[vec].iov_len = 0;
*no_crypt = (vec == 1);
*enc_len = total_len;
*authbuf = aadbuf;
*auth_len = aad_len;
out_uio->uio_iov = dst_iovecs;
out_uio->uio_iovcnt = nr_iovecs;
return (0);
}
/*
* Special case handling routine for encrypting / decrypting dnode blocks.
*/
static int
zio_crypt_init_uios_dnode(boolean_t encrypt, uint64_t version,
uint8_t *plainbuf, uint8_t *cipherbuf, uint_t datalen, boolean_t byteswap,
uio_t *puio, uio_t *out_uio, uint_t *enc_len, uint8_t **authbuf,
uint_t *auth_len, boolean_t *no_crypt)
{
uint8_t *aadbuf = zio_buf_alloc(datalen);
uint8_t *src, *dst, *aadp;
dnode_phys_t *dnp, *adnp, *sdnp, *ddnp;
iovec_t *dst_iovecs;
uint_t nr_iovecs, crypt_len, vec;
uint_t aad_len = 0, total_len = 0;
uint_t i, j, max_dnp = datalen >> DNODE_SHIFT;
if (encrypt) {
src = plainbuf;
dst = cipherbuf;
} else {
src = cipherbuf;
dst = plainbuf;
}
bcopy(src, dst, datalen);
sdnp = (dnode_phys_t *)src;
ddnp = (dnode_phys_t *)dst;
aadp = aadbuf;
/*
* Count the number of iovecs we will need to do the encryption by
* counting the number of bonus buffers that need to be encrypted.
*/
/* We need at least two iovecs -- one for the AAD, one for the MAC. */
nr_iovecs = 2;
for (i = 0; i < max_dnp; i += sdnp[i].dn_extra_slots + 1) {
/*
* This block may still be byteswapped. However, all of the
* values we use are either uint8_t's (for which byteswapping
* is a noop) or a * != 0 check, which will work regardless
* of whether or not we byteswap.
*/
if (sdnp[i].dn_type != DMU_OT_NONE &&
DMU_OT_IS_ENCRYPTED(sdnp[i].dn_bonustype) &&
sdnp[i].dn_bonuslen != 0) {
nr_iovecs++;
}
}
dst_iovecs = kmem_alloc(nr_iovecs * sizeof (iovec_t), KM_SLEEP);
/*
* Iterate through the dnodes again, this time filling in the uios
* we allocated earlier. We also concatenate any data we want to
* authenticate onto aadbuf.
*/
/* The first iovec will contain the authbuf. */
vec = 1;
for (i = 0; i < max_dnp; i += sdnp[i].dn_extra_slots + 1) {
dnp = &sdnp[i];
/* copy over the core fields and blkptrs (kept as plaintext) */
bcopy(dnp, &ddnp[i], (uint8_t *)DN_BONUS(dnp) - (uint8_t *)dnp);
if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
bcopy(DN_SPILL_BLKPTR(dnp), DN_SPILL_BLKPTR(&ddnp[i]),
sizeof (blkptr_t));
}
/*
* Handle authenticated data. We authenticate everything in
* the dnode that can be brought over when we do a raw send.
* This includes all of the core fields as well as the MACs
* stored in the bp checksums and all of the portable bits
* from blk_prop. We include the dnode padding here in case it
* ever gets used in the future. Some dn_flags and dn_used are
* not portable so we mask those out values out of the
* authenticated data.
*/
crypt_len = offsetof(dnode_phys_t, dn_blkptr);
bcopy(dnp, aadp, crypt_len);
adnp = (dnode_phys_t *)aadp;
adnp->dn_flags &= DNODE_CRYPT_PORTABLE_FLAGS_MASK;
adnp->dn_used = 0;
aadp += crypt_len;
aad_len += crypt_len;
for (j = 0; j < dnp->dn_nblkptr; j++) {
zio_crypt_bp_do_aad_updates(&aadp, &aad_len,
version, byteswap, &dnp->dn_blkptr[j]);
}
if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
zio_crypt_bp_do_aad_updates(&aadp, &aad_len,
version, byteswap, DN_SPILL_BLKPTR(dnp));
}
/*
* If this bonus buffer needs to be encrypted, we prepare an
* iovec_t. The encryption / decryption functions will fill
* this in for us with the encrypted or decrypted data.
* Otherwise we add the bonus buffer to the authenticated
* data buffer and copy it over to the destination. The
* encrypted iovec extends to DN_MAX_BONUS_LEN(dnp) so that
* we can guarantee alignment with the AES block size
* (128 bits).
*/
crypt_len = DN_MAX_BONUS_LEN(dnp);
if (dnp->dn_type != DMU_OT_NONE &&
DMU_OT_IS_ENCRYPTED(dnp->dn_bonustype) &&
dnp->dn_bonuslen != 0) {
dst_iovecs[vec].iov_base = DN_BONUS(&ddnp[i]);
dst_iovecs[vec].iov_len = crypt_len;
vec++;
total_len += crypt_len;
} else {
bcopy(DN_BONUS(dnp), DN_BONUS(&ddnp[i]), crypt_len);
bcopy(DN_BONUS(dnp), aadp, crypt_len);
aadp += crypt_len;
aad_len += crypt_len;
}
}
/* The last iovec will contain the MAC. */
ASSERT3U(vec, ==, nr_iovecs - 1);
/* AAD */
dst_iovecs[0].iov_base = aadbuf;
dst_iovecs[0].iov_len = aad_len;
/* MAC */
dst_iovecs[vec].iov_base = 0;
dst_iovecs[vec].iov_len = 0;
*no_crypt = (vec == 1);
*enc_len = total_len;
*authbuf = aadbuf;
*auth_len = aad_len;
out_uio->uio_iov = dst_iovecs;
out_uio->uio_iovcnt = nr_iovecs;
return (0);
}
/* ARGSUSED */
static int
zio_crypt_init_uios_normal(boolean_t encrypt, uint8_t *plainbuf,
uint8_t *cipherbuf, uint_t datalen, uio_t *puio, uio_t *out_uio,
uint_t *enc_len)
{
int ret;
uint_t nr_plain = 1, nr_cipher = 2;
iovec_t *plain_iovecs = NULL, *cipher_iovecs = NULL;
void *src, *dst;
cipher_iovecs = kmem_alloc(nr_cipher * sizeof (iovec_t),
KM_SLEEP);
if (!cipher_iovecs) {
ret = SET_ERROR(ENOMEM);
goto error;
}
bzero(cipher_iovecs, nr_cipher * sizeof (iovec_t));
if (encrypt) {
src = plainbuf;
dst = cipherbuf;
} else {
src = cipherbuf;
dst = plainbuf;
}
bcopy(src, dst, datalen);
cipher_iovecs[0].iov_base = dst;
cipher_iovecs[0].iov_len = datalen;
*enc_len = datalen;
out_uio->uio_iov = cipher_iovecs;
out_uio->uio_iovcnt = nr_cipher;
return (0);
error:
if (plain_iovecs != NULL)
kmem_free(plain_iovecs, nr_plain * sizeof (iovec_t));
if (cipher_iovecs != NULL)
kmem_free(cipher_iovecs, nr_cipher * sizeof (iovec_t));
*enc_len = 0;
out_uio->uio_iov = NULL;
out_uio->uio_iovcnt = 0;
return (ret);
}
/*
* This function builds up the plaintext (puio) and ciphertext (cuio) uios so
* that they can be used for encryption and decryption by zio_do_crypt_uio().
* Most blocks will use zio_crypt_init_uios_normal(), with ZIL and dnode blocks
* requiring special handling to parse out pieces that are to be encrypted. The
* authbuf is used by these special cases to store additional authenticated
* data (AAD) for the encryption modes.
*/
static int
zio_crypt_init_uios(boolean_t encrypt, uint64_t version, dmu_object_type_t ot,
uint8_t *plainbuf, uint8_t *cipherbuf, uint_t datalen, boolean_t byteswap,
uint8_t *mac, uio_t *puio, uio_t *cuio, uint_t *enc_len, uint8_t **authbuf,
uint_t *auth_len, boolean_t *no_crypt)
{
int ret;
iovec_t *mac_iov;
ASSERT(DMU_OT_IS_ENCRYPTED(ot) || ot == DMU_OT_NONE);
/* route to handler */
switch (ot) {
case DMU_OT_INTENT_LOG:
ret = zio_crypt_init_uios_zil(encrypt, plainbuf, cipherbuf,
datalen, byteswap, puio, cuio, enc_len, authbuf, auth_len,
no_crypt);
break;
case DMU_OT_DNODE:
ret = zio_crypt_init_uios_dnode(encrypt, version, plainbuf,
cipherbuf, datalen, byteswap, puio, cuio, enc_len, authbuf,
auth_len, no_crypt);
break;
default:
ret = zio_crypt_init_uios_normal(encrypt, plainbuf, cipherbuf,
datalen, puio, cuio, enc_len);
*authbuf = NULL;
*auth_len = 0;
*no_crypt = B_FALSE;
break;
}
if (ret != 0)
goto error;
/* populate the uios */
cuio->uio_segflg = UIO_SYSSPACE;
mac_iov = ((iovec_t *)&cuio->uio_iov[cuio->uio_iovcnt - 1]);
mac_iov->iov_base = (void *)mac;
mac_iov->iov_len = ZIO_DATA_MAC_LEN;
return (0);
error:
return (ret);
}
void *failed_decrypt_buf;
int faile_decrypt_size;
/*
* Primary encryption / decryption entrypoint for zio data.
*/
int
zio_do_crypt_data(boolean_t encrypt, zio_crypt_key_t *key,
dmu_object_type_t ot, boolean_t byteswap, uint8_t *salt, uint8_t *iv,
uint8_t *mac, uint_t datalen, uint8_t *plainbuf, uint8_t *cipherbuf,
boolean_t *no_crypt)
{
int ret;
boolean_t locked = B_FALSE;
uint64_t crypt = key->zk_crypt;
uint_t keydata_len = zio_crypt_table[crypt].ci_keylen;
uint_t enc_len, auth_len;
uio_t puio, cuio;
uint8_t enc_keydata[MASTER_KEY_MAX_LEN];
crypto_key_t tmp_ckey, *ckey = NULL;
freebsd_crypt_session_t *tmpl = NULL;
uint8_t *authbuf = NULL;
bzero(&puio, sizeof (uio_t));
bzero(&cuio, sizeof (uio_t));
#ifdef FCRYPTO_DEBUG
printf("%s(%s, %p, %p, %d, %p, %p, %u, %s, %p, %p, %p)\n",
__FUNCTION__,
encrypt ? "encrypt" : "decrypt",
key, salt, ot, iv, mac, datalen,
byteswap ? "byteswap" : "native_endian", plainbuf,
cipherbuf, no_crypt);
printf("\tkey = {");
for (int i = 0; i < key->zk_current_key.ck_length/8; i++)
printf("%02x ", ((uint8_t *)key->zk_current_key.ck_data)[i]);
printf("}\n");
#endif
/* create uios for encryption */
ret = zio_crypt_init_uios(encrypt, key->zk_version, ot, plainbuf,
cipherbuf, datalen, byteswap, mac, &puio, &cuio, &enc_len,
&authbuf, &auth_len, no_crypt);
if (ret != 0)
return (ret);
/*
* If the needed key is the current one, just use it. Otherwise we
* need to generate a temporary one from the given salt + master key.
* If we are encrypting, we must return a copy of the current salt
* so that it can be stored in the blkptr_t.
*/
rw_enter(&key->zk_salt_lock, RW_READER);
locked = B_TRUE;
if (bcmp(salt, key->zk_salt, ZIO_DATA_SALT_LEN) == 0) {
ckey = &key->zk_current_key;
tmpl = &key->zk_session;
} else {
rw_exit(&key->zk_salt_lock);
locked = B_FALSE;
ret = hkdf_sha512(key->zk_master_keydata, keydata_len, NULL, 0,
salt, ZIO_DATA_SALT_LEN, enc_keydata, keydata_len);
if (ret != 0)
goto error;
tmp_ckey.ck_format = CRYPTO_KEY_RAW;
tmp_ckey.ck_data = enc_keydata;
tmp_ckey.ck_length = CRYPTO_BYTES2BITS(keydata_len);
ckey = &tmp_ckey;
tmpl = NULL;
}
/* perform the encryption / decryption */
ret = zio_do_crypt_uio_opencrypto(encrypt, tmpl, key->zk_crypt,
ckey, iv, enc_len, &cuio, auth_len);
if (ret != 0)
goto error;
if (locked) {
rw_exit(&key->zk_salt_lock);
locked = B_FALSE;
}
if (authbuf != NULL)
zio_buf_free(authbuf, datalen);
if (ckey == &tmp_ckey)
bzero(enc_keydata, keydata_len);
zio_crypt_destroy_uio(&puio);
zio_crypt_destroy_uio(&cuio);
return (0);
error:
if (!encrypt) {
if (failed_decrypt_buf != NULL)
kmem_free(failed_decrypt_buf, failed_decrypt_size);
failed_decrypt_buf = kmem_alloc(datalen, KM_SLEEP);
failed_decrypt_size = datalen;
bcopy(cipherbuf, failed_decrypt_buf, datalen);
}
if (locked)
rw_exit(&key->zk_salt_lock);
if (authbuf != NULL)
zio_buf_free(authbuf, datalen);
if (ckey == &tmp_ckey)
bzero(enc_keydata, keydata_len);
zio_crypt_destroy_uio(&puio);
zio_crypt_destroy_uio(&cuio);
return (SET_ERROR(ret));
}
/*
* Simple wrapper around zio_do_crypt_data() to work with abd's instead of
* linear buffers.
*/
int
zio_do_crypt_abd(boolean_t encrypt, zio_crypt_key_t *key, dmu_object_type_t ot,
boolean_t byteswap, uint8_t *salt, uint8_t *iv, uint8_t *mac,
uint_t datalen, abd_t *pabd, abd_t *cabd, boolean_t *no_crypt)
{
int ret;
void *ptmp, *ctmp;
if (encrypt) {
ptmp = abd_borrow_buf_copy(pabd, datalen);
ctmp = abd_borrow_buf(cabd, datalen);
} else {
ptmp = abd_borrow_buf(pabd, datalen);
ctmp = abd_borrow_buf_copy(cabd, datalen);
}
ret = zio_do_crypt_data(encrypt, key, ot, byteswap, salt, iv, mac,
datalen, ptmp, ctmp, no_crypt);
if (ret != 0)
goto error;
if (encrypt) {
abd_return_buf(pabd, ptmp, datalen);
abd_return_buf_copy(cabd, ctmp, datalen);
} else {
abd_return_buf_copy(pabd, ptmp, datalen);
abd_return_buf(cabd, ctmp, datalen);
}
return (0);
error:
if (encrypt) {
abd_return_buf(pabd, ptmp, datalen);
abd_return_buf_copy(cabd, ctmp, datalen);
} else {
abd_return_buf_copy(pabd, ptmp, datalen);
abd_return_buf(cabd, ctmp, datalen);
}
return (SET_ERROR(ret));
}
#if defined(_KERNEL) && defined(HAVE_SPL)
/* BEGIN CSTYLED */
module_param(zfs_key_max_salt_uses, ulong, 0644);
MODULE_PARM_DESC(zfs_key_max_salt_uses, "Max number of times a salt value "
"can be used for generating encryption keys before it is rotated");
/* END CSTYLED */
#endif
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