4 * This file and its contents are supplied under the terms of the
5 * Common Development and Distribution License ("CDDL"), version 1.0.
6 * You may only use this file in accordance with the terms of version
9 * A full copy of the text of the CDDL should have accompanied this
10 * source. A copy of the CDDL is also available via the Internet at
11 * http://www.illumos.org/license/CDDL.
17 * Copyright (c) 2017, Datto, Inc. All rights reserved.
20 #include <sys/zio_crypt.h>
22 #include <sys/dmu_objset.h>
23 #include <sys/dnode.h>
24 #include <sys/fs/zfs.h>
32 * This file is responsible for handling all of the details of generating
33 * encryption parameters and performing encryption and authentication.
35 * BLOCK ENCRYPTION PARAMETERS:
36 * Encryption /Authentication Algorithm Suite (crypt):
37 * The encryption algorithm, mode, and key length we are going to use. We
38 * currently support AES in either GCM or CCM modes with 128, 192, and 256 bit
39 * keys. All authentication is currently done with SHA512-HMAC.
42 * The unencrypted data that we want to encrypt.
44 * Initialization Vector (IV):
45 * An initialization vector for the encryption algorithms. This is used to
46 * "tweak" the encryption algorithms so that two blocks of the same data are
47 * encrypted into different ciphertext outputs, thus obfuscating block patterns.
48 * The supported encryption modes (AES-GCM and AES-CCM) require that an IV is
49 * never reused with the same encryption key. This value is stored unencrypted
50 * and must simply be provided to the decryption function. We use a 96 bit IV
51 * (as recommended by NIST) for all block encryption. For non-dedup blocks we
52 * derive the IV randomly. The first 64 bits of the IV are stored in the second
53 * word of DVA[2] and the remaining 32 bits are stored in the upper 32 bits of
54 * blk_fill. This is safe because encrypted blocks can't use the upper 32 bits
55 * of blk_fill. We only encrypt level 0 blocks, which normally have a fill count
56 * of 1. The only exception is for DMU_OT_DNODE objects, where the fill count of
57 * level 0 blocks is the number of allocated dnodes in that block. The on-disk
58 * format supports at most 2^15 slots per L0 dnode block, because the maximum
59 * block size is 16MB (2^24). In either case, for level 0 blocks this number
60 * will still be smaller than UINT32_MAX so it is safe to store the IV in the
61 * top 32 bits of blk_fill, while leaving the bottom 32 bits of the fill count
65 * This is the most important secret data of an encrypted dataset. It is used
66 * along with the salt to generate that actual encryption keys via HKDF. We
67 * do not use the master key to directly encrypt any data because there are
68 * theoretical limits on how much data can actually be safely encrypted with
69 * any encryption mode. The master key is stored encrypted on disk with the
70 * user's wrapping key. Its length is determined by the encryption algorithm.
71 * For details on how this is stored see the block comment in dsl_crypt.c
74 * Used as an input to the HKDF function, along with the master key. We use a
75 * 64 bit salt, stored unencrypted in the first word of DVA[2]. Any given salt
76 * can be used for encrypting many blocks, so we cache the current salt and the
77 * associated derived key in zio_crypt_t so we do not need to derive it again
81 * A secret binary key, generated from an HKDF function used to encrypt and
84 * Message Authentication Code (MAC)
85 * The MAC is an output of authenticated encryption modes such as AES-GCM and
86 * AES-CCM. Its purpose is to ensure that an attacker cannot modify encrypted
87 * data on disk and return garbage to the application. Effectively, it is a
88 * checksum that can not be reproduced by an attacker. We store the MAC in the
89 * second 128 bits of blk_cksum, leaving the first 128 bits for a truncated
90 * regular checksum of the ciphertext which can be used for scrubbing.
92 * OBJECT AUTHENTICATION:
93 * Some object types, such as DMU_OT_MASTER_NODE cannot be encrypted because
94 * they contain some info that always needs to be readable. To prevent this
95 * data from being altered, we authenticate this data using SHA512-HMAC. This
96 * will produce a MAC (similar to the one produced via encryption) which can
97 * be used to verify the object was not modified. HMACs do not require key
98 * rotation or IVs, so we can keep up to the full 3 copies of authenticated
102 * ZIL blocks have their bp written to disk ahead of the associated data, so we
103 * cannot store the MAC there as we normally do. For these blocks the MAC is
104 * stored in the embedded checksum within the zil_chain_t header. The salt and
105 * IV are generated for the block on bp allocation instead of at encryption
106 * time. In addition, ZIL blocks have some pieces that must be left in plaintext
107 * for claiming even though all of the sensitive user data still needs to be
108 * encrypted. The function zio_crypt_init_uios_zil() handles parsing which
109 * pieces of the block need to be encrypted. All data that is not encrypted is
110 * authenticated using the AAD mechanisms that the supported encryption modes
111 * provide for. In order to preserve the semantics of the ZIL for encrypted
112 * datasets, the ZIL is not protected at the objset level as described below.
115 * Similarly to ZIL blocks, the core part of each dnode_phys_t needs to be left
116 * in plaintext for scrubbing and claiming, but the bonus buffers might contain
117 * sensitive user data. The function zio_crypt_init_uios_dnode() handles parsing
118 * which which pieces of the block need to be encrypted. For more details about
119 * dnode authentication and encryption, see zio_crypt_init_uios_dnode().
121 * OBJECT SET AUTHENTICATION:
122 * Up to this point, everything we have encrypted and authenticated has been
123 * at level 0 (or -2 for the ZIL). If we did not do any further work the
124 * on-disk format would be susceptible to attacks that deleted or rearranged
125 * the order of level 0 blocks. Ideally, the cleanest solution would be to
126 * maintain a tree of authentication MACs going up the bp tree. However, this
127 * presents a problem for raw sends. Send files do not send information about
128 * indirect blocks so there would be no convenient way to transfer the MACs and
129 * they cannot be recalculated on the receive side without the master key which
130 * would defeat one of the purposes of raw sends in the first place. Instead,
131 * for the indirect levels of the bp tree, we use a regular SHA512 of the MACs
132 * from the level below. We also include some portable fields from blk_prop such
133 * as the lsize and compression algorithm to prevent the data from being
136 * At the objset level, we maintain 2 separate 256 bit MACs in the
137 * objset_phys_t. The first one is "portable" and is the logical root of the
138 * MAC tree maintained in the metadnode's bps. The second, is "local" and is
139 * used as the root MAC for the user accounting objects, which are also not
140 * transferred via "zfs send". The portable MAC is sent in the DRR_BEGIN payload
141 * of the send file. The useraccounting code ensures that the useraccounting
142 * info is not present upon a receive, so the local MAC can simply be cleared
143 * out at that time. For more info about objset_phys_t authentication, see
144 * zio_crypt_do_objset_hmacs().
146 * CONSIDERATIONS FOR DEDUP:
147 * In order for dedup to work, blocks that we want to dedup with one another
148 * need to use the same IV and encryption key, so that they will have the same
149 * ciphertext. Normally, one should never reuse an IV with the same encryption
150 * key or else AES-GCM and AES-CCM can both actually leak the plaintext of both
151 * blocks. In this case, however, since we are using the same plaintext as
152 * well all that we end up with is a duplicate of the original ciphertext we
153 * already had. As a result, an attacker with read access to the raw disk will
154 * be able to tell which blocks are the same but this information is given away
155 * by dedup anyway. In order to get the same IVs and encryption keys for
156 * equivalent blocks of data we use an HMAC of the plaintext. We use an HMAC
157 * here so that a reproducible checksum of the plaintext is never available to
158 * the attacker. The HMAC key is kept alongside the master key, encrypted on
159 * disk. The first 64 bits of the HMAC are used in place of the random salt, and
160 * the next 96 bits are used as the IV. As a result of this mechanism, dedup
161 * will only work within a clone family since encrypted dedup requires use of
162 * the same master and HMAC keys.
166 * After encrypting many blocks with the same key we may start to run up
167 * against the theoretical limits of how much data can securely be encrypted
168 * with a single key using the supported encryption modes. The most obvious
169 * limitation is that our risk of generating 2 equivalent 96 bit IVs increases
170 * the more IVs we generate (which both GCM and CCM modes strictly forbid).
171 * This risk actually grows surprisingly quickly over time according to the
172 * Birthday Problem. With a total IV space of 2^(96 bits), and assuming we have
173 * generated n IVs with a cryptographically secure RNG, the approximate
174 * probability p(n) of a collision is given as:
176 * p(n) ~= e^(-n*(n-1)/(2*(2^96)))
178 * [http://www.math.cornell.edu/~mec/2008-2009/TianyiZheng/Birthday.html]
180 * Assuming that we want to ensure that p(n) never goes over 1 / 1 trillion
181 * we must not write more than 398,065,730 blocks with the same encryption key.
182 * Therefore, we rotate our keys after 400,000,000 blocks have been written by
183 * generating a new random 64 bit salt for our HKDF encryption key generation
186 #define ZFS_KEY_MAX_SALT_USES_DEFAULT 400000000
187 #define ZFS_CURRENT_MAX_SALT_USES \
188 (MIN(zfs_key_max_salt_uses, ZFS_KEY_MAX_SALT_USES_DEFAULT))
189 unsigned long zfs_key_max_salt_uses = ZFS_KEY_MAX_SALT_USES_DEFAULT;
191 typedef struct blkptr_auth_buf {
192 uint64_t bab_prop; /* blk_prop - portable mask */
193 uint8_t bab_mac[ZIO_DATA_MAC_LEN]; /* MAC from blk_cksum */
\r
194 uint64_t bab_pad; /* reserved for future use */
197 zio_crypt_info_t zio_crypt_table[ZIO_CRYPT_FUNCTIONS] = {
198 {"", ZC_TYPE_NONE, 0, "inherit"},
199 {"", ZC_TYPE_NONE, 0, "on"},
200 {"", ZC_TYPE_NONE, 0, "off"},
201 {SUN_CKM_AES_CCM, ZC_TYPE_CCM, 16, "aes-128-ccm"},
202 {SUN_CKM_AES_CCM, ZC_TYPE_CCM, 24, "aes-192-ccm"},
203 {SUN_CKM_AES_CCM, ZC_TYPE_CCM, 32, "aes-256-ccm"},
204 {SUN_CKM_AES_GCM, ZC_TYPE_GCM, 16, "aes-128-gcm"},
205 {SUN_CKM_AES_GCM, ZC_TYPE_GCM, 24, "aes-192-gcm"},
206 {SUN_CKM_AES_GCM, ZC_TYPE_GCM, 32, "aes-256-gcm"}
210 zio_crypt_key_destroy(zio_crypt_key_t *key)
212 rw_destroy(&key->zk_salt_lock);
214 /* free crypto templates */
215 crypto_destroy_ctx_template(key->zk_current_tmpl);
216 crypto_destroy_ctx_template(key->zk_hmac_tmpl);
218 /* zero out sensitive data */
219 bzero(key, sizeof (zio_crypt_key_t));
223 zio_crypt_key_init(uint64_t crypt, zio_crypt_key_t *key)
226 crypto_mechanism_t mech;
230 ASSERT3U(crypt, <, ZIO_CRYPT_FUNCTIONS);
232 keydata_len = zio_crypt_table[crypt].ci_keylen;
233 bzero(key, sizeof (zio_crypt_key_t));
235 /* fill keydata buffers and salt with random data */
236 ret = random_get_bytes((uint8_t *)&key->zk_guid, sizeof (uint64_t));
240 ret = random_get_bytes(key->zk_master_keydata, keydata_len);
244 ret = random_get_bytes(key->zk_hmac_keydata, SHA512_HMAC_KEYLEN);
248 ret = random_get_bytes(key->zk_salt, ZIO_DATA_SALT_LEN);
252 /* derive the current key from the master key */
253 ret = hkdf_sha512(key->zk_master_keydata, keydata_len, NULL, 0,
254 key->zk_salt, ZIO_DATA_SALT_LEN, key->zk_current_keydata,
259 /* initialize keys for the ICP */
260 key->zk_current_key.ck_format = CRYPTO_KEY_RAW;
261 key->zk_current_key.ck_data = key->zk_current_keydata;
262 key->zk_current_key.ck_length = CRYPTO_BYTES2BITS(keydata_len);
264 key->zk_hmac_key.ck_format = CRYPTO_KEY_RAW;
265 key->zk_hmac_key.ck_data = &key->zk_hmac_key;
266 key->zk_hmac_key.ck_length = CRYPTO_BYTES2BITS(SHA512_HMAC_KEYLEN);
269 * Initialize the crypto templates. It's ok if this fails because
270 * this is just an optimization.
272 mech.cm_type = crypto_mech2id(zio_crypt_table[crypt].ci_mechname);
273 ret = crypto_create_ctx_template(&mech, &key->zk_current_key,
274 &key->zk_current_tmpl, KM_SLEEP);
275 if (ret != CRYPTO_SUCCESS)
276 key->zk_current_tmpl = NULL;
278 mech.cm_type = crypto_mech2id(SUN_CKM_SHA512_HMAC);
279 ret = crypto_create_ctx_template(&mech, &key->zk_hmac_key,
280 &key->zk_hmac_tmpl, KM_SLEEP);
281 if (ret != CRYPTO_SUCCESS)
282 key->zk_hmac_tmpl = NULL;
284 key->zk_crypt = crypt;
285 key->zk_version = ZIO_CRYPT_KEY_CURRENT_VERSION;
286 key->zk_salt_count = 0;
287 rw_init(&key->zk_salt_lock, NULL, RW_DEFAULT, NULL);
292 zio_crypt_key_destroy(key);
297 zio_crypt_key_change_salt(zio_crypt_key_t *key)
300 uint8_t salt[ZIO_DATA_SALT_LEN];
301 crypto_mechanism_t mech;
302 uint_t keydata_len = zio_crypt_table[key->zk_crypt].ci_keylen;
304 /* generate a new salt */
305 ret = random_get_bytes(salt, ZIO_DATA_SALT_LEN);
309 rw_enter(&key->zk_salt_lock, RW_WRITER);
311 /* someone beat us to the salt rotation, just unlock and return */
312 if (key->zk_salt_count < ZFS_CURRENT_MAX_SALT_USES)
315 /* derive the current key from the master key and the new salt */
316 ret = hkdf_sha512(key->zk_master_keydata, keydata_len, NULL, 0,
317 salt, ZIO_DATA_SALT_LEN, key->zk_current_keydata, keydata_len);
321 /* assign the salt and reset the usage count */
322 bcopy(salt, key->zk_salt, ZIO_DATA_SALT_LEN);
323 key->zk_salt_count = 0;
325 /* destroy the old context template and create the new one */
326 crypto_destroy_ctx_template(key->zk_current_tmpl);
327 ret = crypto_create_ctx_template(&mech, &key->zk_current_key,
328 &key->zk_current_tmpl, KM_SLEEP);
329 if (ret != CRYPTO_SUCCESS)
330 key->zk_current_tmpl = NULL;
332 rw_exit(&key->zk_salt_lock);
337 rw_exit(&key->zk_salt_lock);
342 /* See comment above zfs_key_max_salt_uses definition for details */
344 zio_crypt_key_get_salt(zio_crypt_key_t *key, uint8_t *salt)
347 boolean_t salt_change;
349 rw_enter(&key->zk_salt_lock, RW_READER);
351 bcopy(key->zk_salt, salt, ZIO_DATA_SALT_LEN);
352 salt_change = (atomic_inc_64_nv(&key->zk_salt_count) >=
353 ZFS_CURRENT_MAX_SALT_USES);
355 rw_exit(&key->zk_salt_lock);
358 ret = zio_crypt_key_change_salt(key);
370 * This function handles all encryption and decryption in zfs. When
371 * encrypting it expects puio to reference the plaintext and cuio to
372 * reference the ciphertext. cuio must have enough space for the
373 * ciphertext + room for a MAC. datalen should be the length of the
374 * plaintext / ciphertext alone.
377 zio_do_crypt_uio(boolean_t encrypt, uint64_t crypt, crypto_key_t *key,
378 crypto_ctx_template_t tmpl, uint8_t *ivbuf, uint_t datalen,
379 uio_t *puio, uio_t *cuio, uint8_t *authbuf, uint_t auth_len)
382 crypto_data_t plaindata, cipherdata;
383 CK_AES_CCM_PARAMS ccmp;
384 CK_AES_GCM_PARAMS gcmp;
385 crypto_mechanism_t mech;
386 zio_crypt_info_t crypt_info;
387 uint_t plain_full_len, maclen;
389 ASSERT3U(crypt, <, ZIO_CRYPT_FUNCTIONS);
390 ASSERT3U(key->ck_format, ==, CRYPTO_KEY_RAW);
392 /* lookup the encryption info */
393 crypt_info = zio_crypt_table[crypt];
395 /* the mac will always be the last iovec_t in the cipher uio */
396 maclen = cuio->uio_iov[cuio->uio_iovcnt - 1].iov_len;
398 ASSERT(maclen <= ZIO_DATA_MAC_LEN);
400 /* setup encryption mechanism (same as crypt) */
401 mech.cm_type = crypto_mech2id(crypt_info.ci_mechname);
404 * Strangely, the ICP requires that plain_full_len must include
405 * the MAC length when decrypting, even though the UIO does not
406 * need to have the extra space allocated.
409 plain_full_len = datalen;
411 plain_full_len = datalen + maclen;
415 * setup encryption params (currently only AES CCM and AES GCM
418 if (crypt_info.ci_crypt_type == ZC_TYPE_CCM) {
419 ccmp.ulNonceSize = ZIO_DATA_IV_LEN;
420 ccmp.ulAuthDataSize = auth_len;
421 ccmp.authData = authbuf;
422 ccmp.ulMACSize = maclen;
424 ccmp.ulDataSize = plain_full_len;
426 mech.cm_param = (char *)(&ccmp);
427 mech.cm_param_len = sizeof (CK_AES_CCM_PARAMS);
429 gcmp.ulIvLen = ZIO_DATA_IV_LEN;
430 gcmp.ulIvBits = CRYPTO_BYTES2BITS(ZIO_DATA_IV_LEN);
431 gcmp.ulAADLen = auth_len;
433 gcmp.ulTagBits = CRYPTO_BYTES2BITS(maclen);
436 mech.cm_param = (char *)(&gcmp);
437 mech.cm_param_len = sizeof (CK_AES_GCM_PARAMS);
440 /* populate the cipher and plain data structs. */
441 plaindata.cd_format = CRYPTO_DATA_UIO;
442 plaindata.cd_offset = 0;
443 plaindata.cd_uio = puio;
444 plaindata.cd_miscdata = NULL;
445 plaindata.cd_length = plain_full_len;
447 cipherdata.cd_format = CRYPTO_DATA_UIO;
448 cipherdata.cd_offset = 0;
449 cipherdata.cd_uio = cuio;
450 cipherdata.cd_miscdata = NULL;
451 cipherdata.cd_length = datalen + maclen;
453 /* perform the actual encryption */
455 ret = crypto_encrypt(&mech, &plaindata, key, tmpl, &cipherdata,
457 if (ret != CRYPTO_SUCCESS) {
458 ret = SET_ERROR(EIO);
462 ret = crypto_decrypt(&mech, &cipherdata, key, tmpl, &plaindata,
464 if (ret != CRYPTO_SUCCESS) {
465 ASSERT3U(ret, ==, CRYPTO_INVALID_MAC);
466 ret = SET_ERROR(ECKSUM);
478 zio_crypt_key_wrap(crypto_key_t *cwkey, zio_crypt_key_t *key, uint8_t *iv,
479 uint8_t *mac, uint8_t *keydata_out, uint8_t *hmac_keydata_out)
484 iovec_t plain_iovecs[2], cipher_iovecs[3];
485 uint64_t crypt = key->zk_crypt;
486 uint_t enc_len, keydata_len, aad_len;
488 ASSERT3U(crypt, <, ZIO_CRYPT_FUNCTIONS);
489 ASSERT3U(cwkey->ck_format, ==, CRYPTO_KEY_RAW);
491 keydata_len = zio_crypt_table[crypt].ci_keylen;
493 /* generate iv for wrapping the master and hmac key */
494 ret = random_get_pseudo_bytes(iv, WRAPPING_IV_LEN);
498 /* initialize uio_ts */
499 plain_iovecs[0].iov_base = key->zk_master_keydata;
500 plain_iovecs[0].iov_len = keydata_len;
501 plain_iovecs[1].iov_base = key->zk_hmac_keydata;
502 plain_iovecs[1].iov_len = SHA512_HMAC_KEYLEN;
504 cipher_iovecs[0].iov_base = keydata_out;
505 cipher_iovecs[0].iov_len = keydata_len;
506 cipher_iovecs[1].iov_base = hmac_keydata_out;
507 cipher_iovecs[1].iov_len = SHA512_HMAC_KEYLEN;
508 cipher_iovecs[2].iov_base = mac;
509 cipher_iovecs[2].iov_len = WRAPPING_MAC_LEN;
512 * Although we don't support writing to the old format, we do
513 * support rewrapping the key so that the user can move and
514 * quarantine datasets on the old format.
516 if (key->zk_version == 0) {
517 aad_len = sizeof (uint64_t);
518 aad[0] = LE_64(key->zk_guid);
520 ASSERT3U(key->zk_version, ==, ZIO_CRYPT_KEY_CURRENT_VERSION);
521 aad_len = sizeof (uint64_t) * 3;
522 aad[0] = LE_64(key->zk_guid);
523 aad[1] = LE_64(crypt);
524 aad[2] = LE_64(key->zk_version);
527 enc_len = zio_crypt_table[crypt].ci_keylen + SHA512_HMAC_KEYLEN;
528 puio.uio_iov = plain_iovecs;
530 puio.uio_segflg = UIO_SYSSPACE;
531 cuio.uio_iov = cipher_iovecs;
533 cuio.uio_segflg = UIO_SYSSPACE;
535 /* encrypt the keys and store the resulting ciphertext and mac */
536 ret = zio_do_crypt_uio(B_TRUE, crypt, cwkey, NULL, iv, enc_len,
537 &puio, &cuio, (uint8_t *)aad, aad_len);
548 zio_crypt_key_unwrap(crypto_key_t *cwkey, uint64_t crypt, uint64_t version,
549 uint64_t guid, uint8_t *keydata, uint8_t *hmac_keydata, uint8_t *iv,
550 uint8_t *mac, zio_crypt_key_t *key)
552 crypto_mechanism_t mech;
555 iovec_t plain_iovecs[2], cipher_iovecs[3];
556 uint_t enc_len, keydata_len, aad_len;
559 ASSERT3U(crypt, <, ZIO_CRYPT_FUNCTIONS);
560 ASSERT3U(cwkey->ck_format, ==, CRYPTO_KEY_RAW);
562 rw_init(&key->zk_salt_lock, NULL, RW_DEFAULT, NULL);
564 keydata_len = zio_crypt_table[crypt].ci_keylen;
566 /* initialize uio_ts */
567 plain_iovecs[0].iov_base = key->zk_master_keydata;
568 plain_iovecs[0].iov_len = keydata_len;
569 plain_iovecs[1].iov_base = key->zk_hmac_keydata;
570 plain_iovecs[1].iov_len = SHA512_HMAC_KEYLEN;
572 cipher_iovecs[0].iov_base = keydata;
573 cipher_iovecs[0].iov_len = keydata_len;
574 cipher_iovecs[1].iov_base = hmac_keydata;
575 cipher_iovecs[1].iov_len = SHA512_HMAC_KEYLEN;
576 cipher_iovecs[2].iov_base = mac;
577 cipher_iovecs[2].iov_len = WRAPPING_MAC_LEN;
580 aad_len = sizeof (uint64_t);
581 aad[0] = LE_64(guid);
583 ASSERT3U(version, ==, ZIO_CRYPT_KEY_CURRENT_VERSION);
584 aad_len = sizeof (uint64_t) * 3;
585 aad[0] = LE_64(guid);
586 aad[1] = LE_64(crypt);
587 aad[2] = LE_64(version);
590 enc_len = keydata_len + SHA512_HMAC_KEYLEN;
591 puio.uio_iov = plain_iovecs;
592 puio.uio_segflg = UIO_SYSSPACE;
594 cuio.uio_iov = cipher_iovecs;
596 cuio.uio_segflg = UIO_SYSSPACE;
598 /* decrypt the keys and store the result in the output buffers */
599 ret = zio_do_crypt_uio(B_FALSE, crypt, cwkey, NULL, iv, enc_len,
600 &puio, &cuio, (uint8_t *)aad, aad_len);
604 /* generate a fresh salt */
605 ret = random_get_bytes(key->zk_salt, ZIO_DATA_SALT_LEN);
609 /* derive the current key from the master key */
610 ret = hkdf_sha512(key->zk_master_keydata, keydata_len, NULL, 0,
611 key->zk_salt, ZIO_DATA_SALT_LEN, key->zk_current_keydata,
616 /* initialize keys for ICP */
617 key->zk_current_key.ck_format = CRYPTO_KEY_RAW;
618 key->zk_current_key.ck_data = key->zk_current_keydata;
619 key->zk_current_key.ck_length = CRYPTO_BYTES2BITS(keydata_len);
621 key->zk_hmac_key.ck_format = CRYPTO_KEY_RAW;
622 key->zk_hmac_key.ck_data = key->zk_hmac_keydata;
623 key->zk_hmac_key.ck_length = CRYPTO_BYTES2BITS(SHA512_HMAC_KEYLEN);
626 * Initialize the crypto templates. It's ok if this fails because
627 * this is just an optimization.
629 mech.cm_type = crypto_mech2id(zio_crypt_table[crypt].ci_mechname);
630 ret = crypto_create_ctx_template(&mech, &key->zk_current_key,
631 &key->zk_current_tmpl, KM_SLEEP);
632 if (ret != CRYPTO_SUCCESS)
633 key->zk_current_tmpl = NULL;
635 mech.cm_type = crypto_mech2id(SUN_CKM_SHA512_HMAC);
636 ret = crypto_create_ctx_template(&mech, &key->zk_hmac_key,
637 &key->zk_hmac_tmpl, KM_SLEEP);
638 if (ret != CRYPTO_SUCCESS)
639 key->zk_hmac_tmpl = NULL;
641 key->zk_crypt = crypt;
642 key->zk_version = version;
644 key->zk_salt_count = 0;
649 zio_crypt_key_destroy(key);
654 zio_crypt_generate_iv(uint8_t *ivbuf)
658 /* randomly generate the IV */
659 ret = random_get_pseudo_bytes(ivbuf, ZIO_DATA_IV_LEN);
666 bzero(ivbuf, ZIO_DATA_IV_LEN);
671 zio_crypt_do_hmac(zio_crypt_key_t *key, uint8_t *data, uint_t datalen,
672 uint8_t *digestbuf, uint_t digestlen)
675 crypto_mechanism_t mech;
676 crypto_data_t in_data, digest_data;
677 uint8_t raw_digestbuf[SHA512_DIGEST_LENGTH];
679 ASSERT3U(digestlen, <=, SHA512_DIGEST_LENGTH);
681 /* initialize sha512-hmac mechanism and crypto data */
682 mech.cm_type = crypto_mech2id(SUN_CKM_SHA512_HMAC);
683 mech.cm_param = NULL;
684 mech.cm_param_len = 0;
686 /* initialize the crypto data */
687 in_data.cd_format = CRYPTO_DATA_RAW;
688 in_data.cd_offset = 0;
689 in_data.cd_length = datalen;
690 in_data.cd_raw.iov_base = (char *)data;
691 in_data.cd_raw.iov_len = in_data.cd_length;
693 digest_data.cd_format = CRYPTO_DATA_RAW;
694 digest_data.cd_offset = 0;
695 digest_data.cd_length = SHA512_DIGEST_LENGTH;
696 digest_data.cd_raw.iov_base = (char *)raw_digestbuf;
697 digest_data.cd_raw.iov_len = digest_data.cd_length;
699 /* generate the hmac */
700 ret = crypto_mac(&mech, &in_data, &key->zk_hmac_key, key->zk_hmac_tmpl,
702 if (ret != CRYPTO_SUCCESS) {
703 ret = SET_ERROR(EIO);
707 bcopy(raw_digestbuf, digestbuf, digestlen);
712 bzero(digestbuf, digestlen);
717 zio_crypt_generate_iv_salt_dedup(zio_crypt_key_t *key, uint8_t *data,
718 uint_t datalen, uint8_t *ivbuf, uint8_t *salt)
721 uint8_t digestbuf[SHA512_DIGEST_LENGTH];
723 ret = zio_crypt_do_hmac(key, data, datalen,
724 digestbuf, SHA512_DIGEST_LENGTH);
728 bcopy(digestbuf, salt, ZIO_DATA_SALT_LEN);
729 bcopy(digestbuf + ZIO_DATA_SALT_LEN, ivbuf, ZIO_DATA_IV_LEN);
735 * The following functions are used to encode and decode encryption parameters
736 * into blkptr_t and zil_header_t. The ICP wants to use these parameters as
737 * byte strings, which normally means that these strings would not need to deal
738 * with byteswapping at all. However, both blkptr_t and zil_header_t may be
739 * byteswapped by lower layers and so we must "undo" that byteswap here upon
740 * decoding and encoding in a non-native byteorder. These functions require
741 * that the byteorder bit is correct before being called.
744 zio_crypt_encode_params_bp(blkptr_t *bp, uint8_t *salt, uint8_t *iv)
749 ASSERT(BP_IS_ENCRYPTED(bp));
751 if (!BP_SHOULD_BYTESWAP(bp)) {
752 bcopy(salt, &bp->blk_dva[2].dva_word[0], sizeof (uint64_t));
753 bcopy(iv, &bp->blk_dva[2].dva_word[1], sizeof (uint64_t));
754 bcopy(iv + sizeof (uint64_t), &val32, sizeof (uint32_t));
755 BP_SET_IV2(bp, val32);
757 bcopy(salt, &val64, sizeof (uint64_t));
758 bp->blk_dva[2].dva_word[0] = BSWAP_64(val64);
760 bcopy(iv, &val64, sizeof (uint64_t));
761 bp->blk_dva[2].dva_word[1] = BSWAP_64(val64);
763 bcopy(iv + sizeof (uint64_t), &val32, sizeof (uint32_t));
764 BP_SET_IV2(bp, BSWAP_32(val32));
769 zio_crypt_decode_params_bp(const blkptr_t *bp, uint8_t *salt, uint8_t *iv)
774 ASSERT(BP_IS_PROTECTED(bp));
776 /* for convenience, so callers don't need to check */
777 if (BP_IS_AUTHENTICATED(bp)) {
778 bzero(salt, ZIO_DATA_SALT_LEN);
779 bzero(iv, ZIO_DATA_IV_LEN);
783 if (!BP_SHOULD_BYTESWAP(bp)) {
784 bcopy(&bp->blk_dva[2].dva_word[0], salt, sizeof (uint64_t));
785 bcopy(&bp->blk_dva[2].dva_word[1], iv, sizeof (uint64_t));
787 val32 = (uint32_t)BP_GET_IV2(bp);
788 bcopy(&val32, iv + sizeof (uint64_t), sizeof (uint32_t));
790 val64 = BSWAP_64(bp->blk_dva[2].dva_word[0]);
791 bcopy(&val64, salt, sizeof (uint64_t));
793 val64 = BSWAP_64(bp->blk_dva[2].dva_word[1]);
794 bcopy(&val64, iv, sizeof (uint64_t));
796 val32 = BSWAP_32((uint32_t)BP_GET_IV2(bp));
797 bcopy(&val32, iv + sizeof (uint64_t), sizeof (uint32_t));
802 zio_crypt_encode_mac_bp(blkptr_t *bp, uint8_t *mac)
806 ASSERT(BP_USES_CRYPT(bp));
807 ASSERT3U(BP_GET_TYPE(bp), !=, DMU_OT_OBJSET);
809 if (!BP_SHOULD_BYTESWAP(bp)) {
810 bcopy(mac, &bp->blk_cksum.zc_word[2], sizeof (uint64_t));
811 bcopy(mac + sizeof (uint64_t), &bp->blk_cksum.zc_word[3],
814 bcopy(mac, &val64, sizeof (uint64_t));
815 bp->blk_cksum.zc_word[2] = BSWAP_64(val64);
817 bcopy(mac + sizeof (uint64_t), &val64, sizeof (uint64_t));
818 bp->blk_cksum.zc_word[3] = BSWAP_64(val64);
823 zio_crypt_decode_mac_bp(const blkptr_t *bp, uint8_t *mac)
827 ASSERT(BP_USES_CRYPT(bp) || BP_IS_HOLE(bp));
829 /* for convenience, so callers don't need to check */
830 if (BP_GET_TYPE(bp) == DMU_OT_OBJSET) {
831 bzero(mac, ZIO_DATA_MAC_LEN);
835 if (!BP_SHOULD_BYTESWAP(bp)) {
836 bcopy(&bp->blk_cksum.zc_word[2], mac, sizeof (uint64_t));
837 bcopy(&bp->blk_cksum.zc_word[3], mac + sizeof (uint64_t),
840 val64 = BSWAP_64(bp->blk_cksum.zc_word[2]);
841 bcopy(&val64, mac, sizeof (uint64_t));
843 val64 = BSWAP_64(bp->blk_cksum.zc_word[3]);
844 bcopy(&val64, mac + sizeof (uint64_t), sizeof (uint64_t));
849 zio_crypt_encode_mac_zil(void *data, uint8_t *mac)
851 zil_chain_t *zilc = data;
853 bcopy(mac, &zilc->zc_eck.zec_cksum.zc_word[2], sizeof (uint64_t));
854 bcopy(mac + sizeof (uint64_t), &zilc->zc_eck.zec_cksum.zc_word[3],
859 zio_crypt_decode_mac_zil(const void *data, uint8_t *mac)
862 * The ZIL MAC is embedded in the block it protects, which will
863 * not have been byteswapped by the time this function has been called.
864 * As a result, we don't need to worry about byteswapping the MAC.
866 const zil_chain_t *zilc = data;
868 bcopy(&zilc->zc_eck.zec_cksum.zc_word[2], mac, sizeof (uint64_t));
869 bcopy(&zilc->zc_eck.zec_cksum.zc_word[3], mac + sizeof (uint64_t),
874 * This routine takes a block of dnodes (src_abd) and copies only the bonus
875 * buffers to the same offsets in the dst buffer. datalen should be the size
876 * of both the src_abd and the dst buffer (not just the length of the bonus
880 zio_crypt_copy_dnode_bonus(abd_t *src_abd, uint8_t *dst, uint_t datalen)
882 uint_t i, max_dnp = datalen >> DNODE_SHIFT;
884 dnode_phys_t *dnp, *sdnp, *ddnp;
886 src = abd_borrow_buf_copy(src_abd, datalen);
888 sdnp = (dnode_phys_t *)src;
889 ddnp = (dnode_phys_t *)dst;
891 for (i = 0; i < max_dnp; i += sdnp[i].dn_extra_slots + 1) {
893 if (dnp->dn_type != DMU_OT_NONE &&
894 DMU_OT_IS_ENCRYPTED(dnp->dn_bonustype) &&
895 dnp->dn_bonuslen != 0) {
896 bcopy(DN_BONUS(dnp), DN_BONUS(&ddnp[i]),
897 DN_MAX_BONUS_LEN(dnp));
901 abd_return_buf(src_abd, src, datalen);
905 * This function decides what fields from blk_prop are included in
906 * the on-disk various MAC algorithms.
909 zio_crypt_bp_zero_nonportable_blkprop(blkptr_t *bp, uint64_t version)
912 * Version 0 did not properly zero out all non-portable fields
913 * as it should have done. We maintain this code so that we can
914 * do read-only imports of pools on this version.
918 BP_SET_CHECKSUM(bp, 0);
919 BP_SET_PSIZE(bp, SPA_MINBLOCKSIZE);
923 ASSERT3U(version, ==, ZIO_CRYPT_KEY_CURRENT_VERSION);
926 * The hole_birth feature might set these fields even if this bp
927 * is a hole. We zero them out here to guarantee that raw sends
928 * will function with or without the feature.
930 if (BP_IS_HOLE(bp)) {
936 * At L0 we want to verify these fields to ensure that data blocks
937 * can not be reinterpreted. For instance, we do not want an attacker
938 * to trick us into returning raw lz4 compressed data to the user
939 * by modifying the compression bits. At higher levels, we cannot
940 * enforce this policy since raw sends do not convey any information
941 * about indirect blocks, so these values might be different on the
942 * receive side. Fortunately, this does not open any new attack
943 * vectors, since any alterations that can be made to a higher level
944 * bp must still verify the correct order of the layer below it.
946 if (BP_GET_LEVEL(bp) != 0) {
947 BP_SET_BYTEORDER(bp, 0);
948 BP_SET_COMPRESS(bp, 0);
951 * psize cannot be set to zero or it will trigger
952 * asserts, but the value doesn't really matter as
953 * long as it is constant.
955 BP_SET_PSIZE(bp, SPA_MINBLOCKSIZE);
959 BP_SET_CHECKSUM(bp, 0);
963 zio_crypt_bp_auth_init(uint64_t version, boolean_t should_bswap, blkptr_t *bp,
964 blkptr_auth_buf_t *bab, uint_t *bab_len)
966 blkptr_t tmpbp = *bp;
969 byteswap_uint64_array(&tmpbp, sizeof (blkptr_t));
971 ASSERT(BP_USES_CRYPT(&tmpbp) || BP_IS_HOLE(&tmpbp));
972 ASSERT0(BP_IS_EMBEDDED(&tmpbp));
974 zio_crypt_decode_mac_bp(&tmpbp, bab->bab_mac);
977 * We always MAC blk_prop in LE to ensure portability. This
978 * must be done after decoding the mac, since the endianness
979 * will get zero'd out here.
981 zio_crypt_bp_zero_nonportable_blkprop(&tmpbp, version);
982 bab->bab_prop = LE_64(tmpbp.blk_prop);
985 /* version 0 did not include the padding */
986 *bab_len = sizeof (blkptr_auth_buf_t);
988 *bab_len -= sizeof (uint64_t);
992 zio_crypt_bp_do_hmac_updates(crypto_context_t ctx, uint64_t version,
993 boolean_t should_bswap, blkptr_t *bp)
997 blkptr_auth_buf_t bab;
1000 zio_crypt_bp_auth_init(version, should_bswap, bp, &bab, &bab_len);
1001 cd.cd_format = CRYPTO_DATA_RAW;
1003 cd.cd_length = bab_len;
1004 cd.cd_raw.iov_base = (char *)&bab;
1005 cd.cd_raw.iov_len = cd.cd_length;
1007 ret = crypto_mac_update(ctx, &cd, NULL);
1008 if (ret != CRYPTO_SUCCESS) {
1009 ret = SET_ERROR(EIO);
1020 zio_crypt_bp_do_indrect_checksum_updates(SHA2_CTX *ctx, uint64_t version,
1021 boolean_t should_bswap, blkptr_t *bp)
1024 blkptr_auth_buf_t bab;
1026 zio_crypt_bp_auth_init(version, should_bswap, bp, &bab, &bab_len);
1027 SHA2Update(ctx, &bab, bab_len);
1031 zio_crypt_bp_do_aad_updates(uint8_t **aadp, uint_t *aad_len, uint64_t version,
1032 boolean_t should_bswap, blkptr_t *bp)
1035 blkptr_auth_buf_t bab;
1037 zio_crypt_bp_auth_init(version, should_bswap, bp, &bab, &bab_len);
1038 bcopy(&bab, *aadp, bab_len);
1040 *aad_len += bab_len;
1044 zio_crypt_do_dnode_hmac_updates(crypto_context_t ctx, uint64_t version,
1045 boolean_t should_bswap, dnode_phys_t *dnp)
1049 boolean_t le_bswap = (should_bswap == ZFS_HOST_BYTEORDER);
1051 uint8_t tmp_dncore[offsetof(dnode_phys_t, dn_blkptr)];
1053 cd.cd_format = CRYPTO_DATA_RAW;
1056 /* authenticate the core dnode (masking out non-portable bits) */
1057 bcopy(dnp, tmp_dncore, sizeof (tmp_dncore));
1058 adnp = (dnode_phys_t *)tmp_dncore;
1060 adnp->dn_datablkszsec = BSWAP_16(adnp->dn_datablkszsec);
1061 adnp->dn_bonuslen = BSWAP_16(adnp->dn_bonuslen);
1062 adnp->dn_maxblkid = BSWAP_64(adnp->dn_maxblkid);
1063 adnp->dn_used = BSWAP_64(adnp->dn_used);
1065 adnp->dn_flags &= DNODE_CRYPT_PORTABLE_FLAGS_MASK;
1068 cd.cd_length = sizeof (tmp_dncore);
1069 cd.cd_raw.iov_base = (char *)adnp;
1070 cd.cd_raw.iov_len = cd.cd_length;
1072 ret = crypto_mac_update(ctx, &cd, NULL);
1073 if (ret != CRYPTO_SUCCESS) {
1074 ret = SET_ERROR(EIO);
1078 for (i = 0; i < dnp->dn_nblkptr; i++) {
1079 ret = zio_crypt_bp_do_hmac_updates(ctx, version,
1080 should_bswap, &dnp->dn_blkptr[i]);
1085 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
1086 ret = zio_crypt_bp_do_hmac_updates(ctx, version,
1087 should_bswap, DN_SPILL_BLKPTR(dnp));
1099 * objset_phys_t blocks introduce a number of exceptions to the normal
1100 * authentication process. objset_phys_t's contain 2 separate HMACS for
1101 * protecting the integrity of their data. The portable_mac protects the
1102 * metadnode. This MAC can be sent with a raw send and protects against
1103 * reordering of data within the metadnode. The local_mac protects the user
1104 * accounting objects which are not sent from one system to another.
1106 * In addition, objset blocks are the only blocks that can be modified and
1107 * written to disk without the key loaded under certain circumstances. During
1108 * zil_claim() we need to be able to update the zil_header_t to complete
1109 * claiming log blocks and during raw receives we need to write out the
1110 * portable_mac from the send file. Both of these actions are possible
1111 * because these fields are not protected by either MAC so neither one will
1112 * need to modify the MACs without the key. However, when the modified blocks
1113 * are written out they will be byteswapped into the host machine's native
1114 * endianness which will modify fields protected by the MAC. As a result, MAC
1115 * calculation for objset blocks works slightly differently from other block
1116 * types. Where other block types MAC the data in whatever endianness is
1117 * written to disk, objset blocks always MAC little endian version of their
1118 * values. In the code, should_bswap is the value from BP_SHOULD_BYTESWAP()
1119 * and le_bswap indicates whether a byteswap is needed to get this block
1120 * into little endian format.
1123 zio_crypt_do_objset_hmacs(zio_crypt_key_t *key, void *data, uint_t datalen,
1124 boolean_t should_bswap, uint8_t *portable_mac, uint8_t *local_mac)
1127 crypto_mechanism_t mech;
1128 crypto_context_t ctx;
1130 objset_phys_t *osp = data;
1132 boolean_t le_bswap = (should_bswap == ZFS_HOST_BYTEORDER);
1133 uint8_t raw_portable_mac[SHA512_DIGEST_LENGTH];
1134 uint8_t raw_local_mac[SHA512_DIGEST_LENGTH];
1136 /* initialize HMAC mechanism */
1137 mech.cm_type = crypto_mech2id(SUN_CKM_SHA512_HMAC);
1138 mech.cm_param = NULL;
1139 mech.cm_param_len = 0;
1141 cd.cd_format = CRYPTO_DATA_RAW;
1144 /* calculate the portable MAC from the portable fields and metadnode */
1145 ret = crypto_mac_init(&mech, &key->zk_hmac_key, NULL, &ctx, NULL);
1146 if (ret != CRYPTO_SUCCESS) {
1147 ret = SET_ERROR(EIO);
1151 /* add in the os_type */
1152 intval = (le_bswap) ? osp->os_type : BSWAP_64(osp->os_type);
1153 cd.cd_length = sizeof (uint64_t);
1154 cd.cd_raw.iov_base = (char *)&intval;
1155 cd.cd_raw.iov_len = cd.cd_length;
1157 ret = crypto_mac_update(ctx, &cd, NULL);
1158 if (ret != CRYPTO_SUCCESS) {
1159 ret = SET_ERROR(EIO);
1163 /* add in the portable os_flags */
1164 intval = osp->os_flags;
1166 intval = BSWAP_64(intval);
1167 intval &= OBJSET_CRYPT_PORTABLE_FLAGS_MASK;
1168 if (!ZFS_HOST_BYTEORDER)
1169 intval = BSWAP_64(intval);
1171 cd.cd_length = sizeof (uint64_t);
1172 cd.cd_raw.iov_base = (char *)&intval;
1173 cd.cd_raw.iov_len = cd.cd_length;
1175 ret = crypto_mac_update(ctx, &cd, NULL);
1176 if (ret != CRYPTO_SUCCESS) {
1177 ret = SET_ERROR(EIO);
1181 /* add in fields from the metadnode */
1182 ret = zio_crypt_do_dnode_hmac_updates(ctx, key->zk_version,
1183 should_bswap, &osp->os_meta_dnode);
1187 /* store the final digest in a temporary buffer and copy what we need */
1188 cd.cd_length = SHA512_DIGEST_LENGTH;
1189 cd.cd_raw.iov_base = (char *)raw_portable_mac;
1190 cd.cd_raw.iov_len = cd.cd_length;
1192 ret = crypto_mac_final(ctx, &cd, NULL);
1193 if (ret != CRYPTO_SUCCESS) {
1194 ret = SET_ERROR(EIO);
1198 bcopy(raw_portable_mac, portable_mac, ZIO_OBJSET_MAC_LEN);
1201 * The local MAC protects the user, group and project accounting.
1202 * If these objects are not present, the local MAC is zeroed out.
1204 if ((datalen >= OBJSET_PHYS_SIZE_V3 &&
1205 osp->os_userused_dnode.dn_type == DMU_OT_NONE &&
1206 osp->os_groupused_dnode.dn_type == DMU_OT_NONE &&
1207 osp->os_projectused_dnode.dn_type == DMU_OT_NONE) ||
1208 (datalen >= OBJSET_PHYS_SIZE_V2 &&
1209 osp->os_userused_dnode.dn_type == DMU_OT_NONE &&
1210 osp->os_groupused_dnode.dn_type == DMU_OT_NONE) ||
1211 (datalen <= OBJSET_PHYS_SIZE_V1)) {
1212 bzero(local_mac, ZIO_OBJSET_MAC_LEN);
1216 /* calculate the local MAC from the userused and groupused dnodes */
1217 ret = crypto_mac_init(&mech, &key->zk_hmac_key, NULL, &ctx, NULL);
1218 if (ret != CRYPTO_SUCCESS) {
1219 ret = SET_ERROR(EIO);
1223 /* add in the non-portable os_flags */
1224 intval = osp->os_flags;
1226 intval = BSWAP_64(intval);
1227 intval &= ~OBJSET_CRYPT_PORTABLE_FLAGS_MASK;
1228 if (!ZFS_HOST_BYTEORDER)
1229 intval = BSWAP_64(intval);
1231 cd.cd_length = sizeof (uint64_t);
1232 cd.cd_raw.iov_base = (char *)&intval;
1233 cd.cd_raw.iov_len = cd.cd_length;
1235 ret = crypto_mac_update(ctx, &cd, NULL);
1236 if (ret != CRYPTO_SUCCESS) {
1237 ret = SET_ERROR(EIO);
1241 /* add in fields from the user accounting dnodes */
1242 if (osp->os_userused_dnode.dn_type != DMU_OT_NONE) {
1243 ret = zio_crypt_do_dnode_hmac_updates(ctx, key->zk_version,
1244 should_bswap, &osp->os_userused_dnode);
1249 if (osp->os_groupused_dnode.dn_type != DMU_OT_NONE) {
1250 ret = zio_crypt_do_dnode_hmac_updates(ctx, key->zk_version,
1251 should_bswap, &osp->os_groupused_dnode);
1256 if (osp->os_projectused_dnode.dn_type != DMU_OT_NONE &&
1257 datalen >= OBJSET_PHYS_SIZE_V3) {
1258 ret = zio_crypt_do_dnode_hmac_updates(ctx, key->zk_version,
1259 should_bswap, &osp->os_projectused_dnode);
1264 /* store the final digest in a temporary buffer and copy what we need */
1265 cd.cd_length = SHA512_DIGEST_LENGTH;
1266 cd.cd_raw.iov_base = (char *)raw_local_mac;
1267 cd.cd_raw.iov_len = cd.cd_length;
1269 ret = crypto_mac_final(ctx, &cd, NULL);
1270 if (ret != CRYPTO_SUCCESS) {
1271 ret = SET_ERROR(EIO);
1275 bcopy(raw_local_mac, local_mac, ZIO_OBJSET_MAC_LEN);
1280 bzero(portable_mac, ZIO_OBJSET_MAC_LEN);
1281 bzero(local_mac, ZIO_OBJSET_MAC_LEN);
1286 zio_crypt_destroy_uio(uio_t *uio)
1289 kmem_free(uio->uio_iov, uio->uio_iovcnt * sizeof (iovec_t));
1293 * This function parses an uncompressed indirect block and returns a checksum
1294 * of all the portable fields from all of the contained bps. The portable
1295 * fields are the MAC and all of the fields from blk_prop except for the dedup,
1296 * checksum, and psize bits. For an explanation of the purpose of this, see
1297 * the comment block on object set authentication.
1300 zio_crypt_do_indirect_mac_checksum_impl(boolean_t generate, void *buf,
1301 uint_t datalen, uint64_t version, boolean_t byteswap, uint8_t *cksum)
1304 int i, epb = datalen >> SPA_BLKPTRSHIFT;
1306 uint8_t digestbuf[SHA512_DIGEST_LENGTH];
1308 /* checksum all of the MACs from the layer below */
1309 SHA2Init(SHA512, &ctx);
1310 for (i = 0, bp = buf; i < epb; i++, bp++) {
1311 zio_crypt_bp_do_indrect_checksum_updates(&ctx, version,
1314 SHA2Final(digestbuf, &ctx);
1317 bcopy(digestbuf, cksum, ZIO_DATA_MAC_LEN);
1321 if (bcmp(digestbuf, cksum, ZIO_DATA_MAC_LEN) != 0)
1322 return (SET_ERROR(ECKSUM));
1328 zio_crypt_do_indirect_mac_checksum(boolean_t generate, void *buf,
1329 uint_t datalen, boolean_t byteswap, uint8_t *cksum)
1334 * Unfortunately, callers of this function will not always have
1335 * easy access to the on-disk format version. This info is
1336 * normally found in the DSL Crypto Key, but the checksum-of-MACs
1337 * is expected to be verifiable even when the key isn't loaded.
1338 * Here, instead of doing a ZAP lookup for the version for each
1339 * zio, we simply try both existing formats.
1341 ret = zio_crypt_do_indirect_mac_checksum_impl(generate, buf,
1342 datalen, ZIO_CRYPT_KEY_CURRENT_VERSION, byteswap, cksum);
1343 if (ret == ECKSUM) {
1345 ret = zio_crypt_do_indirect_mac_checksum_impl(generate,
1346 buf, datalen, 0, byteswap, cksum);
1353 zio_crypt_do_indirect_mac_checksum_abd(boolean_t generate, abd_t *abd,
1354 uint_t datalen, boolean_t byteswap, uint8_t *cksum)
1359 buf = abd_borrow_buf_copy(abd, datalen);
1360 ret = zio_crypt_do_indirect_mac_checksum(generate, buf, datalen,
1362 abd_return_buf(abd, buf, datalen);
1368 * Special case handling routine for encrypting / decrypting ZIL blocks.
1369 * We do not check for the older ZIL chain because the encryption feature
1370 * was not available before the newer ZIL chain was introduced. The goal
1371 * here is to encrypt everything except the blkptr_t of a lr_write_t and
1372 * the zil_chain_t header. Everything that is not encrypted is authenticated.
1375 zio_crypt_init_uios_zil(boolean_t encrypt, uint8_t *plainbuf,
1376 uint8_t *cipherbuf, uint_t datalen, boolean_t byteswap, uio_t *puio,
1377 uio_t *cuio, uint_t *enc_len, uint8_t **authbuf, uint_t *auth_len,
1378 boolean_t *no_crypt)
1381 uint64_t txtype, lr_len;
1382 uint_t nr_src, nr_dst, crypt_len;
1383 uint_t aad_len = 0, nr_iovecs = 0, total_len = 0;
1384 iovec_t *src_iovecs = NULL, *dst_iovecs = NULL;
1385 uint8_t *src, *dst, *slrp, *dlrp, *blkend, *aadp;
1388 uint8_t *aadbuf = zio_buf_alloc(datalen);
1390 /* cipherbuf always needs an extra iovec for the MAC */
1403 /* find the start and end record of the log block */
1404 zilc = (zil_chain_t *)src;
1405 slrp = src + sizeof (zil_chain_t);
1407 blkend = src + ((byteswap) ? BSWAP_64(zilc->zc_nused) : zilc->zc_nused);
1409 /* calculate the number of encrypted iovecs we will need */
1410 for (; slrp < blkend; slrp += lr_len) {
1414 txtype = lr->lrc_txtype;
1415 lr_len = lr->lrc_reclen;
1417 txtype = BSWAP_64(lr->lrc_txtype);
1418 lr_len = BSWAP_64(lr->lrc_reclen);
1422 if (txtype == TX_WRITE && lr_len != sizeof (lr_write_t))
1426 nr_src += nr_iovecs;
1427 nr_dst += nr_iovecs;
1429 /* allocate the iovec arrays */
1431 src_iovecs = kmem_alloc(nr_src * sizeof (iovec_t), KM_SLEEP);
1432 if (src_iovecs == NULL) {
1433 ret = SET_ERROR(ENOMEM);
1439 dst_iovecs = kmem_alloc(nr_dst * sizeof (iovec_t), KM_SLEEP);
1440 if (dst_iovecs == NULL) {
1441 ret = SET_ERROR(ENOMEM);
1447 * Copy the plain zil header over and authenticate everything except
1448 * the checksum that will store our MAC. If we are writing the data
1449 * the embedded checksum will not have been calculated yet, so we don't
1450 * authenticate that.
1452 bcopy(src, dst, sizeof (zil_chain_t));
1453 bcopy(src, aadp, sizeof (zil_chain_t) - sizeof (zio_eck_t));
1454 aadp += sizeof (zil_chain_t) - sizeof (zio_eck_t);
1455 aad_len += sizeof (zil_chain_t) - sizeof (zio_eck_t);
1457 /* loop over records again, filling in iovecs */
1459 slrp = src + sizeof (zil_chain_t);
1460 dlrp = dst + sizeof (zil_chain_t);
1462 for (; slrp < blkend; slrp += lr_len, dlrp += lr_len) {
1466 txtype = lr->lrc_txtype;
1467 lr_len = lr->lrc_reclen;
1469 txtype = BSWAP_64(lr->lrc_txtype);
1470 lr_len = BSWAP_64(lr->lrc_reclen);
1473 /* copy the common lr_t */
1474 bcopy(slrp, dlrp, sizeof (lr_t));
1475 bcopy(slrp, aadp, sizeof (lr_t));
1476 aadp += sizeof (lr_t);
1477 aad_len += sizeof (lr_t);
1479 ASSERT3P(src_iovecs, !=, NULL);
1480 ASSERT3P(dst_iovecs, !=, NULL);
1483 * If this is a TX_WRITE record we want to encrypt everything
1484 * except the bp if exists. If the bp does exist we want to
1487 if (txtype == TX_WRITE) {
1488 crypt_len = sizeof (lr_write_t) -
1489 sizeof (lr_t) - sizeof (blkptr_t);
1490 src_iovecs[nr_iovecs].iov_base = slrp + sizeof (lr_t);
1491 src_iovecs[nr_iovecs].iov_len = crypt_len;
1492 dst_iovecs[nr_iovecs].iov_base = dlrp + sizeof (lr_t);
1493 dst_iovecs[nr_iovecs].iov_len = crypt_len;
1495 /* copy the bp now since it will not be encrypted */
1496 bcopy(slrp + sizeof (lr_write_t) - sizeof (blkptr_t),
1497 dlrp + sizeof (lr_write_t) - sizeof (blkptr_t),
1499 bcopy(slrp + sizeof (lr_write_t) - sizeof (blkptr_t),
1500 aadp, sizeof (blkptr_t));
1501 aadp += sizeof (blkptr_t);
1502 aad_len += sizeof (blkptr_t);
1504 total_len += crypt_len;
1506 if (lr_len != sizeof (lr_write_t)) {
1507 crypt_len = lr_len - sizeof (lr_write_t);
1508 src_iovecs[nr_iovecs].iov_base =
1509 slrp + sizeof (lr_write_t);
1510 src_iovecs[nr_iovecs].iov_len = crypt_len;
1511 dst_iovecs[nr_iovecs].iov_base =
1512 dlrp + sizeof (lr_write_t);
1513 dst_iovecs[nr_iovecs].iov_len = crypt_len;
1515 total_len += crypt_len;
1518 crypt_len = lr_len - sizeof (lr_t);
1519 src_iovecs[nr_iovecs].iov_base = slrp + sizeof (lr_t);
1520 src_iovecs[nr_iovecs].iov_len = crypt_len;
1521 dst_iovecs[nr_iovecs].iov_base = dlrp + sizeof (lr_t);
1522 dst_iovecs[nr_iovecs].iov_len = crypt_len;
1524 total_len += crypt_len;
1528 *no_crypt = (nr_iovecs == 0);
1529 *enc_len = total_len;
1531 *auth_len = aad_len;
1534 puio->uio_iov = src_iovecs;
1535 puio->uio_iovcnt = nr_src;
1536 cuio->uio_iov = dst_iovecs;
1537 cuio->uio_iovcnt = nr_dst;
1539 puio->uio_iov = dst_iovecs;
1540 puio->uio_iovcnt = nr_dst;
1541 cuio->uio_iov = src_iovecs;
1542 cuio->uio_iovcnt = nr_src;
1548 zio_buf_free(aadbuf, datalen);
1549 if (src_iovecs != NULL)
1550 kmem_free(src_iovecs, nr_src * sizeof (iovec_t));
1551 if (dst_iovecs != NULL)
1552 kmem_free(dst_iovecs, nr_dst * sizeof (iovec_t));
1557 *no_crypt = B_FALSE;
1558 puio->uio_iov = NULL;
1559 puio->uio_iovcnt = 0;
1560 cuio->uio_iov = NULL;
1561 cuio->uio_iovcnt = 0;
1566 * Special case handling routine for encrypting / decrypting dnode blocks.
1569 zio_crypt_init_uios_dnode(boolean_t encrypt, uint64_t version,
1570 uint8_t *plainbuf, uint8_t *cipherbuf, uint_t datalen, boolean_t byteswap,
1571 uio_t *puio, uio_t *cuio, uint_t *enc_len, uint8_t **authbuf,
1572 uint_t *auth_len, boolean_t *no_crypt)
1575 uint_t nr_src, nr_dst, crypt_len;
1576 uint_t aad_len = 0, nr_iovecs = 0, total_len = 0;
1577 uint_t i, j, max_dnp = datalen >> DNODE_SHIFT;
1578 iovec_t *src_iovecs = NULL, *dst_iovecs = NULL;
1579 uint8_t *src, *dst, *aadp;
1580 dnode_phys_t *dnp, *adnp, *sdnp, *ddnp;
1581 uint8_t *aadbuf = zio_buf_alloc(datalen);
1595 sdnp = (dnode_phys_t *)src;
1596 ddnp = (dnode_phys_t *)dst;
1600 * Count the number of iovecs we will need to do the encryption by
1601 * counting the number of bonus buffers that need to be encrypted.
1603 for (i = 0; i < max_dnp; i += sdnp[i].dn_extra_slots + 1) {
1605 * This block may still be byteswapped. However, all of the
1606 * values we use are either uint8_t's (for which byteswapping
1607 * is a noop) or a * != 0 check, which will work regardless
1608 * of whether or not we byteswap.
1610 if (sdnp[i].dn_type != DMU_OT_NONE &&
1611 DMU_OT_IS_ENCRYPTED(sdnp[i].dn_bonustype) &&
1612 sdnp[i].dn_bonuslen != 0) {
1617 nr_src += nr_iovecs;
1618 nr_dst += nr_iovecs;
1621 src_iovecs = kmem_alloc(nr_src * sizeof (iovec_t), KM_SLEEP);
1622 if (src_iovecs == NULL) {
1623 ret = SET_ERROR(ENOMEM);
1629 dst_iovecs = kmem_alloc(nr_dst * sizeof (iovec_t), KM_SLEEP);
1630 if (dst_iovecs == NULL) {
1631 ret = SET_ERROR(ENOMEM);
1639 * Iterate through the dnodes again, this time filling in the uios
1640 * we allocated earlier. We also concatenate any data we want to
1641 * authenticate onto aadbuf.
1643 for (i = 0; i < max_dnp; i += sdnp[i].dn_extra_slots + 1) {
1646 /* copy over the core fields and blkptrs (kept as plaintext) */
1647 bcopy(dnp, &ddnp[i], (uint8_t *)DN_BONUS(dnp) - (uint8_t *)dnp);
1649 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
1650 bcopy(DN_SPILL_BLKPTR(dnp), DN_SPILL_BLKPTR(&ddnp[i]),
1655 * Handle authenticated data. We authenticate everything in
1656 * the dnode that can be brought over when we do a raw send.
1657 * This includes all of the core fields as well as the MACs
1658 * stored in the bp checksums and all of the portable bits
1659 * from blk_prop. We include the dnode padding here in case it
1660 * ever gets used in the future. Some dn_flags and dn_used are
1661 * not portable so we mask those out values out of the
1662 * authenticated data.
1664 crypt_len = offsetof(dnode_phys_t, dn_blkptr);
1665 bcopy(dnp, aadp, crypt_len);
1666 adnp = (dnode_phys_t *)aadp;
1667 adnp->dn_flags &= DNODE_CRYPT_PORTABLE_FLAGS_MASK;
1670 aad_len += crypt_len;
1672 for (j = 0; j < dnp->dn_nblkptr; j++) {
1673 zio_crypt_bp_do_aad_updates(&aadp, &aad_len,
1674 version, byteswap, &dnp->dn_blkptr[j]);
1677 if (dnp->dn_flags & DNODE_FLAG_SPILL_BLKPTR) {
1678 zio_crypt_bp_do_aad_updates(&aadp, &aad_len,
1679 version, byteswap, DN_SPILL_BLKPTR(dnp));
1683 * If this bonus buffer needs to be encrypted, we prepare an
1684 * iovec_t. The encryption / decryption functions will fill
1685 * this in for us with the encrypted or decrypted data.
1686 * Otherwise we add the bonus buffer to the authenticated
1687 * data buffer and copy it over to the destination. The
1688 * encrypted iovec extends to DN_MAX_BONUS_LEN(dnp) so that
1689 * we can guarantee alignment with the AES block size
1692 crypt_len = DN_MAX_BONUS_LEN(dnp);
1693 if (dnp->dn_type != DMU_OT_NONE &&
1694 DMU_OT_IS_ENCRYPTED(dnp->dn_bonustype) &&
1695 dnp->dn_bonuslen != 0) {
1696 ASSERT3U(nr_iovecs, <, nr_src);
1697 ASSERT3U(nr_iovecs, <, nr_dst);
1698 ASSERT3P(src_iovecs, !=, NULL);
1699 ASSERT3P(dst_iovecs, !=, NULL);
1700 src_iovecs[nr_iovecs].iov_base = DN_BONUS(dnp);
1701 src_iovecs[nr_iovecs].iov_len = crypt_len;
1702 dst_iovecs[nr_iovecs].iov_base = DN_BONUS(&ddnp[i]);
1703 dst_iovecs[nr_iovecs].iov_len = crypt_len;
1706 total_len += crypt_len;
1708 bcopy(DN_BONUS(dnp), DN_BONUS(&ddnp[i]), crypt_len);
1709 bcopy(DN_BONUS(dnp), aadp, crypt_len);
1711 aad_len += crypt_len;
1715 *no_crypt = (nr_iovecs == 0);
1716 *enc_len = total_len;
1718 *auth_len = aad_len;
1721 puio->uio_iov = src_iovecs;
1722 puio->uio_iovcnt = nr_src;
1723 cuio->uio_iov = dst_iovecs;
1724 cuio->uio_iovcnt = nr_dst;
1726 puio->uio_iov = dst_iovecs;
1727 puio->uio_iovcnt = nr_dst;
1728 cuio->uio_iov = src_iovecs;
1729 cuio->uio_iovcnt = nr_src;
1735 zio_buf_free(aadbuf, datalen);
1736 if (src_iovecs != NULL)
1737 kmem_free(src_iovecs, nr_src * sizeof (iovec_t));
1738 if (dst_iovecs != NULL)
1739 kmem_free(dst_iovecs, nr_dst * sizeof (iovec_t));
1744 *no_crypt = B_FALSE;
1745 puio->uio_iov = NULL;
1746 puio->uio_iovcnt = 0;
1747 cuio->uio_iov = NULL;
1748 cuio->uio_iovcnt = 0;
1753 zio_crypt_init_uios_normal(boolean_t encrypt, uint8_t *plainbuf,
1754 uint8_t *cipherbuf, uint_t datalen, uio_t *puio, uio_t *cuio,
1758 uint_t nr_plain = 1, nr_cipher = 2;
1759 iovec_t *plain_iovecs = NULL, *cipher_iovecs = NULL;
1761 /* allocate the iovecs for the plain and cipher data */
1762 plain_iovecs = kmem_alloc(nr_plain * sizeof (iovec_t),
1764 if (!plain_iovecs) {
1765 ret = SET_ERROR(ENOMEM);
1769 cipher_iovecs = kmem_alloc(nr_cipher * sizeof (iovec_t),
1771 if (!cipher_iovecs) {
1772 ret = SET_ERROR(ENOMEM);
1776 plain_iovecs[0].iov_base = plainbuf;
1777 plain_iovecs[0].iov_len = datalen;
1778 cipher_iovecs[0].iov_base = cipherbuf;
1779 cipher_iovecs[0].iov_len = datalen;
1782 puio->uio_iov = plain_iovecs;
1783 puio->uio_iovcnt = nr_plain;
1784 cuio->uio_iov = cipher_iovecs;
1785 cuio->uio_iovcnt = nr_cipher;
1790 if (plain_iovecs != NULL)
1791 kmem_free(plain_iovecs, nr_plain * sizeof (iovec_t));
1792 if (cipher_iovecs != NULL)
1793 kmem_free(cipher_iovecs, nr_cipher * sizeof (iovec_t));
1796 puio->uio_iov = NULL;
1797 puio->uio_iovcnt = 0;
1798 cuio->uio_iov = NULL;
1799 cuio->uio_iovcnt = 0;
1804 * This function builds up the plaintext (puio) and ciphertext (cuio) uios so
1805 * that they can be used for encryption and decryption by zio_do_crypt_uio().
1806 * Most blocks will use zio_crypt_init_uios_normal(), with ZIL and dnode blocks
1807 * requiring special handling to parse out pieces that are to be encrypted. The
1808 * authbuf is used by these special cases to store additional authenticated
1809 * data (AAD) for the encryption modes.
1812 zio_crypt_init_uios(boolean_t encrypt, uint64_t version, dmu_object_type_t ot,
1813 uint8_t *plainbuf, uint8_t *cipherbuf, uint_t datalen, boolean_t byteswap,
1814 uint8_t *mac, uio_t *puio, uio_t *cuio, uint_t *enc_len, uint8_t **authbuf,
1815 uint_t *auth_len, boolean_t *no_crypt)
1820 ASSERT(DMU_OT_IS_ENCRYPTED(ot) || ot == DMU_OT_NONE);
1822 /* route to handler */
1824 case DMU_OT_INTENT_LOG:
1825 ret = zio_crypt_init_uios_zil(encrypt, plainbuf, cipherbuf,
1826 datalen, byteswap, puio, cuio, enc_len, authbuf, auth_len,
1830 ret = zio_crypt_init_uios_dnode(encrypt, version, plainbuf,
1831 cipherbuf, datalen, byteswap, puio, cuio, enc_len, authbuf,
1832 auth_len, no_crypt);
1835 ret = zio_crypt_init_uios_normal(encrypt, plainbuf, cipherbuf,
1836 datalen, puio, cuio, enc_len);
1839 *no_crypt = B_FALSE;
1846 /* populate the uios */
1847 puio->uio_segflg = UIO_SYSSPACE;
1848 cuio->uio_segflg = UIO_SYSSPACE;
1850 mac_iov = ((iovec_t *)&cuio->uio_iov[cuio->uio_iovcnt - 1]);
1851 mac_iov->iov_base = mac;
1852 mac_iov->iov_len = ZIO_DATA_MAC_LEN;
1861 * Primary encryption / decryption entrypoint for zio data.
1864 zio_do_crypt_data(boolean_t encrypt, zio_crypt_key_t *key,
1865 dmu_object_type_t ot, boolean_t byteswap, uint8_t *salt, uint8_t *iv,
1866 uint8_t *mac, uint_t datalen, uint8_t *plainbuf, uint8_t *cipherbuf,
1867 boolean_t *no_crypt)
1870 boolean_t locked = B_FALSE;
1871 uint64_t crypt = key->zk_crypt;
1872 uint_t keydata_len = zio_crypt_table[crypt].ci_keylen;
1873 uint_t enc_len, auth_len;
1875 uint8_t enc_keydata[MASTER_KEY_MAX_LEN];
1876 crypto_key_t tmp_ckey, *ckey = NULL;
1877 crypto_ctx_template_t tmpl;
1878 uint8_t *authbuf = NULL;
1881 * If the needed key is the current one, just use it. Otherwise we
1882 * need to generate a temporary one from the given salt + master key.
1883 * If we are encrypting, we must return a copy of the current salt
1884 * so that it can be stored in the blkptr_t.
1886 rw_enter(&key->zk_salt_lock, RW_READER);
1889 if (bcmp(salt, key->zk_salt, ZIO_DATA_SALT_LEN) == 0) {
1890 ckey = &key->zk_current_key;
1891 tmpl = key->zk_current_tmpl;
1893 rw_exit(&key->zk_salt_lock);
1896 ret = hkdf_sha512(key->zk_master_keydata, keydata_len, NULL, 0,
1897 salt, ZIO_DATA_SALT_LEN, enc_keydata, keydata_len);
1901 tmp_ckey.ck_format = CRYPTO_KEY_RAW;
1902 tmp_ckey.ck_data = enc_keydata;
1903 tmp_ckey.ck_length = CRYPTO_BYTES2BITS(keydata_len);
1910 * Attempt to use QAT acceleration if we can. We currently don't
1911 * do this for metadnode and ZIL blocks, since they have a much
1912 * more involved buffer layout and the qat_crypt() function only
1915 if (qat_crypt_use_accel(datalen) &&
1916 ot != DMU_OT_INTENT_LOG && ot != DMU_OT_DNODE) {
1917 uint8_t *srcbuf, *dstbuf;
1927 ret = qat_crypt((encrypt) ? QAT_ENCRYPT : QAT_DECRYPT, srcbuf,
1928 dstbuf, NULL, 0, iv, mac, ckey, key->zk_crypt, datalen);
1929 if (ret == CPA_STATUS_SUCCESS) {
1931 rw_exit(&key->zk_salt_lock);
1937 /* If the hardware implementation fails fall back to software */
1940 bzero(&puio, sizeof (uio_t));
1941 bzero(&cuio, sizeof (uio_t));
1943 /* create uios for encryption */
1944 ret = zio_crypt_init_uios(encrypt, key->zk_version, ot, plainbuf,
1945 cipherbuf, datalen, byteswap, mac, &puio, &cuio, &enc_len,
1946 &authbuf, &auth_len, no_crypt);
1950 /* perform the encryption / decryption in software */
1951 ret = zio_do_crypt_uio(encrypt, key->zk_crypt, ckey, tmpl, iv, enc_len,
1952 &puio, &cuio, authbuf, auth_len);
1957 rw_exit(&key->zk_salt_lock);
1961 if (authbuf != NULL)
1962 zio_buf_free(authbuf, datalen);
1963 if (ckey == &tmp_ckey)
1964 bzero(enc_keydata, keydata_len);
1965 zio_crypt_destroy_uio(&puio);
1966 zio_crypt_destroy_uio(&cuio);
1972 rw_exit(&key->zk_salt_lock);
1973 if (authbuf != NULL)
1974 zio_buf_free(authbuf, datalen);
1975 if (ckey == &tmp_ckey)
1976 bzero(enc_keydata, keydata_len);
1977 zio_crypt_destroy_uio(&puio);
1978 zio_crypt_destroy_uio(&cuio);
1984 * Simple wrapper around zio_do_crypt_data() to work with abd's instead of
1988 zio_do_crypt_abd(boolean_t encrypt, zio_crypt_key_t *key, dmu_object_type_t ot,
1989 boolean_t byteswap, uint8_t *salt, uint8_t *iv, uint8_t *mac,
1990 uint_t datalen, abd_t *pabd, abd_t *cabd, boolean_t *no_crypt)
1996 ptmp = abd_borrow_buf_copy(pabd, datalen);
1997 ctmp = abd_borrow_buf(cabd, datalen);
1999 ptmp = abd_borrow_buf(pabd, datalen);
2000 ctmp = abd_borrow_buf_copy(cabd, datalen);
2003 ret = zio_do_crypt_data(encrypt, key, ot, byteswap, salt, iv, mac,
2004 datalen, ptmp, ctmp, no_crypt);
2009 abd_return_buf(pabd, ptmp, datalen);
2010 abd_return_buf_copy(cabd, ctmp, datalen);
2012 abd_return_buf_copy(pabd, ptmp, datalen);
2013 abd_return_buf(cabd, ctmp, datalen);
2020 abd_return_buf(pabd, ptmp, datalen);
2021 abd_return_buf_copy(cabd, ctmp, datalen);
2023 abd_return_buf_copy(pabd, ptmp, datalen);
2024 abd_return_buf(cabd, ctmp, datalen);
2030 #if defined(_KERNEL)
2032 module_param(zfs_key_max_salt_uses, ulong, 0644);
2033 MODULE_PARM_DESC(zfs_key_max_salt_uses, "Max number of times a salt value "
2034 "can be used for generating encryption keys before it is rotated");