freebsd-nq/include/sys/zio_crypt.h
Tom Caputi ae76f45cda Encryption Stability and On-Disk Format Fixes
The on-disk format for encrypted datasets protects not only
the encrypted and authenticated blocks themselves, but also
the order and interpretation of these blocks. In order to
make this work while maintaining the ability to do raw
sends, the indirect bps maintain a secure checksum of all
the MACs in the block below it along with a few other
fields that determine how the data is interpreted.

Unfortunately, the current on-disk format erroneously
includes some fields which are not portable and thus cannot
support raw sends. It is not possible to easily work around
this issue due to a separate and much smaller bug which
causes indirect blocks for encrypted dnodes to not be
compressed, which conflicts with the previous bug. In
addition, the current code generates incompatible on-disk
formats on big endian and little endian systems due to an
issue with how block pointers are authenticated. Finally,
raw send streams do not currently include dn_maxblkid when
sending both the metadnode and normal dnodes which are
needed in order to ensure that we are correctly maintaining
the portable objset MAC.

This patch zero's out the offending fields when computing
the bp MAC and ensures that these MACs are always
calculated in little endian order (regardless of the host
system's byte order). This patch also registers an errata
for the old on-disk format, which we detect by adding a
"version" field to newly created DSL Crypto Keys. We allow
datasets without a version (version 0) to only be mounted
for read so that they can easily be migrated. We also now
include dn_maxblkid in raw send streams to ensure the MAC
can be maintained correctly.

This patch also contains minor bug fixes and cleanups.

Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed by: Matthew Ahrens <mahrens@delphix.com>
Signed-off-by: Tom Caputi <tcaputi@datto.com>
Closes #6845
Closes #6864
Closes #7052
2018-02-02 11:37:16 -08:00

144 lines
4.8 KiB
C

/*
* 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.
*/
#ifndef _SYS_ZIO_CRYPT_H
#define _SYS_ZIO_CRYPT_H
#include <sys/dmu.h>
#include <sys/refcount.h>
#include <sys/crypto/api.h>
#include <sys/nvpair.h>
#include <sys/avl.h>
#include <sys/zio.h>
/* forward declarations */
struct zbookmark_phys;
#define WRAPPING_KEY_LEN 32
#define WRAPPING_IV_LEN ZIO_DATA_IV_LEN
#define WRAPPING_MAC_LEN ZIO_DATA_MAC_LEN
#define MASTER_KEY_MAX_LEN 32
#define SHA512_HMAC_KEYLEN 64
#define ZIO_CRYPT_KEY_CURRENT_VERSION 1ULL
typedef enum zio_crypt_type {
ZC_TYPE_NONE = 0,
ZC_TYPE_CCM,
ZC_TYPE_GCM
} zio_crypt_type_t;
/* table of supported crypto algorithms, modes and keylengths. */
typedef struct zio_crypt_info {
/* mechanism name, needed by ICP */
crypto_mech_name_t ci_mechname;
/* cipher mode type (GCM, CCM) */
zio_crypt_type_t ci_crypt_type;
/* length of the encryption key */
size_t ci_keylen;
/* human-readable name of the encryption alforithm */
char *ci_name;
} zio_crypt_info_t;
extern zio_crypt_info_t zio_crypt_table[ZIO_CRYPT_FUNCTIONS];
/* in memory representation of an unwrapped key that is loaded into memory */
typedef struct zio_crypt_key {
/* encryption algorithm */
uint64_t zk_crypt;
/* on-disk format version */
uint64_t zk_version;
/* GUID for uniquely identifying this key. Not encrypted on disk. */
uint64_t zk_guid;
/* buffer for master key */
uint8_t zk_master_keydata[MASTER_KEY_MAX_LEN];
/* buffer for hmac key */
uint8_t zk_hmac_keydata[SHA512_HMAC_KEYLEN];
/* buffer for currrent encryption key derived from master key */
uint8_t zk_current_keydata[MASTER_KEY_MAX_LEN];
/* current 64 bit salt for deriving an encryption key */
uint8_t zk_salt[ZIO_DATA_SALT_LEN];
/* count of how many times the current salt has been used */
uint64_t zk_salt_count;
/* illumos crypto api current encryption key */
crypto_key_t zk_current_key;
/* template of current encryption key for illumos crypto api */
crypto_ctx_template_t zk_current_tmpl;
/* illumos crypto api current hmac key */
crypto_key_t zk_hmac_key;
/* template of hmac key for illumos crypto api */
crypto_ctx_template_t zk_hmac_tmpl;
/* lock for changing the salt and dependant values */
krwlock_t zk_salt_lock;
} zio_crypt_key_t;
void zio_crypt_key_destroy(zio_crypt_key_t *key);
int zio_crypt_key_init(uint64_t crypt, zio_crypt_key_t *key);
int zio_crypt_key_get_salt(zio_crypt_key_t *key, uint8_t *salt_out);
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 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 zio_crypt_generate_iv(uint8_t *ivbuf);
int zio_crypt_generate_iv_salt_dedup(zio_crypt_key_t *key, uint8_t *data,
uint_t datalen, uint8_t *ivbuf, uint8_t *salt);
void zio_crypt_encode_params_bp(blkptr_t *bp, uint8_t *salt, uint8_t *iv);
void zio_crypt_decode_params_bp(const blkptr_t *bp, uint8_t *salt, uint8_t *iv);
void zio_crypt_encode_mac_bp(blkptr_t *bp, uint8_t *mac);
void zio_crypt_decode_mac_bp(const blkptr_t *bp, uint8_t *mac);
void zio_crypt_encode_mac_zil(void *data, uint8_t *mac);
void zio_crypt_decode_mac_zil(const void *data, uint8_t *mac);
void zio_crypt_copy_dnode_bonus(abd_t *src_abd, uint8_t *dst, uint_t datalen);
int zio_crypt_do_indirect_mac_checksum(boolean_t generate, void *buf,
uint_t datalen, boolean_t byteswap, uint8_t *cksum);
int zio_crypt_do_indirect_mac_checksum_abd(boolean_t generate, abd_t *abd,
uint_t datalen, boolean_t byteswap, uint8_t *cksum);
int zio_crypt_do_hmac(zio_crypt_key_t *key, uint8_t *data, uint_t datalen,
uint8_t *digestbuf, uint_t digestlen);
int zio_crypt_do_objset_hmacs(zio_crypt_key_t *key, void *data, uint_t datalen,
boolean_t byteswap, uint8_t *portable_mac, uint8_t *local_mac);
int zio_do_crypt_data(boolean_t encrypt, zio_crypt_key_t *key, uint8_t *salt,
dmu_object_type_t ot, uint8_t *iv, uint8_t *mac, uint_t datalen,
boolean_t byteswap, uint8_t *plainbuf, uint8_t *cipherbuf,
boolean_t *no_crypt);
int zio_do_crypt_abd(boolean_t encrypt, zio_crypt_key_t *key, uint8_t *salt,
dmu_object_type_t ot, uint8_t *iv, uint8_t *mac, uint_t datalen,
boolean_t byteswap, abd_t *pabd, abd_t *cabd, boolean_t *no_crypt);
#endif