zfs/include/sys/dsl_crypt.h

/*
 * 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_DSL_CRYPT_H
#define	_SYS_DSL_CRYPT_H

#include <sys/dmu_tx.h>
#include <sys/dmu.h>
#include <sys/zio_crypt.h>
#include <sys/spa.h>
#include <sys/dsl_dataset.h>

/*
 * ZAP entry keys for DSL Crypto Keys stored on disk. In addition,
 * ZFS_PROP_KEYFORMAT, ZFS_PROP_PBKDF2_SALT, and ZFS_PROP_PBKDF2_ITERS are
 * also maintained here using their respective property names.
 */
#define	DSL_CRYPTO_KEY_CRYPTO_SUITE	"DSL_CRYPTO_SUITE"
#define	DSL_CRYPTO_KEY_GUID		"DSL_CRYPTO_GUID"
#define	DSL_CRYPTO_KEY_IV		"DSL_CRYPTO_IV"
#define	DSL_CRYPTO_KEY_MAC		"DSL_CRYPTO_MAC"
#define	DSL_CRYPTO_KEY_MASTER_KEY	"DSL_CRYPTO_MASTER_KEY_1"
#define	DSL_CRYPTO_KEY_HMAC_KEY		"DSL_CRYPTO_HMAC_KEY_1"
#define	DSL_CRYPTO_KEY_ROOT_DDOBJ	"DSL_CRYPTO_ROOT_DDOBJ"
#define	DSL_CRYPTO_KEY_REFCOUNT		"DSL_CRYPTO_REFCOUNT"


/*
 * In-memory representation of a wrapping key. One of these structs will exist
 * for each encryption root with its key loaded.
 */
typedef struct dsl_wrapping_key {
	/* link on spa_keystore_t:sk_wkeys */
	avl_node_t wk_avl_link;

	/* keyformat property enum */
	zfs_keyformat_t wk_keyformat;

	/* the pbkdf2 salt, if the keyformat is of type passphrase */
	uint64_t wk_salt;

	/* the pbkdf2 iterations, if the keyformat is of type passphrase */
	uint64_t wk_iters;

	/* actual wrapping key */
	crypto_key_t wk_key;

	/* refcount of number of dsl_crypto_key_t's holding this struct */
	refcount_t wk_refcnt;

	/* dsl directory object that owns this wrapping key */
	uint64_t wk_ddobj;
} dsl_wrapping_key_t;

/* enum of commands indicating special actions that should be run */
typedef enum dcp_cmd {
	/* key creation commands */
	DCP_CMD_NONE = 0,	/* no specific command */
	DCP_CMD_RAW_RECV,	/* raw receive */

	/* key changing commands */
	DCP_CMD_NEW_KEY,	/* rewrap key as an encryption root */
	DCP_CMD_INHERIT,	/* rewrap key with parent's wrapping key */
	DCP_CMD_FORCE_NEW_KEY,	/* change to encryption root without rewrap */
	DCP_CMD_FORCE_INHERIT,	/* inherit parent's key without rewrap */

	DCP_CMD_MAX
} dcp_cmd_t;

/*
 * This struct is a simple wrapper around all the parameters that are usually
 * required to setup encryption. It exists so that all of the params can be
 * passed around the kernel together for convenience.
 */
typedef struct dsl_crypto_params {
	/* command indicating intended action */
	dcp_cmd_t cp_cmd;

	/* the encryption algorithm */
	enum zio_encrypt cp_crypt;

	/* keylocation property string */
	char *cp_keylocation;

	/* the wrapping key */
	dsl_wrapping_key_t *cp_wkey;
} dsl_crypto_params_t;

/*
 * In-memory representation of a DSL Crypto Key object. One of these structs
 * (and corresponding on-disk ZAP object) will exist for each encrypted
 * clone family that is mounted or otherwise reading protected data.
 */
typedef struct dsl_crypto_key {
	/* link on spa_keystore_t:sk_dsl_keys */
	avl_node_t dck_avl_link;

	/* refcount of dsl_key_mapping_t's holding this key */
	refcount_t dck_holds;

	/* master key used to derive encryption keys */
	zio_crypt_key_t dck_key;

	/* wrapping key for syncing this structure to disk */
	dsl_wrapping_key_t *dck_wkey;

	/* on-disk object id */
	uint64_t dck_obj;
} dsl_crypto_key_t;

/*
 * In-memory mapping of a dataset object id to a DSL Crypto Key. This is used
 * to look up the corresponding dsl_crypto_key_t from the zio layer for
 * performing data encryption and decryption.
 */
typedef struct dsl_key_mapping {
	/* link on spa_keystore_t:sk_key_mappings */
	avl_node_t km_avl_link;

	/* refcount of how many users are depending on this mapping */
	refcount_t km_refcnt;

	/* dataset this crypto key belongs to (index) */
	uint64_t km_dsobj;

	/* crypto key (value) of this record */
	dsl_crypto_key_t *km_key;
} dsl_key_mapping_t;

/* in memory structure for holding all wrapping and dsl keys */
typedef struct spa_keystore {
	/* lock for protecting sk_dsl_keys */
	krwlock_t sk_dk_lock;

	/* tree of all dsl_crypto_key_t's */
	avl_tree_t sk_dsl_keys;

	/* lock for protecting sk_key_mappings */
	krwlock_t sk_km_lock;

	/* tree of all dsl_key_mapping_t's, indexed by dsobj */
	avl_tree_t sk_key_mappings;

	/* lock for protecting the wrapping keys tree */
	krwlock_t sk_wkeys_lock;

	/* tree of all dsl_wrapping_key_t's, indexed by ddobj */
	avl_tree_t sk_wkeys;
} spa_keystore_t;

int dsl_crypto_params_create_nvlist(dcp_cmd_t cmd, nvlist_t *props,
    nvlist_t *crypto_args, dsl_crypto_params_t **dcp_out);
void dsl_crypto_params_free(dsl_crypto_params_t *dcp, boolean_t unload);
void dsl_dataset_crypt_stats(struct dsl_dataset *ds, nvlist_t *nv);
int dsl_crypto_can_set_keylocation(const char *dsname, const char *keylocation);

void spa_keystore_init(spa_keystore_t *sk);
void spa_keystore_fini(spa_keystore_t *sk);

void spa_keystore_dsl_key_rele(spa_t *spa, dsl_crypto_key_t *dck, void *tag);
int spa_keystore_load_wkey_impl(spa_t *spa, dsl_wrapping_key_t *wkey);
int spa_keystore_load_wkey(const char *dsname, dsl_crypto_params_t *dcp,
    boolean_t noop);
int spa_keystore_unload_wkey_impl(spa_t *spa, uint64_t ddobj);
int spa_keystore_unload_wkey(const char *dsname);

int spa_keystore_create_mapping_impl(spa_t *spa, uint64_t dsobj, dsl_dir_t *dd,
    void *tag);
int spa_keystore_create_mapping(spa_t *spa, struct dsl_dataset *ds, void *tag);
int spa_keystore_remove_mapping(spa_t *spa, uint64_t dsobj, void *tag);
int spa_keystore_lookup_key(spa_t *spa, uint64_t dsobj, void *tag,
    dsl_crypto_key_t **dck_out);

int dsl_crypto_populate_key_nvlist(struct dsl_dataset *ds, nvlist_t **nvl_out);
int dsl_crypto_recv_key(const char *poolname, uint64_t dsobj,
    dmu_objset_type_t ostype, nvlist_t *nvl);

int spa_keystore_change_key(const char *dsname, dsl_crypto_params_t *dcp);
int dsl_dir_rename_crypt_check(dsl_dir_t *dd, dsl_dir_t *newparent);
int dsl_dataset_promote_crypt_check(dsl_dir_t *target, dsl_dir_t *origin);
void dsl_dataset_promote_crypt_sync(dsl_dir_t *target, dsl_dir_t *origin,
    dmu_tx_t *tx);
int dmu_objset_create_crypt_check(dsl_dir_t *parentdd,
    dsl_crypto_params_t *dcp);
void dsl_dataset_create_crypt_sync(uint64_t dsobj, dsl_dir_t *dd,
    struct dsl_dataset *origin, dsl_crypto_params_t *dcp, dmu_tx_t *tx);
uint64_t dsl_crypto_key_create_sync(uint64_t crypt, dsl_wrapping_key_t *wkey,
    dmu_tx_t *tx);
int dmu_objset_clone_crypt_check(dsl_dir_t *parentdd, dsl_dir_t *origindd);
uint64_t dsl_crypto_key_clone_sync(dsl_dir_t *origindd, dmu_tx_t *tx);
void dsl_crypto_key_destroy_sync(uint64_t dckobj, dmu_tx_t *tx);

int spa_crypt_get_salt(spa_t *spa, uint64_t dsobj, uint8_t *salt);
int spa_do_crypt_mac_abd(boolean_t generate, spa_t *spa, uint64_t dsobj,
    abd_t *abd, uint_t datalen, uint8_t *mac);
int spa_do_crypt_objset_mac_abd(boolean_t generate, spa_t *spa, uint64_t dsobj,
    abd_t *abd, uint_t datalen, boolean_t byteswap);
int spa_do_crypt_abd(boolean_t encrypt, spa_t *spa, uint64_t dsobj,
    const blkptr_t *bp, uint64_t txgid, uint_t datalen, abd_t *pabd,
    abd_t *cabd, uint8_t *iv, uint8_t *mac, uint8_t *salt, boolean_t *no_crypt);

#endif