Files
cryptsetup/lib/luks2/luks2_keyslot_reenc.c
Ondrej Kozina 8f97d9b6e6 Do not refresh reencryption digest when not needed.
Due to commit 0113ac2d88
we recalculate reencryption digest whenever LUKS2 reencryption
keyslot gets updated. Until now we perform reencryption digest
refresh every time we call LUKS2_keyslot_reencrypt_update even
when no metadata was updated.

This improves on it and should speed up reencryption resume
process.
2022-05-26 12:13:06 +00:00

655 lines
20 KiB
C

/*
* LUKS - Linux Unified Key Setup v2, reencryption keyslot handler
*
* Copyright (C) 2016-2022 Red Hat, Inc. All rights reserved.
* Copyright (C) 2016-2022 Ondrej Kozina
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "luks2_internal.h"
static int reenc_keyslot_open(struct crypt_device *cd __attribute__((unused)),
int keyslot __attribute__((unused)),
const char *password __attribute__((unused)),
size_t password_len __attribute__((unused)),
char *volume_key __attribute__((unused)),
size_t volume_key_len __attribute__((unused)))
{
return -ENOENT;
}
static json_object *reencrypt_keyslot_area_jobj(struct crypt_device *cd,
const struct crypt_params_reencrypt *params,
size_t alignment,
uint64_t area_offset,
uint64_t area_length)
{
json_object *jobj_area = json_object_new_object();
if (!jobj_area || !params || !params->resilience)
return NULL;
json_object_object_add(jobj_area, "offset", crypt_jobj_new_uint64(area_offset));
json_object_object_add(jobj_area, "size", crypt_jobj_new_uint64(area_length));
json_object_object_add(jobj_area, "type", json_object_new_string(params->resilience));
if (!strcmp(params->resilience, "checksum")) {
log_dbg(cd, "Setting reencrypt keyslot for checksum protection.");
json_object_object_add(jobj_area, "hash", json_object_new_string(params->hash));
json_object_object_add(jobj_area, "sector_size", json_object_new_int64(alignment));
} else if (!strcmp(params->resilience, "journal")) {
log_dbg(cd, "Setting reencrypt keyslot for journal protection.");
} else if (!strcmp(params->resilience, "none")) {
log_dbg(cd, "Setting reencrypt keyslot for none protection.");
} else if (!strcmp(params->resilience, "datashift")) {
log_dbg(cd, "Setting reencrypt keyslot for datashift protection.");
json_object_object_add(jobj_area, "shift_size", crypt_jobj_new_uint64(params->data_shift << SECTOR_SHIFT));
} else {
json_object_put(jobj_area);
return NULL;
}
return jobj_area;
}
static json_object *reencrypt_keyslot_area_jobj_update_block_size(struct crypt_device *cd,
json_object *jobj_area, size_t alignment)
{
json_object *jobj_type, *jobj_area_new = NULL;
if (!jobj_area ||
!json_object_object_get_ex(jobj_area, "type", &jobj_type) ||
strcmp(json_object_get_string(jobj_type), "checksum"))
return NULL;
if (json_object_copy(jobj_area, &jobj_area_new))
return NULL;
log_dbg(cd, "Updating reencrypt resilience checksum block size.");
json_object_object_add(jobj_area_new, "sector_size", json_object_new_int64(alignment));
return jobj_area_new;
}
static int reenc_keyslot_alloc(struct crypt_device *cd,
struct luks2_hdr *hdr,
int keyslot,
const struct crypt_params_reencrypt *params,
size_t alignment)
{
int r;
json_object *jobj_keyslots, *jobj_keyslot, *jobj_area;
uint64_t area_offset, area_length;
log_dbg(cd, "Allocating reencrypt keyslot %d.", keyslot);
if (!params || !params->resilience || params->direction > CRYPT_REENCRYPT_BACKWARD)
return -EINVAL;
if (keyslot < 0 || keyslot >= LUKS2_KEYSLOTS_MAX)
return -ENOMEM;
if (!json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots))
return -EINVAL;
/* encryption doesn't require area (we shift data and backup will be available) */
if (strcmp(params->resilience, "datashift")) {
r = LUKS2_find_area_max_gap(cd, hdr, &area_offset, &area_length);
if (r < 0)
return r;
} else { /* we can't have keyslot w/o area...bug? */
r = LUKS2_find_area_gap(cd, hdr, 1, &area_offset, &area_length);
if (r < 0)
return r;
}
jobj_area = reencrypt_keyslot_area_jobj(cd, params, alignment, area_offset, area_length);
if (!jobj_area)
return -EINVAL;
jobj_keyslot = json_object_new_object();
if (!jobj_keyslot) {
json_object_put(jobj_area);
return -ENOMEM;
}
json_object_object_add(jobj_keyslot, "area", jobj_area);
json_object_object_add(jobj_keyslot, "type", json_object_new_string("reencrypt"));
json_object_object_add(jobj_keyslot, "key_size", json_object_new_int(1)); /* useless but mandatory */
json_object_object_add(jobj_keyslot, "mode", json_object_new_string(crypt_reencrypt_mode_to_str(params->mode)));
if (params->direction == CRYPT_REENCRYPT_FORWARD)
json_object_object_add(jobj_keyslot, "direction", json_object_new_string("forward"));
else
json_object_object_add(jobj_keyslot, "direction", json_object_new_string("backward"));
json_object_object_add_by_uint(jobj_keyslots, keyslot, jobj_keyslot);
if (LUKS2_check_json_size(cd, hdr)) {
log_dbg(cd, "New keyslot too large to fit in free metadata space.");
json_object_object_del_by_uint(jobj_keyslots, keyslot);
return -ENOSPC;
}
JSON_DBG(cd, hdr->jobj, "JSON:");
return 0;
}
static int reenc_keyslot_store_data(struct crypt_device *cd,
json_object *jobj_keyslot,
const void *buffer, size_t buffer_len)
{
int devfd, r;
json_object *jobj_area, *jobj_offset, *jobj_length;
uint64_t area_offset, area_length;
struct device *device = crypt_metadata_device(cd);
if (!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area) ||
!json_object_object_get_ex(jobj_area, "offset", &jobj_offset) ||
!json_object_object_get_ex(jobj_area, "size", &jobj_length))
return -EINVAL;
area_offset = crypt_jobj_get_uint64(jobj_offset);
area_length = crypt_jobj_get_uint64(jobj_length);
if (!area_offset || !area_length || ((uint64_t)buffer_len > area_length))
return -EINVAL;
devfd = device_open_locked(cd, device, O_RDWR);
if (devfd >= 0) {
if (write_lseek_blockwise(devfd, device_block_size(cd, device),
device_alignment(device), CONST_CAST(void *)buffer,
buffer_len, area_offset) < 0)
r = -EIO;
else
r = 0;
} else
r = -EINVAL;
if (r)
log_err(cd, _("IO error while encrypting keyslot."));
return r;
}
static int reenc_keyslot_store(struct crypt_device *cd,
int keyslot,
const char *password __attribute__((unused)),
size_t password_len __attribute__((unused)),
const char *buffer,
size_t buffer_len)
{
struct luks2_hdr *hdr;
json_object *jobj_keyslot;
int r = 0;
if (!cd || !buffer || !buffer_len)
return -EINVAL;
if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
return -EINVAL;
log_dbg(cd, "Reencrypt keyslot %d store.", keyslot);
jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
if (!jobj_keyslot)
return -EINVAL;
r = LUKS2_device_write_lock(cd, hdr, crypt_metadata_device(cd));
if (r)
return r;
r = reenc_keyslot_store_data(cd, jobj_keyslot, buffer, buffer_len);
if (r < 0) {
device_write_unlock(cd, crypt_metadata_device(cd));
return r;
}
r = LUKS2_hdr_write(cd, hdr);
device_write_unlock(cd, crypt_metadata_device(cd));
return r < 0 ? r : keyslot;
}
static int reenc_keyslot_wipe(struct crypt_device *cd,
int keyslot)
{
struct luks2_hdr *hdr;
if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
return -EINVAL;
/* remove reencryption verification data */
LUKS2_digest_assign(cd, hdr, keyslot, CRYPT_ANY_DIGEST, 0, 0);
return 0;
}
static int reenc_keyslot_dump(struct crypt_device *cd, int keyslot)
{
json_object *jobj_keyslot, *jobj_area, *jobj_direction, *jobj_mode, *jobj_resilience,
*jobj1;
jobj_keyslot = LUKS2_get_keyslot_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), keyslot);
if (!jobj_keyslot)
return -EINVAL;
if (!json_object_object_get_ex(jobj_keyslot, "direction", &jobj_direction) ||
!json_object_object_get_ex(jobj_keyslot, "mode", &jobj_mode) ||
!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area) ||
!json_object_object_get_ex(jobj_area, "type", &jobj_resilience))
return -EINVAL;
log_std(cd, "\t%-12s%s\n", "Mode:", json_object_get_string(jobj_mode));
log_std(cd, "\t%-12s%s\n", "Direction:", json_object_get_string(jobj_direction));
log_std(cd, "\t%-12s%s\n", "Resilience:", json_object_get_string(jobj_resilience));
if (!strcmp(json_object_get_string(jobj_resilience), "checksum")) {
json_object_object_get_ex(jobj_area, "hash", &jobj1);
log_std(cd, "\t%-12s%s\n", "Hash:", json_object_get_string(jobj1));
json_object_object_get_ex(jobj_area, "sector_size", &jobj1);
log_std(cd, "\t%-12s%d [bytes]\n", "Hash data:", json_object_get_int(jobj1));
} else if (!strcmp(json_object_get_string(jobj_resilience), "datashift")) {
json_object_object_get_ex(jobj_area, "shift_size", &jobj1);
log_std(cd, "\t%-12s%" PRIu64 "[bytes]\n", "Shift size:", crypt_jobj_get_uint64(jobj1));
}
json_object_object_get_ex(jobj_area, "offset", &jobj1);
log_std(cd, "\tArea offset:%" PRIu64 " [bytes]\n", crypt_jobj_get_uint64(jobj1));
json_object_object_get_ex(jobj_area, "size", &jobj1);
log_std(cd, "\tArea length:%" PRIu64 " [bytes]\n", crypt_jobj_get_uint64(jobj1));
return 0;
}
static int reenc_keyslot_validate(struct crypt_device *cd, json_object *jobj_keyslot)
{
json_object *jobj_mode, *jobj_area, *jobj_type, *jobj_shift_size, *jobj_hash, *jobj_sector_size, *jobj_direction, *jobj_key_size;
const char *mode, *type, *direction;
uint32_t sector_size;
uint64_t shift_size;
/* mode (string: encrypt,reencrypt,decrypt)
* direction (string:)
* area {
* type: (string: datashift, journal, checksum, none)
* hash: (string: checksum only)
* sector_size (uint32: checksum only)
* shift_size (uint64: datashift only)
* }
*/
/* area and area type are validated in general validation code */
if (!jobj_keyslot || !json_object_object_get_ex(jobj_keyslot, "area", &jobj_area) ||
!json_object_object_get_ex(jobj_area, "type", &jobj_type))
return -EINVAL;
jobj_key_size = json_contains(cd, jobj_keyslot, "", "reencrypt keyslot", "key_size", json_type_int);
jobj_mode = json_contains(cd, jobj_keyslot, "", "reencrypt keyslot", "mode", json_type_string);
jobj_direction = json_contains(cd, jobj_keyslot, "", "reencrypt keyslot", "direction", json_type_string);
if (!jobj_mode || !jobj_direction || !jobj_key_size)
return -EINVAL;
if (!validate_json_uint32(jobj_key_size) || crypt_jobj_get_uint32(jobj_key_size) != 1) {
log_dbg(cd, "Illegal reencrypt key size.");
return -EINVAL;
}
mode = json_object_get_string(jobj_mode);
type = json_object_get_string(jobj_type);
direction = json_object_get_string(jobj_direction);
if (strcmp(mode, "reencrypt") && strcmp(mode, "encrypt") &&
strcmp(mode, "decrypt")) {
log_dbg(cd, "Illegal reencrypt mode %s.", mode);
return -EINVAL;
}
if (strcmp(direction, "forward") && strcmp(direction, "backward")) {
log_dbg(cd, "Illegal reencrypt direction %s.", direction);
return -EINVAL;
}
if (!strcmp(type, "checksum")) {
jobj_hash = json_contains(cd, jobj_area, "type:checksum", "Keyslot area", "hash", json_type_string);
jobj_sector_size = json_contains(cd, jobj_area, "type:checksum", "Keyslot area", "sector_size", json_type_int);
if (!jobj_hash || !jobj_sector_size)
return -EINVAL;
if (!validate_json_uint32(jobj_sector_size))
return -EINVAL;
sector_size = crypt_jobj_get_uint32(jobj_sector_size);
if (sector_size < SECTOR_SIZE || NOTPOW2(sector_size)) {
log_dbg(cd, "Invalid sector_size (%" PRIu32 ") for checksum resilience mode.", sector_size);
return -EINVAL;
}
} else if (!strcmp(type, "datashift")) {
if (!(jobj_shift_size = json_contains(cd, jobj_area, "type:datashift", "Keyslot area", "shift_size", json_type_string)))
return -EINVAL;
shift_size = crypt_jobj_get_uint64(jobj_shift_size);
if (!shift_size)
return -EINVAL;
if (MISALIGNED_512(shift_size)) {
log_dbg(cd, "Shift size field has to be aligned to sector size: %" PRIu32, SECTOR_SIZE);
return -EINVAL;
}
}
return 0;
}
static int reenc_keyslot_update_needed(struct crypt_device *cd,
json_object *jobj_keyslot,
const struct crypt_params_reencrypt *params,
size_t alignment)
{
const char *type;
json_object *jobj_area, *jobj_type, *jobj;
if (!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area) ||
!json_object_object_get_ex(jobj_area, "type", &jobj_type) ||
!(type = json_object_get_string(jobj_type)))
return -EINVAL;
/*
* If no resilience mode change is requested and effective
* resilience mode is 'checksum' then check alignment matches
* stored checksum block size.
*/
if (!params || !params->resilience) {
if (!strcmp(json_object_get_string(jobj_type), "checksum"))
return (json_object_object_get_ex(jobj_area, "sector_size", &jobj) ||
alignment != crypt_jobj_get_uint32(jobj));
return 0;
}
if (strcmp(params->resilience, type))
return 1;
if (!strcmp(type, "checksum")) {
if (!params->hash)
return -EINVAL;
return (!json_object_object_get_ex(jobj_area, "hash", &jobj) ||
strcmp(json_object_get_string(jobj), params->hash) ||
!json_object_object_get_ex(jobj_area, "sector_size", &jobj) ||
crypt_jobj_get_uint32(jobj) != alignment);
} else if (!strcmp(type, "datashift")) {
if (!json_object_object_get_ex(jobj_area, "shift_size", &jobj))
return -EINVAL;
return ((params->data_shift << SECTOR_SHIFT) != crypt_jobj_get_uint64(jobj));
}
/* nothing to compare with 'none' and 'journal' */
return 0;
}
static int load_checksum_protection(struct crypt_device *cd,
json_object *jobj_area,
uint64_t area_length,
struct reenc_protection *rp)
{
int r;
json_object *jobj_hash, *jobj_block_size;
if (!jobj_area || !rp ||
!json_object_object_get_ex(jobj_area, "hash", &jobj_hash) ||
!json_object_object_get_ex(jobj_area, "sector_size", &jobj_block_size))
return -EINVAL;
r = snprintf(rp->p.csum.hash, sizeof(rp->p.csum.hash), "%s", json_object_get_string(jobj_hash));
if (r < 0 || (size_t)r >= sizeof(rp->p.csum.hash))
return -EINVAL;
if (crypt_hash_init(&rp->p.csum.ch, rp->p.csum.hash)) {
log_err(cd, _("Hash algorithm %s is not available."), rp->p.csum.hash);
return -EINVAL;
}
r = crypt_hash_size(rp->p.csum.hash);
if (r <= 0) {
crypt_hash_destroy(rp->p.csum.ch);
rp->p.csum.ch = NULL;
log_dbg(cd, "Invalid hash size");
return -EINVAL;
}
rp->p.csum.hash_size = r;
rp->p.csum.block_size = crypt_jobj_get_uint32(jobj_block_size);
rp->p.csum.checksums_len = area_length;
if (posix_memalign(&rp->p.csum.checksums, device_alignment(crypt_metadata_device(cd)),
rp->p.csum.checksums_len)) {
crypt_hash_destroy(rp->p.csum.ch);
rp->p.csum.ch = NULL;
return -ENOMEM;
}
rp->type = REENC_PROTECTION_CHECKSUM;
return 0;
}
static int reenc_keyslot_load_resilience(struct crypt_device *cd,
json_object *jobj_keyslot,
struct reenc_protection *rp)
{
const char *type;
int r;
json_object *jobj_area, *jobj_type, *jobj;
uint64_t dummy, area_length;
if (!rp || !json_object_object_get_ex(jobj_keyslot, "area", &jobj_area) ||
!json_object_object_get_ex(jobj_area, "type", &jobj_type))
return -EINVAL;
r = LUKS2_keyslot_jobj_area(jobj_keyslot, &dummy, &area_length);
if (r < 0)
return r;
type = json_object_get_string(jobj_type);
if (!type)
return -EINVAL;
if (!strcmp(type, "checksum")) {
log_dbg(cd, "Initializing checksum resilience mode.");
return load_checksum_protection(cd, jobj_area, area_length, rp);
} else if (!strcmp(type, "journal")) {
log_dbg(cd, "Initializing journal resilience mode.");
rp->type = REENC_PROTECTION_JOURNAL;
} else if (!strcmp(type, "none")) {
log_dbg(cd, "Initializing none resilience mode.");
rp->type = REENC_PROTECTION_NONE;
} else if (!strcmp(type, "datashift")) {
log_dbg(cd, "Initializing datashift resilience mode.");
if (!json_object_object_get_ex(jobj_area, "shift_size", &jobj))
return -EINVAL;
rp->type = REENC_PROTECTION_DATASHIFT;
rp->p.ds.data_shift = crypt_jobj_get_uint64(jobj);
} else
return -EINVAL;
return 0;
}
static bool reenc_keyslot_update_is_valid(struct crypt_device *cd,
json_object *jobj_area,
const struct crypt_params_reencrypt *params)
{
const char *type;
json_object *jobj_type, *jobj;
if (!json_object_object_get_ex(jobj_area, "type", &jobj_type) ||
!(type = json_object_get_string(jobj_type)))
return false;
/* do not allow switch to/away from datashift resilience type */
if ((strcmp(params->resilience, "datashift") && !strcmp(type, "datashift")) ||
(!strcmp(params->resilience, "datashift") && strcmp(type, "datashift")))
return false;
/* datashift value is also immutable */
if (!strcmp(type, "datashift")) {
if (!json_object_object_get_ex(jobj_area, "shift_size", &jobj))
return false;
return (params->data_shift << SECTOR_SHIFT) == crypt_jobj_get_uint64(jobj);
}
return true;
}
static int reenc_keyslot_update(struct crypt_device *cd,
json_object *jobj_keyslot,
const struct crypt_params_reencrypt *params,
size_t alignment)
{
int r;
json_object *jobj_area, *jobj_area_new;
uint64_t area_offset, area_length;
if (!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
return -EINVAL;
r = LUKS2_keyslot_jobj_area(jobj_keyslot, &area_offset, &area_length);
if (r < 0)
return r;
if (!params || !params->resilience)
jobj_area_new = reencrypt_keyslot_area_jobj_update_block_size(cd, jobj_area, alignment);
else {
if (!reenc_keyslot_update_is_valid(cd, jobj_area, params)) {
log_err(cd, _("Invalid reencryption resilience mode change requested."));
return -EINVAL;
}
jobj_area_new = reencrypt_keyslot_area_jobj(cd, params, alignment,
area_offset, area_length);
}
if (!jobj_area_new)
return -EINVAL;
json_object_object_add(jobj_keyslot, "area", jobj_area_new);
return 0;
}
int LUKS2_keyslot_reencrypt_allocate(struct crypt_device *cd,
struct luks2_hdr *hdr,
int keyslot,
const struct crypt_params_reencrypt *params,
size_t alignment)
{
int r;
if (keyslot == CRYPT_ANY_SLOT)
return -EINVAL;
r = reenc_keyslot_alloc(cd, hdr, keyslot, params, alignment);
if (r < 0)
return r;
r = LUKS2_keyslot_priority_set(cd, hdr, keyslot, CRYPT_SLOT_PRIORITY_IGNORE, 0);
if (r < 0)
return r;
r = reenc_keyslot_validate(cd, LUKS2_get_keyslot_jobj(hdr, keyslot));
if (r) {
log_dbg(cd, "Keyslot validation failed.");
return r;
}
return 0;
}
int LUKS2_keyslot_reencrypt_update_needed(struct crypt_device *cd,
struct luks2_hdr *hdr,
int keyslot,
const struct crypt_params_reencrypt *params,
size_t alignment)
{
int r;
json_object *jobj_type, *jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
if (!jobj_keyslot ||
!json_object_object_get_ex(jobj_keyslot, "type", &jobj_type) ||
strcmp(json_object_get_string(jobj_type), "reencrypt"))
return -EINVAL;
r = reenc_keyslot_update_needed(cd, jobj_keyslot, params, alignment);
if (!r)
log_dbg(cd, "No update of reencrypt keyslot needed.");
return r;
}
int LUKS2_keyslot_reencrypt_update(struct crypt_device *cd,
struct luks2_hdr *hdr,
int keyslot,
const struct crypt_params_reencrypt *params,
size_t alignment,
struct volume_key *vks)
{
int r;
json_object *jobj_type, *jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
if (!jobj_keyslot ||
!json_object_object_get_ex(jobj_keyslot, "type", &jobj_type) ||
strcmp(json_object_get_string(jobj_type), "reencrypt"))
return -EINVAL;
/* verify existing reencryption metadata before updating */
r = LUKS2_reencrypt_digest_verify(cd, hdr, vks);
if (r < 0)
return r;
r = reenc_keyslot_update(cd, jobj_keyslot, params, alignment);
if (r < 0)
return r;
r = LUKS2_keyslot_reencrypt_digest_create(cd, hdr, vks);
if (r < 0)
log_err(cd, _("Failed to refresh reencryption verification digest."));
return r;
}
int LUKS2_keyslot_reencrypt_load(struct crypt_device *cd,
struct luks2_hdr *hdr,
int keyslot,
struct reenc_protection *rp)
{
json_object *jobj_type, *jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
if (!jobj_keyslot ||
!json_object_object_get_ex(jobj_keyslot, "type", &jobj_type) ||
strcmp(json_object_get_string(jobj_type), "reencrypt"))
return -EINVAL;
return reenc_keyslot_load_resilience(cd, jobj_keyslot, rp);
}
const keyslot_handler reenc_keyslot = {
.name = "reencrypt",
.open = reenc_keyslot_open,
.store = reenc_keyslot_store, /* initialization only or also per every chunk write */
.wipe = reenc_keyslot_wipe,
.dump = reenc_keyslot_dump,
.validate = reenc_keyslot_validate
};