diff options
Diffstat (limited to 'lib/luks2/luks2_keyslot.c')
| -rw-r--r-- | lib/luks2/luks2_keyslot.c | 977 |
1 files changed, 977 insertions, 0 deletions
diff --git a/lib/luks2/luks2_keyslot.c b/lib/luks2/luks2_keyslot.c new file mode 100644 index 0000000..5cf4b83 --- /dev/null +++ b/lib/luks2/luks2_keyslot.c @@ -0,0 +1,977 @@ +/* + * LUKS - Linux Unified Key Setup v2, keyslot handling + * + * Copyright (C) 2015-2023 Red Hat, Inc. All rights reserved. + * Copyright (C) 2015-2023 Milan Broz + * + * 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" + +/* Internal implementations */ +extern const keyslot_handler luks2_keyslot; +extern const keyslot_handler reenc_keyslot; + +static const keyslot_handler *keyslot_handlers[LUKS2_KEYSLOTS_MAX] = { + &luks2_keyslot, +#if USE_LUKS2_REENCRYPTION + &reenc_keyslot, +#endif + NULL +}; + +static const keyslot_handler +*LUKS2_keyslot_handler_type(const char *type) +{ + int i; + + for (i = 0; i < LUKS2_KEYSLOTS_MAX && keyslot_handlers[i]; i++) { + if (!strcmp(keyslot_handlers[i]->name, type)) + return keyslot_handlers[i]; + } + + return NULL; +} + +static const keyslot_handler +*LUKS2_keyslot_handler(struct crypt_device *cd, int keyslot) +{ + struct luks2_hdr *hdr; + json_object *jobj1, *jobj2; + + if (keyslot < 0) + return NULL; + + if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2))) + return NULL; + + if (!(jobj1 = LUKS2_get_keyslot_jobj(hdr, keyslot))) + return NULL; + + if (!json_object_object_get_ex(jobj1, "type", &jobj2)) + return NULL; + + return LUKS2_keyslot_handler_type(json_object_get_string(jobj2)); +} + +int LUKS2_keyslot_find_empty(struct crypt_device *cd, struct luks2_hdr *hdr, size_t keylength) +{ + int i; + + for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++) + if (!LUKS2_get_keyslot_jobj(hdr, i)) + break; + + if (i == LUKS2_KEYSLOTS_MAX) + return -EINVAL; + + /* Check also there is a space for the key in keyslots area */ + if (keylength && LUKS2_find_area_gap(cd, hdr, keylength, NULL, NULL) < 0) + return -ENOSPC; + + return i; +} + +/* Check if a keyslot is assigned to specific segment */ +static int _keyslot_for_segment(struct luks2_hdr *hdr, int keyslot, int segment) +{ + int keyslot_digest, count = 0; + unsigned s; + + keyslot_digest = LUKS2_digest_by_keyslot(hdr, keyslot); + if (keyslot_digest < 0) + return keyslot_digest; + + if (segment >= 0) + return keyslot_digest == LUKS2_digest_by_segment(hdr, segment); + + for (s = 0; s < json_segments_count(LUKS2_get_segments_jobj(hdr)); s++) { + if (keyslot_digest == LUKS2_digest_by_segment(hdr, s)) + count++; + } + + return count; +} + +static int _keyslot_for_digest(struct luks2_hdr *hdr, int keyslot, int digest) +{ + int r = -EINVAL; + + r = LUKS2_digest_by_keyslot(hdr, keyslot); + if (r < 0) + return r; + return r == digest ? 0 : -ENOENT; +} + +int LUKS2_keyslot_for_segment(struct luks2_hdr *hdr, int keyslot, int segment) +{ + int r = -EINVAL; + + /* no need to check anything */ + if (segment == CRYPT_ANY_SEGMENT) + return 0; /* ok */ + if (segment == CRYPT_DEFAULT_SEGMENT) { + segment = LUKS2_get_default_segment(hdr); + if (segment < 0) + return segment; + } + + r = _keyslot_for_segment(hdr, keyslot, segment); + if (r < 0) + return r; + + return r >= 1 ? 0 : -ENOENT; +} + +/* Number of keyslots assigned to a segment or all keyslots for CRYPT_ANY_SEGMENT */ +int LUKS2_keyslot_active_count(struct luks2_hdr *hdr, int segment) +{ + int num = 0; + json_object *jobj_keyslots; + + json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots); + + json_object_object_foreach(jobj_keyslots, slot, val) { + UNUSED(val); + if (!LUKS2_keyslot_for_segment(hdr, atoi(slot), segment)) + num++; + } + + return num; +} + +int LUKS2_keyslot_cipher_incompatible(struct crypt_device *cd, const char *cipher_spec) +{ + char cipher[MAX_CIPHER_LEN], cipher_mode[MAX_CIPHER_LEN]; + + if (!cipher_spec || crypt_is_cipher_null(cipher_spec)) + return 1; + + if (crypt_parse_name_and_mode(cipher_spec, cipher, NULL, cipher_mode) < 0) + return 1; + + /* Keyslot is already authenticated; we cannot use integrity tags here */ + if (crypt_get_integrity_tag_size(cd)) + return 1; + + /* Wrapped key schemes cannot be used for keyslot encryption */ + if (crypt_cipher_wrapped_key(cipher, cipher_mode)) + return 1; + + /* Check if crypto backend can use the cipher */ + if (crypt_cipher_ivsize(cipher, cipher_mode) < 0) + return 1; + + return 0; +} + +int LUKS2_keyslot_params_default(struct crypt_device *cd, struct luks2_hdr *hdr, + struct luks2_keyslot_params *params) +{ + const struct crypt_pbkdf_type *pbkdf = crypt_get_pbkdf_type(cd); + const char *cipher_spec; + size_t key_size; + int r; + + if (!hdr || !pbkdf || !params) + return -EINVAL; + + /* + * set keyslot area encryption parameters + */ + params->area_type = LUKS2_KEYSLOT_AREA_RAW; + cipher_spec = crypt_keyslot_get_encryption(cd, CRYPT_ANY_SLOT, &key_size); + if (!cipher_spec || !key_size) + return -EINVAL; + + params->area.raw.key_size = key_size; + r = snprintf(params->area.raw.encryption, sizeof(params->area.raw.encryption), "%s", cipher_spec); + if (r < 0 || (size_t)r >= sizeof(params->area.raw.encryption)) + return -EINVAL; + + /* + * set keyslot AF parameters + */ + params->af_type = LUKS2_KEYSLOT_AF_LUKS1; + /* currently we use hash for AF from pbkdf settings */ + r = snprintf(params->af.luks1.hash, sizeof(params->af.luks1.hash), "%s", pbkdf->hash ?: DEFAULT_LUKS1_HASH); + if (r < 0 || (size_t)r >= sizeof(params->af.luks1.hash)) + return -EINVAL; + params->af.luks1.stripes = 4000; + + return 0; +} + +int LUKS2_keyslot_pbkdf(struct luks2_hdr *hdr, int keyslot, struct crypt_pbkdf_type *pbkdf) +{ + json_object *jobj_keyslot, *jobj_kdf, *jobj; + + if (!hdr || !pbkdf) + return -EINVAL; + + if (LUKS2_keyslot_info(hdr, keyslot) == CRYPT_SLOT_INVALID) + return -EINVAL; + + jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot); + if (!jobj_keyslot) + return -ENOENT; + + if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf)) + return -EINVAL; + + if (!json_object_object_get_ex(jobj_kdf, "type", &jobj)) + return -EINVAL; + + memset(pbkdf, 0, sizeof(*pbkdf)); + + pbkdf->type = json_object_get_string(jobj); + if (json_object_object_get_ex(jobj_kdf, "hash", &jobj)) + pbkdf->hash = json_object_get_string(jobj); + if (json_object_object_get_ex(jobj_kdf, "iterations", &jobj)) + pbkdf->iterations = json_object_get_int(jobj); + if (json_object_object_get_ex(jobj_kdf, "time", &jobj)) + pbkdf->iterations = json_object_get_int(jobj); + if (json_object_object_get_ex(jobj_kdf, "memory", &jobj)) + pbkdf->max_memory_kb = json_object_get_int(jobj); + if (json_object_object_get_ex(jobj_kdf, "cpus", &jobj)) + pbkdf->parallel_threads = json_object_get_int(jobj); + + return 0; +} + +static int LUKS2_keyslot_unbound(struct luks2_hdr *hdr, int keyslot) +{ + json_object *jobj_digest, *jobj_segments; + int digest = LUKS2_digest_by_keyslot(hdr, keyslot); + + if (digest < 0) + return 0; + + if (!(jobj_digest = LUKS2_get_digest_jobj(hdr, digest))) + return 0; + + json_object_object_get_ex(jobj_digest, "segments", &jobj_segments); + if (!jobj_segments || !json_object_is_type(jobj_segments, json_type_array) || + json_object_array_length(jobj_segments) == 0) + return 1; + + return 0; +} + +crypt_keyslot_info LUKS2_keyslot_info(struct luks2_hdr *hdr, int keyslot) +{ + if(keyslot >= LUKS2_KEYSLOTS_MAX || keyslot < 0) + return CRYPT_SLOT_INVALID; + + if (!LUKS2_get_keyslot_jobj(hdr, keyslot)) + return CRYPT_SLOT_INACTIVE; + + if (LUKS2_digest_by_keyslot(hdr, keyslot) < 0 || + LUKS2_keyslot_unbound(hdr, keyslot)) + return CRYPT_SLOT_UNBOUND; + + if (LUKS2_keyslot_active_count(hdr, CRYPT_DEFAULT_SEGMENT) == 1 && + !LUKS2_keyslot_for_segment(hdr, keyslot, CRYPT_DEFAULT_SEGMENT)) + return CRYPT_SLOT_ACTIVE_LAST; + + return CRYPT_SLOT_ACTIVE; +} + +int LUKS2_keyslot_jobj_area(json_object *jobj_keyslot, uint64_t *offset, uint64_t *length) +{ + json_object *jobj_area, *jobj; + + if (!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area)) + return -EINVAL; + + if (!json_object_object_get_ex(jobj_area, "offset", &jobj)) + return -EINVAL; + *offset = crypt_jobj_get_uint64(jobj); + + if (!json_object_object_get_ex(jobj_area, "size", &jobj)) + return -EINVAL; + *length = crypt_jobj_get_uint64(jobj); + + return 0; +} + +int LUKS2_keyslot_area(struct luks2_hdr *hdr, + int keyslot, + uint64_t *offset, + uint64_t *length) +{ + json_object *jobj_keyslot; + + if (LUKS2_keyslot_info(hdr, keyslot) == CRYPT_SLOT_INVALID) + return -EINVAL; + + jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot); + if (!jobj_keyslot) + return -ENOENT; + + return LUKS2_keyslot_jobj_area(jobj_keyslot, offset, length); +} + +static int _open_and_verify(struct crypt_device *cd, + struct luks2_hdr *hdr, + const keyslot_handler *h, + int keyslot, + const char *password, + size_t password_len, + struct volume_key **vk) +{ + int r, key_size = LUKS2_get_keyslot_stored_key_size(hdr, keyslot); + + if (key_size < 0) + return -EINVAL; + + *vk = crypt_alloc_volume_key(key_size, NULL); + if (!*vk) + return -ENOMEM; + + r = h->open(cd, keyslot, password, password_len, (*vk)->key, (*vk)->keylength); + if (r < 0) + log_dbg(cd, "Keyslot %d (%s) open failed with %d.", keyslot, h->name, r); + else + r = LUKS2_digest_verify(cd, hdr, *vk, keyslot); + + if (r < 0) { + crypt_free_volume_key(*vk); + *vk = NULL; + } + + crypt_volume_key_set_id(*vk, r); + + return r < 0 ? r : keyslot; +} + +static int LUKS2_open_and_verify_by_digest(struct crypt_device *cd, + struct luks2_hdr *hdr, + int keyslot, + int digest, + const char *password, + size_t password_len, + struct volume_key **vk) +{ + const keyslot_handler *h; + int r; + + if (!(h = LUKS2_keyslot_handler(cd, keyslot))) + return -ENOENT; + + r = h->validate(cd, LUKS2_get_keyslot_jobj(hdr, keyslot)); + if (r) { + log_dbg(cd, "Keyslot %d validation failed.", keyslot); + return r; + } + + r = _keyslot_for_digest(hdr, keyslot, digest); + if (r) { + if (r == -ENOENT) + log_dbg(cd, "Keyslot %d unusable for digest %d.", keyslot, digest); + return r; + } + + return _open_and_verify(cd, hdr, h, keyslot, password, password_len, vk); +} + +static int LUKS2_open_and_verify(struct crypt_device *cd, + struct luks2_hdr *hdr, + int keyslot, + int segment, + const char *password, + size_t password_len, + struct volume_key **vk) +{ + const keyslot_handler *h; + int r; + + if (!(h = LUKS2_keyslot_handler(cd, keyslot))) + return -ENOENT; + + r = h->validate(cd, LUKS2_get_keyslot_jobj(hdr, keyslot)); + if (r) { + log_dbg(cd, "Keyslot %d validation failed.", keyslot); + return r; + } + + r = LUKS2_keyslot_for_segment(hdr, keyslot, segment); + if (r) { + if (r == -ENOENT) + log_dbg(cd, "Keyslot %d unusable for segment %d.", keyslot, segment); + return r; + } + + return _open_and_verify(cd, hdr, h, keyslot, password, password_len, vk); +} + +static int LUKS2_keyslot_open_priority_digest(struct crypt_device *cd, + struct luks2_hdr *hdr, + crypt_keyslot_priority priority, + const char *password, + size_t password_len, + int digest, + struct volume_key **vk) +{ + json_object *jobj_keyslots, *jobj; + crypt_keyslot_priority slot_priority; + int keyslot, r = -ENOENT; + + json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots); + + json_object_object_foreach(jobj_keyslots, slot, val) { + if (!json_object_object_get_ex(val, "priority", &jobj)) + slot_priority = CRYPT_SLOT_PRIORITY_NORMAL; + else + slot_priority = json_object_get_int(jobj); + + keyslot = atoi(slot); + if (slot_priority != priority) { + log_dbg(cd, "Keyslot %d priority %d != %d (required), skipped.", + keyslot, slot_priority, priority); + continue; + } + + r = LUKS2_open_and_verify_by_digest(cd, hdr, keyslot, digest, password, password_len, vk); + + /* Do not retry for errors that are no -EPERM or -ENOENT, + former meaning password wrong, latter key slot unusable for segment */ + if ((r != -EPERM) && (r != -ENOENT)) + break; + } + + return r; +} + +static int LUKS2_keyslot_open_priority(struct crypt_device *cd, + struct luks2_hdr *hdr, + crypt_keyslot_priority priority, + const char *password, + size_t password_len, + int segment, + struct volume_key **vk) +{ + json_object *jobj_keyslots, *jobj; + crypt_keyslot_priority slot_priority; + int keyslot, r = -ENOENT; + + json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots); + + json_object_object_foreach(jobj_keyslots, slot, val) { + if (!json_object_object_get_ex(val, "priority", &jobj)) + slot_priority = CRYPT_SLOT_PRIORITY_NORMAL; + else + slot_priority = json_object_get_int(jobj); + + keyslot = atoi(slot); + if (slot_priority != priority) { + log_dbg(cd, "Keyslot %d priority %d != %d (required), skipped.", + keyslot, slot_priority, priority); + continue; + } + + r = LUKS2_open_and_verify(cd, hdr, keyslot, segment, password, password_len, vk); + + /* Do not retry for errors that are no -EPERM or -ENOENT, + former meaning password wrong, latter key slot unusable for segment */ + if ((r != -EPERM) && (r != -ENOENT)) + break; + } + + return r; +} + +static int LUKS2_keyslot_open_by_digest(struct crypt_device *cd, + struct luks2_hdr *hdr, + int keyslot, + int digest, + const char *password, + size_t password_len, + struct volume_key **vk) +{ + int r_prio, r = -EINVAL; + + if (digest < 0) + return r; + + if (keyslot == CRYPT_ANY_SLOT) { + r_prio = LUKS2_keyslot_open_priority_digest(cd, hdr, CRYPT_SLOT_PRIORITY_PREFER, + password, password_len, digest, vk); + if (r_prio >= 0) + r = r_prio; + else if (r_prio != -EPERM && r_prio != -ENOENT) + r = r_prio; + else + r = LUKS2_keyslot_open_priority_digest(cd, hdr, CRYPT_SLOT_PRIORITY_NORMAL, + password, password_len, digest, vk); + /* Prefer password wrong to no entry from priority slot */ + if (r_prio == -EPERM && r == -ENOENT) + r = r_prio; + } else + r = LUKS2_open_and_verify_by_digest(cd, hdr, keyslot, digest, password, password_len, vk); + + return r; +} + +int LUKS2_keyslot_open_all_segments(struct crypt_device *cd, + int keyslot_old, + int keyslot_new, + const char *password, + size_t password_len, + struct volume_key **vks) +{ + struct volume_key *vk = NULL; + int digest_old, digest_new, r = -EINVAL; + struct luks2_hdr *hdr = crypt_get_hdr(cd, CRYPT_LUKS2); + + digest_old = LUKS2_reencrypt_digest_old(hdr); + if (digest_old >= 0) { + log_dbg(cd, "Trying to unlock volume key (digest: %d) using keyslot %d.", digest_old, keyslot_old); + r = LUKS2_keyslot_open_by_digest(cd, hdr, keyslot_old, digest_old, password, password_len, &vk); + if (r < 0) + goto out; + crypt_volume_key_add_next(vks, vk); + } + + digest_new = LUKS2_reencrypt_digest_new(hdr); + if (digest_new >= 0 && digest_old != digest_new) { + log_dbg(cd, "Trying to unlock volume key (digest: %d) using keyslot %d.", digest_new, keyslot_new); + r = LUKS2_keyslot_open_by_digest(cd, hdr, keyslot_new, digest_new, password, password_len, &vk); + if (r < 0) + goto out; + crypt_volume_key_add_next(vks, vk); + } +out: + if (r < 0) { + crypt_free_volume_key(*vks); + *vks = NULL; + + if (r == -ENOMEM) + log_err(cd, _("Not enough available memory to open a keyslot.")); + else if (r != -EPERM && r != -ENOENT) + log_err(cd, _("Keyslot open failed.")); + } + return r; +} + +int LUKS2_keyslot_open(struct crypt_device *cd, + int keyslot, + int segment, + const char *password, + size_t password_len, + struct volume_key **vk) +{ + struct luks2_hdr *hdr; + int r_prio, r = -EINVAL; + + hdr = crypt_get_hdr(cd, CRYPT_LUKS2); + + if (keyslot == CRYPT_ANY_SLOT) { + r_prio = LUKS2_keyslot_open_priority(cd, hdr, CRYPT_SLOT_PRIORITY_PREFER, + password, password_len, segment, vk); + if (r_prio >= 0) + r = r_prio; + else if (r_prio != -EPERM && r_prio != -ENOENT) + r = r_prio; + else + r = LUKS2_keyslot_open_priority(cd, hdr, CRYPT_SLOT_PRIORITY_NORMAL, + password, password_len, segment, vk); + /* Prefer password wrong to no entry from priority slot */ + if (r_prio == -EPERM && r == -ENOENT) + r = r_prio; + } else + r = LUKS2_open_and_verify(cd, hdr, keyslot, segment, password, password_len, vk); + + if (r < 0) { + if (r == -ENOMEM) + log_err(cd, _("Not enough available memory to open a keyslot.")); + else if (r != -EPERM && r != -ENOENT) + log_err(cd, _("Keyslot open failed.")); + } + + return r; +} + +int LUKS2_keyslot_reencrypt_store(struct crypt_device *cd, + struct luks2_hdr *hdr, + int keyslot, + const void *buffer, + size_t buffer_length) +{ + const keyslot_handler *h; + int r; + + if (!(h = LUKS2_keyslot_handler(cd, keyslot)) || strcmp(h->name, "reencrypt")) + return -EINVAL; + + r = h->validate(cd, LUKS2_get_keyslot_jobj(hdr, keyslot)); + if (r) { + log_dbg(cd, "Keyslot validation failed."); + return r; + } + + return h->store(cd, keyslot, NULL, 0, + buffer, buffer_length); +} + +int LUKS2_keyslot_store(struct crypt_device *cd, + struct luks2_hdr *hdr, + int keyslot, + const char *password, + size_t password_len, + const struct volume_key *vk, + const struct luks2_keyslot_params *params) +{ + const keyslot_handler *h; + int r; + + if (keyslot == CRYPT_ANY_SLOT) + return -EINVAL; + + if (!LUKS2_get_keyslot_jobj(hdr, keyslot)) { + /* Try to allocate default and empty keyslot type */ + h = LUKS2_keyslot_handler_type("luks2"); + if (!h) + return -EINVAL; + + r = h->alloc(cd, keyslot, vk->keylength, params); + if (r) + return r; + } else { + if (!(h = LUKS2_keyslot_handler(cd, keyslot))) + return -EINVAL; + + r = h->update(cd, keyslot, params); + if (r) { + log_dbg(cd, "Failed to update keyslot %d json.", keyslot); + return r; + } + } + + r = h->validate(cd, LUKS2_get_keyslot_jobj(hdr, keyslot)); + if (r) { + log_dbg(cd, "Keyslot validation failed."); + return r; + } + + if (LUKS2_hdr_validate(cd, hdr->jobj, hdr->hdr_size - LUKS2_HDR_BIN_LEN)) + return -EINVAL; + + return h->store(cd, keyslot, password, password_len, + vk->key, vk->keylength); +} + +int LUKS2_keyslot_wipe(struct crypt_device *cd, + struct luks2_hdr *hdr, + int keyslot, + int wipe_area_only) +{ + struct device *device = crypt_metadata_device(cd); + uint64_t area_offset, area_length; + int r; + json_object *jobj_keyslot, *jobj_keyslots; + const keyslot_handler *h; + + h = LUKS2_keyslot_handler(cd, keyslot); + + if (!json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots)) + return -EINVAL; + + jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot); + if (!jobj_keyslot) + return -ENOENT; + + if (wipe_area_only) + log_dbg(cd, "Wiping keyslot %d area only.", keyslot); + + r = LUKS2_device_write_lock(cd, hdr, device); + if (r) + return r; + + /* secure deletion of possible key material in keyslot area */ + r = crypt_keyslot_area(cd, keyslot, &area_offset, &area_length); + if (r && r != -ENOENT) + goto out; + + if (!r) { + r = crypt_wipe_device(cd, device, CRYPT_WIPE_SPECIAL, area_offset, + area_length, area_length, NULL, NULL); + if (r) { + if (r == -EACCES) { + log_err(cd, _("Cannot write to device %s, permission denied."), + device_path(device)); + r = -EINVAL; + } else + log_err(cd, _("Cannot wipe device %s."), device_path(device)); + goto out; + } + } + + if (wipe_area_only) + goto out; + + /* Slot specific wipe */ + if (h) { + r = h->wipe(cd, keyslot); + if (r < 0) + goto out; + } else + log_dbg(cd, "Wiping keyslot %d without specific-slot handler loaded.", keyslot); + + json_object_object_del_by_uint(jobj_keyslots, keyslot); + + r = LUKS2_hdr_write(cd, hdr); +out: + device_write_unlock(cd, crypt_metadata_device(cd)); + return r; +} + +int LUKS2_keyslot_dump(struct crypt_device *cd, int keyslot) +{ + const keyslot_handler *h; + + if (!(h = LUKS2_keyslot_handler(cd, keyslot))) + return -EINVAL; + + return h->dump(cd, keyslot); +} + +crypt_keyslot_priority LUKS2_keyslot_priority_get(struct luks2_hdr *hdr, int keyslot) +{ + json_object *jobj_keyslot, *jobj_priority; + + jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot); + if (!jobj_keyslot) + return CRYPT_SLOT_PRIORITY_INVALID; + + if (!json_object_object_get_ex(jobj_keyslot, "priority", &jobj_priority)) + return CRYPT_SLOT_PRIORITY_NORMAL; + + return json_object_get_int(jobj_priority); +} + +int LUKS2_keyslot_priority_set(struct crypt_device *cd, struct luks2_hdr *hdr, + int keyslot, crypt_keyslot_priority priority, int commit) +{ + json_object *jobj_keyslot; + + jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot); + if (!jobj_keyslot) + return -EINVAL; + + if (priority == CRYPT_SLOT_PRIORITY_NORMAL) + json_object_object_del(jobj_keyslot, "priority"); + else + json_object_object_add(jobj_keyslot, "priority", json_object_new_int(priority)); + + return commit ? LUKS2_hdr_write(cd, hdr) : 0; +} + +int placeholder_keyslot_alloc(struct crypt_device *cd, + int keyslot, + uint64_t area_offset, + uint64_t area_length) +{ + struct luks2_hdr *hdr; + json_object *jobj_keyslots, *jobj_keyslot, *jobj_area; + + log_dbg(cd, "Allocating placeholder keyslot %d for LUKS1 down conversion.", keyslot); + + if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2))) + return -EINVAL; + + if (keyslot < 0 || keyslot >= LUKS2_KEYSLOTS_MAX) + return -EINVAL; + + if (LUKS2_get_keyslot_jobj(hdr, keyslot)) + return -EINVAL; + + if (!json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots)) + return -EINVAL; + + jobj_keyslot = json_object_new_object(); + json_object_object_add(jobj_keyslot, "type", json_object_new_string("placeholder")); + /* + * key_size = -1 makes placeholder keyslot impossible to pass validation. + * It's a safeguard against accidentally storing temporary conversion + * LUKS2 header. + */ + json_object_object_add(jobj_keyslot, "key_size", json_object_new_int(-1)); + + /* Area object */ + jobj_area = json_object_new_object(); + 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_keyslot, "area", jobj_area); + + json_object_object_add_by_uint(jobj_keyslots, keyslot, jobj_keyslot); + + return 0; +} + +static unsigned LUKS2_get_keyslot_digests_count(json_object *hdr_jobj, int keyslot) +{ + char num[16]; + json_object *jobj_digests, *jobj_keyslots; + unsigned count = 0; + + if (!json_object_object_get_ex(hdr_jobj, "digests", &jobj_digests)) + return 0; + + if (snprintf(num, sizeof(num), "%u", keyslot) < 0) + return 0; + + json_object_object_foreach(jobj_digests, key, val) { + UNUSED(key); + json_object_object_get_ex(val, "keyslots", &jobj_keyslots); + if (LUKS2_array_jobj(jobj_keyslots, num)) + count++; + } + + return count; +} + +/* run only on header that passed basic format validation */ +int LUKS2_keyslots_validate(struct crypt_device *cd, json_object *hdr_jobj) +{ + const keyslot_handler *h; + int keyslot; + json_object *jobj_keyslots, *jobj_type; + uint32_t reqs, reencrypt_count = 0; + struct luks2_hdr dummy = { + .jobj = hdr_jobj + }; + + if (!json_object_object_get_ex(hdr_jobj, "keyslots", &jobj_keyslots)) + return -EINVAL; + + if (LUKS2_config_get_requirements(cd, &dummy, &reqs)) + return -EINVAL; + + json_object_object_foreach(jobj_keyslots, slot, val) { + keyslot = atoi(slot); + json_object_object_get_ex(val, "type", &jobj_type); + h = LUKS2_keyslot_handler_type(json_object_get_string(jobj_type)); + if (!h) + continue; + if (h->validate && h->validate(cd, val)) { + log_dbg(cd, "Keyslot type %s validation failed on keyslot %d.", h->name, keyslot); + return -EINVAL; + } + + if (!strcmp(h->name, "luks2") && LUKS2_get_keyslot_digests_count(hdr_jobj, keyslot) != 1) { + log_dbg(cd, "Keyslot %d is not assigned to exactly 1 digest.", keyslot); + return -EINVAL; + } + + if (!strcmp(h->name, "reencrypt")) + reencrypt_count++; + } + + if ((reqs & CRYPT_REQUIREMENT_ONLINE_REENCRYPT) && reencrypt_count == 0) { + log_dbg(cd, "Missing reencryption keyslot."); + return -EINVAL; + } + + if (reencrypt_count && !LUKS2_reencrypt_requirement_candidate(&dummy)) { + log_dbg(cd, "Missing reencryption requirement flag."); + return -EINVAL; + } + + if (reencrypt_count > 1) { + log_dbg(cd, "Too many reencryption keyslots."); + return -EINVAL; + } + + return 0; +} + +void LUKS2_keyslots_repair(struct crypt_device *cd, json_object *jobj_keyslots) +{ + const keyslot_handler *h; + json_object *jobj_type; + + json_object_object_foreach(jobj_keyslots, slot, val) { + UNUSED(slot); + if (!json_object_is_type(val, json_type_object) || + !json_object_object_get_ex(val, "type", &jobj_type) || + !json_object_is_type(jobj_type, json_type_string)) + continue; + + h = LUKS2_keyslot_handler_type(json_object_get_string(jobj_type)); + if (h && h->repair) + h->repair(val); + } +} + +/* assumes valid header */ +int LUKS2_find_keyslot(struct luks2_hdr *hdr, const char *type) +{ + int i; + json_object *jobj_keyslot, *jobj_type; + + if (!type) + return -EINVAL; + + for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++) { + jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, i); + if (!jobj_keyslot) + continue; + + json_object_object_get_ex(jobj_keyslot, "type", &jobj_type); + if (!strcmp(json_object_get_string(jobj_type), type)) + return i; + } + + return -ENOENT; +} + +/* assumes valid header, it does not move references in tokens/digests etc! */ +int LUKS2_keyslot_swap(struct crypt_device *cd, struct luks2_hdr *hdr, + int keyslot, int keyslot2) +{ + json_object *jobj_keyslots, *jobj_keyslot, *jobj_keyslot2; + int r; + + if (!json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots)) + return -EINVAL; + + jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot); + if (!jobj_keyslot) + return -EINVAL; + + jobj_keyslot2 = LUKS2_get_keyslot_jobj(hdr, keyslot2); + if (!jobj_keyslot2) + return -EINVAL; + + /* This transfer owner of object, no need for json_object_put */ + json_object_get(jobj_keyslot); + json_object_get(jobj_keyslot2); + + json_object_object_del_by_uint(jobj_keyslots, keyslot); + r = json_object_object_add_by_uint(jobj_keyslots, keyslot, jobj_keyslot2); + if (r < 0) { + log_dbg(cd, "Failed to swap keyslot %d.", keyslot); + return r; + } + + json_object_object_del_by_uint(jobj_keyslots, keyslot2); + r = json_object_object_add_by_uint(jobj_keyslots, keyslot2, jobj_keyslot); + if (r < 0) + log_dbg(cd, "Failed to swap keyslot2 %d.", keyslot2); + + return r; +} |