Adding upstream version 2:2.3.7.upstream/2%2.3.7upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 2601 insertions, 0 deletions

diff --git a/lib/luks2/luks2_json_metadata.c b/lib/luks2/luks2_json_metadata.c
new file mode 100644
index 0000000..8469257
--- /dev/null
+++ b/lib/luks2/luks2_json_metadata.c
@@ -0,0 +1,2601 @@
+/*
+ * LUKS - Linux Unified Key Setup v2
+ *
+ * Copyright (C) 2015-2021 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2021 Milan Broz
+ * Copyright (C) 2015-2021 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"
+#include "../integrity/integrity.h"
+#include <assert.h>
+#include <ctype.h>
+#include <uuid/uuid.h>
+
+#define LUKS_STRIPES 4000
+
+struct interval {
+	uint64_t offset;
+	uint64_t length;
+};
+
+void hexprint_base64(struct crypt_device *cd, json_object *jobj,
+		     const char *sep, const char *line_sep)
+{
+	char *buf = NULL;
+	size_t buf_len;
+	unsigned int i;
+
+	if (!base64_decode_alloc(json_object_get_string(jobj),
+				 json_object_get_string_len(jobj),
+				 &buf, &buf_len))
+		return;
+
+	for (i = 0; i < buf_len; i++) {
+		if (i && !(i % 16))
+			log_std(cd, "\n\t%s", line_sep);
+		log_std(cd, "%02hhx%s", buf[i], sep);
+	}
+	log_std(cd, "\n");
+	free(buf);
+}
+
+void JSON_DBG(struct crypt_device *cd, json_object *jobj, const char *desc)
+{
+	if (desc)
+		crypt_log(cd, CRYPT_LOG_DEBUG_JSON, desc);
+	crypt_log(cd, CRYPT_LOG_DEBUG_JSON, json_object_to_json_string_ext(jobj,
+		JSON_C_TO_STRING_PRETTY | JSON_C_TO_STRING_NOSLASHESCAPE));
+}
+
+/*
+ * JSON array helpers
+ */
+struct json_object *LUKS2_array_jobj(struct json_object *array, const char *num)
+{
+	struct json_object *jobj1;
+	int i;
+
+	for (i = 0; i < (int) json_object_array_length(array); i++) {
+		jobj1 = json_object_array_get_idx(array, i);
+		if (!strcmp(num, json_object_get_string(jobj1)))
+			return jobj1;
+	}
+
+	return NULL;
+}
+
+struct json_object *LUKS2_array_remove(struct json_object *array, const char *num)
+{
+	struct json_object *jobj1, *jobj_removing = NULL, *array_new;
+	int i;
+
+	jobj_removing = LUKS2_array_jobj(array, num);
+	if (!jobj_removing)
+		return NULL;
+
+	/* Create new array without jobj_removing. */
+	array_new = json_object_new_array();
+	for (i = 0; i < (int) json_object_array_length(array); i++) {
+		jobj1 = json_object_array_get_idx(array, i);
+		if (jobj1 != jobj_removing)
+			json_object_array_add(array_new, json_object_get(jobj1));
+	}
+
+	return array_new;
+}
+
+/*
+ * JSON struct access helpers
+ */
+json_object *LUKS2_get_keyslot_jobj(struct luks2_hdr *hdr, int keyslot)
+{
+	json_object *jobj1, *jobj2;
+	char keyslot_name[16];
+
+	if (!hdr || keyslot < 0)
+		return NULL;
+
+	if (snprintf(keyslot_name, sizeof(keyslot_name), "%u", keyslot) < 1)
+		return NULL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "keyslots", &jobj1))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj1, keyslot_name, &jobj2))
+		return NULL;
+
+	return jobj2;
+}
+
+json_object *LUKS2_get_tokens_jobj(struct luks2_hdr *hdr)
+{
+	json_object *jobj_tokens;
+
+	if (!hdr || !json_object_object_get_ex(hdr->jobj, "tokens", &jobj_tokens))
+		return NULL;
+
+	return jobj_tokens;
+}
+
+json_object *LUKS2_get_token_jobj(struct luks2_hdr *hdr, int token)
+{
+	json_object *jobj1, *jobj2;
+	char token_name[16];
+
+	if (!hdr || token < 0)
+		return NULL;
+
+	jobj1 = LUKS2_get_tokens_jobj(hdr);
+	if (!jobj1)
+		return NULL;
+
+	if (snprintf(token_name, sizeof(token_name), "%u", token) < 1)
+		return NULL;
+
+	json_object_object_get_ex(jobj1, token_name, &jobj2);
+	return jobj2;
+}
+
+json_object *LUKS2_get_digest_jobj(struct luks2_hdr *hdr, int digest)
+{
+	json_object *jobj1, *jobj2;
+	char digest_name[16];
+
+	if (!hdr || digest < 0)
+		return NULL;
+
+	if (snprintf(digest_name, sizeof(digest_name), "%u", digest) < 1)
+		return NULL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "digests", &jobj1))
+		return NULL;
+
+	json_object_object_get_ex(jobj1, digest_name, &jobj2);
+	return jobj2;
+}
+
+static json_object *json_get_segments_jobj(json_object *hdr_jobj)
+{
+	json_object *jobj_segments;
+
+	if (!hdr_jobj || !json_object_object_get_ex(hdr_jobj, "segments", &jobj_segments))
+		return NULL;
+
+	return jobj_segments;
+}
+
+json_object *LUKS2_get_segment_jobj(struct luks2_hdr *hdr, int segment)
+{
+	if (!hdr)
+		return NULL;
+
+	if (segment == CRYPT_DEFAULT_SEGMENT)
+		segment = LUKS2_get_default_segment(hdr);
+
+	return json_segments_get_segment(json_get_segments_jobj(hdr->jobj), segment);
+}
+
+json_object *LUKS2_get_segments_jobj(struct luks2_hdr *hdr)
+{
+	return hdr ? json_get_segments_jobj(hdr->jobj) : NULL;
+}
+
+int LUKS2_segments_count(struct luks2_hdr *hdr)
+{
+	if (!hdr)
+		return -EINVAL;
+
+	return json_segments_count(LUKS2_get_segments_jobj(hdr));
+}
+
+int LUKS2_get_default_segment(struct luks2_hdr *hdr)
+{
+	int s = LUKS2_get_segment_id_by_flag(hdr, "backup-final");
+	if (s >= 0)
+		return s;
+
+	if (LUKS2_segments_count(hdr) == 1)
+		return 0;
+
+	return -EINVAL;
+}
+
+/*
+ * json_type_int needs to be validated first.
+ * See validate_json_uint32()
+ */
+uint32_t crypt_jobj_get_uint32(json_object *jobj)
+{
+	return json_object_get_int64(jobj);
+}
+
+/* jobj has to be json_type_string and numbered */
+static json_bool json_str_to_uint64(json_object *jobj, uint64_t *value)
+{
+	char *endptr;
+	unsigned long long tmp;
+
+	errno = 0;
+	tmp = strtoull(json_object_get_string(jobj), &endptr, 10);
+	if (*endptr || errno) {
+		*value = 0;
+		return 0;
+	}
+
+	*value = tmp;
+	return 1;
+}
+
+uint64_t crypt_jobj_get_uint64(json_object *jobj)
+{
+	uint64_t r;
+	json_str_to_uint64(jobj, &r);
+	return r;
+}
+
+json_object *crypt_jobj_new_uint64(uint64_t value)
+{
+	/* 18446744073709551615 */
+	char num[21];
+	int r;
+	json_object *jobj;
+
+	r = snprintf(num, sizeof(num), "%" PRIu64, value);
+	if (r < 0 || (size_t)r >= sizeof(num))
+		return NULL;
+
+	jobj = json_object_new_string(num);
+	return jobj;
+}
+
+/*
+ * Validate helpers
+ */
+static json_bool numbered(struct crypt_device *cd, const char *name, const char *key)
+{
+	int i;
+
+	for (i = 0; key[i]; i++)
+		if (!isdigit(key[i])) {
+			log_dbg(cd, "%s \"%s\" is not in numbered form.", name, key);
+			return 0;
+		}
+	return 1;
+}
+
+json_object *json_contains(struct crypt_device *cd, json_object *jobj, const char *name,
+			   const char *section, const char *key, json_type type)
+{
+	json_object *sobj;
+
+	if (!json_object_object_get_ex(jobj, key, &sobj) ||
+	    !json_object_is_type(sobj, type)) {
+		log_dbg(cd, "%s \"%s\" is missing \"%s\" (%s) specification.",
+			section, name, key, json_type_to_name(type));
+		return NULL;
+	}
+
+	return sobj;
+}
+
+json_bool validate_json_uint32(json_object *jobj)
+{
+	int64_t tmp;
+
+	errno = 0;
+	tmp = json_object_get_int64(jobj);
+
+	return (errno || tmp < 0 || tmp > UINT32_MAX) ? 0 : 1;
+}
+
+static json_bool validate_keyslots_array(struct crypt_device *cd,
+					 json_object *jarr, json_object *jobj_keys)
+{
+	json_object *jobj;
+	int i = 0, length = (int) json_object_array_length(jarr);
+
+	while (i < length) {
+		jobj = json_object_array_get_idx(jarr, i);
+		if (!json_object_is_type(jobj, json_type_string)) {
+			log_dbg(cd, "Illegal value type in keyslots array at index %d.", i);
+			return 0;
+		}
+
+		if (!json_contains(cd, jobj_keys, "", "Keyslots section",
+				   json_object_get_string(jobj), json_type_object))
+			return 0;
+
+		i++;
+	}
+
+	return 1;
+}
+
+static json_bool validate_segments_array(struct crypt_device *cd,
+					 json_object *jarr, json_object *jobj_segments)
+{
+	json_object *jobj;
+	int i = 0, length = (int) json_object_array_length(jarr);
+
+	while (i < length) {
+		jobj = json_object_array_get_idx(jarr, i);
+		if (!json_object_is_type(jobj, json_type_string)) {
+			log_dbg(cd, "Illegal value type in segments array at index %d.", i);
+			return 0;
+		}
+
+		if (!json_contains(cd, jobj_segments, "", "Segments section",
+				   json_object_get_string(jobj), json_type_object))
+			return 0;
+
+		i++;
+	}
+
+	return 1;
+}
+
+static json_bool segment_has_digest(const char *segment_name, json_object *jobj_digests)
+{
+	json_object *jobj_segments;
+
+	json_object_object_foreach(jobj_digests, key, val) {
+		UNUSED(key);
+		json_object_object_get_ex(val, "segments", &jobj_segments);
+		if (LUKS2_array_jobj(jobj_segments, segment_name))
+			return 1;
+	}
+
+	return 0;
+}
+
+static json_bool validate_intervals(struct crypt_device *cd,
+				    int length, const struct interval *ix,
+				    uint64_t metadata_size, uint64_t keyslots_area_end)
+{
+	int j, i = 0;
+
+	while (i < length) {
+		if (ix[i].offset < 2 * metadata_size) {
+			log_dbg(cd, "Illegal area offset: %" PRIu64 ".", ix[i].offset);
+			return 0;
+		}
+
+		if (!ix[i].length) {
+			log_dbg(cd, "Area length must be greater than zero.");
+			return 0;
+		}
+
+		if ((ix[i].offset + ix[i].length) > keyslots_area_end) {
+			log_dbg(cd, "Area [%" PRIu64 ", %" PRIu64 "] overflows binary keyslots area (ends at offset: %" PRIu64 ").",
+				ix[i].offset, ix[i].offset + ix[i].length, keyslots_area_end);
+			return 0;
+		}
+
+		for (j = 0; j < length; j++) {
+			if (i == j)
+				continue;
+			if ((ix[i].offset >= ix[j].offset) && (ix[i].offset < (ix[j].offset + ix[j].length))) {
+				log_dbg(cd, "Overlapping areas [%" PRIu64 ",%" PRIu64 "] and [%" PRIu64 ",%" PRIu64 "].",
+					ix[i].offset, ix[i].offset + ix[i].length,
+					ix[j].offset, ix[j].offset + ix[j].length);
+				return 0;
+			}
+		}
+
+		i++;
+	}
+
+	return 1;
+}
+
+static int LUKS2_keyslot_validate(struct crypt_device *cd, json_object *hdr_jobj, json_object *hdr_keyslot, const char *key)
+{
+	json_object *jobj_key_size;
+
+	if (!json_contains(cd, hdr_keyslot, key, "Keyslot", "type", json_type_string))
+		return 1;
+	if (!(jobj_key_size = json_contains(cd, hdr_keyslot, key, "Keyslot", "key_size", json_type_int)))
+		return 1;
+
+	/* enforce uint32_t type */
+	if (!validate_json_uint32(jobj_key_size)) {
+		log_dbg(cd, "Illegal field \"key_size\":%s.",
+			json_object_get_string(jobj_key_size));
+		return 1;
+	}
+
+	return 0;
+}
+
+int LUKS2_token_validate(struct crypt_device *cd,
+			 json_object *hdr_jobj, json_object *jobj_token, const char *key)
+{
+	json_object *jarr, *jobj_keyslots;
+
+	/* keyslots are not yet validated, but we need to know token doesn't reference missing keyslot */
+	if (!json_object_object_get_ex(hdr_jobj, "keyslots", &jobj_keyslots))
+		return 1;
+
+	if (!json_contains(cd, jobj_token, key, "Token", "type", json_type_string))
+		return 1;
+
+	jarr = json_contains(cd, jobj_token, key, "Token", "keyslots", json_type_array);
+	if (!jarr)
+		return 1;
+
+	if (!validate_keyslots_array(cd, jarr, jobj_keyslots))
+		return 1;
+
+	return 0;
+}
+
+static int hdr_validate_json_size(struct crypt_device *cd, json_object *hdr_jobj, uint64_t hdr_json_size)
+{
+	json_object *jobj, *jobj1;
+	const char *json;
+	uint64_t json_area_size, json_size;
+
+	json_object_object_get_ex(hdr_jobj, "config", &jobj);
+	json_object_object_get_ex(jobj, "json_size", &jobj1);
+
+	json = json_object_to_json_string_ext(hdr_jobj,
+		JSON_C_TO_STRING_PLAIN | JSON_C_TO_STRING_NOSLASHESCAPE);
+	json_area_size = crypt_jobj_get_uint64(jobj1);
+	json_size = (uint64_t)strlen(json);
+
+	if (hdr_json_size != json_area_size) {
+		log_dbg(cd, "JSON area size does not match value in binary header.");
+		return 1;
+	}
+
+	if (json_size > json_area_size) {
+		log_dbg(cd, "JSON does not fit in the designated area.");
+		return 1;
+	}
+
+	return 0;
+}
+
+int LUKS2_check_json_size(struct crypt_device *cd, const struct luks2_hdr *hdr)
+{
+	return hdr_validate_json_size(cd, hdr->jobj, hdr->hdr_size - LUKS2_HDR_BIN_LEN);
+}
+
+static int hdr_validate_keyslots(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	json_object *jobj;
+
+	if (!json_object_object_get_ex(hdr_jobj, "keyslots", &jobj)) {
+		log_dbg(cd, "Missing keyslots section.");
+		return 1;
+	}
+
+	json_object_object_foreach(jobj, key, val) {
+		if (!numbered(cd, "Keyslot", key))
+			return 1;
+		if (LUKS2_keyslot_validate(cd, hdr_jobj, val, key))
+			return 1;
+	}
+
+	return 0;
+}
+
+static int hdr_validate_tokens(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	json_object *jobj;
+
+	if (!json_object_object_get_ex(hdr_jobj, "tokens", &jobj)) {
+		log_dbg(cd, "Missing tokens section.");
+		return 1;
+	}
+
+	json_object_object_foreach(jobj, key, val) {
+		if (!numbered(cd, "Token", key))
+			return 1;
+		if (LUKS2_token_validate(cd, hdr_jobj, val, key))
+			return 1;
+	}
+
+	return 0;
+}
+
+static int hdr_validate_crypt_segment(struct crypt_device *cd,
+				      json_object *jobj, const char *key, json_object *jobj_digests,
+	uint64_t offset, uint64_t size)
+{
+	json_object *jobj_ivoffset, *jobj_sector_size, *jobj_integrity;
+	uint32_t sector_size;
+	uint64_t ivoffset;
+
+	if (!(jobj_ivoffset = json_contains(cd, jobj, key, "Segment", "iv_tweak", json_type_string)) ||
+	    !json_contains(cd, jobj, key, "Segment", "encryption", json_type_string) ||
+	    !(jobj_sector_size = json_contains(cd, jobj, key, "Segment", "sector_size", json_type_int)))
+		return 1;
+
+	/* integrity */
+	if (json_object_object_get_ex(jobj, "integrity", &jobj_integrity)) {
+		if (!json_contains(cd, jobj, key, "Segment", "integrity", json_type_object) ||
+		    !json_contains(cd, jobj_integrity, key, "Segment integrity", "type", json_type_string) ||
+		    !json_contains(cd, jobj_integrity, key, "Segment integrity", "journal_encryption", json_type_string) ||
+		    !json_contains(cd, jobj_integrity, key, "Segment integrity", "journal_integrity", json_type_string))
+			return 1;
+	}
+
+	/* enforce uint32_t type */
+	if (!validate_json_uint32(jobj_sector_size)) {
+		log_dbg(cd, "Illegal field \"sector_size\":%s.",
+			json_object_get_string(jobj_sector_size));
+		return 1;
+	}
+
+	sector_size = crypt_jobj_get_uint32(jobj_sector_size);
+	if (!sector_size || MISALIGNED_512(sector_size)) {
+		log_dbg(cd, "Illegal sector size: %" PRIu32, sector_size);
+		return 1;
+	}
+
+	if (!numbered(cd, "iv_tweak", json_object_get_string(jobj_ivoffset)) ||
+	    !json_str_to_uint64(jobj_ivoffset, &ivoffset)) {
+		log_dbg(cd, "Illegal iv_tweak value.");
+		return 1;
+	}
+
+	if (size % sector_size) {
+		log_dbg(cd, "Size field has to be aligned to sector size: %" PRIu32, sector_size);
+		return 1;
+	}
+
+	return !segment_has_digest(key, jobj_digests);
+}
+
+static bool validate_segment_intervals(struct crypt_device *cd,
+				    int length, const struct interval *ix)
+{
+	int j, i = 0;
+
+	while (i < length) {
+		if (ix[i].length == UINT64_MAX && (i != (length - 1))) {
+			log_dbg(cd, "Only last regular segment is allowed to have 'dynamic' size.");
+			return false;
+		}
+
+		for (j = 0; j < length; j++) {
+			if (i == j)
+				continue;
+			if ((ix[i].offset >= ix[j].offset) && (ix[j].length == UINT64_MAX || (ix[i].offset < (ix[j].offset + ix[j].length)))) {
+				log_dbg(cd, "Overlapping segments [%" PRIu64 ",%" PRIu64 "]%s and [%" PRIu64 ",%" PRIu64 "]%s.",
+					ix[i].offset, ix[i].offset + ix[i].length, ix[i].length == UINT64_MAX ? "(dynamic)" : "",
+					ix[j].offset, ix[j].offset + ix[j].length, ix[j].length == UINT64_MAX ? "(dynamic)" : "");
+				return false;
+			}
+		}
+
+		i++;
+	}
+
+	return true;
+}
+
+static int reqs_unknown(uint32_t reqs)
+{
+	return reqs & CRYPT_REQUIREMENT_UNKNOWN;
+}
+
+static int reqs_reencrypt(uint32_t reqs)
+{
+	return reqs & CRYPT_REQUIREMENT_OFFLINE_REENCRYPT;
+}
+
+static int reqs_reencrypt_online(uint32_t reqs)
+{
+	return reqs & CRYPT_REQUIREMENT_ONLINE_REENCRYPT;
+}
+
+/*
+ * Config section requirements object must be valid.
+ * Also general segments section must be validated first.
+ */
+static int validate_reencrypt_segments(struct crypt_device *cd, json_object *hdr_jobj, json_object *jobj_segments, int first_backup, int segments_count)
+{
+	json_object *jobj, *jobj_backup_previous = NULL, *jobj_backup_final = NULL;
+	uint32_t reqs;
+	int i, r;
+	struct luks2_hdr dummy = {
+		.jobj = hdr_jobj
+	};
+
+	r = LUKS2_config_get_requirements(cd, &dummy, &reqs);
+	if (r)
+		return 1;
+
+	if (reqs_reencrypt_online(reqs)) {
+		for (i = first_backup; i < segments_count; i++) {
+			jobj = json_segments_get_segment(jobj_segments, i);
+			if (!jobj)
+				return 1;
+			if (json_segment_contains_flag(jobj, "backup-final", 0))
+				jobj_backup_final = jobj;
+			else if (json_segment_contains_flag(jobj, "backup-previous", 0))
+				jobj_backup_previous = jobj;
+		}
+
+		if (!jobj_backup_final || !jobj_backup_previous) {
+			log_dbg(cd, "Backup segment is missing.");
+			return 1;
+		}
+
+		for (i = 0; i < first_backup; i++) {
+			jobj = json_segments_get_segment(jobj_segments, i);
+			if (!jobj)
+				return 1;
+
+			if (json_segment_contains_flag(jobj, "in-reencryption", 0)) {
+				if (!json_segment_cmp(jobj, jobj_backup_final)) {
+					log_dbg(cd, "Segment in reencryption does not match backup final segment.");
+					return 1;
+				}
+				continue;
+			}
+
+			if (!json_segment_cmp(jobj, jobj_backup_final) &&
+			    !json_segment_cmp(jobj, jobj_backup_previous)) {
+				log_dbg(cd, "Segment does not match neither backup final or backup previous segment.");
+				return 1;
+			}
+		}
+	}
+
+	return 0;
+}
+
+static int hdr_validate_segments(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	json_object *jobj_segments, *jobj_digests, *jobj_offset, *jobj_size, *jobj_type, *jobj_flags, *jobj;
+	uint64_t offset, size;
+	int i, r, count, first_backup = -1;
+	struct interval *intervals = NULL;
+
+	if (!json_object_object_get_ex(hdr_jobj, "segments", &jobj_segments)) {
+		log_dbg(cd, "Missing segments section.");
+		return 1;
+	}
+
+	count = json_object_object_length(jobj_segments);
+	if (count < 1) {
+		log_dbg(cd, "Empty segments section.");
+		return 1;
+	}
+
+	/* digests should already be validated */
+	if (!json_object_object_get_ex(hdr_jobj, "digests", &jobj_digests))
+		return 1;
+
+	json_object_object_foreach(jobj_segments, key, val) {
+		if (!numbered(cd, "Segment", key))
+			return 1;
+
+		/* those fields are mandatory for all segment types */
+		if (!(jobj_type =   json_contains(cd, val, key, "Segment", "type",   json_type_string)) ||
+		    !(jobj_offset = json_contains(cd, val, key, "Segment", "offset", json_type_string)) ||
+		    !(jobj_size =   json_contains(cd, val, key, "Segment", "size",   json_type_string)))
+			return 1;
+
+		if (!numbered(cd, "offset", json_object_get_string(jobj_offset)) ||
+		    !json_str_to_uint64(jobj_offset, &offset))
+			return 1;
+
+		/* size "dynamic" means whole device starting at 'offset' */
+		if (strcmp(json_object_get_string(jobj_size), "dynamic")) {
+			if (!numbered(cd, "size", json_object_get_string(jobj_size)) ||
+			    !json_str_to_uint64(jobj_size, &size) || !size)
+				return 1;
+		} else
+			size = 0;
+
+		/* all device-mapper devices are aligned to 512 sector size */
+		if (MISALIGNED_512(offset)) {
+			log_dbg(cd, "Offset field has to be aligned to sector size: %" PRIu32, SECTOR_SIZE);
+			return 1;
+		}
+		if (MISALIGNED_512(size)) {
+			log_dbg(cd, "Size field has to be aligned to sector size: %" PRIu32, SECTOR_SIZE);
+			return 1;
+		}
+
+		/* flags array is optional and must contain strings */
+		if (json_object_object_get_ex(val, "flags", NULL)) {
+			if (!(jobj_flags = json_contains(cd, val, key, "Segment", "flags", json_type_array)))
+				return 1;
+			for (i = 0; i < (int) json_object_array_length(jobj_flags); i++)
+				if (!json_object_is_type(json_object_array_get_idx(jobj_flags, i), json_type_string))
+					return 1;
+		}
+
+		i = atoi(key);
+		if (json_segment_is_backup(val)) {
+			if (first_backup < 0 || i < first_backup)
+				first_backup = i;
+		} else {
+			if ((first_backup >= 0) && i >= first_backup) {
+				log_dbg(cd, "Regular segment at %d is behind backup segment at %d", i, first_backup);
+				return 1;
+			}
+		}
+
+		/* crypt */
+		if (!strcmp(json_object_get_string(jobj_type), "crypt") &&
+		    hdr_validate_crypt_segment(cd, val, key, jobj_digests, offset, size))
+			return 1;
+	}
+
+	if (first_backup == 0) {
+		log_dbg(cd, "No regular segment.");
+		return 1;
+	}
+
+	/* avoid needlessly large allocation when first backup segment is invalid */
+	if (first_backup >= count) {
+		log_dbg(cd, "Gap between last regular segment and backup segment at key %d.", first_backup);
+		return 1;
+	}
+
+	if (first_backup < 0)
+		first_backup = count;
+
+	if ((size_t)first_backup < SIZE_MAX / sizeof(*intervals))
+		intervals = malloc(first_backup * sizeof(*intervals));
+
+	if (!intervals) {
+		log_dbg(cd, "Not enough memory.");
+		return 1;
+	}
+
+	for (i = 0; i < first_backup; i++) {
+		jobj = json_segments_get_segment(jobj_segments, i);
+		if (!jobj) {
+			log_dbg(cd, "Gap at key %d in segments object.", i);
+			free(intervals);
+			return 1;
+		}
+		intervals[i].offset = json_segment_get_offset(jobj, 0);
+		intervals[i].length = json_segment_get_size(jobj, 0) ?: UINT64_MAX;
+	}
+
+	r = !validate_segment_intervals(cd, first_backup, intervals);
+	free(intervals);
+
+	if (r)
+		return 1;
+
+	for (; i < count; i++) {
+		if (!json_segments_get_segment(jobj_segments, i)) {
+			log_dbg(cd, "Gap at key %d in segments object.", i);
+			return 1;
+		}
+	}
+
+	return validate_reencrypt_segments(cd, hdr_jobj, jobj_segments, first_backup, count);
+}
+
+static uint64_t LUKS2_metadata_size_jobj(json_object *jobj)
+{
+	json_object *jobj1, *jobj2;
+	uint64_t json_size;
+
+	json_object_object_get_ex(jobj, "config", &jobj1);
+	json_object_object_get_ex(jobj1, "json_size", &jobj2);
+	json_str_to_uint64(jobj2, &json_size);
+
+	return json_size + LUKS2_HDR_BIN_LEN;
+}
+
+uint64_t LUKS2_metadata_size(struct luks2_hdr *hdr)
+{
+	return LUKS2_metadata_size_jobj(hdr->jobj);
+}
+
+static int hdr_validate_areas(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	struct interval *intervals;
+	json_object *jobj_keyslots, *jobj_offset, *jobj_length, *jobj_segments, *jobj_area;
+	int length, ret, i = 0;
+	uint64_t metadata_size;
+
+	if (!json_object_object_get_ex(hdr_jobj, "keyslots", &jobj_keyslots))
+		return 1;
+
+	/* segments are already validated */
+	if (!json_object_object_get_ex(hdr_jobj, "segments", &jobj_segments))
+		return 1;
+
+	/* config is already validated */
+	metadata_size = LUKS2_metadata_size_jobj(hdr_jobj);
+
+	length = json_object_object_length(jobj_keyslots);
+
+	/* Empty section */
+	if (length == 0)
+		return 0;
+
+	if (length < 0) {
+		log_dbg(cd, "Invalid keyslot areas specification.");
+		return 1;
+	}
+
+	intervals = malloc(length * sizeof(*intervals));
+	if (!intervals) {
+		log_dbg(cd, "Not enough memory.");
+		return -ENOMEM;
+	}
+
+	json_object_object_foreach(jobj_keyslots, key, val) {
+
+		if (!(jobj_area = json_contains(cd, val, key, "Keyslot", "area", json_type_object)) ||
+		    !json_contains(cd, jobj_area, key, "Keyslot area", "type", json_type_string) ||
+		    !(jobj_offset = json_contains(cd, jobj_area, key, "Keyslot", "offset", json_type_string)) ||
+		    !(jobj_length = json_contains(cd, jobj_area, key, "Keyslot", "size", json_type_string)) ||
+		    !numbered(cd, "offset", json_object_get_string(jobj_offset)) ||
+		    !numbered(cd, "size", json_object_get_string(jobj_length))) {
+			free(intervals);
+			return 1;
+		}
+
+		/* rule out values > UINT64_MAX */
+		if (!json_str_to_uint64(jobj_offset, &intervals[i].offset) ||
+		    !json_str_to_uint64(jobj_length, &intervals[i].length)) {
+			free(intervals);
+			return 1;
+		}
+
+		i++;
+	}
+
+	if (length != i) {
+		free(intervals);
+		return 1;
+	}
+
+	ret = validate_intervals(cd, length, intervals, metadata_size, LUKS2_hdr_and_areas_size_jobj(hdr_jobj)) ? 0 : 1;
+
+	free(intervals);
+
+	return ret;
+}
+
+static int hdr_validate_digests(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	json_object *jarr_keys, *jarr_segs, *jobj, *jobj_keyslots, *jobj_segments;
+
+	if (!json_object_object_get_ex(hdr_jobj, "digests", &jobj)) {
+		log_dbg(cd, "Missing digests section.");
+		return 1;
+	}
+
+	/* keyslots are not yet validated, but we need to know digest doesn't reference missing keyslot */
+	if (!json_object_object_get_ex(hdr_jobj, "keyslots", &jobj_keyslots))
+		return 1;
+
+	/* segments are not yet validated, but we need to know digest doesn't reference missing segment */
+	if (!json_object_object_get_ex(hdr_jobj, "segments", &jobj_segments))
+		return 1;
+
+	json_object_object_foreach(jobj, key, val) {
+		if (!numbered(cd, "Digest", key))
+			return 1;
+
+		if (!json_contains(cd, val, key, "Digest", "type", json_type_string) ||
+		    !(jarr_keys = json_contains(cd, val, key, "Digest", "keyslots", json_type_array)) ||
+		    !(jarr_segs = json_contains(cd, val, key, "Digest", "segments", json_type_array)))
+			return 1;
+
+		if (!validate_keyslots_array(cd, jarr_keys, jobj_keyslots))
+			return 1;
+		if (!validate_segments_array(cd, jarr_segs, jobj_segments))
+			return 1;
+	}
+
+	return 0;
+}
+
+/* requirements being validated in stand-alone routine */
+static int hdr_validate_config(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	json_object *jobj_config, *jobj;
+	int i;
+	uint64_t keyslots_size, metadata_size, segment_offset;
+
+	if (!json_object_object_get_ex(hdr_jobj, "config", &jobj_config)) {
+		log_dbg(cd, "Missing config section.");
+		return 1;
+	}
+
+	if (!(jobj = json_contains(cd, jobj_config, "section", "Config", "json_size", json_type_string)) ||
+	    !json_str_to_uint64(jobj, &metadata_size))
+		return 1;
+
+	/* single metadata instance is assembled from json area size plus
+	 * binary header size */
+	metadata_size += LUKS2_HDR_BIN_LEN;
+
+	if (!(jobj = json_contains(cd, jobj_config, "section", "Config", "keyslots_size", json_type_string)) ||
+	    !json_str_to_uint64(jobj, &keyslots_size))
+		return 1;
+
+	if (LUKS2_check_metadata_area_size(metadata_size)) {
+		log_dbg(cd, "Unsupported LUKS2 header size (%" PRIu64 ").", metadata_size);
+		return 1;
+	}
+
+	if (LUKS2_check_keyslots_area_size(keyslots_size)) {
+		log_dbg(cd, "Unsupported LUKS2 keyslots size (%" PRIu64 ").", keyslots_size);
+		return 1;
+	}
+
+	/*
+	 * validate keyslots_size fits in between (2 * metadata_size) and first
+	 * segment_offset (except detached header)
+	 */
+	segment_offset = json_segments_get_minimal_offset(json_get_segments_jobj(hdr_jobj), 0);
+	if (segment_offset &&
+	    (segment_offset < keyslots_size ||
+	     (segment_offset - keyslots_size) < (2 * metadata_size))) {
+		log_dbg(cd, "keyslots_size is too large %" PRIu64 " (bytes). Data offset: %" PRIu64
+			", keyslots offset: %" PRIu64, keyslots_size, segment_offset, 2 * metadata_size);
+		return 1;
+	}
+
+	/* Flags array is optional */
+	if (json_object_object_get_ex(jobj_config, "flags", &jobj)) {
+		if (!json_contains(cd, jobj_config, "section", "Config", "flags", json_type_array))
+			return 1;
+
+		/* All array members must be strings */
+		for (i = 0; i < (int) json_object_array_length(jobj); i++)
+			if (!json_object_is_type(json_object_array_get_idx(jobj, i), json_type_string))
+				return 1;
+	}
+
+	return 0;
+}
+
+static int hdr_validate_requirements(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	int i;
+	json_object *jobj_config, *jobj, *jobj1;
+
+	if (!json_object_object_get_ex(hdr_jobj, "config", &jobj_config)) {
+		log_dbg(cd, "Missing config section.");
+		return 1;
+	}
+
+	/* Requirements object is optional */
+	if (json_object_object_get_ex(jobj_config, "requirements", &jobj)) {
+		if (!json_contains(cd, jobj_config, "section", "Config", "requirements", json_type_object))
+			return 1;
+
+		/* Mandatory array is optional */
+		if (json_object_object_get_ex(jobj, "mandatory", &jobj1)) {
+			if (!json_contains(cd, jobj, "section", "Requirements", "mandatory", json_type_array))
+				return 1;
+
+			/* All array members must be strings */
+			for (i = 0; i < (int) json_object_array_length(jobj1); i++)
+				if (!json_object_is_type(json_object_array_get_idx(jobj1, i), json_type_string))
+					return 1;
+		}
+	}
+
+	return 0;
+}
+
+int LUKS2_hdr_validate(struct crypt_device *cd, json_object *hdr_jobj, uint64_t json_size)
+{
+	struct {
+		int (*validate)(struct crypt_device *, json_object *);
+	} checks[] = {
+		{ hdr_validate_requirements },
+		{ hdr_validate_tokens   },
+		{ hdr_validate_digests  },
+		{ hdr_validate_segments },
+		{ hdr_validate_keyslots },
+		{ hdr_validate_config   },
+		{ hdr_validate_areas    },
+		{ NULL }
+	};
+	int i;
+
+	if (!hdr_jobj)
+		return 1;
+
+	for (i = 0; checks[i].validate; i++)
+		if (checks[i].validate && checks[i].validate(cd, hdr_jobj))
+			return 1;
+
+	if (hdr_validate_json_size(cd, hdr_jobj, json_size))
+		return 1;
+
+	/* validate keyslot implementations */
+	if (LUKS2_keyslots_validate(cd, hdr_jobj))
+		return 1;
+
+	return 0;
+}
+
+/* FIXME: should we expose do_recovery parameter explicitly? */
+int LUKS2_hdr_read(struct crypt_device *cd, struct luks2_hdr *hdr, int repair)
+{
+	int r;
+
+	r = device_read_lock(cd, crypt_metadata_device(cd));
+	if (r) {
+		log_err(cd, _("Failed to acquire read lock on device %s."),
+			device_path(crypt_metadata_device(cd)));
+		return r;
+	}
+
+	r = LUKS2_disk_hdr_read(cd, hdr, crypt_metadata_device(cd), 1, !repair);
+	if (r == -EAGAIN) {
+		/* unlikely: auto-recovery is required and failed due to read lock being held */
+		device_read_unlock(cd, crypt_metadata_device(cd));
+
+		/* Do not use LUKS2_device_write lock. Recovery. */
+		r = device_write_lock(cd, crypt_metadata_device(cd));
+		if (r < 0) {
+			log_err(cd, _("Failed to acquire write lock on device %s."),
+				device_path(crypt_metadata_device(cd)));
+			return r;
+		}
+
+		r = LUKS2_disk_hdr_read(cd, hdr, crypt_metadata_device(cd), 1, !repair);
+
+		device_write_unlock(cd, crypt_metadata_device(cd));
+	} else
+		device_read_unlock(cd, crypt_metadata_device(cd));
+
+	return r;
+}
+
+static int hdr_cleanup_and_validate(struct crypt_device *cd, struct luks2_hdr *hdr)
+{
+	LUKS2_digests_erase_unused(cd, hdr);
+
+	return LUKS2_hdr_validate(cd, hdr->jobj, hdr->hdr_size - LUKS2_HDR_BIN_LEN);
+}
+
+int LUKS2_hdr_write_force(struct crypt_device *cd, struct luks2_hdr *hdr)
+{
+	if (hdr_cleanup_and_validate(cd, hdr))
+		return -EINVAL;
+
+	return LUKS2_disk_hdr_write(cd, hdr, crypt_metadata_device(cd), false);
+}
+
+int LUKS2_hdr_write(struct crypt_device *cd, struct luks2_hdr *hdr)
+{
+	if (hdr_cleanup_and_validate(cd, hdr))
+		return -EINVAL;
+
+	return LUKS2_disk_hdr_write(cd, hdr, crypt_metadata_device(cd), true);
+}
+
+int LUKS2_hdr_uuid(struct crypt_device *cd, struct luks2_hdr *hdr, const char *uuid)
+{
+	uuid_t partitionUuid;
+
+	if (uuid && uuid_parse(uuid, partitionUuid) == -1) {
+		log_err(cd, _("Wrong LUKS UUID format provided."));
+		return -EINVAL;
+	}
+	if (!uuid)
+		uuid_generate(partitionUuid);
+
+	uuid_unparse(partitionUuid, hdr->uuid);
+
+	return LUKS2_hdr_write(cd, hdr);
+}
+
+int LUKS2_hdr_labels(struct crypt_device *cd, struct luks2_hdr *hdr,
+		     const char *label, const char *subsystem, int commit)
+{
+	//FIXME: check if the labels are the same and skip this.
+
+	memset(hdr->label, 0, LUKS2_LABEL_L);
+	if (label)
+		strncpy(hdr->label, label, LUKS2_LABEL_L-1);
+
+	memset(hdr->subsystem, 0, LUKS2_LABEL_L);
+	if (subsystem)
+		strncpy(hdr->subsystem, subsystem, LUKS2_LABEL_L-1);
+
+	return commit ? LUKS2_hdr_write(cd, hdr) : 0;
+}
+
+void LUKS2_hdr_free(struct crypt_device *cd, struct luks2_hdr *hdr)
+{
+	if (json_object_put(hdr->jobj))
+		hdr->jobj = NULL;
+	else if (hdr->jobj)
+		log_dbg(cd, "LUKS2 header still in use");
+}
+
+static uint64_t LUKS2_keyslots_size_jobj(json_object *jobj)
+{
+	json_object *jobj1, *jobj2;
+	uint64_t keyslots_size;
+
+	json_object_object_get_ex(jobj, "config", &jobj1);
+	json_object_object_get_ex(jobj1, "keyslots_size", &jobj2);
+	json_str_to_uint64(jobj2, &keyslots_size);
+
+	return keyslots_size;
+}
+
+uint64_t LUKS2_keyslots_size(struct luks2_hdr *hdr)
+{
+	return LUKS2_keyslots_size_jobj(hdr->jobj);
+}
+
+uint64_t LUKS2_hdr_and_areas_size_jobj(json_object *jobj)
+{
+	return 2 * LUKS2_metadata_size_jobj(jobj) + LUKS2_keyslots_size_jobj(jobj);
+}
+
+uint64_t LUKS2_hdr_and_areas_size(struct luks2_hdr *hdr)
+{
+	return LUKS2_hdr_and_areas_size_jobj(hdr->jobj);
+}
+
+int LUKS2_hdr_backup(struct crypt_device *cd, struct luks2_hdr *hdr,
+		     const char *backup_file)
+{
+	struct device *device = crypt_metadata_device(cd);
+	int fd, devfd, r = 0;
+	ssize_t hdr_size;
+	ssize_t ret, buffer_size;
+	char *buffer = NULL;
+
+	hdr_size = LUKS2_hdr_and_areas_size(hdr);
+	buffer_size = size_round_up(hdr_size, crypt_getpagesize());
+
+	buffer = crypt_safe_alloc(buffer_size);
+	if (!buffer)
+		return -ENOMEM;
+
+	log_dbg(cd, "Storing backup of header (%zu bytes).", hdr_size);
+	log_dbg(cd, "Output backup file size: %zu bytes.", buffer_size);
+
+	r = device_read_lock(cd, device);
+	if (r) {
+		log_err(cd, _("Failed to acquire read lock on device %s."),
+			device_path(crypt_metadata_device(cd)));
+		crypt_safe_free(buffer);
+		return r;
+	}
+
+	devfd = device_open_locked(cd, device, O_RDONLY);
+	if (devfd < 0) {
+		device_read_unlock(cd, device);
+		log_err(cd, _("Device %s is not a valid LUKS device."), device_path(device));
+		crypt_safe_free(buffer);
+		return devfd == -1 ? -EINVAL : devfd;
+	}
+
+	if (read_lseek_blockwise(devfd, device_block_size(cd, device),
+			   device_alignment(device), buffer, hdr_size, 0) < hdr_size) {
+		device_read_unlock(cd, device);
+		crypt_safe_free(buffer);
+		return -EIO;
+	}
+
+	device_read_unlock(cd, device);
+
+	fd = open(backup_file, O_CREAT|O_EXCL|O_WRONLY, S_IRUSR);
+	if (fd == -1) {
+		if (errno == EEXIST)
+			log_err(cd, _("Requested header backup file %s already exists."), backup_file);
+		else
+			log_err(cd, _("Cannot create header backup file %s."), backup_file);
+		crypt_safe_free(buffer);
+		return -EINVAL;
+	}
+	ret = write_buffer(fd, buffer, buffer_size);
+	close(fd);
+	if (ret < buffer_size) {
+		log_err(cd, _("Cannot write header backup file %s."), backup_file);
+		r = -EIO;
+	} else
+		r = 0;
+
+	crypt_safe_free(buffer);
+	return r;
+}
+
+int LUKS2_hdr_restore(struct crypt_device *cd, struct luks2_hdr *hdr,
+		     const char *backup_file)
+{
+	struct device *backup_device, *device = crypt_metadata_device(cd);
+	int r, fd, devfd = -1, diff_uuid = 0;
+	ssize_t ret, buffer_size = 0;
+	char *buffer = NULL, msg[1024];
+	struct luks2_hdr hdr_file;
+	struct luks2_hdr tmp_hdr = {};
+	uint32_t reqs = 0;
+
+	r = device_alloc(cd, &backup_device, backup_file);
+	if (r < 0)
+		return r;
+
+	r = device_read_lock(cd, backup_device);
+	if (r) {
+		log_err(cd, _("Failed to acquire read lock on device %s."),
+			device_path(backup_device));
+		device_free(cd, backup_device);
+		return r;
+	}
+
+	r = LUKS2_disk_hdr_read(cd, &hdr_file, backup_device, 0, 0);
+	device_read_unlock(cd, backup_device);
+	device_free(cd, backup_device);
+
+	if (r < 0) {
+		log_err(cd, _("Backup file does not contain valid LUKS header."));
+		goto out;
+	}
+
+	/* do not allow header restore from backup with unmet requirements */
+	if (LUKS2_unmet_requirements(cd, &hdr_file, CRYPT_REQUIREMENT_ONLINE_REENCRYPT, 1)) {
+		log_err(cd, _("Forbidden LUKS2 requirements detected in backup %s."),
+			backup_file);
+		r = -ETXTBSY;
+		goto out;
+	}
+
+	buffer_size = LUKS2_hdr_and_areas_size(&hdr_file);
+	buffer = crypt_safe_alloc(buffer_size);
+	if (!buffer) {
+		r = -ENOMEM;
+		goto out;
+	}
+
+	fd = open(backup_file, O_RDONLY);
+	if (fd == -1) {
+		log_err(cd, _("Cannot open header backup file %s."), backup_file);
+		r = -EINVAL;
+		goto out;
+	}
+
+	ret = read_buffer(fd, buffer, buffer_size);
+	close(fd);
+	if (ret < buffer_size) {
+		log_err(cd, _("Cannot read header backup file %s."), backup_file);
+		r = -EIO;
+		goto out;
+	}
+
+	r = LUKS2_hdr_read(cd, &tmp_hdr, 0);
+	if (r == 0) {
+		log_dbg(cd, "Device %s already contains LUKS2 header, checking UUID and requirements.", device_path(device));
+		r = LUKS2_config_get_requirements(cd, &tmp_hdr, &reqs);
+		if (r)
+			goto out;
+
+		if (memcmp(tmp_hdr.uuid, hdr_file.uuid, LUKS2_UUID_L))
+			diff_uuid = 1;
+
+		if (!reqs_reencrypt(reqs)) {
+			log_dbg(cd, "Checking LUKS2 header size and offsets.");
+			if (LUKS2_get_data_offset(&tmp_hdr) != LUKS2_get_data_offset(&hdr_file)) {
+				log_err(cd, _("Data offset differ on device and backup, restore failed."));
+				r = -EINVAL;
+				goto out;
+			}
+			/* FIXME: what could go wrong? Erase if we're fine with consequences */
+			if (buffer_size != (ssize_t) LUKS2_hdr_and_areas_size(&tmp_hdr)) {
+				log_err(cd, _("Binary header with keyslot areas size differ on device and backup, restore failed."));
+				r = -EINVAL;
+				goto out;
+			}
+		}
+	}
+
+	r = snprintf(msg, sizeof(msg), _("Device %s %s%s%s%s"), device_path(device),
+		     r ? _("does not contain LUKS2 header. Replacing header can destroy data on that device.") :
+			 _("already contains LUKS2 header. Replacing header will destroy existing keyslots."),
+		     diff_uuid ? _("\nWARNING: real device header has different UUID than backup!") : "",
+		     reqs_unknown(reqs) ? _("\nWARNING: unknown LUKS2 requirements detected in real device header!"
+					    "\nReplacing header with backup may corrupt the data on that device!") : "",
+		     reqs_reencrypt(reqs) ? _("\nWARNING: Unfinished offline reencryption detected on the device!"
+					      "\nReplacing header with backup may corrupt data.") : "");
+	if (r < 0 || (size_t) r >= sizeof(msg)) {
+		r = -ENOMEM;
+		goto out;
+	}
+
+	if (!crypt_confirm(cd, msg)) {
+		r = -EINVAL;
+		goto out;
+	}
+
+	log_dbg(cd, "Storing backup of header (%zu bytes) to device %s.", buffer_size, device_path(device));
+
+	/* Do not use LUKS2_device_write lock for checking sequence id on restore */
+	r = device_write_lock(cd, device);
+	if (r < 0) {
+		log_err(cd, _("Failed to acquire write lock on device %s."),
+			device_path(device));
+		goto out;
+	}
+
+	devfd = device_open_locked(cd, device, O_RDWR);
+	if (devfd < 0) {
+		if (errno == EACCES)
+			log_err(cd, _("Cannot write to device %s, permission denied."),
+				device_path(device));
+		else
+			log_err(cd, _("Cannot open device %s."), device_path(device));
+		device_write_unlock(cd, device);
+		r = -EINVAL;
+		goto out;
+	}
+
+	if (write_lseek_blockwise(devfd, device_block_size(cd, device),
+			    device_alignment(device), buffer, buffer_size, 0) < buffer_size)
+		r = -EIO;
+	else
+		r = 0;
+
+	device_write_unlock(cd, device);
+out:
+	LUKS2_hdr_free(cd, hdr);
+	LUKS2_hdr_free(cd, &hdr_file);
+	LUKS2_hdr_free(cd, &tmp_hdr);
+	crypt_safe_memzero(&hdr_file, sizeof(hdr_file));
+	crypt_safe_memzero(&tmp_hdr, sizeof(tmp_hdr));
+	crypt_safe_free(buffer);
+
+	device_sync(cd, device);
+
+	return r;
+}
+
+/*
+ * Persistent config flags
+ */
+static const struct  {
+	uint32_t flag;
+	const char *description;
+} persistent_flags[] = {
+	{ CRYPT_ACTIVATE_ALLOW_DISCARDS,         "allow-discards" },
+	{ CRYPT_ACTIVATE_SAME_CPU_CRYPT,         "same-cpu-crypt" },
+	{ CRYPT_ACTIVATE_SUBMIT_FROM_CRYPT_CPUS, "submit-from-crypt-cpus" },
+	{ CRYPT_ACTIVATE_NO_JOURNAL,             "no-journal" },
+	{ CRYPT_ACTIVATE_NO_READ_WORKQUEUE,      "no-read-workqueue" },
+	{ CRYPT_ACTIVATE_NO_WRITE_WORKQUEUE,     "no-write-workqueue" },
+	{ 0, NULL }
+};
+
+int LUKS2_config_get_flags(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t *flags)
+{
+	json_object *jobj1, *jobj_config, *jobj_flags;
+	int i, j, found;
+
+	if (!hdr || !flags)
+		return -EINVAL;
+
+	*flags = 0;
+
+	if (!json_object_object_get_ex(hdr->jobj, "config", &jobj_config))
+		return 0;
+
+	if (!json_object_object_get_ex(jobj_config, "flags", &jobj_flags))
+		return 0;
+
+	for (i = 0; i < (int) json_object_array_length(jobj_flags); i++) {
+		jobj1 = json_object_array_get_idx(jobj_flags, i);
+		found = 0;
+		for (j = 0; persistent_flags[j].description && !found; j++)
+			if (!strcmp(persistent_flags[j].description,
+				    json_object_get_string(jobj1))) {
+				*flags |= persistent_flags[j].flag;
+				log_dbg(cd, "Using persistent flag %s.",
+					json_object_get_string(jobj1));
+				found = 1;
+			}
+		if (!found)
+			log_verbose(cd, _("Ignored unknown flag %s."),
+				    json_object_get_string(jobj1));
+	}
+
+	return 0;
+}
+
+int LUKS2_config_set_flags(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t flags)
+{
+	json_object *jobj_config, *jobj_flags;
+	int i;
+
+	if (!json_object_object_get_ex(hdr->jobj, "config", &jobj_config))
+		return 0;
+
+	jobj_flags = json_object_new_array();
+
+	for (i = 0; persistent_flags[i].description; i++) {
+		if (flags & persistent_flags[i].flag) {
+			log_dbg(cd, "Setting persistent flag: %s.", persistent_flags[i].description);
+			json_object_array_add(jobj_flags,
+				json_object_new_string(persistent_flags[i].description));
+		}
+	}
+
+	/* Replace or add new flags array */
+	json_object_object_add(jobj_config, "flags", jobj_flags);
+
+	return LUKS2_hdr_write(cd, hdr);
+}
+
+/*
+ * json format example (mandatory array must not be ignored,
+ * all other future fields may be added later)
+ *
+ * "requirements": {
+ *       mandatory : [],
+ *       optional0 : [],
+ *       optional1 : "lala"
+ * }
+ */
+
+/* LUKS2 library requirements */
+struct requirement_flag {
+	uint32_t flag;
+	uint32_t version;
+	const char *description;
+};
+
+static const struct requirement_flag unknown_requirement_flag = { CRYPT_REQUIREMENT_UNKNOWN, 0, NULL };
+
+static const struct requirement_flag requirements_flags[] = {
+	{ CRYPT_REQUIREMENT_OFFLINE_REENCRYPT,1, "offline-reencrypt" },
+	{ CRYPT_REQUIREMENT_ONLINE_REENCRYPT, 2, "online-reencrypt-v2" },
+	{ CRYPT_REQUIREMENT_ONLINE_REENCRYPT, 1, "online-reencrypt" },
+	{ 0, 0, NULL }
+};
+
+static const struct requirement_flag *get_requirement_by_name(const char *requirement)
+{
+	int i;
+
+	for (i = 0; requirements_flags[i].description; i++)
+		if (!strcmp(requirement, requirements_flags[i].description))
+			return requirements_flags + i;
+
+	return &unknown_requirement_flag;
+}
+
+int LUKS2_config_get_reencrypt_version(struct luks2_hdr *hdr, uint32_t *version)
+{
+	json_object *jobj_config, *jobj_requirements, *jobj_mandatory, *jobj;
+	int i, len;
+	const struct requirement_flag *req;
+
+	assert(hdr && version);
+	if (!hdr || !version)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "config", &jobj_config))
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_config, "requirements", &jobj_requirements))
+		return -ENOENT;
+
+	if (!json_object_object_get_ex(jobj_requirements, "mandatory", &jobj_mandatory))
+		return -ENOENT;
+
+	len = (int) json_object_array_length(jobj_mandatory);
+	if (len <= 0)
+		return -ENOENT;
+
+	for (i = 0; i < len; i++) {
+		jobj = json_object_array_get_idx(jobj_mandatory, i);
+
+		/* search for requirements prefixed with "online-reencrypt" */
+		if (strncmp(json_object_get_string(jobj), "online-reencrypt", 16))
+			continue;
+
+		/* check current library is aware of the requirement */
+		req = get_requirement_by_name(json_object_get_string(jobj));
+		if (req->flag == (uint32_t)CRYPT_REQUIREMENT_UNKNOWN)
+			continue;
+
+		*version = req->version;
+
+		return 0;
+	}
+
+	return -ENOENT;
+}
+
+static const struct requirement_flag *stored_requirement_name_by_id(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t req_id)
+{
+	json_object *jobj_config, *jobj_requirements, *jobj_mandatory, *jobj;
+	int i, len;
+	const struct requirement_flag *req;
+
+	assert(hdr);
+	if (!hdr)
+		return NULL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "config", &jobj_config))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj_config, "requirements", &jobj_requirements))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj_requirements, "mandatory", &jobj_mandatory))
+		return NULL;
+
+	len = (int) json_object_array_length(jobj_mandatory);
+	if (len <= 0)
+		return 0;
+
+	for (i = 0; i < len; i++) {
+		jobj = json_object_array_get_idx(jobj_mandatory, i);
+		req = get_requirement_by_name(json_object_get_string(jobj));
+		if (req->flag == req_id)
+			return req;
+	}
+
+	return NULL;
+}
+
+/*
+ * returns count of requirements (past cryptsetup 2.0 release)
+ */
+int LUKS2_config_get_requirements(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t *reqs)
+{
+	json_object *jobj_config, *jobj_requirements, *jobj_mandatory, *jobj;
+	int i, len;
+	const struct requirement_flag *req;
+
+	assert(hdr);
+	if (!hdr || !reqs)
+		return -EINVAL;
+
+	*reqs = 0;
+
+	if (!json_object_object_get_ex(hdr->jobj, "config", &jobj_config))
+		return 0;
+
+	if (!json_object_object_get_ex(jobj_config, "requirements", &jobj_requirements))
+		return 0;
+
+	if (!json_object_object_get_ex(jobj_requirements, "mandatory", &jobj_mandatory))
+		return 0;
+
+	len = (int) json_object_array_length(jobj_mandatory);
+	if (len <= 0)
+		return 0;
+
+	log_dbg(cd, "LUKS2 requirements detected:");
+
+	for (i = 0; i < len; i++) {
+		jobj = json_object_array_get_idx(jobj_mandatory, i);
+		req = get_requirement_by_name(json_object_get_string(jobj));
+		log_dbg(cd, "%s - %sknown", json_object_get_string(jobj),
+				        reqs_unknown(req->flag) ? "un" : "");
+		*reqs |= req->flag;
+	}
+
+	return 0;
+}
+
+int LUKS2_config_set_requirements(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t reqs, bool commit)
+{
+	json_object *jobj_config, *jobj_requirements, *jobj_mandatory, *jobj;
+	int i, r = -EINVAL;
+	const struct requirement_flag *req;
+	uint32_t req_id;
+
+	if (!hdr)
+		return -EINVAL;
+
+	jobj_mandatory = json_object_new_array();
+	if (!jobj_mandatory)
+		return -ENOMEM;
+
+	for (i = 0; requirements_flags[i].description; i++) {
+		req_id = reqs & requirements_flags[i].flag;
+		if (req_id) {
+			/* retain already stored version of requirement flag */
+			req = stored_requirement_name_by_id(cd, hdr, req_id);
+			if (req)
+				jobj = json_object_new_string(req->description);
+			else
+				jobj = json_object_new_string(requirements_flags[i].description);
+			if (!jobj) {
+				r = -ENOMEM;
+				goto err;
+			}
+			json_object_array_add(jobj_mandatory, jobj);
+			/* erase processed flag from input set */
+			reqs &= ~(requirements_flags[i].flag);
+		}
+	}
+
+	/* any remaining bit in requirements is unknown therefore illegal */
+	if (reqs) {
+		log_dbg(cd, "Illegal requirement flag(s) requested");
+		goto err;
+	}
+
+	if (!json_object_object_get_ex(hdr->jobj, "config", &jobj_config))
+		goto err;
+
+	if (!json_object_object_get_ex(jobj_config, "requirements", &jobj_requirements)) {
+		jobj_requirements = json_object_new_object();
+		if (!jobj_requirements) {
+			r = -ENOMEM;
+			goto err;
+		}
+		json_object_object_add(jobj_config, "requirements", jobj_requirements);
+	}
+
+	if (json_object_array_length(jobj_mandatory) > 0) {
+		/* replace mandatory field with new values */
+		json_object_object_add(jobj_requirements, "mandatory", jobj_mandatory);
+	} else {
+		/* new mandatory field was empty, delete old one */
+		json_object_object_del(jobj_requirements, "mandatory");
+		json_object_put(jobj_mandatory);
+	}
+
+	/* remove empty requirements object */
+	if (!json_object_object_length(jobj_requirements))
+		json_object_object_del(jobj_config, "requirements");
+
+	return commit ? LUKS2_hdr_write(cd, hdr) : 0;
+err:
+	json_object_put(jobj_mandatory);
+	return r;
+}
+
+/*
+ * Header dump
+ */
+static void hdr_dump_config(struct crypt_device *cd, json_object *hdr_jobj)
+{
+
+	json_object *jobj1, *jobj_config, *jobj_flags, *jobj_requirements, *jobj_mandatory;
+	int i = 0, flags = 0, reqs = 0;
+
+	log_std(cd, "Flags:       \t");
+
+	if (json_object_object_get_ex(hdr_jobj, "config", &jobj_config)) {
+		if (json_object_object_get_ex(jobj_config, "flags", &jobj_flags))
+			flags = (int) json_object_array_length(jobj_flags);
+		if (json_object_object_get_ex(jobj_config, "requirements", &jobj_requirements) &&
+		    json_object_object_get_ex(jobj_requirements, "mandatory", &jobj_mandatory))
+			reqs = (int) json_object_array_length(jobj_mandatory);
+	}
+
+	for (i = 0; i < flags; i++) {
+		jobj1 = json_object_array_get_idx(jobj_flags, i);
+		log_std(cd, "%s ", json_object_get_string(jobj1));
+	}
+
+	log_std(cd, "%s\n%s", flags > 0 ? "" : "(no flags)", reqs > 0 ? "" : "\n");
+
+	if (reqs > 0) {
+		log_std(cd, "Requirements:\t");
+		for (i = 0; i < reqs; i++) {
+			jobj1 = json_object_array_get_idx(jobj_mandatory, i);
+			log_std(cd, "%s ", json_object_get_string(jobj1));
+		}
+		log_std(cd, "\n\n");
+	}
+}
+
+static const char *get_priority_desc(json_object *jobj)
+{
+	crypt_keyslot_priority priority;
+	json_object *jobj_priority;
+	const char *text;
+
+	if (json_object_object_get_ex(jobj, "priority", &jobj_priority))
+		priority = (crypt_keyslot_priority)(int)json_object_get_int(jobj_priority);
+	else
+		priority = CRYPT_SLOT_PRIORITY_NORMAL;
+
+	switch (priority) {
+		case CRYPT_SLOT_PRIORITY_IGNORE: text = "ignored"; break;
+		case CRYPT_SLOT_PRIORITY_PREFER: text = "preferred"; break;
+		case CRYPT_SLOT_PRIORITY_NORMAL: text = "normal"; break;
+		default: text = "invalid";
+	}
+
+	return text;
+}
+
+static void hdr_dump_keyslots(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	char slot[16];
+	json_object *keyslots_jobj, *digests_jobj, *jobj2, *jobj3, *val;
+	const char *tmps;
+	int i, j, r;
+
+	log_std(cd, "Keyslots:\n");
+	json_object_object_get_ex(hdr_jobj, "keyslots", &keyslots_jobj);
+
+	for (j = 0; j < LUKS2_KEYSLOTS_MAX; j++) {
+		(void) snprintf(slot, sizeof(slot), "%i", j);
+		json_object_object_get_ex(keyslots_jobj, slot, &val);
+		if (!val)
+			continue;
+
+		json_object_object_get_ex(val, "type", &jobj2);
+		tmps = json_object_get_string(jobj2);
+
+		r = LUKS2_keyslot_for_segment(crypt_get_hdr(cd, CRYPT_LUKS2), j, CRYPT_ONE_SEGMENT);
+		log_std(cd, "  %s: %s%s\n", slot, tmps, r == -ENOENT ? " (unbound)" : "");
+
+		if (json_object_object_get_ex(val, "key_size", &jobj2))
+			log_std(cd, "\tKey:        %u bits\n", crypt_jobj_get_uint32(jobj2) * 8);
+
+		log_std(cd, "\tPriority:   %s\n", get_priority_desc(val));
+
+		LUKS2_keyslot_dump(cd, j);
+
+		json_object_object_get_ex(hdr_jobj, "digests", &digests_jobj);
+		json_object_object_foreach(digests_jobj, key2, val2) {
+			json_object_object_get_ex(val2, "keyslots", &jobj2);
+			for (i = 0; i < (int) json_object_array_length(jobj2); i++) {
+				jobj3 = json_object_array_get_idx(jobj2, i);
+				if (!strcmp(slot, json_object_get_string(jobj3))) {
+					log_std(cd, "\tDigest ID:  %s\n", key2);
+				}
+			}
+		}
+	}
+}
+
+static void hdr_dump_tokens(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	char token[16];
+	json_object *tokens_jobj, *jobj2, *jobj3, *val;
+	const char *tmps;
+	int i, j;
+
+	log_std(cd, "Tokens:\n");
+	json_object_object_get_ex(hdr_jobj, "tokens", &tokens_jobj);
+
+	for (j = 0; j < LUKS2_TOKENS_MAX; j++) {
+		(void) snprintf(token, sizeof(token), "%i", j);
+		json_object_object_get_ex(tokens_jobj, token, &val);
+		if (!val)
+			continue;
+
+		json_object_object_get_ex(val, "type", &jobj2);
+		tmps = json_object_get_string(jobj2);
+		log_std(cd, "  %s: %s\n", token, tmps);
+
+		LUKS2_token_dump(cd, j);
+
+		json_object_object_get_ex(val, "keyslots", &jobj2);
+		for (i = 0; i < (int) json_object_array_length(jobj2); i++) {
+			jobj3 = json_object_array_get_idx(jobj2, i);
+			log_std(cd, "\tKeyslot:  %s\n", json_object_get_string(jobj3));
+		}
+	}
+}
+
+static void hdr_dump_segments(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	char segment[16];
+	json_object *jobj_segments, *jobj_segment, *jobj1, *jobj2;
+	int i, j, flags;
+	uint64_t value;
+
+	log_std(cd, "Data segments:\n");
+	json_object_object_get_ex(hdr_jobj, "segments", &jobj_segments);
+
+	for (i = 0; i < LUKS2_SEGMENT_MAX; i++) {
+		(void) snprintf(segment, sizeof(segment), "%i", i);
+		if (!json_object_object_get_ex(jobj_segments, segment, &jobj_segment))
+			continue;
+
+		json_object_object_get_ex(jobj_segment, "type", &jobj1);
+		log_std(cd, "  %s: %s\n", segment, json_object_get_string(jobj1));
+
+		json_object_object_get_ex(jobj_segment, "offset", &jobj1);
+		json_str_to_uint64(jobj1, &value);
+		log_std(cd, "\toffset: %" PRIu64 " [bytes]\n", value);
+
+		json_object_object_get_ex(jobj_segment, "size", &jobj1);
+		if (!(strcmp(json_object_get_string(jobj1), "dynamic")))
+			log_std(cd, "\tlength: (whole device)\n");
+		else {
+			json_str_to_uint64(jobj1, &value);
+			log_std(cd, "\tlength: %" PRIu64 " [bytes]\n", value);
+		}
+
+		if (json_object_object_get_ex(jobj_segment, "encryption", &jobj1))
+			log_std(cd, "\tcipher: %s\n", json_object_get_string(jobj1));
+
+		if (json_object_object_get_ex(jobj_segment, "sector_size", &jobj1))
+			log_std(cd, "\tsector: %" PRIu32 " [bytes]\n", crypt_jobj_get_uint32(jobj1));
+
+		if (json_object_object_get_ex(jobj_segment, "integrity", &jobj1) &&
+		    json_object_object_get_ex(jobj1, "type", &jobj2))
+			log_std(cd, "\tintegrity: %s\n", json_object_get_string(jobj2));
+
+		if (json_object_object_get_ex(jobj_segment, "flags", &jobj1) &&
+		    (flags = (int)json_object_array_length(jobj1)) > 0) {
+			jobj2 = json_object_array_get_idx(jobj1, 0);
+			log_std(cd, "\tflags : %s", json_object_get_string(jobj2));
+			for (j = 1; j < flags; j++) {
+				jobj2 = json_object_array_get_idx(jobj1, j);
+				log_std(cd, ", %s", json_object_get_string(jobj2));
+			}
+			log_std(cd, "\n");
+		}
+
+		log_std(cd, "\n");
+	}
+}
+
+static void hdr_dump_digests(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	char key[16];
+	json_object *jobj1, *jobj2, *val;
+	const char *tmps;
+	int i;
+
+	log_std(cd, "Digests:\n");
+	json_object_object_get_ex(hdr_jobj, "digests", &jobj1);
+
+	for (i = 0; i < LUKS2_DIGEST_MAX; i++) {
+		(void) snprintf(key, sizeof(key), "%i", i);
+		json_object_object_get_ex(jobj1, key, &val);
+		if (!val)
+			continue;
+
+		json_object_object_get_ex(val, "type", &jobj2);
+		tmps = json_object_get_string(jobj2);
+		log_std(cd, "  %s: %s\n", key, tmps);
+
+		LUKS2_digest_dump(cd, i);
+	}
+}
+
+int LUKS2_hdr_dump(struct crypt_device *cd, struct luks2_hdr *hdr)
+{
+	if (!hdr->jobj)
+		return -EINVAL;
+
+	JSON_DBG(cd, hdr->jobj, NULL);
+
+	log_std(cd, "LUKS header information\n");
+	log_std(cd, "Version:       \t%u\n", hdr->version);
+	log_std(cd, "Epoch:         \t%" PRIu64 "\n", hdr->seqid);
+	log_std(cd, "Metadata area: \t%" PRIu64 " [bytes]\n", LUKS2_metadata_size(hdr));
+	log_std(cd, "Keyslots area: \t%" PRIu64 " [bytes]\n", LUKS2_keyslots_size(hdr));
+	log_std(cd, "UUID:          \t%s\n", *hdr->uuid ? hdr->uuid : "(no UUID)");
+	log_std(cd, "Label:         \t%s\n", *hdr->label ? hdr->label : "(no label)");
+	log_std(cd, "Subsystem:     \t%s\n", *hdr->subsystem ? hdr->subsystem : "(no subsystem)");
+
+	hdr_dump_config(cd, hdr->jobj);
+	hdr_dump_segments(cd, hdr->jobj);
+	hdr_dump_keyslots(cd, hdr->jobj);
+	hdr_dump_tokens(cd, hdr->jobj);
+	hdr_dump_digests(cd, hdr->jobj);
+
+	return 0;
+}
+
+int LUKS2_get_data_size(struct luks2_hdr *hdr, uint64_t *size, bool *dynamic)
+{
+	int sector_size;
+	json_object *jobj_segments, *jobj_size;
+	uint64_t tmp = 0;
+
+	if (!size || !json_object_object_get_ex(hdr->jobj, "segments", &jobj_segments))
+		return -EINVAL;
+
+	json_object_object_foreach(jobj_segments, key, val) {
+		UNUSED(key);
+		if (json_segment_is_backup(val))
+			continue;
+
+		json_object_object_get_ex(val, "size", &jobj_size);
+		if (!strcmp(json_object_get_string(jobj_size), "dynamic")) {
+			sector_size = json_segment_get_sector_size(val);
+			/* last dynamic segment must have at least one sector in size */
+			if (tmp)
+				*size = tmp + (sector_size > 0 ? sector_size : SECTOR_SIZE);
+			else
+				*size = 0;
+			if (dynamic)
+				*dynamic = true;
+			return 0;
+		}
+
+		tmp += crypt_jobj_get_uint64(jobj_size);
+	}
+
+	/* impossible, real device size must not be zero */
+	if (!tmp)
+		return -EINVAL;
+
+	*size = tmp;
+	if (dynamic)
+		*dynamic = false;
+	return 0;
+}
+
+uint64_t LUKS2_get_data_offset(struct luks2_hdr *hdr)
+{
+	crypt_reencrypt_info ri;
+	json_object *jobj;
+
+	ri = LUKS2_reencrypt_status(hdr);
+	if (ri == CRYPT_REENCRYPT_CLEAN || ri == CRYPT_REENCRYPT_CRASH) {
+		jobj = LUKS2_get_segment_by_flag(hdr, "backup-final");
+		if (jobj)
+			return json_segment_get_offset(jobj, 1);
+	}
+
+	return json_segments_get_minimal_offset(LUKS2_get_segments_jobj(hdr), 1);
+}
+
+const char *LUKS2_get_cipher(struct luks2_hdr *hdr, int segment)
+{
+	json_object *jobj_segment;
+
+	if (!hdr)
+		return NULL;
+
+	if (segment == CRYPT_DEFAULT_SEGMENT)
+		segment = LUKS2_get_default_segment(hdr);
+
+	jobj_segment = json_segments_get_segment(json_get_segments_jobj(hdr->jobj), segment);
+	if (!jobj_segment)
+		return NULL;
+
+	/* FIXME: default encryption (for other segment types) must be string here. */
+	return json_segment_get_cipher(jobj_segment) ?: "null";
+}
+
+crypt_reencrypt_info LUKS2_reencrypt_status(struct luks2_hdr *hdr)
+{
+	uint32_t reqs;
+
+	/*
+	 * Any unknown requirement or offline reencryption should abort
+	 * anything related to online-reencryption handling
+	 */
+	if (LUKS2_config_get_requirements(NULL, hdr, &reqs))
+		return CRYPT_REENCRYPT_INVALID;
+
+	if (!reqs_reencrypt_online(reqs))
+		return CRYPT_REENCRYPT_NONE;
+
+	if (json_segments_segment_in_reencrypt(LUKS2_get_segments_jobj(hdr)) < 0)
+		return CRYPT_REENCRYPT_CLEAN;
+
+	return CRYPT_REENCRYPT_CRASH;
+}
+
+const char *LUKS2_get_keyslot_cipher(struct luks2_hdr *hdr, int keyslot, size_t *key_size)
+{
+	json_object *jobj_keyslot, *jobj_area, *jobj1;
+
+	jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
+	if (!jobj_keyslot)
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
+		return NULL;
+
+	/* currently we only support raw length preserving area encryption */
+	json_object_object_get_ex(jobj_area, "type", &jobj1);
+	if (strcmp(json_object_get_string(jobj1), "raw"))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj_area, "key_size", &jobj1))
+		return NULL;
+	*key_size = json_object_get_int(jobj1);
+
+	if (!json_object_object_get_ex(jobj_area, "encryption", &jobj1))
+		return NULL;
+
+	return json_object_get_string(jobj1);
+}
+
+const char *LUKS2_get_integrity(struct luks2_hdr *hdr, int segment)
+{
+	json_object *jobj1, *jobj2, *jobj3;
+
+	jobj1 = LUKS2_get_segment_jobj(hdr, segment);
+	if (!jobj1)
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj1, "integrity", &jobj2))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj2, "type", &jobj3))
+		return NULL;
+
+	return json_object_get_string(jobj3);
+}
+
+/* FIXME: this only ensures that once we have journal encryption, it is not ignored. */
+/* implement segment count and type restrictions (crypt and only single crypt) */
+static int LUKS2_integrity_compatible(struct luks2_hdr *hdr)
+{
+	json_object *jobj1, *jobj2, *jobj3, *jobj4;
+	const char *str;
+
+	if (!json_object_object_get_ex(hdr->jobj, "segments", &jobj1))
+		return 0;
+
+	if (!(jobj2 = LUKS2_get_segment_jobj(hdr, CRYPT_DEFAULT_SEGMENT)))
+		return 0;
+
+	if (!json_object_object_get_ex(jobj2, "integrity", &jobj3))
+		return 0;
+
+	if (!json_object_object_get_ex(jobj3, "journal_encryption", &jobj4) ||
+	    !(str = json_object_get_string(jobj4)) ||
+	    strcmp(str, "none"))
+		return 0;
+
+	if (!json_object_object_get_ex(jobj3, "journal_integrity", &jobj4) ||
+	    !(str = json_object_get_string(jobj4)) ||
+	    strcmp(str, "none"))
+		return 0;
+
+	return 1;
+}
+
+static int LUKS2_keyslot_get_volume_key_size(struct luks2_hdr *hdr, const char *keyslot)
+{
+	json_object *jobj1, *jobj2, *jobj3;
+
+	if (!json_object_object_get_ex(hdr->jobj, "keyslots", &jobj1))
+		return -1;
+
+	if (!json_object_object_get_ex(jobj1, keyslot, &jobj2))
+		return -1;
+
+	if (!json_object_object_get_ex(jobj2, "key_size", &jobj3))
+		return -1;
+
+	return json_object_get_int(jobj3);
+}
+
+/* Key size used for encryption of keyslot */
+int LUKS2_get_keyslot_stored_key_size(struct luks2_hdr *hdr, int keyslot)
+{
+	char keyslot_name[16];
+
+	if (snprintf(keyslot_name, sizeof(keyslot_name), "%u", keyslot) < 1)
+		return -1;
+
+	return LUKS2_keyslot_get_volume_key_size(hdr, keyslot_name);
+}
+
+int LUKS2_get_volume_key_size(struct luks2_hdr *hdr, int segment)
+{
+	json_object *jobj_digests, *jobj_digest_segments, *jobj_digest_keyslots, *jobj1;
+	char buf[16];
+
+	if (segment == CRYPT_DEFAULT_SEGMENT)
+		segment = LUKS2_get_default_segment(hdr);
+
+	if (snprintf(buf, sizeof(buf), "%u", segment) < 1)
+		return -1;
+
+	json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
+
+	json_object_object_foreach(jobj_digests, key, val) {
+		UNUSED(key);
+		json_object_object_get_ex(val, "segments", &jobj_digest_segments);
+		json_object_object_get_ex(val, "keyslots", &jobj_digest_keyslots);
+
+		if (!LUKS2_array_jobj(jobj_digest_segments, buf))
+			continue;
+		if (json_object_array_length(jobj_digest_keyslots) <= 0)
+			continue;
+
+		jobj1 = json_object_array_get_idx(jobj_digest_keyslots, 0);
+
+		return LUKS2_keyslot_get_volume_key_size(hdr, json_object_get_string(jobj1));
+	}
+
+	return -1;
+}
+
+int LUKS2_get_sector_size(struct luks2_hdr *hdr)
+{
+	json_object *jobj_segment;
+
+	jobj_segment = LUKS2_get_segment_jobj(hdr, CRYPT_DEFAULT_SEGMENT);
+	if (!jobj_segment)
+		return SECTOR_SIZE;
+
+	return json_segment_get_sector_size(jobj_segment) ?: SECTOR_SIZE;
+}
+
+int LUKS2_assembly_multisegment_dmd(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	struct volume_key *vks,
+	json_object *jobj_segments,
+	struct crypt_dm_active_device *dmd)
+{
+	struct volume_key *vk;
+	json_object *jobj;
+	enum devcheck device_check;
+	int r;
+	unsigned s = 0;
+	uint64_t data_offset, segment_size, segment_offset, segment_start = 0;
+	struct dm_target *t = &dmd->segment;
+
+	if (dmd->flags & CRYPT_ACTIVATE_SHARED)
+		device_check = DEV_OK;
+	else
+		device_check = DEV_EXCL;
+
+	data_offset = LUKS2_reencrypt_data_offset(hdr, true);
+
+	r = device_block_adjust(cd, crypt_data_device(cd), device_check,
+			                                data_offset, &dmd->size, &dmd->flags);
+	if (r)
+		return r;
+
+	r = dm_targets_allocate(&dmd->segment, json_segments_count(jobj_segments));
+	if (r)
+		goto err;
+
+	r = -EINVAL;
+
+	while (t) {
+		jobj = json_segments_get_segment(jobj_segments, s);
+		if (!jobj) {
+			log_dbg(cd, "Internal error. Segment %u is null.", s);
+			r = -EINVAL;
+			goto err;
+		}
+
+		segment_offset = json_segment_get_offset(jobj, 1);
+		segment_size = json_segment_get_size(jobj, 1);
+		/* 'dynamic' length allowed in last segment only */
+		if (!segment_size && !t->next)
+			segment_size = dmd->size - segment_start;
+		if (!segment_size) {
+			log_dbg(cd, "Internal error. Wrong segment size %u", s);
+			r = -EINVAL;
+			goto err;
+		}
+
+		if (!strcmp(json_segment_type(jobj), "crypt")) {
+			vk = crypt_volume_key_by_id(vks, LUKS2_digest_by_segment(hdr, s));
+			if (!vk) {
+				log_err(cd, _("Missing key for dm-crypt segment %u"), s);
+				r = -EINVAL;
+				goto err;
+			}
+
+			r = dm_crypt_target_set(t, segment_start, segment_size,
+					crypt_data_device(cd), vk,
+					json_segment_get_cipher(jobj),
+					json_segment_get_iv_offset(jobj),
+					segment_offset, "none", 0,
+					json_segment_get_sector_size(jobj));
+			if (r) {
+				log_err(cd, _("Failed to set dm-crypt segment."));
+				goto err;
+			}
+		} else if (!strcmp(json_segment_type(jobj), "linear")) {
+			r = dm_linear_target_set(t, segment_start, segment_size, crypt_data_device(cd), segment_offset);
+			if (r) {
+				log_err(cd, _("Failed to set dm-linear segment."));
+				goto err;
+			}
+		} else {
+			r = -EINVAL;
+			goto err;
+		}
+
+		segment_start += segment_size;
+		t = t->next;
+		s++;
+	}
+
+	return r;
+err:
+	dm_targets_free(cd, dmd);
+	return r;
+}
+
+/* FIXME: This shares almost all code with activate_multi_custom */
+static int _reload_custom_multi(struct crypt_device *cd,
+	const char *name,
+	struct volume_key *vks,
+	json_object *jobj_segments,
+	uint64_t device_size,
+	uint32_t flags)
+{
+	int r;
+	struct luks2_hdr *hdr = crypt_get_hdr(cd, CRYPT_LUKS2);
+	struct crypt_dm_active_device dmd =  {
+		.uuid   = crypt_get_uuid(cd),
+		.size = device_size >> SECTOR_SHIFT
+	};
+
+	/* do not allow activation when particular requirements detected */
+	if ((r = LUKS2_unmet_requirements(cd, hdr, CRYPT_REQUIREMENT_ONLINE_REENCRYPT, 0)))
+		return r;
+
+	/* Add persistent activation flags */
+	if (!(flags & CRYPT_ACTIVATE_IGNORE_PERSISTENT))
+		LUKS2_config_get_flags(cd, hdr, &dmd.flags);
+
+	dmd.flags |= (flags | CRYPT_ACTIVATE_SHARED);
+
+	r = LUKS2_assembly_multisegment_dmd(cd, hdr, vks, jobj_segments, &dmd);
+	if (!r)
+		r = dm_reload_device(cd, name, &dmd, 0, 0);
+
+	dm_targets_free(cd, &dmd);
+	return r;
+}
+
+int LUKS2_reload(struct crypt_device *cd,
+	const char *name,
+	struct volume_key *vks,
+	uint64_t device_size,
+	uint32_t flags)
+{
+	if (crypt_get_integrity_tag_size(cd))
+		return -ENOTSUP;
+
+	return _reload_custom_multi(cd, name, vks,
+			LUKS2_get_segments_jobj(crypt_get_hdr(cd, CRYPT_LUKS2)), device_size, flags);
+}
+
+int LUKS2_activate_multi(struct crypt_device *cd,
+	const char *name,
+	struct volume_key *vks,
+	uint64_t device_size,
+	uint32_t flags)
+{
+	struct luks2_hdr *hdr = crypt_get_hdr(cd, CRYPT_LUKS2);
+	json_object *jobj_segments = LUKS2_get_segments_jobj(hdr);
+	int r;
+	struct crypt_dm_active_device dmd = {
+		.size	= device_size,
+		.uuid   = crypt_get_uuid(cd)
+	};
+
+	/* do not allow activation when particular requirements detected */
+	if ((r = LUKS2_unmet_requirements(cd, hdr, CRYPT_REQUIREMENT_ONLINE_REENCRYPT, 0)))
+		return r;
+
+	/* Add persistent activation flags */
+	if (!(flags & CRYPT_ACTIVATE_IGNORE_PERSISTENT))
+		LUKS2_config_get_flags(cd, hdr, &dmd.flags);
+
+	dmd.flags |= flags;
+
+	r = LUKS2_assembly_multisegment_dmd(cd, hdr, vks, jobj_segments, &dmd);
+	if (!r)
+		r = dm_create_device(cd, name, CRYPT_LUKS2, &dmd);
+
+	dm_targets_free(cd, &dmd);
+	return r;
+}
+
+int LUKS2_activate(struct crypt_device *cd,
+	const char *name,
+	struct volume_key *vk,
+	uint32_t flags)
+{
+	int r;
+	struct luks2_hdr *hdr = crypt_get_hdr(cd, CRYPT_LUKS2);
+	struct crypt_dm_active_device dmdi = {}, dmd = {
+		.uuid   = crypt_get_uuid(cd)
+	};
+
+	/* do not allow activation when particular requirements detected */
+	if ((r = LUKS2_unmet_requirements(cd, hdr, 0, 0)))
+		return r;
+
+	r = dm_crypt_target_set(&dmd.segment, 0, dmd.size, crypt_data_device(cd),
+			vk, crypt_get_cipher_spec(cd), crypt_get_iv_offset(cd),
+			crypt_get_data_offset(cd), crypt_get_integrity(cd) ?: "none",
+			crypt_get_integrity_tag_size(cd), crypt_get_sector_size(cd));
+	if (r < 0)
+		return r;
+
+	/* Add persistent activation flags */
+	if (!(flags & CRYPT_ACTIVATE_IGNORE_PERSISTENT))
+		LUKS2_config_get_flags(cd, hdr, &dmd.flags);
+
+	dmd.flags |= flags;
+
+	if (crypt_get_integrity_tag_size(cd)) {
+		if (!LUKS2_integrity_compatible(hdr)) {
+			log_err(cd, _("Unsupported device integrity configuration."));
+			return -EINVAL;
+		}
+
+		if (dmd.flags & CRYPT_ACTIVATE_ALLOW_DISCARDS) {
+			log_err(cd, _("Discard/TRIM is not supported."));
+			return -EINVAL;
+		}
+
+		r = INTEGRITY_create_dmd_device(cd, NULL, NULL, NULL, NULL, &dmdi, dmd.flags, 0);
+		if (r)
+			return r;
+
+		dmdi.flags |= CRYPT_ACTIVATE_PRIVATE;
+		dmdi.uuid = dmd.uuid;
+		dmd.segment.u.crypt.offset = 0;
+		dmd.segment.size = dmdi.segment.size;
+
+		r = create_or_reload_device_with_integrity(cd, name, CRYPT_LUKS2, &dmd, &dmdi);
+	} else
+		r = create_or_reload_device(cd, name, CRYPT_LUKS2, &dmd);
+
+	dm_targets_free(cd, &dmd);
+	dm_targets_free(cd, &dmdi);
+
+	return r;
+}
+
+static bool is_reencryption_helper(const char *name)
+{
+	size_t len;
+
+	if (!name)
+		return false;
+
+	len = strlen(name);
+	return (len >= 9 && (!strncmp(name + len - 8, "-hotzone-", 9) ||
+			     !strcmp(name + len - 8, "-overlay")));
+
+}
+
+static bool contains_reencryption_helper(char **names)
+{
+	while (*names) {
+		if (is_reencryption_helper(*names++))
+			return true;
+	}
+
+	return false;
+}
+
+int LUKS2_deactivate(struct crypt_device *cd, const char *name, struct luks2_hdr *hdr, struct crypt_dm_active_device *dmd, uint32_t flags)
+{
+	int r, ret;
+	struct dm_target *tgt;
+	crypt_status_info ci;
+	struct crypt_dm_active_device dmdc;
+	char **dep, deps_uuid_prefix[40], *deps[MAX_DM_DEPS+1] = { 0 };
+	const char *namei = NULL;
+	struct crypt_lock_handle *reencrypt_lock = NULL;
+
+	if (!dmd || !dmd->uuid || strncmp(CRYPT_LUKS2, dmd->uuid, sizeof(CRYPT_LUKS2)-1))
+		return -EINVAL;
+
+	/* uuid mismatch with metadata (if available) */
+	if (hdr && crypt_uuid_cmp(dmd->uuid, hdr->uuid))
+		return -EINVAL;
+
+	r = snprintf(deps_uuid_prefix, sizeof(deps_uuid_prefix), CRYPT_SUBDEV "-%.32s", dmd->uuid + 6);
+	if (r < 0 || (size_t)r != (sizeof(deps_uuid_prefix) - 1))
+		return -EINVAL;
+
+	tgt = &dmd->segment;
+
+	/* TODO: We have LUKS2 dependencies now */
+	if (hdr && single_segment(dmd) && tgt->type == DM_CRYPT && crypt_get_integrity_tag_size(cd))
+		namei = device_dm_name(tgt->data_device);
+
+	r = dm_device_deps(cd, name, deps_uuid_prefix, deps, ARRAY_SIZE(deps));
+	if (r < 0)
+		goto out;
+
+	if (contains_reencryption_helper(deps)) {
+		r = LUKS2_reencrypt_lock_by_dm_uuid(cd, dmd->uuid, &reencrypt_lock);
+		if (r) {
+			if (r == -EBUSY)
+				log_err(cd, _("Reencryption in-progress. Cannot deactivate device."));
+			else
+				log_err(cd, _("Failed to get reencryption lock."));
+			goto out;
+		}
+	}
+
+	dep = deps;
+	while (*dep) {
+		if (is_reencryption_helper(*dep) && (dm_status_suspended(cd, *dep) > 0)) {
+			if (dm_error_device(cd, *dep))
+				log_err(cd, _("Failed to replace suspended device %s with dm-error target."), *dep);
+		}
+		dep++;
+	}
+
+	r = dm_query_device(cd, name, DM_ACTIVE_CRYPT_KEY | DM_ACTIVE_CRYPT_KEYSIZE, &dmdc);
+	if (r < 0) {
+		memset(&dmdc, 0, sizeof(dmdc));
+		dmdc.segment.type = DM_UNKNOWN;
+	}
+
+	/* Remove top level device first */
+	r = dm_remove_device(cd, name, flags);
+	if (!r) {
+		tgt = &dmdc.segment;
+		while (tgt) {
+			if (tgt->type == DM_CRYPT)
+				crypt_drop_keyring_key_by_description(cd, tgt->u.crypt.vk->key_description, LOGON_KEY);
+			tgt = tgt->next;
+		}
+	}
+	dm_targets_free(cd, &dmdc);
+
+	/* TODO: We have LUKS2 dependencies now */
+	if (r >= 0 && namei) {
+		log_dbg(cd, "Deactivating integrity device %s.", namei);
+		r = dm_remove_device(cd, namei, 0);
+	}
+
+	if (!r) {
+		ret = 0;
+		dep = deps;
+		while (*dep) {
+			log_dbg(cd, "Deactivating LUKS2 dependent device %s.", *dep);
+			r = dm_query_device(cd, *dep, DM_ACTIVE_CRYPT_KEY | DM_ACTIVE_CRYPT_KEYSIZE, &dmdc);
+			if (r < 0) {
+				memset(&dmdc, 0, sizeof(dmdc));
+				dmdc.segment.type = DM_UNKNOWN;
+			}
+
+			r = dm_remove_device(cd, *dep, flags);
+			if (r < 0) {
+				ci = crypt_status(cd, *dep);
+				if (ci == CRYPT_BUSY)
+					log_err(cd, _("Device %s is still in use."), *dep);
+				if (ci == CRYPT_INACTIVE)
+					r = 0;
+			}
+			if (!r) {
+				tgt = &dmdc.segment;
+				while (tgt) {
+					if (tgt->type == DM_CRYPT)
+						crypt_drop_keyring_key_by_description(cd, tgt->u.crypt.vk->key_description, LOGON_KEY);
+					tgt = tgt->next;
+				}
+			}
+			dm_targets_free(cd, &dmdc);
+			if (r && !ret)
+				ret = r;
+			dep++;
+		}
+		r = ret;
+	}
+
+out:
+	LUKS2_reencrypt_unlock(cd, reencrypt_lock);
+	dep = deps;
+	while (*dep)
+		free(*dep++);
+
+	return r;
+}
+
+int LUKS2_unmet_requirements(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t reqs_mask, int quiet)
+{
+	uint32_t reqs;
+	int r = LUKS2_config_get_requirements(cd, hdr, &reqs);
+
+	if (r) {
+		if (!quiet)
+			log_err(cd, _("Failed to read LUKS2 requirements."));
+		return r;
+	}
+
+	/* do not mask unknown requirements check */
+	if (reqs_unknown(reqs)) {
+		if (!quiet)
+			log_err(cd, _("Unmet LUKS2 requirements detected."));
+		return -ETXTBSY;
+	}
+
+	/* mask out permitted requirements */
+	reqs &= ~reqs_mask;
+
+	if (reqs_reencrypt(reqs) && !quiet)
+		log_err(cd, _("Operation incompatible with device marked for legacy reencryption. Aborting."));
+	if (reqs_reencrypt_online(reqs) && !quiet)
+		log_err(cd, _("Operation incompatible with device marked for LUKS2 reencryption. Aborting."));
+
+	/* any remaining unmasked requirement fails the check */
+	return reqs ? -EINVAL : 0;
+}
+
+/*
+ * NOTE: this routine is called on json object that failed validation.
+ * 	 Proceed with caution :)
+ *
+ * known glitches so far:
+ *
+ * any version < 2.0.3:
+ *  - luks2 keyslot pbkdf params change via crypt_keyslot_change_by_passphrase()
+ *    could leave previous type parameters behind. Correct this by purging
+ *    all params not needed by current type.
+ */
+void LUKS2_hdr_repair(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	json_object *jobj_keyslots;
+
+	if (!json_object_object_get_ex(hdr_jobj, "keyslots", &jobj_keyslots))
+		return;
+	if (!json_object_is_type(jobj_keyslots, json_type_object))
+		return;
+
+	LUKS2_keyslots_repair(cd, jobj_keyslots);
+}
+
+void json_object_object_del_by_uint(json_object *jobj, unsigned key)
+{
+	char key_name[16];
+
+	if (snprintf(key_name, sizeof(key_name), "%u", key) < 1)
+		return;
+	json_object_object_del(jobj, key_name);
+}
+
+int json_object_object_add_by_uint(json_object *jobj, unsigned key, json_object *jobj_val)
+{
+	char key_name[16];
+
+	if (snprintf(key_name, sizeof(key_name), "%u", key) < 1)
+		return -EINVAL;
+
+#if HAVE_DECL_JSON_OBJECT_OBJECT_ADD_EX
+	return json_object_object_add_ex(jobj, key_name, jobj_val, 0) ? -ENOMEM : 0;
+#else
+	json_object_object_add(jobj, key_name, jobj_val);
+	return 0;
+#endif
+}
+
+/* jobj_dst must contain pointer initialized to NULL (see json-c json_object_deep_copy API) */
+int json_object_copy(json_object *jobj_src, json_object **jobj_dst)
+{
+	if (!jobj_src || !jobj_dst || *jobj_dst)
+		return -1;
+
+#if HAVE_DECL_JSON_OBJECT_DEEP_COPY
+	return json_object_deep_copy(jobj_src, jobj_dst, NULL);
+#else
+	*jobj_dst = json_tokener_parse(json_object_get_string(jobj_src));
+	return *jobj_dst ? 0 : -1;
+#endif
+}