Adding upstream version 2:2.1.0.upstream/2%2.1.0upstream

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

12 files changed, 7276 insertions, 0 deletions

diff --git a/lib/luks2/luks2.h b/lib/luks2/luks2.h
new file mode 100644
index 0000000..261d622
--- /dev/null
+++ b/lib/luks2/luks2.h
@@ -0,0 +1,388 @@
+/*
+ * LUKS - Linux Unified Key Setup v2
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 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.
+ */
+
+#ifndef _CRYPTSETUP_LUKS2_ONDISK_H
+#define _CRYPTSETUP_LUKS2_ONDISK_H
+
+#include "libcryptsetup.h"
+
+#define LUKS2_MAGIC_1ST "LUKS\xba\xbe"
+#define LUKS2_MAGIC_2ND "SKUL\xba\xbe"
+#define LUKS2_MAGIC_L 6
+#define LUKS2_UUID_L 40
+#define LUKS2_LABEL_L 48
+#define LUKS2_SALT_L 64
+#define LUKS2_CHECKSUM_ALG_L 32
+#define LUKS2_CHECKSUM_L 64
+
+#define LUKS2_KEYSLOTS_MAX       32
+#define LUKS2_TOKENS_MAX         32
+#define LUKS2_SEGMENT_MAX        32
+
+#define LUKS2_BUILTIN_TOKEN_PREFIX "luks2-"
+#define LUKS2_BUILTIN_TOKEN_PREFIX_LEN 6
+
+#define LUKS2_TOKEN_KEYRING LUKS2_BUILTIN_TOKEN_PREFIX "keyring"
+
+#define LUKS2_DIGEST_MAX 8
+
+#define CRYPT_ANY_SEGMENT -1
+#define CRYPT_DEFAULT_SEGMENT 0
+#define CRYPT_DEFAULT_SEGMENT_STR "0"
+
+#define CRYPT_ANY_DIGEST -1
+
+/*
+ * LUKS2 header on-disk.
+ *
+ * Binary header is followed by JSON area.
+ * JSON area is followed by keyslot area and data area,
+ * these are described in JSON metadata.
+ *
+ * Note: uuid, csum_alg are intentionally on the same offset as LUKS1
+ * (checksum alg replaces hash in LUKS1)
+ *
+ * String (char) should be zero terminated.
+ * Padding should be wiped.
+ * Checksum is calculated with csum zeroed (+ full JSON area).
+ */
+struct luks2_hdr_disk {
+	char		magic[LUKS2_MAGIC_L];
+	uint16_t	version;	/* Version 2 */
+	uint64_t	hdr_size;	/* in bytes, including JSON area */
+	uint64_t	seqid;		/* increased on every update */
+	char		label[LUKS2_LABEL_L];
+	char		checksum_alg[LUKS2_CHECKSUM_ALG_L];
+	uint8_t		salt[LUKS2_SALT_L]; /* unique for every header/offset */
+	char		uuid[LUKS2_UUID_L];
+	char		subsystem[LUKS2_LABEL_L]; /* owner subsystem label */
+	uint64_t	hdr_offset;	/* offset from device start in bytes */
+	char		_padding[184];
+	uint8_t		csum[LUKS2_CHECKSUM_L];
+	char		_padding4096[7*512];
+	/* JSON area starts here */
+} __attribute__ ((packed));
+
+/*
+ * LUKS2 header in-memory.
+ */
+typedef struct json_object json_object;
+struct luks2_hdr {
+	size_t		hdr_size;
+	uint64_t	seqid;
+	unsigned int	version;
+	char		label[LUKS2_LABEL_L];
+	char		subsystem[LUKS2_LABEL_L];
+	char		checksum_alg[LUKS2_CHECKSUM_ALG_L];
+	uint8_t		salt1[LUKS2_SALT_L];
+	uint8_t		salt2[LUKS2_SALT_L];
+	char		uuid[LUKS2_UUID_L];
+	json_object	*jobj;
+};
+
+struct luks2_keyslot_params {
+	enum { LUKS2_KEYSLOT_AF_LUKS1 = 0 } af_type;
+	enum { LUKS2_KEYSLOT_AREA_RAW = 0 } area_type;
+
+	union {
+	struct {
+		char hash[LUKS2_CHECKSUM_ALG_L]; // or include luks.h
+		unsigned int stripes;
+	} luks1;
+	} af;
+
+	union {
+	struct {
+		char encryption[65]; // or include utils_crypt.h
+		size_t key_size;
+	} raw;
+	} area;
+};
+
+/*
+ * Supportable header sizes (hdr_disk + JSON area)
+ * Also used as offset for the 2nd header.
+ */
+#define LUKS2_HDR_16K_LEN 0x4000
+
+#define LUKS2_HDR_BIN_LEN sizeof(struct luks2_hdr_disk)
+
+//#define LUKS2_DEFAULT_HDR_SIZE 0x400000  /* 4 MiB */
+#define LUKS2_DEFAULT_HDR_SIZE 0x1000000 /* 16 MiB */
+
+#define LUKS2_MAX_KEYSLOTS_SIZE 0x8000000 /* 128 MiB */
+
+#define LUKS2_HDR_OFFSET_MAX 0x400000 /* 4 MiB */
+
+/* Offsets for secondary header (for scan if primary header is corrupted). */
+#define LUKS2_HDR2_OFFSETS { 0x04000, 0x008000, 0x010000, 0x020000, \
+                             0x40000, 0x080000, 0x100000, 0x200000, LUKS2_HDR_OFFSET_MAX }
+
+int LUKS2_hdr_version_unlocked(struct crypt_device *cd,
+	const char *backup_file);
+
+int LUKS2_hdr_read(struct crypt_device *cd, struct luks2_hdr *hdr, int repair);
+int LUKS2_hdr_write(struct crypt_device *cd, struct luks2_hdr *hdr);
+int LUKS2_hdr_dump(struct crypt_device *cd, struct luks2_hdr *hdr);
+
+int LUKS2_hdr_uuid(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	const char *uuid);
+
+int LUKS2_hdr_labels(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	const char *label,
+	const char *subsystem,
+	int commit);
+
+void LUKS2_hdr_free(struct crypt_device *cd, struct luks2_hdr *hdr);
+
+int LUKS2_hdr_backup(struct crypt_device *cd,
+		     struct luks2_hdr *hdr,
+		     const char *backup_file);
+int LUKS2_hdr_restore(struct crypt_device *cd,
+		      struct luks2_hdr *hdr,
+		      const char *backup_file);
+
+uint64_t LUKS2_hdr_and_areas_size(json_object *jobj);
+uint64_t LUKS2_keyslots_size(json_object *jobj);
+uint64_t LUKS2_metadata_size(json_object *jobj);
+
+int LUKS2_keyslot_cipher_incompatible(struct crypt_device *cd, const char *cipher_spec);
+
+/*
+ * Generic LUKS2 keyslot
+ */
+int LUKS2_keyslot_open(struct crypt_device *cd,
+	int keyslot,
+	int segment,
+	const char *password,
+	size_t password_len,
+	struct volume_key **vk);
+
+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);
+
+int LUKS2_keyslot_wipe(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int keyslot,
+	int wipe_area_only);
+
+int LUKS2_keyslot_dump(struct crypt_device *cd,
+	int keyslot);
+
+crypt_keyslot_priority LUKS2_keyslot_priority_get(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int keyslot);
+
+int LUKS2_keyslot_priority_set(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int keyslot,
+	crypt_keyslot_priority priority,
+	int commit);
+
+/*
+ * Generic LUKS2 token
+ */
+int LUKS2_token_json_get(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char **json);
+
+int LUKS2_token_assign(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int keyslot,
+	int token,
+	int assign,
+	int commit);
+
+int LUKS2_token_is_assigned(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int keyslot,
+	int token);
+
+int LUKS2_token_create(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char *json,
+	int commit);
+
+crypt_token_info LUKS2_token_status(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char **type);
+
+int LUKS2_builtin_token_get(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char *type,
+	void *params);
+
+int LUKS2_builtin_token_create(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char *type,
+	const void *params,
+	int commit);
+
+int LUKS2_token_open_and_activate(struct crypt_device *cd,
+		struct luks2_hdr *hdr,
+		int token,
+		const char *name,
+		uint32_t flags,
+		void *usrptr);
+
+int LUKS2_token_open_and_activate_any(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	const char *name,
+	uint32_t flags);
+
+int LUKS2_tokens_count(struct luks2_hdr *hdr);
+
+/*
+ * Generic LUKS2 digest
+ */
+int LUKS2_digest_by_segment(struct luks2_hdr *hdr, int segment);
+
+int LUKS2_digest_verify_by_segment(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int segment,
+	const struct volume_key *vk);
+
+void LUKS2_digests_erase_unused(struct crypt_device *cd,
+	struct luks2_hdr *hdr);
+
+int LUKS2_digest_verify(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	struct volume_key *vk,
+	int keyslot);
+
+int LUKS2_digest_dump(struct crypt_device *cd,
+	int digest);
+
+int LUKS2_digest_assign(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int keyslot,
+	int digest,
+	int assign,
+	int commit);
+
+int LUKS2_digest_segment_assign(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int segment,
+	int digest,
+	int assign,
+	int commit);
+
+int LUKS2_digest_by_keyslot(struct luks2_hdr *hdr, int keyslot);
+
+int LUKS2_digest_create(struct crypt_device *cd,
+	const char *type,
+	struct luks2_hdr *hdr,
+	const struct volume_key *vk);
+
+/*
+ * LUKS2 generic
+ */
+int LUKS2_activate(struct crypt_device *cd,
+	const char *name,
+	struct volume_key *vk,
+	uint32_t flags);
+
+int LUKS2_keyslot_luks2_format(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int keyslot,
+	const char *cipher,
+	size_t keylength);
+
+int LUKS2_generate_hdr(
+	struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	const struct volume_key *vk,
+	const char *cipherName,
+	const char *cipherMode,
+	const char *integrity,
+	const char *uuid,
+	unsigned int sector_size,
+	uint64_t data_offset,
+	uint64_t align_offset,
+	uint64_t required_alignment,
+	uint64_t metadata_size,
+	uint64_t keyslots_size);
+
+int LUKS2_check_metadata_area_size(uint64_t metadata_size);
+int LUKS2_check_keyslots_area_size(uint64_t keyslots_size);
+
+int LUKS2_wipe_header_areas(struct crypt_device *cd,
+	struct luks2_hdr *hdr);
+
+uint64_t LUKS2_get_data_offset(struct luks2_hdr *hdr);
+int LUKS2_get_sector_size(struct luks2_hdr *hdr);
+const char *LUKS2_get_cipher(struct luks2_hdr *hdr, int segment);
+const char *LUKS2_get_integrity(struct luks2_hdr *hdr, int segment);
+int LUKS2_keyslot_params_default(struct crypt_device *cd, struct luks2_hdr *hdr,
+	 struct luks2_keyslot_params *params);
+int LUKS2_get_volume_key_size(struct luks2_hdr *hdr, int segment);
+int LUKS2_get_keyslot_stored_key_size(struct luks2_hdr *hdr, int keyslot);
+const char *LUKS2_get_keyslot_cipher(struct luks2_hdr *hdr, int keyslot, size_t *key_size);
+int LUKS2_keyslot_find_empty(struct luks2_hdr *hdr, const char *type);
+int LUKS2_keyslot_active_count(struct luks2_hdr *hdr, int segment);
+int LUKS2_keyslot_for_segment(struct luks2_hdr *hdr, int keyslot, int segment);
+crypt_keyslot_info LUKS2_keyslot_info(struct luks2_hdr *hdr, int keyslot);
+int LUKS2_keyslot_area(struct luks2_hdr *hdr,
+	int keyslot,
+	uint64_t *offset,
+	uint64_t *length);
+int LUKS2_keyslot_pbkdf(struct luks2_hdr *hdr, int keyslot, struct crypt_pbkdf_type *pbkdf);
+
+/*
+ * Permanent activation flags stored in header
+ */
+int LUKS2_config_get_flags(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t *flags);
+int LUKS2_config_set_flags(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t flags);
+
+/*
+ * Requirements for device activation or header modification
+ */
+int LUKS2_config_get_requirements(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t *reqs);
+int LUKS2_config_set_requirements(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t reqs);
+
+int LUKS2_unmet_requirements(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t reqs_mask, int quiet);
+
+int LUKS2_key_description_by_segment(struct crypt_device *cd,
+		struct luks2_hdr *hdr, struct volume_key *vk, int segment);
+int LUKS2_volume_key_load_in_keyring_by_keyslot(struct crypt_device *cd,
+		struct luks2_hdr *hdr, struct volume_key *vk, int keyslot);
+
+struct luks_phdr;
+int LUKS2_luks1_to_luks2(struct crypt_device *cd,
+			 struct luks_phdr *hdr1,
+			 struct luks2_hdr *hdr2);
+int LUKS2_luks2_to_luks1(struct crypt_device *cd,
+			 struct luks2_hdr *hdr2,
+			 struct luks_phdr *hdr1);
+
+#endif
diff --git a/lib/luks2/luks2_digest.c b/lib/luks2/luks2_digest.c
new file mode 100644
index 0000000..246903c
--- /dev/null
+++ b/lib/luks2/luks2_digest.c
@@ -0,0 +1,393 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, digest handling
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 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"
+
+extern const digest_handler PBKDF2_digest;
+
+static const digest_handler *digest_handlers[LUKS2_DIGEST_MAX] = {
+	&PBKDF2_digest,
+	NULL
+};
+
+const digest_handler *LUKS2_digest_handler_type(struct crypt_device *cd, const char *type)
+{
+	int i;
+
+	for (i = 0; i < LUKS2_DIGEST_MAX && digest_handlers[i]; i++) {
+		if (!strcmp(digest_handlers[i]->name, type))
+			return digest_handlers[i];
+	}
+
+	return NULL;
+}
+
+static const digest_handler *LUKS2_digest_handler(struct crypt_device *cd, int digest)
+{
+	struct luks2_hdr *hdr;
+	json_object *jobj1, *jobj2;
+
+	if (digest < 0)
+		return NULL;
+
+	if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
+		return NULL;
+
+	if (!(jobj1 = LUKS2_get_digest_jobj(hdr, digest)))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj1, "type", &jobj2))
+		return NULL;
+
+	return LUKS2_digest_handler_type(cd, json_object_get_string(jobj2));
+}
+
+static int LUKS2_digest_find_free(struct crypt_device *cd, struct luks2_hdr *hdr)
+{
+	int digest = 0;
+
+	while (LUKS2_get_digest_jobj(hdr, digest) && digest < LUKS2_DIGEST_MAX)
+		digest++;
+
+	return digest < LUKS2_DIGEST_MAX ? digest : -1;
+}
+
+int LUKS2_digest_create(struct crypt_device *cd,
+	const char *type,
+	struct luks2_hdr *hdr,
+	const struct volume_key *vk)
+{
+	int digest;
+	const digest_handler *dh;
+
+	dh = LUKS2_digest_handler_type(cd, type);
+	if (!dh)
+		return -EINVAL;
+
+	digest = LUKS2_digest_find_free(cd, hdr);
+	if (digest < 0)
+		return -EINVAL;
+
+	log_dbg(cd, "Creating new digest %d (%s).", digest, type);
+
+	return dh->store(cd, digest, vk->key, vk->keylength) ?: digest;
+}
+
+int LUKS2_digest_by_keyslot(struct luks2_hdr *hdr, int keyslot)
+{
+	char keyslot_name[16];
+	json_object *jobj_digests, *jobj_digest_keyslots;
+
+	if (snprintf(keyslot_name, sizeof(keyslot_name), "%u", keyslot) < 1)
+		return -ENOMEM;
+
+	json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
+
+	json_object_object_foreach(jobj_digests, key, val) {
+		json_object_object_get_ex(val, "keyslots", &jobj_digest_keyslots);
+		if (LUKS2_array_jobj(jobj_digest_keyslots, keyslot_name))
+			return atoi(key);
+	}
+
+	return -ENOENT;
+}
+
+int LUKS2_digest_verify(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	struct volume_key *vk,
+	int keyslot)
+{
+	const digest_handler *h;
+	int digest, r;
+
+	digest = LUKS2_digest_by_keyslot(hdr, keyslot);
+	if (digest < 0)
+		return digest;
+
+	log_dbg(cd, "Verifying key from keyslot %d, digest %d.", keyslot, digest);
+	h = LUKS2_digest_handler(cd, digest);
+	if (!h)
+		return -EINVAL;
+
+	r = h->verify(cd, digest, vk->key, vk->keylength);
+	if (r < 0) {
+		log_dbg(cd, "Digest %d (%s) verify failed with %d.", digest, h->name, r);
+		return r;
+	}
+
+	return digest;
+}
+
+int LUKS2_digest_dump(struct crypt_device *cd, int digest)
+{
+	const digest_handler *h;
+
+	if (!(h = LUKS2_digest_handler(cd, digest)))
+		return -EINVAL;
+
+	return h->dump(cd, digest);
+}
+
+int LUKS2_digest_verify_by_segment(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int segment,
+	const struct volume_key *vk)
+{
+	const digest_handler *h;
+	int digest, r;
+
+	digest = LUKS2_digest_by_segment(hdr, segment);
+	if (digest < 0)
+		return digest;
+
+	log_dbg(cd, "Verifying key digest %d.", digest);
+
+	h = LUKS2_digest_handler(cd, digest);
+	if (!h)
+		return -EINVAL;
+
+	r = h->verify(cd, digest, vk->key, vk->keylength);
+	if (r < 0) {
+		log_dbg(cd, "Digest %d (%s) verify failed with %d.", digest, h->name, r);
+		return r;
+	}
+
+	return digest;
+}
+
+/* FIXME: segment can have more digests */
+int LUKS2_digest_by_segment(struct luks2_hdr *hdr, int segment)
+{
+	char segment_name[16];
+	json_object *jobj_digests, *jobj_digest_segments;
+
+	json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
+
+	if (snprintf(segment_name, sizeof(segment_name), "%u", segment) < 1)
+		return -EINVAL;
+
+	json_object_object_foreach(jobj_digests, key, val) {
+		json_object_object_get_ex(val, "segments", &jobj_digest_segments);
+		if (!LUKS2_array_jobj(jobj_digest_segments, segment_name))
+			continue;
+
+		return atoi(key);
+	}
+
+	return -ENOENT;
+}
+
+static int assign_one_digest(struct crypt_device *cd, struct luks2_hdr *hdr,
+			     int keyslot, int digest, int assign)
+{
+	json_object *jobj1, *jobj_digest, *jobj_digest_keyslots;
+	char num[16];
+
+	log_dbg(cd, "Keyslot %i %s digest %i.", keyslot, assign ? "assigned to" : "unassigned from", digest);
+
+	jobj_digest = LUKS2_get_digest_jobj(hdr, digest);
+	if (!jobj_digest)
+		return -EINVAL;
+
+	json_object_object_get_ex(jobj_digest, "keyslots", &jobj_digest_keyslots);
+	if (!jobj_digest_keyslots)
+		return -EINVAL;
+
+	snprintf(num, sizeof(num), "%d", keyslot);
+	if (assign) {
+		jobj1 = LUKS2_array_jobj(jobj_digest_keyslots, num);
+		if (!jobj1)
+			json_object_array_add(jobj_digest_keyslots, json_object_new_string(num));
+	} else {
+		jobj1 = LUKS2_array_remove(jobj_digest_keyslots, num);
+		if (jobj1)
+			json_object_object_add(jobj_digest, "keyslots", jobj1);
+	}
+
+	return 0;
+}
+
+int LUKS2_digest_assign(struct crypt_device *cd, struct luks2_hdr *hdr,
+			int keyslot, int digest, int assign, int commit)
+{
+	json_object *jobj_digests;
+	int r = 0;
+
+	if (digest == CRYPT_ANY_DIGEST) {
+		json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
+
+		json_object_object_foreach(jobj_digests, key, val) {
+			UNUSED(val);
+			r = assign_one_digest(cd, hdr, keyslot, atoi(key), assign);
+			if (r < 0)
+				break;
+		}
+	} else
+		r = assign_one_digest(cd, hdr, keyslot, digest, assign);
+
+	if (r < 0)
+		return r;
+
+	// FIXME: do not write header in nothing changed
+	return commit ? LUKS2_hdr_write(cd, hdr) : 0;
+}
+
+static int assign_one_segment(struct crypt_device *cd, struct luks2_hdr *hdr,
+			     int segment, int digest, int assign)
+{
+	json_object *jobj1, *jobj_digest, *jobj_digest_segments;
+	char num[16];
+
+	log_dbg(cd, "Segment %i %s digest %i.", segment, assign ? "assigned to" : "unassigned from", digest);
+
+	jobj_digest = LUKS2_get_digest_jobj(hdr, digest);
+	if (!jobj_digest)
+		return -EINVAL;
+
+	json_object_object_get_ex(jobj_digest, "segments", &jobj_digest_segments);
+	if (!jobj_digest_segments)
+		return -EINVAL;
+
+	snprintf(num, sizeof(num), "%d", segment);
+	if (assign) {
+		jobj1 = LUKS2_array_jobj(jobj_digest_segments, num);
+		if (!jobj1)
+			json_object_array_add(jobj_digest_segments, json_object_new_string(num));
+	} else {
+		jobj1 = LUKS2_array_remove(jobj_digest_segments, num);
+		if (jobj1)
+			json_object_object_add(jobj_digest, "segments", jobj1);
+	}
+
+	return 0;
+}
+
+int LUKS2_digest_segment_assign(struct crypt_device *cd, struct luks2_hdr *hdr,
+			int segment, int digest, int assign, int commit)
+{
+	json_object *jobj_digests;
+	int r = 0;
+
+	if (digest == CRYPT_ANY_DIGEST) {
+		json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
+
+		json_object_object_foreach(jobj_digests, key, val) {
+			UNUSED(val);
+			r = assign_one_segment(cd, hdr, segment, atoi(key), assign);
+			if (r < 0)
+				break;
+		}
+	} else
+		r = assign_one_segment(cd, hdr, segment, digest, assign);
+
+	if (r < 0)
+		return r;
+
+	// FIXME: do not write header in nothing changed
+	return commit ? LUKS2_hdr_write(cd, hdr) : 0;
+}
+
+static int digest_unused(json_object *jobj_digest)
+{
+	json_object *jobj;
+
+	json_object_object_get_ex(jobj_digest, "segments", &jobj);
+	if (!jobj || !json_object_is_type(jobj, json_type_array) || json_object_array_length(jobj) > 0)
+		return 0;
+
+	json_object_object_get_ex(jobj_digest, "keyslots", &jobj);
+	if (!jobj || !json_object_is_type(jobj, json_type_array))
+		return 0;
+
+	return json_object_array_length(jobj) > 0 ? 0 : 1;
+}
+
+void LUKS2_digests_erase_unused(struct crypt_device *cd,
+	struct luks2_hdr *hdr)
+{
+	json_object *jobj_digests;
+
+	json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
+	if (!jobj_digests || !json_object_is_type(jobj_digests, json_type_object))
+		return;
+
+	json_object_object_foreach(jobj_digests, key, val) {
+		if (digest_unused(val)) {
+			log_dbg(cd, "Erasing unused digest %d.", atoi(key));
+			json_object_object_del(jobj_digests, key);
+		}
+	}
+}
+
+/* Key description helpers */
+static char *get_key_description_by_digest(struct crypt_device *cd, int digest)
+{
+	char *desc, digest_str[3];
+	int r;
+	size_t len;
+
+	if (!crypt_get_uuid(cd))
+		return NULL;
+
+	r = snprintf(digest_str, sizeof(digest_str), "d%u", digest);
+	if (r < 0 || (size_t)r >= sizeof(digest_str))
+		return NULL;
+
+	/* "cryptsetup:<uuid>-<digest_str>" + \0 */
+	len = strlen(crypt_get_uuid(cd)) + strlen(digest_str) + 13;
+
+	desc = malloc(len);
+	if (!desc)
+	       return NULL;
+
+	r = snprintf(desc, len, "%s:%s-%s", "cryptsetup", crypt_get_uuid(cd), digest_str);
+	if (r < 0 || (size_t)r >= len) {
+	       free(desc);
+	       return NULL;
+	}
+
+	return desc;
+}
+
+int LUKS2_key_description_by_segment(struct crypt_device *cd,
+		struct luks2_hdr *hdr, struct volume_key *vk, int segment)
+{
+	char *desc = get_key_description_by_digest(cd, LUKS2_digest_by_segment(hdr, segment));
+	int r;
+
+	r = crypt_volume_key_set_description(vk, desc);
+	free(desc);
+	return r;
+}
+
+int LUKS2_volume_key_load_in_keyring_by_keyslot(struct crypt_device *cd,
+		struct luks2_hdr *hdr, struct volume_key *vk, int keyslot)
+{
+	char *desc = get_key_description_by_digest(cd, LUKS2_digest_by_keyslot(hdr, keyslot));
+	int r;
+
+	r = crypt_volume_key_set_description(vk, desc);
+	if (!r)
+		r = crypt_volume_key_load_in_keyring(cd, vk);
+
+	free(desc);
+	return r;
+}
diff --git a/lib/luks2/luks2_digest_pbkdf2.c b/lib/luks2/luks2_digest_pbkdf2.c
new file mode 100644
index 0000000..e4413ab
--- /dev/null
+++ b/lib/luks2/luks2_digest_pbkdf2.c
@@ -0,0 +1,211 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, PBKDF2 digest handler (LUKS1 compatible)
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 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"
+
+#define LUKS_DIGESTSIZE 20 // since SHA1
+#define LUKS_SALTSIZE 32
+#define LUKS_MKD_ITERATIONS_MS 125
+
+static int PBKDF2_digest_verify(struct crypt_device *cd,
+	int digest,
+	const char *volume_key,
+	size_t volume_key_len)
+{
+	char checkHashBuf[64];
+	json_object *jobj_digest, *jobj1;
+	const char *hashSpec;
+	char *mkDigest = NULL, mkDigestSalt[LUKS_SALTSIZE];
+	unsigned int mkDigestIterations;
+	size_t len;
+	int r;
+
+	/* This can be done only for internally linked digests */
+	jobj_digest = LUKS2_get_digest_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), digest);
+	if (!jobj_digest)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_digest, "hash", &jobj1))
+		return -EINVAL;
+	hashSpec = json_object_get_string(jobj1);
+
+	if (!json_object_object_get_ex(jobj_digest, "iterations", &jobj1))
+		return -EINVAL;
+	mkDigestIterations = json_object_get_int64(jobj1);
+
+	if (!json_object_object_get_ex(jobj_digest, "salt", &jobj1))
+		return -EINVAL;
+	len = sizeof(mkDigestSalt);
+	if (!base64_decode(json_object_get_string(jobj1),
+			   json_object_get_string_len(jobj1), mkDigestSalt, &len))
+		return -EINVAL;
+	if (len != LUKS_SALTSIZE)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_digest, "digest", &jobj1))
+		return -EINVAL;
+	len = 0;
+	if (!base64_decode_alloc(json_object_get_string(jobj1),
+			   json_object_get_string_len(jobj1), &mkDigest, &len))
+		return -EINVAL;
+	if (len < LUKS_DIGESTSIZE ||
+	    len > sizeof(checkHashBuf) ||
+	    (len != LUKS_DIGESTSIZE && len != (size_t)crypt_hash_size(hashSpec))) {
+		free(mkDigest);
+		return -EINVAL;
+	}
+
+	r = -EPERM;
+	if (crypt_pbkdf(CRYPT_KDF_PBKDF2, hashSpec, volume_key, volume_key_len,
+			mkDigestSalt, LUKS_SALTSIZE,
+			checkHashBuf, len,
+			mkDigestIterations, 0, 0) < 0) {
+		r = -EINVAL;
+	} else {
+		if (memcmp(checkHashBuf, mkDigest, len) == 0)
+			r = 0;
+	}
+
+	free(mkDigest);
+	return r;
+}
+
+static int PBKDF2_digest_store(struct crypt_device *cd,
+	int digest,
+	const char *volume_key,
+	size_t volume_key_len)
+{
+	json_object *jobj_digest, *jobj_digests;
+	char salt[LUKS_SALTSIZE], digest_raw[128];
+	int hmac_size, r;
+	char *base64_str;
+	struct luks2_hdr *hdr;
+	struct crypt_pbkdf_limits pbkdf_limits;
+	const struct crypt_pbkdf_type *pbkdf_cd;
+	struct crypt_pbkdf_type pbkdf = {
+		.type = CRYPT_KDF_PBKDF2,
+		.time_ms = LUKS_MKD_ITERATIONS_MS,
+	};
+
+	/* Inherit hash from PBKDF setting */
+	pbkdf_cd = crypt_get_pbkdf_type(cd);
+	if (pbkdf_cd)
+		pbkdf.hash = pbkdf_cd->hash;
+	if (!pbkdf.hash)
+		pbkdf.hash = DEFAULT_LUKS1_HASH;
+
+	log_dbg(cd, "Setting PBKDF2 type key digest %d.", digest);
+
+	r = crypt_random_get(cd, salt, LUKS_SALTSIZE, CRYPT_RND_SALT);
+	if (r < 0)
+		return r;
+
+	r = crypt_pbkdf_get_limits(CRYPT_KDF_PBKDF2, &pbkdf_limits);
+	if (r < 0)
+		return r;
+
+	if (crypt_get_pbkdf(cd)->flags & CRYPT_PBKDF_NO_BENCHMARK)
+		pbkdf.iterations = pbkdf_limits.min_iterations;
+	else {
+		r = crypt_benchmark_pbkdf_internal(cd, &pbkdf, volume_key_len);
+		if (r < 0)
+			return r;
+	}
+
+	hmac_size = crypt_hmac_size(pbkdf.hash);
+	if (hmac_size < 0)
+		return hmac_size;
+
+	r = crypt_pbkdf(CRYPT_KDF_PBKDF2, pbkdf.hash, volume_key, volume_key_len,
+			salt, LUKS_SALTSIZE, digest_raw, hmac_size,
+			pbkdf.iterations, 0, 0);
+	if (r < 0)
+		return r;
+
+	jobj_digest = LUKS2_get_digest_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), digest);
+	jobj_digests = NULL;
+	if (!jobj_digest) {
+		hdr = crypt_get_hdr(cd, CRYPT_LUKS2);
+		jobj_digest = json_object_new_object();
+		json_object_object_get_ex(hdr->jobj, "digests", &jobj_digests);
+	}
+
+	json_object_object_add(jobj_digest, "type", json_object_new_string("pbkdf2"));
+	json_object_object_add(jobj_digest, "keyslots", json_object_new_array());
+	json_object_object_add(jobj_digest, "segments", json_object_new_array());
+	json_object_object_add(jobj_digest, "hash", json_object_new_string(pbkdf.hash));
+	json_object_object_add(jobj_digest, "iterations", json_object_new_int(pbkdf.iterations));
+
+	base64_encode_alloc(salt, LUKS_SALTSIZE, &base64_str);
+	if (!base64_str) {
+		json_object_put(jobj_digest);
+		return -ENOMEM;
+	}
+	json_object_object_add(jobj_digest, "salt", json_object_new_string(base64_str));
+	free(base64_str);
+
+	base64_encode_alloc(digest_raw, hmac_size, &base64_str);
+	if (!base64_str) {
+		json_object_put(jobj_digest);
+		return -ENOMEM;
+	}
+	json_object_object_add(jobj_digest, "digest", json_object_new_string(base64_str));
+	free(base64_str);
+
+	if (jobj_digests)
+		json_object_object_add_by_uint(jobj_digests, digest, jobj_digest);
+
+	JSON_DBG(cd, jobj_digest, "Digest JSON:");
+	return 0;
+}
+
+static int PBKDF2_digest_dump(struct crypt_device *cd, int digest)
+{
+	json_object *jobj_digest, *jobj1;
+
+	/* This can be done only for internally linked digests */
+	jobj_digest = LUKS2_get_digest_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), digest);
+	if (!jobj_digest)
+		return -EINVAL;
+
+	json_object_object_get_ex(jobj_digest, "hash", &jobj1);
+	log_std(cd, "\tHash:       %s\n", json_object_get_string(jobj1));
+
+	json_object_object_get_ex(jobj_digest, "iterations", &jobj1);
+	log_std(cd, "\tIterations: %" PRIu64 "\n", json_object_get_int64(jobj1));
+
+	json_object_object_get_ex(jobj_digest, "salt", &jobj1);
+	log_std(cd, "\tSalt:       ");
+	hexprint_base64(cd, jobj1, " ", "            ");
+
+	json_object_object_get_ex(jobj_digest, "digest", &jobj1);
+	log_std(cd, "\tDigest:     ");
+	hexprint_base64(cd, jobj1, " ", "            ");
+
+	return 0;
+}
+
+const digest_handler PBKDF2_digest = {
+	.name   = "pbkdf2",
+	.verify = PBKDF2_digest_verify,
+	.store  = PBKDF2_digest_store,
+	.dump   = PBKDF2_digest_dump,
+};
diff --git a/lib/luks2/luks2_disk_metadata.c b/lib/luks2/luks2_disk_metadata.c
new file mode 100644
index 0000000..c6a121a
--- /dev/null
+++ b/lib/luks2/luks2_disk_metadata.c
@@ -0,0 +1,769 @@
+/*
+ * LUKS - Linux Unified Key Setup v2
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 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 <assert.h>
+
+#include "luks2_internal.h"
+
+/*
+ * Helper functions
+ */
+json_object *parse_json_len(struct crypt_device *cd, const char *json_area,
+			    uint64_t max_length, int *json_len)
+{
+	json_object *jobj;
+	struct json_tokener *jtok;
+
+	 /* INT32_MAX is internal (json-c) json_tokener_parse_ex() limit */
+	if (!json_area || max_length > INT32_MAX)
+		return NULL;
+
+	jtok = json_tokener_new();
+	if (!jtok) {
+		log_dbg(cd, "ERROR: Failed to init json tokener");
+		return NULL;
+	}
+
+	jobj = json_tokener_parse_ex(jtok, json_area, max_length);
+	if (!jobj)
+		log_dbg(cd, "ERROR: Failed to parse json data (%d): %s",
+			json_tokener_get_error(jtok),
+			json_tokener_error_desc(json_tokener_get_error(jtok)));
+	else
+		*json_len = jtok->char_offset;
+
+	json_tokener_free(jtok);
+
+	return jobj;
+}
+
+static void log_dbg_checksum(struct crypt_device *cd,
+			     const uint8_t *csum, const char *csum_alg, const char *info)
+{
+	char csum_txt[2*LUKS2_CHECKSUM_L+1];
+	int i;
+
+	for (i = 0; i < crypt_hash_size(csum_alg); i++)
+		snprintf(&csum_txt[i*2], 3, "%02hhx", (const char)csum[i]);
+	csum_txt[i*2+1] = '\0'; /* Just to be safe, sprintf should write \0 there. */
+
+	log_dbg(cd, "Checksum:%s (%s)", &csum_txt[0], info);
+}
+
+/*
+ * Calculate hash (checksum) of |LUKS2_bin|LUKS2_JSON_area| from in-memory structs.
+ * LUKS2 on-disk header contains uniques salt both for primary and secondary header.
+ * Checksum is always calculated with zeroed checksum field in binary header.
+ */
+static int hdr_checksum_calculate(const char *alg, struct luks2_hdr_disk *hdr_disk,
+				  const char *json_area, size_t json_len)
+{
+	struct crypt_hash *hd = NULL;
+	int hash_size, r;
+
+	hash_size = crypt_hash_size(alg);
+	if (hash_size <= 0 || crypt_hash_init(&hd, alg))
+		return -EINVAL;
+
+	/* Binary header, csum zeroed. */
+	r = crypt_hash_write(hd, (char*)hdr_disk, LUKS2_HDR_BIN_LEN);
+
+	/* JSON area (including unused space) */
+	if (!r)
+		r = crypt_hash_write(hd, json_area, json_len);
+
+	if (!r)
+		r = crypt_hash_final(hd, (char*)hdr_disk->csum, (size_t)hash_size);
+
+	crypt_hash_destroy(hd);
+	return r;
+}
+
+/*
+ * Compare hash (checksum) of on-disk and in-memory header.
+ */
+static int hdr_checksum_check(struct crypt_device *cd,
+			      const char *alg, struct luks2_hdr_disk *hdr_disk,
+			      const char *json_area, size_t json_len)
+{
+	struct luks2_hdr_disk hdr_tmp;
+	int hash_size, r;
+
+	hash_size = crypt_hash_size(alg);
+	if (hash_size <= 0)
+		return -EINVAL;
+
+	/* Copy header and zero checksum. */
+	memcpy(&hdr_tmp, hdr_disk, LUKS2_HDR_BIN_LEN);
+	memset(&hdr_tmp.csum, 0, sizeof(hdr_tmp.csum));
+
+	r = hdr_checksum_calculate(alg, &hdr_tmp, json_area, json_len);
+	if (r < 0)
+		return r;
+
+	log_dbg_checksum(cd, hdr_disk->csum, alg, "on-disk");
+	log_dbg_checksum(cd, hdr_tmp.csum, alg, "in-memory");
+
+	if (memcmp(hdr_tmp.csum, hdr_disk->csum, (size_t)hash_size))
+		return -EINVAL;
+
+	return 0;
+}
+
+/*
+ * Convert header from on-disk format to in-memory struct
+ */
+static void hdr_from_disk(struct luks2_hdr_disk *hdr_disk1,
+			  struct luks2_hdr_disk *hdr_disk2,
+			  struct luks2_hdr *hdr,
+			  int secondary)
+{
+	hdr->version  = be16_to_cpu(hdr_disk1->version);
+	hdr->hdr_size = be64_to_cpu(hdr_disk1->hdr_size);
+	hdr->seqid    = be64_to_cpu(hdr_disk1->seqid);
+
+	memcpy(hdr->label, hdr_disk1->label, LUKS2_LABEL_L);
+	hdr->label[LUKS2_LABEL_L - 1] = '\0';
+	memcpy(hdr->subsystem, hdr_disk1->subsystem, LUKS2_LABEL_L);
+	hdr->subsystem[LUKS2_LABEL_L - 1] = '\0';
+	memcpy(hdr->checksum_alg, hdr_disk1->checksum_alg, LUKS2_CHECKSUM_ALG_L);
+	hdr->checksum_alg[LUKS2_CHECKSUM_ALG_L - 1] = '\0';
+	memcpy(hdr->uuid, hdr_disk1->uuid, LUKS2_UUID_L);
+	hdr->uuid[LUKS2_UUID_L - 1] = '\0';
+
+	if (secondary) {
+		memcpy(hdr->salt1, hdr_disk2->salt, LUKS2_SALT_L);
+		memcpy(hdr->salt2, hdr_disk1->salt, LUKS2_SALT_L);
+	} else {
+		memcpy(hdr->salt1, hdr_disk1->salt, LUKS2_SALT_L);
+		memcpy(hdr->salt2, hdr_disk2->salt, LUKS2_SALT_L);
+	}
+}
+
+/*
+ * Convert header from in-memory struct to on-disk format
+ */
+static void hdr_to_disk(struct luks2_hdr *hdr,
+			struct luks2_hdr_disk *hdr_disk,
+			int secondary, uint64_t offset)
+{
+	assert(((char*)&(hdr_disk->_padding4096) - (char*)&(hdr_disk->magic)) == 512);
+
+	memset(hdr_disk, 0, LUKS2_HDR_BIN_LEN);
+
+	memcpy(&hdr_disk->magic, secondary ? LUKS2_MAGIC_2ND : LUKS2_MAGIC_1ST, LUKS2_MAGIC_L);
+	hdr_disk->version     = cpu_to_be16(hdr->version);
+	hdr_disk->hdr_size    = cpu_to_be64(hdr->hdr_size);
+	hdr_disk->hdr_offset  = cpu_to_be64(offset);
+	hdr_disk->seqid       = cpu_to_be64(hdr->seqid);
+
+	strncpy(hdr_disk->label, hdr->label, LUKS2_LABEL_L);
+	hdr_disk->label[LUKS2_LABEL_L - 1] = '\0';
+	strncpy(hdr_disk->subsystem, hdr->subsystem, LUKS2_LABEL_L);
+	hdr_disk->subsystem[LUKS2_LABEL_L - 1] = '\0';
+	strncpy(hdr_disk->checksum_alg, hdr->checksum_alg, LUKS2_CHECKSUM_ALG_L);
+	hdr_disk->checksum_alg[LUKS2_CHECKSUM_ALG_L - 1] = '\0';
+	strncpy(hdr_disk->uuid, hdr->uuid, LUKS2_UUID_L);
+	hdr_disk->uuid[LUKS2_UUID_L - 1] = '\0';
+
+	memcpy(hdr_disk->salt, secondary ? hdr->salt2 : hdr->salt1, LUKS2_SALT_L);
+}
+
+/*
+ * Sanity checks before checksum is validated
+ */
+static int hdr_disk_sanity_check_pre(struct crypt_device *cd,
+				     struct luks2_hdr_disk *hdr,
+				     size_t *hdr_json_size, int secondary,
+				     uint64_t offset)
+{
+	if (memcmp(hdr->magic, secondary ? LUKS2_MAGIC_2ND : LUKS2_MAGIC_1ST, LUKS2_MAGIC_L))
+		return -EINVAL;
+
+	if (be16_to_cpu(hdr->version) != 2) {
+		log_dbg(cd, "Unsupported LUKS2 header version %u.", be16_to_cpu(hdr->version));
+		return -EINVAL;
+	}
+
+	if (offset != be64_to_cpu(hdr->hdr_offset)) {
+		log_dbg(cd, "LUKS2 offset 0x%04x on device differs to expected offset 0x%04x.",
+			(unsigned)be64_to_cpu(hdr->hdr_offset), (unsigned)offset);
+		return -EINVAL;
+	}
+
+	if (secondary && (offset != be64_to_cpu(hdr->hdr_size))) {
+		log_dbg(cd, "LUKS2 offset 0x%04x in secondary header doesn't match size 0x%04x.",
+			(unsigned)offset, (unsigned)be64_to_cpu(hdr->hdr_size));
+		return -EINVAL;
+	}
+
+	/* FIXME: sanity check checksum alg. */
+
+	log_dbg(cd, "LUKS2 header version %u of size %u bytes, checksum %s.",
+		(unsigned)be16_to_cpu(hdr->version), (unsigned)be64_to_cpu(hdr->hdr_size),
+		hdr->checksum_alg);
+
+	*hdr_json_size = be64_to_cpu(hdr->hdr_size) - LUKS2_HDR_BIN_LEN;
+	return 0;
+}
+
+/*
+ * Read LUKS2 header from disk at specific offset.
+ */
+static int hdr_read_disk(struct crypt_device *cd,
+			 struct device *device, struct luks2_hdr_disk *hdr_disk,
+			 char **json_area, uint64_t offset, int secondary)
+{
+	size_t hdr_json_size = 0;
+	int devfd = -1, r;
+
+	log_dbg(cd, "Trying to read %s LUKS2 header at offset 0x%" PRIx64 ".",
+		secondary ? "secondary" : "primary", offset);
+
+	devfd = device_open_locked(cd, device, O_RDONLY);
+	if (devfd < 0)
+		return devfd == -1 ? -EIO : devfd;
+
+	/*
+	 * Read binary header and run sanity check before reading
+	 * JSON area and validating checksum.
+	 */
+	if (read_lseek_blockwise(devfd, device_block_size(cd, device),
+				 device_alignment(device), hdr_disk,
+				 LUKS2_HDR_BIN_LEN, offset) != LUKS2_HDR_BIN_LEN) {
+		close(devfd);
+		return -EIO;
+	}
+
+	r = hdr_disk_sanity_check_pre(cd, hdr_disk, &hdr_json_size, secondary, offset);
+	if (r < 0) {
+		close(devfd);
+		return r;
+	}
+
+	/*
+	 * Allocate and read JSON area. Always the whole area must be read.
+	 */
+	*json_area = malloc(hdr_json_size);
+	if (!*json_area) {
+		close(devfd);
+		return -ENOMEM;
+	}
+
+	if (read_lseek_blockwise(devfd, device_block_size(cd, device),
+				 device_alignment(device), *json_area, hdr_json_size,
+				 offset + LUKS2_HDR_BIN_LEN) != (ssize_t)hdr_json_size) {
+		close(devfd);
+		free(*json_area);
+		*json_area = NULL;
+		return -EIO;
+	}
+
+	close(devfd);
+
+	/*
+	 * Calculate and validate checksum and zero it afterwards.
+	 */
+	if (hdr_checksum_check(cd, hdr_disk->checksum_alg, hdr_disk,
+				*json_area, hdr_json_size)) {
+		log_dbg(cd, "LUKS2 header checksum error (offset %" PRIu64 ").", offset);
+		r = -EINVAL;
+	}
+	memset(hdr_disk->csum, 0, LUKS2_CHECKSUM_L);
+
+	return r;
+}
+
+/*
+ * Write LUKS2 header to disk at specific offset.
+ */
+static int hdr_write_disk(struct crypt_device *cd,
+			  struct device *device, struct luks2_hdr *hdr,
+			  const char *json_area, int secondary)
+{
+	struct luks2_hdr_disk hdr_disk;
+	uint64_t offset = secondary ? hdr->hdr_size : 0;
+	size_t hdr_json_len;
+	int devfd = -1, r;
+
+	log_dbg(cd, "Trying to write LUKS2 header (%zu bytes) at offset %" PRIu64 ".",
+		hdr->hdr_size, offset);
+
+	/* FIXME: read-only device silent fail? */
+
+	devfd = device_open_locked(cd, device, O_RDWR);
+	if (devfd < 0)
+		return devfd == -1 ? -EINVAL : devfd;
+
+	hdr_json_len = hdr->hdr_size - LUKS2_HDR_BIN_LEN;
+
+	hdr_to_disk(hdr, &hdr_disk, secondary, offset);
+
+	/*
+	 * Write header without checksum but with proper seqid.
+	 */
+	if (write_lseek_blockwise(devfd, device_block_size(cd, device),
+				  device_alignment(device), (char *)&hdr_disk,
+				  LUKS2_HDR_BIN_LEN, offset) < (ssize_t)LUKS2_HDR_BIN_LEN) {
+		close(devfd);
+		return -EIO;
+	}
+
+	/*
+	 * Write json area.
+	 */
+	if (write_lseek_blockwise(devfd, device_block_size(cd, device),
+				  device_alignment(device),
+				  CONST_CAST(char*)json_area, hdr_json_len,
+				  LUKS2_HDR_BIN_LEN + offset) < (ssize_t)hdr_json_len) {
+		close(devfd);
+		return -EIO;
+	}
+
+	/*
+	 * Calculate checksum and write header with checksum.
+	 */
+	r = hdr_checksum_calculate(hdr_disk.checksum_alg, &hdr_disk,
+				   json_area, hdr_json_len);
+	if (r < 0) {
+		close(devfd);
+		return r;
+	}
+	log_dbg_checksum(cd, hdr_disk.csum, hdr_disk.checksum_alg, "in-memory");
+
+	if (write_lseek_blockwise(devfd, device_block_size(cd, device),
+				  device_alignment(device), (char *)&hdr_disk,
+				  LUKS2_HDR_BIN_LEN, offset) < (ssize_t)LUKS2_HDR_BIN_LEN)
+		r = -EIO;
+
+	device_sync(cd, device, devfd);
+	close(devfd);
+	return r;
+}
+
+/*
+ * Convert in-memory LUKS2 header and write it to disk.
+ * This will increase sequence id, write both header copies and calculate checksum.
+ */
+int LUKS2_disk_hdr_write(struct crypt_device *cd, struct luks2_hdr *hdr, struct device *device)
+{
+	char *json_area;
+	const char *json_text;
+	size_t json_area_len;
+	int r;
+
+	if (hdr->version != 2) {
+		log_dbg(cd, "Unsupported LUKS2 header version (%u).", hdr->version);
+		return -EINVAL;
+	}
+
+	r = device_check_size(cd, crypt_metadata_device(cd), LUKS2_hdr_and_areas_size(hdr->jobj), 1);
+	if (r)
+		return r;
+
+	/*
+	 * Allocate and zero JSON area (of proper header size).
+	 */
+	json_area_len = hdr->hdr_size - LUKS2_HDR_BIN_LEN;
+	json_area = malloc(json_area_len);
+	if (!json_area)
+		return -ENOMEM;
+	memset(json_area, 0, json_area_len);
+
+	/*
+	 * Generate text space-efficient JSON representation to json area.
+	 */
+	json_text = json_object_to_json_string_ext(hdr->jobj,
+			JSON_C_TO_STRING_PLAIN | JSON_C_TO_STRING_NOSLASHESCAPE);
+	if (!json_text || !*json_text) {
+		log_dbg(cd, "Cannot parse JSON object to text representation.");
+		free(json_area);
+		return -ENOMEM;
+	}
+	if (strlen(json_text) > (json_area_len - 1)) {
+		log_dbg(cd, "JSON is too large (%zu > %zu).", strlen(json_text), json_area_len);
+		free(json_area);
+		return -EINVAL;
+	}
+	strncpy(json_area, json_text, json_area_len);
+
+	/* Increase sequence id before writing it to disk. */
+	hdr->seqid++;
+
+	r = device_write_lock(cd, device);
+	if (r) {
+		log_err(cd, _("Failed to acquire write device lock."));
+		free(json_area);
+		return r;
+	}
+
+	/* Write primary and secondary header */
+	r = hdr_write_disk(cd, device, hdr, json_area, 0);
+	if (!r)
+		r = hdr_write_disk(cd, device, hdr, json_area, 1);
+
+	if (r)
+		log_dbg(cd, "LUKS2 header write failed (%d).", r);
+
+	device_write_unlock(cd, device);
+
+	/* FIXME: try recovery here? */
+
+	free(json_area);
+	return r;
+}
+static int validate_json_area(struct crypt_device *cd, const char *json_area,
+			      uint64_t json_len, uint64_t max_length)
+{
+	char c;
+
+	/* Enforce there are no needless opening bytes */
+	if (*json_area != '{') {
+		log_dbg(cd, "ERROR: Opening character must be left curly bracket: '{'.");
+		return -EINVAL;
+	}
+
+	if (json_len >= max_length) {
+		log_dbg(cd, "ERROR: Missing trailing null byte beyond parsed json data string.");
+		return -EINVAL;
+	}
+
+	/*
+	 * TODO:
+	 *	validate there are legal json format characters between
+	 *	'json_area' and 'json_area + json_len'
+	 */
+
+	do {
+		c = *(json_area + json_len);
+		if (c != '\0') {
+			log_dbg(cd, "ERROR: Forbidden ascii code 0x%02hhx found beyond json data string at offset %" PRIu64,
+				c, json_len);
+			return -EINVAL;
+		}
+	} while (++json_len < max_length);
+
+	return 0;
+}
+
+static int validate_luks2_json_object(struct crypt_device *cd, json_object *jobj_hdr, uint64_t length)
+{
+	int r;
+
+	/* we require top level object to be of json_type_object */
+	r = !json_object_is_type(jobj_hdr, json_type_object);
+	if (r) {
+		log_dbg(cd, "ERROR: Resulting object is not a json object type");
+		return r;
+	}
+
+	r = LUKS2_hdr_validate(cd, jobj_hdr, length);
+	if (r) {
+		log_dbg(cd, "Repairing JSON metadata.");
+		/* try to correct known glitches */
+		LUKS2_hdr_repair(cd, jobj_hdr);
+
+		/* run validation again */
+		r = LUKS2_hdr_validate(cd, jobj_hdr, length);
+	}
+
+	if (r)
+		log_dbg(cd, "ERROR: LUKS2 validation failed");
+
+	return r;
+}
+
+static json_object *parse_and_validate_json(struct crypt_device *cd,
+					    const char *json_area, uint64_t max_length)
+{
+	int json_len, r;
+	json_object *jobj = parse_json_len(cd, json_area, max_length, &json_len);
+
+	if (!jobj)
+		return NULL;
+
+	/* successful parse_json_len must not return offset <= 0 */
+	assert(json_len > 0);
+
+	r = validate_json_area(cd, json_area, json_len, max_length);
+	if (!r)
+		r = validate_luks2_json_object(cd, jobj, max_length);
+
+	if (r) {
+		json_object_put(jobj);
+		jobj = NULL;
+	}
+
+	return jobj;
+}
+
+static int detect_device_signatures(struct crypt_device *cd, const char *path)
+{
+	blk_probe_status prb_state;
+	int r;
+	struct blkid_handle *h;
+
+	if (!blk_supported()) {
+		log_dbg(cd, "Blkid probing of device signatures disabled.");
+		return 0;
+	}
+
+	if ((r = blk_init_by_path(&h, path))) {
+		log_dbg(cd, "Failed to initialize blkid_handle by path.");
+		return -EINVAL;
+	}
+
+	/* We don't care about details. Be fast. */
+	blk_set_chains_for_fast_detection(h);
+
+	/* Filter out crypto_LUKS. we don't care now */
+	blk_superblocks_filter_luks(h);
+
+	prb_state = blk_safeprobe(h);
+
+	switch (prb_state) {
+	case PRB_AMBIGUOUS:
+		log_dbg(cd, "Blkid probe couldn't decide device type unambiguously.");
+		/* fall through */
+	case PRB_FAIL:
+		log_dbg(cd, "Blkid probe failed.");
+		r = -EINVAL;
+		break;
+	case PRB_OK: /* crypto_LUKS type is filtered out */
+		r = -EINVAL;
+
+		if (blk_is_partition(h))
+			log_dbg(cd, "Blkid probe detected partition type '%s'", blk_get_partition_type(h));
+		else if (blk_is_superblock(h))
+			log_dbg(cd, "blkid probe detected superblock type '%s'", blk_get_superblock_type(h));
+		break;
+	case PRB_EMPTY:
+		log_dbg(cd, "Blkid probe detected no foreign device signature.");
+	}
+	blk_free(h);
+	return r;
+}
+
+/*
+ * Read and convert on-disk LUKS2 header to in-memory representation..
+ * Try to do recovery if on-disk state is not consistent.
+ */
+int LUKS2_disk_hdr_read(struct crypt_device *cd, struct luks2_hdr *hdr,
+			struct device *device, int do_recovery, int do_blkprobe)
+{
+	enum { HDR_OK, HDR_OBSOLETE, HDR_FAIL, HDR_FAIL_IO } state_hdr1, state_hdr2;
+	struct luks2_hdr_disk hdr_disk1, hdr_disk2;
+	char *json_area1 = NULL, *json_area2 = NULL;
+	json_object *jobj_hdr1 = NULL, *jobj_hdr2 = NULL;
+	unsigned int i;
+	int r;
+	uint64_t hdr_size;
+	uint64_t hdr2_offsets[] = LUKS2_HDR2_OFFSETS;
+
+	/* Skip auto-recovery if locks are disabled and we're not doing LUKS2 explicit repair */
+	if (do_recovery && do_blkprobe && !crypt_metadata_locking_enabled()) {
+		do_recovery = 0;
+		log_dbg(cd, "Disabling header auto-recovery due to locking being disabled.");
+	}
+
+	/*
+	 * Read primary LUKS2 header (offset 0).
+	 */
+	state_hdr1 = HDR_FAIL;
+	r = hdr_read_disk(cd, device, &hdr_disk1, &json_area1, 0, 0);
+	if (r == 0) {
+		jobj_hdr1 = parse_and_validate_json(cd, json_area1, be64_to_cpu(hdr_disk1.hdr_size) - LUKS2_HDR_BIN_LEN);
+		state_hdr1 = jobj_hdr1 ? HDR_OK : HDR_OBSOLETE;
+	} else if (r == -EIO)
+		state_hdr1 = HDR_FAIL_IO;
+
+	/*
+	 * Read secondary LUKS2 header (follows primary).
+	 */
+	state_hdr2 = HDR_FAIL;
+	if (state_hdr1 != HDR_FAIL && state_hdr1 != HDR_FAIL_IO) {
+		r = hdr_read_disk(cd, device, &hdr_disk2, &json_area2, be64_to_cpu(hdr_disk1.hdr_size), 1);
+		if (r == 0) {
+			jobj_hdr2 = parse_and_validate_json(cd, json_area2, be64_to_cpu(hdr_disk2.hdr_size) - LUKS2_HDR_BIN_LEN);
+			state_hdr2 = jobj_hdr2 ? HDR_OK : HDR_OBSOLETE;
+		} else if (r == -EIO)
+			state_hdr2 = HDR_FAIL_IO;
+	} else {
+		/*
+		 * No header size, check all known offsets.
+		 */
+		for (r = -EINVAL,i = 0; r < 0 && i < ARRAY_SIZE(hdr2_offsets); i++)
+			r = hdr_read_disk(cd, device, &hdr_disk2, &json_area2, hdr2_offsets[i], 1);
+
+		if (r == 0) {
+			jobj_hdr2 = parse_and_validate_json(cd, json_area2, be64_to_cpu(hdr_disk2.hdr_size) - LUKS2_HDR_BIN_LEN);
+			state_hdr2 = jobj_hdr2 ? HDR_OK : HDR_OBSOLETE;
+		} else if (r == -EIO)
+			state_hdr2 = HDR_FAIL_IO;
+	}
+
+	/*
+	 * Check sequence id if both headers are read correctly.
+	 */
+	if (state_hdr1 == HDR_OK && state_hdr2 == HDR_OK) {
+		if (be64_to_cpu(hdr_disk1.seqid) > be64_to_cpu(hdr_disk2.seqid))
+			state_hdr2 = HDR_OBSOLETE;
+		else if (be64_to_cpu(hdr_disk1.seqid) < be64_to_cpu(hdr_disk2.seqid))
+			state_hdr1 = HDR_OBSOLETE;
+	}
+
+	/* check header with keyslots to fit the device */
+	if (state_hdr1 == HDR_OK)
+		hdr_size = LUKS2_hdr_and_areas_size(jobj_hdr1);
+	else if (state_hdr2 == HDR_OK)
+		hdr_size = LUKS2_hdr_and_areas_size(jobj_hdr2);
+	else {
+		r = (state_hdr1 == HDR_FAIL_IO && state_hdr2 == HDR_FAIL_IO) ? -EIO : -EINVAL;
+		goto err;
+	}
+
+	r = device_check_size(cd, device, hdr_size, 0);
+	if (r)
+		goto err;
+
+	/*
+	 * Try to rewrite (recover) bad header. Always regenerate salt for bad header.
+	 */
+	if (state_hdr1 == HDR_OK && state_hdr2 != HDR_OK) {
+		log_dbg(cd, "Secondary LUKS2 header requires recovery.");
+
+		if (do_blkprobe && (r = detect_device_signatures(cd, device_path(device)))) {
+			log_err(cd, _("Device contains ambiguous signatures, cannot auto-recover LUKS2.\n"
+				      "Please run \"cryptsetup repair\" for recovery."));
+			goto err;
+		}
+
+		if (do_recovery) {
+			memcpy(&hdr_disk2, &hdr_disk1, LUKS2_HDR_BIN_LEN);
+			r = crypt_random_get(cd, (char*)hdr_disk2.salt, sizeof(hdr_disk2.salt), CRYPT_RND_SALT);
+			if (r)
+				log_dbg(cd, "Cannot generate master salt.");
+			else {
+				hdr_from_disk(&hdr_disk1, &hdr_disk2, hdr, 0);
+				r = hdr_write_disk(cd, device, hdr, json_area1, 1);
+			}
+			if (r)
+				log_dbg(cd, "Secondary LUKS2 header recovery failed.");
+		}
+	} else if (state_hdr1 != HDR_OK && state_hdr2 == HDR_OK) {
+		log_dbg(cd, "Primary LUKS2 header requires recovery.");
+
+		if (do_blkprobe && (r = detect_device_signatures(cd, device_path(device)))) {
+			log_err(cd, _("Device contains ambiguous signatures, cannot auto-recover LUKS2.\n"
+				      "Please run \"cryptsetup repair\" for recovery."));
+			goto err;
+		}
+
+		if (do_recovery) {
+			memcpy(&hdr_disk1, &hdr_disk2, LUKS2_HDR_BIN_LEN);
+			r = crypt_random_get(cd, (char*)hdr_disk1.salt, sizeof(hdr_disk1.salt), CRYPT_RND_SALT);
+			if (r)
+				log_dbg(cd, "Cannot generate master salt.");
+			else {
+				hdr_from_disk(&hdr_disk2, &hdr_disk1, hdr, 1);
+				r = hdr_write_disk(cd, device, hdr, json_area2, 0);
+			}
+			if (r)
+				log_dbg(cd, "Primary LUKS2 header recovery failed.");
+		}
+	}
+
+	free(json_area1);
+	json_area1 = NULL;
+	free(json_area2);
+	json_area2 = NULL;
+
+	/* wrong lock for write mode during recovery attempt */
+	if (r == -EAGAIN)
+		goto err;
+
+	/*
+	 * Even if status is failed, the second header includes salt.
+	 */
+	if (state_hdr1 == HDR_OK) {
+		hdr_from_disk(&hdr_disk1, &hdr_disk2, hdr, 0);
+		hdr->jobj = jobj_hdr1;
+		json_object_put(jobj_hdr2);
+	} else if (state_hdr2 == HDR_OK) {
+		hdr_from_disk(&hdr_disk2, &hdr_disk1, hdr, 1);
+		hdr->jobj = jobj_hdr2;
+		json_object_put(jobj_hdr1);
+	}
+
+	/*
+	 * FIXME: should this fail? At least one header was read correctly.
+	 * r = (state_hdr1 == HDR_FAIL_IO || state_hdr2 == HDR_FAIL_IO) ? -EIO : -EINVAL;
+	 */
+	return 0;
+err:
+	log_dbg(cd, "LUKS2 header read failed (%d).", r);
+
+	free(json_area1);
+	free(json_area2);
+	json_object_put(jobj_hdr1);
+	json_object_put(jobj_hdr2);
+	hdr->jobj = NULL;
+	return r;
+}
+
+int LUKS2_hdr_version_unlocked(struct crypt_device *cd, const char *backup_file)
+{
+	struct {
+		char magic[LUKS2_MAGIC_L];
+		uint16_t version;
+	}  __attribute__ ((packed)) hdr;
+	struct device *device = NULL;
+	int r = 0, devfd = -1, flags;
+
+	if (!backup_file)
+		device = crypt_metadata_device(cd);
+	else if (device_alloc(cd, &device, backup_file) < 0)
+		return 0;
+
+	if (!device)
+		return 0;
+
+	flags = O_RDONLY;
+	if (device_direct_io(device))
+		flags |= O_DIRECT;
+
+	devfd = open(device_path(device), flags);
+	if (devfd < 0)
+		goto err;
+
+	if ((read_lseek_blockwise(devfd, device_block_size(cd, device),
+	     device_alignment(device), &hdr, sizeof(hdr), 0) == sizeof(hdr)) &&
+	    !memcmp(hdr.magic, LUKS2_MAGIC_1ST, LUKS2_MAGIC_L))
+		r = (int)be16_to_cpu(hdr.version);
+err:
+	if (devfd != -1)
+		close(devfd);
+
+	if (backup_file)
+		device_free(cd, device);
+
+	return r;
+}
diff --git a/lib/luks2/luks2_internal.h b/lib/luks2/luks2_internal.h
new file mode 100644
index 0000000..5fbb56e
--- /dev/null
+++ b/lib/luks2/luks2_internal.h
@@ -0,0 +1,182 @@
+/*
+ * LUKS - Linux Unified Key Setup v2
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 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.
+ */
+
+#ifndef _CRYPTSETUP_LUKS2_INTERNAL_H
+#define _CRYPTSETUP_LUKS2_INTERNAL_H
+
+#include <stdio.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <json-c/json.h>
+
+#include "internal.h"
+#include "base64.h"
+#include "luks2.h"
+
+#define UNUSED(x) (void)(x)
+
+/* override useless forward slash escape when supported by json-c */
+#ifndef JSON_C_TO_STRING_NOSLASHESCAPE
+#define JSON_C_TO_STRING_NOSLASHESCAPE 0
+#endif
+
+/*
+ * On-disk access function prototypes
+ */
+int LUKS2_disk_hdr_read(struct crypt_device *cd, struct luks2_hdr *hdr,
+			struct device *device, int do_recovery, int do_blkprobe);
+int LUKS2_disk_hdr_write(struct crypt_device *cd, struct luks2_hdr *hdr,
+			 struct device *device);
+
+/*
+ * JSON struct access helpers
+ */
+json_object *LUKS2_get_keyslot_jobj(struct luks2_hdr *hdr, int keyslot);
+json_object *LUKS2_get_token_jobj(struct luks2_hdr *hdr, int token);
+json_object *LUKS2_get_digest_jobj(struct luks2_hdr *hdr, int digest);
+json_object *LUKS2_get_segment_jobj(struct luks2_hdr *hdr, int segment);
+json_object *LUKS2_get_tokens_jobj(struct luks2_hdr *hdr);
+
+void hexprint_base64(struct crypt_device *cd, json_object *jobj,
+		     const char *sep, const char *line_sep);
+
+json_object *parse_json_len(struct crypt_device *cd, const char *json_area,
+			    uint64_t max_length, int *json_len);
+uint64_t json_object_get_uint64(json_object *jobj);
+uint32_t json_object_get_uint32(json_object *jobj);
+json_object *json_object_new_uint64(uint64_t value);
+int json_object_object_add_by_uint(json_object *jobj, unsigned key, json_object *jobj_val);
+void json_object_object_del_by_uint(json_object *jobj, unsigned key);
+
+void JSON_DBG(struct crypt_device *cd, json_object *jobj, const char *desc);
+
+/*
+ * LUKS2 JSON validation
+ */
+
+/* validation helper */
+json_object *json_contains(struct crypt_device *cd, json_object *jobj, const char *name,
+			   const char *section, const char *key, json_type type);
+
+int LUKS2_hdr_validate(struct crypt_device *cd, json_object *hdr_jobj, uint64_t json_size);
+int LUKS2_keyslot_validate(struct crypt_device *cd, json_object *hdr_jobj,
+			   json_object *hdr_keyslot, const char *key);
+int LUKS2_check_json_size(struct crypt_device *cd, const struct luks2_hdr *hdr);
+int LUKS2_token_validate(struct crypt_device *cd, json_object *hdr_jobj,
+			 json_object *jobj_token, const char *key);
+void LUKS2_token_dump(struct crypt_device *cd, int token);
+
+/*
+ * LUKS2 JSON repair for known glitches
+ */
+void LUKS2_hdr_repair(struct crypt_device *cd, json_object *jobj_hdr);
+void LUKS2_keyslots_repair(struct crypt_device *cd, json_object *jobj_hdr);
+
+/*
+ * JSON array helpers
+ */
+struct json_object *LUKS2_array_jobj(struct json_object *array, const char *num);
+struct json_object *LUKS2_array_remove(struct json_object *array, const char *num);
+
+/*
+ * Plugins API
+ */
+
+/**
+ * LUKS2 keyslots handlers (EXPERIMENTAL)
+ */
+typedef int (*keyslot_alloc_func)(struct crypt_device *cd, int keyslot,
+				  size_t volume_key_len,
+				  const struct luks2_keyslot_params *params);
+typedef int (*keyslot_update_func)(struct crypt_device *cd, int keyslot,
+				   const struct luks2_keyslot_params *params);
+typedef int (*keyslot_open_func) (struct crypt_device *cd, int keyslot,
+				  const char *password, size_t password_len,
+				  char *volume_key, size_t volume_key_len);
+typedef int (*keyslot_store_func)(struct crypt_device *cd, int keyslot,
+				  const char *password, size_t password_len,
+				  const char *volume_key, size_t volume_key_len);
+typedef int (*keyslot_wipe_func) (struct crypt_device *cd, int keyslot);
+typedef int (*keyslot_dump_func) (struct crypt_device *cd, int keyslot);
+typedef int (*keyslot_validate_func) (struct crypt_device *cd, json_object *jobj_keyslot);
+typedef void(*keyslot_repair_func) (struct crypt_device *cd, json_object *jobj_keyslot);
+
+/* see LUKS2_luks2_to_luks1 */
+int placeholder_keyslot_alloc(struct crypt_device *cd,
+	int keyslot,
+	uint64_t area_offset,
+	uint64_t area_length,
+	size_t volume_key_len);
+
+/* validate all keyslot implementations in hdr json */
+int LUKS2_keyslots_validate(struct crypt_device *cd, json_object *hdr_jobj);
+
+typedef struct  {
+	const char *name;
+	keyslot_alloc_func alloc;
+	keyslot_update_func update;
+	keyslot_open_func  open;
+	keyslot_store_func store;
+	keyslot_wipe_func  wipe;
+	keyslot_dump_func  dump;
+	keyslot_validate_func validate;
+	keyslot_repair_func repair;
+} keyslot_handler;
+
+/**
+ * LUKS2 digest handlers (EXPERIMENTAL)
+ */
+typedef int (*digest_verify_func)(struct crypt_device *cd, int digest,
+				  const char *volume_key, size_t volume_key_len);
+typedef int (*digest_store_func) (struct crypt_device *cd, int digest,
+				  const char *volume_key, size_t volume_key_len);
+typedef int (*digest_dump_func)  (struct crypt_device *cd, int digest);
+
+typedef struct  {
+	const char *name;
+	digest_verify_func verify;
+	digest_store_func  store;
+	digest_dump_func   dump;
+} digest_handler;
+
+const digest_handler *LUKS2_digest_handler_type(struct crypt_device *cd, const char *type);
+
+/**
+ * LUKS2 token handlers (internal use only)
+ */
+typedef int (*builtin_token_get_func) (json_object *jobj_token, void *params);
+typedef int (*builtin_token_set_func) (json_object **jobj_token, const void *params);
+
+typedef struct {
+	/* internal only section used by builtin tokens */
+	builtin_token_get_func get;
+	builtin_token_set_func set;
+	/* public token handler */
+	const crypt_token_handler *h;
+} token_handler;
+
+int token_keyring_set(json_object **, const void *);
+int token_keyring_get(json_object *, void *);
+
+int LUKS2_find_area_gap(struct crypt_device *cd, struct luks2_hdr *hdr,
+			size_t keylength, uint64_t *area_offset, uint64_t *area_length);
+
+#endif
diff --git a/lib/luks2/luks2_json_format.c b/lib/luks2/luks2_json_format.c
new file mode 100644
index 0000000..a2cd331
--- /dev/null
+++ b/lib/luks2/luks2_json_format.c
@@ -0,0 +1,311 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, LUKS2 header format code
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 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"
+#include <uuid/uuid.h>
+#include <assert.h>
+
+struct area {
+	uint64_t offset;
+	uint64_t length;
+};
+
+static size_t get_area_size(size_t keylength)
+{
+	//FIXME: calculate this properly, for now it is AF_split_sectors
+	return size_round_up(keylength * 4000, 4096);
+}
+
+static size_t get_min_offset(struct luks2_hdr *hdr)
+{
+	return 2 * hdr->hdr_size;
+}
+
+static size_t get_max_offset(struct crypt_device *cd)
+{
+	return crypt_get_data_offset(cd) * SECTOR_SIZE;
+}
+
+int LUKS2_find_area_gap(struct crypt_device *cd, struct luks2_hdr *hdr,
+			size_t keylength, uint64_t *area_offset, uint64_t *area_length)
+{
+	struct area areas[LUKS2_KEYSLOTS_MAX], sorted_areas[LUKS2_KEYSLOTS_MAX] = {};
+	int i, j, k, area_i;
+	size_t offset, length;
+
+	/* fill area offset + length table */
+	for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++) {
+		if (!LUKS2_keyslot_area(hdr, i, &areas[i].offset, &areas[i].length))
+			continue;
+		areas[i].length = 0;
+		areas[i].offset = 0;
+	}
+
+	/* sort table */
+	k = 0; /* index in sorted table */
+	for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++) {
+		offset = get_max_offset(cd) ?: UINT64_MAX;
+		area_i = -1;
+		/* search for the smallest offset in table */
+		for (j = 0; j < LUKS2_KEYSLOTS_MAX; j++)
+			if (areas[j].offset && areas[j].offset <= offset) {
+				area_i = j;
+				offset = areas[j].offset;
+			}
+
+		if (area_i >= 0) {
+			sorted_areas[k].length = areas[area_i].length;
+			sorted_areas[k].offset = areas[area_i].offset;
+			areas[area_i].length = 0;
+			areas[area_i].offset = 0;
+			k++;
+		}
+	}
+
+	/* search for the gap we can use */
+	offset = get_min_offset(hdr);
+	length = get_area_size(keylength);
+	for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++) {
+		/* skip empty */
+		if (sorted_areas[i].offset == 0 || sorted_areas[i].length == 0)
+			continue;
+
+		/* enough space before the used area */
+		if ((offset < sorted_areas[i].offset) && ((offset + length) <= sorted_areas[i].offset))
+			break;
+
+		/* both offset and length are already aligned to 4096 bytes */
+		offset = sorted_areas[i].offset + sorted_areas[i].length;
+	}
+
+	if (get_max_offset(cd) && (offset + length) > get_max_offset(cd)) {
+		log_err(cd, _("No space for new keyslot."));
+		return -EINVAL;
+	}
+
+	log_dbg(cd, "Found area %zu -> %zu", offset, length + offset);
+/*
+	log_dbg("Area offset min: %zu, max %zu, slots max %u",
+	       get_min_offset(hdr), get_max_offset(cd), LUKS2_KEYSLOTS_MAX);
+	for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++)
+		log_dbg("SLOT[%02i]: %-8" PRIu64 " -> %-8" PRIu64, i,
+			sorted_areas[i].offset,
+			sorted_areas[i].length + sorted_areas[i].offset);
+*/
+	*area_offset = offset;
+	*area_length = length;
+	return 0;
+}
+
+int LUKS2_check_metadata_area_size(uint64_t metadata_size)
+{
+	/* see LUKS2_HDR2_OFFSETS */
+	return (metadata_size != 0x004000 &&
+		metadata_size != 0x008000 && metadata_size != 0x010000 &&
+		metadata_size != 0x020000 && metadata_size != 0x040000 &&
+		metadata_size != 0x080000 && metadata_size != 0x100000 &&
+		metadata_size != 0x200000 && metadata_size != 0x400000);
+}
+
+int LUKS2_check_keyslots_area_size(uint64_t keyslots_size)
+{
+	return (MISALIGNED_4K(keyslots_size) ||
+		keyslots_size > LUKS2_MAX_KEYSLOTS_SIZE);
+}
+
+int LUKS2_generate_hdr(
+	struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	const struct volume_key *vk,
+	const char *cipherName,
+	const char *cipherMode,
+	const char *integrity,
+	const char *uuid,
+	unsigned int sector_size,  /* in bytes */
+	uint64_t data_offset,      /* in bytes */
+	uint64_t align_offset,     /* in bytes */
+	uint64_t required_alignment,
+	uint64_t metadata_size,
+	uint64_t keyslots_size)
+{
+	struct json_object *jobj_segment, *jobj_integrity, *jobj_keyslots, *jobj_segments, *jobj_config;
+	char cipher[128];
+	uuid_t partitionUuid;
+	int digest;
+
+	if (!metadata_size)
+		metadata_size = LUKS2_HDR_16K_LEN;
+	hdr->hdr_size = metadata_size;
+
+	if (data_offset && data_offset < get_min_offset(hdr)) {
+		log_err(cd, _("Requested data offset is too small."));
+		return -EINVAL;
+	}
+
+	/* Increase keyslot size according to data offset */
+	if (!keyslots_size && data_offset)
+		keyslots_size = data_offset - get_min_offset(hdr);
+
+	/* keyslots size has to be 4 KiB aligned */
+	keyslots_size -= (keyslots_size % 4096);
+
+	if (keyslots_size > LUKS2_MAX_KEYSLOTS_SIZE)
+		keyslots_size = LUKS2_MAX_KEYSLOTS_SIZE;
+
+	if (!keyslots_size) {
+		assert(LUKS2_DEFAULT_HDR_SIZE > 2 * LUKS2_HDR_OFFSET_MAX);
+		keyslots_size = LUKS2_DEFAULT_HDR_SIZE - get_min_offset(hdr);
+	}
+
+	/* Decrease keyslots_size if we have smaller data_offset */
+	if (data_offset && (keyslots_size + get_min_offset(hdr)) > data_offset) {
+		keyslots_size = data_offset - get_min_offset(hdr);
+		log_dbg(cd, "Decreasing keyslot area size to %" PRIu64
+			" bytes due to the requested data offset %"
+			PRIu64 " bytes.", keyslots_size, data_offset);
+	}
+
+	/* Data offset has priority */
+	if (!data_offset && required_alignment) {
+		data_offset = size_round_up(get_min_offset(hdr) + keyslots_size,
+					    (size_t)required_alignment);
+		data_offset += align_offset;
+	}
+
+	log_dbg(cd, "Formatting LUKS2 with JSON metadata area %" PRIu64
+		" bytes and keyslots area %" PRIu64 " bytes.",
+		metadata_size - LUKS2_HDR_BIN_LEN, keyslots_size);
+
+	if (keyslots_size < (LUKS2_HDR_OFFSET_MAX - 2*LUKS2_HDR_16K_LEN))
+		log_std(cd, _("WARNING: keyslots area (%" PRIu64 " bytes) is very small,"
+			" available LUKS2 keyslot count is very limited.\n"),
+			keyslots_size);
+
+	hdr->seqid = 1;
+	hdr->version = 2;
+	memset(hdr->label, 0, LUKS2_LABEL_L);
+	strcpy(hdr->checksum_alg, "sha256");
+	crypt_random_get(cd, (char*)hdr->salt1, LUKS2_SALT_L, CRYPT_RND_SALT);
+	crypt_random_get(cd, (char*)hdr->salt2, LUKS2_SALT_L, CRYPT_RND_SALT);
+
+	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);
+
+	if (*cipherMode != '\0')
+		snprintf(cipher, sizeof(cipher), "%s-%s", cipherName, cipherMode);
+	else
+		snprintf(cipher, sizeof(cipher), "%s", cipherName);
+
+	hdr->jobj = json_object_new_object();
+
+	jobj_keyslots = json_object_new_object();
+	json_object_object_add(hdr->jobj, "keyslots", jobj_keyslots);
+	json_object_object_add(hdr->jobj, "tokens", json_object_new_object());
+	jobj_segments = json_object_new_object();
+	json_object_object_add(hdr->jobj, "segments", jobj_segments);
+	json_object_object_add(hdr->jobj, "digests", json_object_new_object());
+	jobj_config = json_object_new_object();
+	json_object_object_add(hdr->jobj, "config", jobj_config);
+
+	digest = LUKS2_digest_create(cd, "pbkdf2", hdr, vk);
+	if (digest < 0) {
+		json_object_put(hdr->jobj);
+		hdr->jobj = NULL;
+		return -EINVAL;
+	}
+
+	if (LUKS2_digest_segment_assign(cd, hdr, CRYPT_DEFAULT_SEGMENT, digest, 1, 0) < 0) {
+		json_object_put(hdr->jobj);
+		hdr->jobj = NULL;
+		return -EINVAL;
+	}
+
+	jobj_segment = json_object_new_object();
+	json_object_object_add(jobj_segment, "type", json_object_new_string("crypt"));
+	json_object_object_add(jobj_segment, "offset", json_object_new_uint64(data_offset));
+	json_object_object_add(jobj_segment, "iv_tweak", json_object_new_string("0"));
+	json_object_object_add(jobj_segment, "size", json_object_new_string("dynamic"));
+	json_object_object_add(jobj_segment, "encryption", json_object_new_string(cipher));
+	json_object_object_add(jobj_segment, "sector_size", json_object_new_int(sector_size));
+
+	if (integrity) {
+		jobj_integrity = json_object_new_object();
+		json_object_object_add(jobj_integrity, "type", json_object_new_string(integrity));
+		json_object_object_add(jobj_integrity, "journal_encryption", json_object_new_string("none"));
+		json_object_object_add(jobj_integrity, "journal_integrity", json_object_new_string("none"));
+		json_object_object_add(jobj_segment, "integrity", jobj_integrity);
+	}
+
+	json_object_object_add_by_uint(jobj_segments, CRYPT_DEFAULT_SEGMENT, jobj_segment);
+
+	json_object_object_add(jobj_config, "json_size", json_object_new_uint64(metadata_size - LUKS2_HDR_BIN_LEN));
+	json_object_object_add(jobj_config, "keyslots_size", json_object_new_uint64(keyslots_size));
+
+	JSON_DBG(cd, hdr->jobj, "Header JSON:");
+	return 0;
+}
+
+int LUKS2_wipe_header_areas(struct crypt_device *cd,
+	struct luks2_hdr *hdr)
+{
+	int r;
+	uint64_t offset, length;
+	size_t wipe_block;
+
+	/* Wipe complete header, keyslots and padding areas with zeroes. */
+	offset = 0;
+	length = LUKS2_get_data_offset(hdr) * SECTOR_SIZE;
+	wipe_block = 1024 * 1024;
+
+	if (LUKS2_hdr_validate(cd, hdr->jobj, hdr->hdr_size - LUKS2_HDR_BIN_LEN))
+		return -EINVAL;
+
+	/* On detached header wipe at least the first 4k */
+	if (length == 0) {
+		length = 4096;
+		wipe_block = 4096;
+	}
+
+	log_dbg(cd, "Wiping LUKS areas (0x%06" PRIx64 " - 0x%06" PRIx64") with zeroes.",
+		offset, length + offset);
+
+	r = crypt_wipe_device(cd, crypt_metadata_device(cd), CRYPT_WIPE_ZERO,
+			      offset, length, wipe_block, NULL, NULL);
+	if (r < 0)
+		return r;
+
+	/* Wipe keyslot area */
+	wipe_block = 1024 * 1024;
+	offset = get_min_offset(hdr);
+	length = LUKS2_keyslots_size(hdr->jobj);
+
+	log_dbg(cd, "Wiping keyslots area (0x%06" PRIx64 " - 0x%06" PRIx64") with random data.",
+		offset, length + offset);
+
+	return crypt_wipe_device(cd, crypt_metadata_device(cd), CRYPT_WIPE_RANDOM,
+				 offset, length, wipe_block, NULL, NULL);
+}
diff --git a/lib/luks2/luks2_json_metadata.c b/lib/luks2/luks2_json_metadata.c
new file mode 100644
index 0000000..de8d018
--- /dev/null
+++ b/lib/luks2/luks2_json_metadata.c
@@ -0,0 +1,1935 @@
+/*
+ * LUKS - Linux Unified Key Setup v2
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 Milan Broz
+ * Copyright (C) 2015-2019 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 / 2; i++)
+		log_std(cd, "%02hhx%s", buf[i], sep);
+	log_std(cd, "\n\t%s", line_sep);
+	for (i = buf_len / 2; i < buf_len; i++)
+		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;
+
+	json_object_object_get_ex(jobj1, keyslot_name, &jobj2);
+	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;
+}
+
+json_object *LUKS2_get_segment_jobj(struct luks2_hdr *hdr, int segment)
+{
+	json_object *jobj1, *jobj2;
+	char segment_name[16];
+
+	if (!hdr || segment < 0)
+		return NULL;
+
+	if (snprintf(segment_name, sizeof(segment_name), "%u", segment) < 1)
+		return NULL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "segments", &jobj1))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj1, segment_name, &jobj2))
+		return NULL;
+
+	return jobj2;
+}
+
+/*
+ * json_type_int needs to be validated first.
+ * See validate_json_uint32()
+ */
+uint32_t json_object_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 FALSE;
+	}
+
+	*value = tmp;
+	return TRUE;
+}
+
+uint64_t json_object_get_uint64(json_object *jobj)
+{
+	uint64_t r;
+	return json_str_to_uint64(jobj, &r) ? r : 0;
+}
+
+json_object *json_object_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 FALSE;
+		}
+	return TRUE;
+}
+
+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;
+}
+
+/* use only on already validated 'segments' object */
+static uint64_t get_first_data_offset(json_object *jobj_segs, const char *type)
+{
+	json_object *jobj_offset, *jobj_type;
+	uint64_t tmp, min = UINT64_MAX;
+
+	json_object_object_foreach(jobj_segs, key, val) {
+		UNUSED(key);
+
+		if (type) {
+			json_object_object_get_ex(val, "type", &jobj_type);
+			if (strcmp(type, json_object_get_string(jobj_type)))
+				continue;
+		}
+
+		json_object_object_get_ex(val, "offset", &jobj_offset);
+		tmp = json_object_get_uint64(jobj_offset);
+
+		if (!tmp)
+			return tmp;
+
+		if (tmp < min)
+			min = tmp;
+	}
+
+	return min;
+}
+
+static 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) ? FALSE : TRUE;
+}
+
+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 FALSE;
+		}
+
+		if (!json_contains(cd, jobj_keys, "", "Keyslots section",
+				   json_object_get_string(jobj), json_type_object))
+			return FALSE;
+
+		i++;
+	}
+
+	return TRUE;
+}
+
+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 FALSE;
+		}
+
+		if (!json_contains(cd, jobj_segments, "", "Segments section",
+				   json_object_get_string(jobj), json_type_object))
+			return FALSE;
+
+		i++;
+	}
+
+	return TRUE;
+}
+
+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 TRUE;
+	}
+
+	return FALSE;
+}
+
+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 FALSE;
+		}
+
+		if (!ix[i].length) {
+			log_dbg(cd, "Area length must be greater than zero.");
+			return FALSE;
+		}
+
+		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 FALSE;
+		}
+
+		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 FALSE;
+			}
+		}
+
+		i++;
+	}
+
+	return TRUE;
+}
+
+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 = json_object_get_uint64(jobj1);
+	json_size = (uint64_t)strlen(json);
+
+	if (hdr_json_size != json_area_size) {
+		log_dbg(cd, "JSON area size doesn't match value in binary header.");
+		return 1;
+	}
+
+	if (json_size > json_area_size) {
+		log_dbg(cd, "JSON doesn't 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 = json_object_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 int hdr_validate_segments(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	json_object *jobj, *jobj_digests, *jobj_offset, *jobj_size, *jobj_type, *jobj_flags;
+	int i;
+	uint64_t offset, size;
+
+	if (!json_object_object_get_ex(hdr_jobj, "segments", &jobj)) {
+		log_dbg(cd, "Missing segments section.");
+		return 1;
+	}
+
+	if (json_object_object_length(jobj) < 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, 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;
+		}
+
+		/* crypt */
+		if (!strcmp(json_object_get_string(jobj_type), "crypt") &&
+		    hdr_validate_crypt_segment(cd, val, key, jobj_digests, offset, size))
+			return 1;
+	}
+
+	return 0;
+}
+
+uint64_t LUKS2_metadata_size(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;
+}
+
+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(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)) ||
+		    !(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(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;
+}
+
+static int hdr_validate_config(struct crypt_device *cd, json_object *hdr_jobj)
+{
+	json_object *jobj_config, *jobj, *jobj1;
+	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)
+	 */
+	json_object_object_get_ex(hdr_jobj, "segments", &jobj);
+	segment_offset = get_first_data_offset(jobj, "crypt");
+	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;
+	}
+
+	/* 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_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));
+
+		r = device_write_lock(cd, crypt_metadata_device(cd));
+		if (r) {
+			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;
+}
+
+int LUKS2_hdr_write(struct crypt_device *cd, struct luks2_hdr *hdr)
+{
+	/* NOTE: is called before LUKS2 validation routines */
+	/* erase unused digests (no assigned keyslot or segment) */
+	LUKS2_digests_erase_unused(cd, hdr);
+
+	if (LUKS2_hdr_validate(cd, hdr->jobj, hdr->hdr_size - LUKS2_HDR_BIN_LEN))
+		return -EINVAL;
+
+	return LUKS2_disk_hdr_write(cd, hdr, crypt_metadata_device(cd));
+}
+
+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");
+}
+
+uint64_t LUKS2_keyslots_size(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_hdr_and_areas_size(json_object *jobj)
+{
+	return 2 * LUKS2_metadata_size(jobj) + LUKS2_keyslots_size(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 r = 0, devfd = -1;
+	ssize_t hdr_size;
+	ssize_t buffer_size;
+	char *buffer = NULL;
+
+	hdr_size = LUKS2_hdr_and_areas_size(hdr->jobj);
+	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_blockwise(devfd, device_block_size(cd, device),
+			   device_alignment(device), buffer, hdr_size) < hdr_size) {
+		close(devfd);
+		device_read_unlock(cd, device);
+		crypt_safe_free(buffer);
+		return -EIO;
+	}
+	close(devfd);
+
+	device_read_unlock(cd, device);
+
+	devfd = open(backup_file, O_CREAT|O_EXCL|O_WRONLY, S_IRUSR);
+	if (devfd == -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;
+	}
+	if (write_buffer(devfd, buffer, buffer_size) < buffer_size) {
+		log_err(cd, _("Cannot write header backup file %s."), backup_file);
+		r = -EIO;
+	} else
+		r = 0;
+
+	close(devfd);
+	crypt_safe_free(buffer);
+	return r;
+}
+
+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;
+}
+
+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, devfd = -1, diff_uuid = 0;
+	ssize_t 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;
+
+	/* FIXME: why lock backup device ? */
+	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 doesn't contain valid LUKS header."));
+		goto out;
+	}
+
+	/* do not allow header restore from backup with unmet requirements */
+	if (LUKS2_unmet_requirements(cd, &hdr_file, 0, 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.jobj);
+	buffer = crypt_safe_alloc(buffer_size);
+	if (!buffer) {
+		r = -ENOMEM;
+		goto out;
+	}
+
+	devfd = open(backup_file, O_RDONLY);
+	if (devfd == -1) {
+		log_err(cd, _("Cannot open header backup file %s."), backup_file);
+		r = -EINVAL;
+		goto out;
+	}
+
+	if (read_buffer(devfd, buffer, buffer_size) < buffer_size) {
+		log_err(cd, _("Cannot read header backup file %s."), backup_file);
+		r = -EIO;
+		goto out;
+	}
+	close(devfd);
+	devfd = -1;
+
+	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.jobj)) {
+				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));
+
+	/* TODO: perform header restore on bdev in stand-alone routine? */
+	r = device_write_lock(cd, device);
+	if (r) {
+		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_blockwise(devfd, device_block_size(cd, device),
+			    device_alignment(device), buffer, buffer_size) < buffer_size)
+		r = -EIO;
+	else
+		r = 0;
+
+	device_write_unlock(cd, device);
+	/* end of TODO */
+
+out:
+	LUKS2_hdr_free(cd, hdr);
+	LUKS2_hdr_free(cd, &hdr_file);
+	LUKS2_hdr_free(cd, &tmp_hdr);
+	crypt_memzero(&hdr_file, sizeof(hdr_file));
+	crypt_memzero(&tmp_hdr, sizeof(tmp_hdr));
+	crypt_safe_free(buffer);
+
+	if (devfd >= 0) {
+		device_sync(cd, device, devfd);
+		close(devfd);
+	}
+
+
+	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" },
+	{ 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 */
+static const struct  {
+	uint32_t flag;
+	const char *description;
+} requirements_flags[] = {
+	{ CRYPT_REQUIREMENT_OFFLINE_REENCRYPT, "offline-reencrypt" },
+	{ 0, NULL }
+};
+
+static uint32_t 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].flag;
+
+	return CRYPT_REQUIREMENT_UNKNOWN;
+}
+
+/*
+ * 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;
+	uint32_t 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) ? "un" : "");
+		*reqs |= req;
+	}
+
+	return 0;
+}
+
+int LUKS2_config_set_requirements(struct crypt_device *cd, struct luks2_hdr *hdr, uint32_t reqs)
+{
+	json_object *jobj_config, *jobj_requirements, *jobj_mandatory, *jobj;
+	int i, r = -EINVAL;
+
+	if (!hdr)
+		return -EINVAL;
+
+	jobj_mandatory = json_object_new_array();
+	if (!jobj_mandatory)
+		return -ENOMEM;
+
+	for (i = 0; requirements_flags[i].description; i++) {
+		if (reqs & requirements_flags[i].flag) {
+			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 LUKS2_hdr_write(cd, hdr);
+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_DEFAULT_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", json_object_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", json_object_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->jobj));
+	log_std(cd, "Keyslots area: \t%" PRIu64 " [bytes]\n", LUKS2_keyslots_size(hdr->jobj));
+	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;
+}
+
+uint64_t LUKS2_get_data_offset(struct luks2_hdr *hdr)
+{
+	json_object *jobj1;
+
+	if (!json_object_object_get_ex(hdr->jobj, "segments", &jobj1))
+		return 0;
+
+	return get_first_data_offset(jobj1, "crypt") / SECTOR_SIZE;
+}
+
+const char *LUKS2_get_cipher(struct luks2_hdr *hdr, int segment)
+{
+	json_object *jobj1, *jobj2, *jobj3;
+	char buf[16];
+
+	if (segment < 0 || snprintf(buf, sizeof(buf), "%u", segment) < 1)
+		return NULL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "segments", &jobj1))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj1, buf, &jobj2))
+		return NULL;
+
+	if (json_object_object_get_ex(jobj2, "encryption", &jobj3))
+		return json_object_get_string(jobj3);
+
+	/* FIXME: default encryption (for other segment types) must be string here. */
+	return "null";
+
+}
+
+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, *jobj4;
+	char buf[16];
+
+	if (segment < 0 || snprintf(buf, sizeof(buf), "%u", segment) < 1)
+		return NULL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "segments", &jobj1))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj1, buf, &jobj2))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj2, "integrity", &jobj3))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj3, "type", &jobj4))
+		return NULL;
+
+	return json_object_get_string(jobj4);
+}
+
+/* FIXME: this only ensures that once we have journal encryption, it is not ignored. */
+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 (!json_object_object_get_ex(jobj1, CRYPT_DEFAULT_SEGMENT_STR, &jobj2))
+		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 (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 *jobj1, *jobj_segment;
+
+	jobj_segment = LUKS2_get_segment_jobj(hdr, CRYPT_DEFAULT_SEGMENT);
+	if (!jobj_segment)
+		return SECTOR_SIZE;
+
+	json_object_object_get_ex(jobj_segment, "sector_size", &jobj1);
+	if (!jobj1)
+		return SECTOR_SIZE;
+
+	return json_object_get_int(jobj1);
+}
+
+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;
+		}
+
+		r = INTEGRITY_create_dmd_device(cd, NULL, NULL, NULL, NULL, &dmdi, dmd.flags);
+		if (r)
+			return r;
+
+		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;
+}
+
+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, _("Offline reencryption in progress. 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
+}
diff --git a/lib/luks2/luks2_keyslot.c b/lib/luks2/luks2_keyslot.c
new file mode 100644
index 0000000..b897ba3
--- /dev/null
+++ b/lib/luks2/luks2_keyslot.c
@@ -0,0 +1,663 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, keyslot handling
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 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;
+
+static const keyslot_handler *keyslot_handlers[LUKS2_KEYSLOTS_MAX] = {
+	&luks2_keyslot,
+	NULL
+};
+
+static const keyslot_handler
+*LUKS2_keyslot_handler_type(struct crypt_device *cd, 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(cd, json_object_get_string(jobj2));
+}
+
+int LUKS2_keyslot_find_empty(struct luks2_hdr *hdr, const char *type)
+{
+	int i;
+
+	for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++)
+		if (!LUKS2_get_keyslot_jobj(hdr, i))
+			return i;
+
+	return -EINVAL;
+}
+
+/* Check if a keyslot is asssigned to specific segment */
+int LUKS2_keyslot_for_segment(struct luks2_hdr *hdr, int keyslot, int segment)
+{
+	int keyslot_digest, segment_digest;
+
+	/* no need to check anything */
+	if (segment == CRYPT_ANY_SEGMENT)
+		return 0;
+
+	keyslot_digest = LUKS2_digest_by_keyslot(hdr, keyslot);
+	if (keyslot_digest < 0)
+		return -EINVAL;
+
+	segment_digest = LUKS2_digest_by_segment(hdr, segment);
+	if (segment_digest < 0)
+		return segment_digest;
+
+	return segment_digest == keyslot_digest ? 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 || !strcmp(cipher_spec, "null") || !strcmp(cipher_spec, "cipher_null"))
+		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);
+	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_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_area(struct luks2_hdr *hdr,
+	int keyslot,
+	uint64_t *offset,
+	uint64_t *length)
+{
+	json_object *jobj_keyslot, *jobj_area, *jobj;
+
+	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, "area", &jobj_area))
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_area, "offset", &jobj))
+		return -EINVAL;
+	*offset = json_object_get_int64(jobj);
+
+	if (!json_object_object_get_ex(jobj_area, "size", &jobj))
+		return -EINVAL;
+	*length = json_object_get_int64(jobj);
+
+	return 0;
+}
+
+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 key_size, 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;
+	}
+
+	key_size = LUKS2_get_volume_key_size(hdr, segment);
+	if (key_size < 0)
+		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;
+	}
+
+	return r < 0 ? r : keyslot;
+}
+
+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;
+}
+
+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);
+
+	return r;
+}
+
+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(cd, "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;
+	}
+
+	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);
+
+	/* Just check that nobody uses the metadata now */
+	r = device_write_lock(cd, device);
+	if (r) {
+		log_err(cd, _("Failed to acquire write lock on device %s."),
+			device_path(device));
+		return r;
+	}
+	device_write_unlock(cd, device);
+
+	/* secure deletion of possible key material in keyslot area */
+	r = crypt_keyslot_area(cd, keyslot, &area_offset, &area_length);
+	if (r && r != -ENOENT)
+		return r;
+
+	/* We can destroy the binary keyslot area now without lock */
+	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));
+			return r;
+		}
+	}
+
+	if (wipe_area_only)
+		return r;
+
+	/* Slot specific wipe */
+	if (h) {
+		r = h->wipe(cd, keyslot);
+		if (r < 0)
+			return r;
+	} else
+		log_dbg(cd, "Wiping keyslot %d without specific-slot handler loaded.", keyslot);
+
+	json_object_object_del_by_uint(jobj_keyslots, keyslot);
+
+	return LUKS2_hdr_write(cd, hdr);
+}
+
+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 crypt_device *cd,
+	  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,
+	size_t volume_key_len)
+{
+	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", json_object_new_uint64(area_offset));
+	json_object_object_add(jobj_area, "size", json_object_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;
+
+	if (!json_object_object_get_ex(hdr_jobj, "keyslots", &jobj_keyslots))
+		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(cd, 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;
+		}
+	}
+
+	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(cd, json_object_get_string(jobj_type));
+		if (h && h->repair)
+			h->repair(cd, val);
+	}
+}
diff --git a/lib/luks2/luks2_keyslot_luks2.c b/lib/luks2/luks2_keyslot_luks2.c
new file mode 100644
index 0000000..26fe9b1
--- /dev/null
+++ b/lib/luks2/luks2_keyslot_luks2.c
@@ -0,0 +1,785 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, LUKS2 type keyslot handler
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 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"
+
+/* FIXME: move keyslot encryption to crypto backend */
+#include "../luks1/af.h"
+
+#define LUKS_SALTSIZE 32
+#define LUKS_SLOT_ITERATIONS_MIN 1000
+#define LUKS_STRIPES 4000
+
+static int luks2_encrypt_to_storage(char *src, size_t srcLength,
+	const char *cipher, const char *cipher_mode,
+	struct volume_key *vk, unsigned int sector,
+	struct crypt_device *cd)
+{
+	struct device *device = crypt_metadata_device(cd);
+#ifndef ENABLE_AF_ALG /* Support for old kernel without Crypto API */
+	int r = device_write_lock(cd, device);
+	if (r) {
+		log_err(cd, _("Failed to acquire write lock on device %s."), device_path(device));
+		return r;
+	}
+	r = LUKS_encrypt_to_storage(src, srcLength, cipher, cipher_mode, vk, sector, cd);
+	device_write_unlock(cd, crypt_metadata_device(cd));
+	return r;
+#else
+	struct crypt_storage *s;
+	int devfd = -1, r;
+
+	/* Only whole sector writes supported */
+	if (MISALIGNED_512(srcLength))
+		return -EINVAL;
+
+	/* Encrypt buffer */
+	r = crypt_storage_init(&s, 0, cipher, cipher_mode, vk->key, vk->keylength);
+	if (r) {
+		log_dbg(cd, "Userspace crypto wrapper cannot use %s-%s (%d).",
+			cipher, cipher_mode, r);
+		return r;
+	}
+
+	r = crypt_storage_encrypt(s, 0, srcLength / SECTOR_SIZE, src);
+	crypt_storage_destroy(s);
+	if (r)
+		return r;
+
+	r = device_write_lock(cd, device);
+	if (r) {
+		log_err(cd, _("Failed to acquire write lock on device %s."),
+			device_path(device));
+		return r;
+	}
+
+	devfd = device_open_locked(cd, device, O_RDWR);
+	if (devfd >= 0) {
+		if (write_lseek_blockwise(devfd, device_block_size(cd, device),
+					  device_alignment(device), src,
+					  srcLength, sector * SECTOR_SIZE) < 0)
+			r = -EIO;
+		else
+			r = 0;
+
+		device_sync(cd, device, devfd);
+		close(devfd);
+	} else
+		r = -EIO;
+
+	device_write_unlock(cd, device);
+
+	if (r)
+		log_err(cd, _("IO error while encrypting keyslot."));
+
+	return r;
+#endif
+}
+
+static int luks2_decrypt_from_storage(char *dst, size_t dstLength,
+	const char *cipher, const char *cipher_mode, struct volume_key *vk,
+	unsigned int sector, struct crypt_device *cd)
+{
+	struct device *device = crypt_metadata_device(cd);
+#ifndef ENABLE_AF_ALG /* Support for old kernel without Crypto API */
+	int r = device_read_lock(cd, device);
+	if (r) {
+		log_err(cd, _("Failed to acquire read lock on device %s."), device_path(device));
+		return r;
+	}
+	r = LUKS_decrypt_from_storage(dst, dstLength, cipher, cipher_mode, vk, sector, cd);
+	device_read_unlock(cd, crypt_metadata_device(cd));
+	return r;
+#else
+	struct crypt_storage *s;
+	int devfd = -1, r;
+
+	/* Only whole sector writes supported */
+	if (MISALIGNED_512(dstLength))
+		return -EINVAL;
+
+	r = crypt_storage_init(&s, 0, cipher, cipher_mode, vk->key, vk->keylength);
+	if (r) {
+		log_dbg(cd, "Userspace crypto wrapper cannot use %s-%s (%d).",
+			cipher, cipher_mode, r);
+		return r;
+	}
+
+	r = device_read_lock(cd, device);
+	if (r) {
+		log_err(cd, _("Failed to acquire read lock on device %s."),
+			device_path(device));
+		crypt_storage_destroy(s);
+		return r;
+	}
+
+	devfd = device_open_locked(cd, device, O_RDONLY);
+	if (devfd >= 0) {
+		if (read_lseek_blockwise(devfd, device_block_size(cd, device),
+					 device_alignment(device), dst,
+					 dstLength, sector * SECTOR_SIZE) < 0)
+			r = -EIO;
+		else
+			r = 0;
+		close(devfd);
+	} else
+		r = -EIO;
+
+	device_read_unlock(cd, device);
+
+	/* Decrypt buffer */
+	if (!r)
+		r = crypt_storage_decrypt(s, 0, dstLength / SECTOR_SIZE, dst);
+	else
+		log_err(cd, _("IO error while decrypting keyslot."));
+
+	crypt_storage_destroy(s);
+	return r;
+#endif
+}
+
+static int luks2_keyslot_get_pbkdf_params(json_object *jobj_keyslot,
+		                struct crypt_pbkdf_type *pbkdf, char *salt)
+{
+	json_object *jobj_kdf, *jobj1, *jobj2;
+	size_t salt_len;
+
+	if (!jobj_keyslot || !pbkdf)
+		return -EINVAL;
+
+	memset(pbkdf, 0, sizeof(*pbkdf));
+
+	if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf))
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_kdf, "type", &jobj1))
+		return -EINVAL;
+	pbkdf->type = json_object_get_string(jobj1);
+	if (!strcmp(pbkdf->type, CRYPT_KDF_PBKDF2)) {
+		if (!json_object_object_get_ex(jobj_kdf, "hash", &jobj2))
+			return -EINVAL;
+		pbkdf->hash = json_object_get_string(jobj2);
+		if (!json_object_object_get_ex(jobj_kdf, "iterations", &jobj2))
+			return -EINVAL;
+		pbkdf->iterations = json_object_get_int(jobj2);
+		pbkdf->max_memory_kb = 0;
+		pbkdf->parallel_threads = 0;
+	} else {
+		if (!json_object_object_get_ex(jobj_kdf, "time", &jobj2))
+			return -EINVAL;
+		pbkdf->iterations = json_object_get_int(jobj2);
+		if (!json_object_object_get_ex(jobj_kdf, "memory", &jobj2))
+			return -EINVAL;
+		pbkdf->max_memory_kb = json_object_get_int(jobj2);
+		if (!json_object_object_get_ex(jobj_kdf, "cpus", &jobj2))
+			return -EINVAL;
+		pbkdf->parallel_threads = json_object_get_int(jobj2);
+	}
+
+	if (!json_object_object_get_ex(jobj_kdf, "salt", &jobj2))
+		return -EINVAL;
+	salt_len = LUKS_SALTSIZE;
+	if (!base64_decode(json_object_get_string(jobj2),
+			   json_object_get_string_len(jobj2),
+			   salt, &salt_len))
+		return -EINVAL;
+	if (salt_len != LUKS_SALTSIZE)
+		return -EINVAL;
+
+	return 0;
+}
+
+static int luks2_keyslot_set_key(struct crypt_device *cd,
+	json_object *jobj_keyslot,
+	const char *password, size_t passwordLen,
+	const char *volume_key, size_t volume_key_len)
+{
+	struct volume_key *derived_key;
+	char salt[LUKS_SALTSIZE], cipher[MAX_CIPHER_LEN], cipher_mode[MAX_CIPHER_LEN];
+	char *AfKey = NULL;
+	const char *af_hash = NULL;
+	size_t AFEKSize, keyslot_key_len;
+	json_object *jobj2, *jobj_kdf, *jobj_af, *jobj_area;
+	uint64_t area_offset;
+	struct crypt_pbkdf_type pbkdf;
+	int r;
+
+	if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf) ||
+	    !json_object_object_get_ex(jobj_keyslot, "af", &jobj_af) ||
+	    !json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
+		return -EINVAL;
+
+	/* prevent accidental volume key size change after allocation */
+	if (!json_object_object_get_ex(jobj_keyslot, "key_size", &jobj2))
+		return -EINVAL;
+	if (json_object_get_int(jobj2) != (int)volume_key_len)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_area, "offset", &jobj2))
+		return -EINVAL;
+	area_offset = json_object_get_uint64(jobj2);
+
+	if (!json_object_object_get_ex(jobj_area, "encryption", &jobj2))
+		return -EINVAL;
+	r = crypt_parse_name_and_mode(json_object_get_string(jobj2), cipher, NULL, cipher_mode);
+	if (r < 0)
+		return r;
+
+	if (!json_object_object_get_ex(jobj_area, "key_size", &jobj2))
+		return -EINVAL;
+	keyslot_key_len = json_object_get_int(jobj2);
+
+	if (!json_object_object_get_ex(jobj_af, "hash", &jobj2))
+		return -EINVAL;
+	af_hash = json_object_get_string(jobj2);
+
+	if (luks2_keyslot_get_pbkdf_params(jobj_keyslot, &pbkdf, salt))
+		return -EINVAL;
+
+	/*
+	 * Allocate derived key storage.
+	 */
+	derived_key = crypt_alloc_volume_key(keyslot_key_len, NULL);
+	if (!derived_key)
+		return -ENOMEM;
+	/*
+	 * Calculate keyslot content, split and store it to keyslot area.
+	 */
+	r = crypt_pbkdf(pbkdf.type, pbkdf.hash, password, passwordLen,
+			salt, LUKS_SALTSIZE,
+			derived_key->key, derived_key->keylength,
+			pbkdf.iterations, pbkdf.max_memory_kb,
+			pbkdf.parallel_threads);
+	if (r < 0) {
+		crypt_free_volume_key(derived_key);
+		return r;
+	}
+
+	// FIXME: verity key_size to AFEKSize
+	AFEKSize = AF_split_sectors(volume_key_len, LUKS_STRIPES) * SECTOR_SIZE;
+	AfKey = crypt_safe_alloc(AFEKSize);
+	if (!AfKey) {
+		crypt_free_volume_key(derived_key);
+		return -ENOMEM;
+	}
+
+	r = AF_split(cd, volume_key, AfKey, volume_key_len, LUKS_STRIPES, af_hash);
+
+	if (r == 0) {
+		log_dbg(cd, "Updating keyslot area [0x%04x].", (unsigned)area_offset);
+		/* FIXME: sector_offset should be size_t, fix LUKS_encrypt... accordingly */
+		r = luks2_encrypt_to_storage(AfKey, AFEKSize, cipher, cipher_mode,
+				    derived_key, (unsigned)(area_offset / SECTOR_SIZE), cd);
+	}
+
+	crypt_safe_free(AfKey);
+	crypt_free_volume_key(derived_key);
+	if (r < 0)
+		return r;
+
+	return 0;
+}
+
+static int luks2_keyslot_get_key(struct crypt_device *cd,
+	json_object *jobj_keyslot,
+	const char *password, size_t passwordLen,
+	char *volume_key, size_t volume_key_len)
+{
+	struct volume_key *derived_key;
+	struct crypt_pbkdf_type pbkdf;
+	char *AfKey;
+	size_t AFEKSize;
+	const char *af_hash = NULL;
+	char salt[LUKS_SALTSIZE], cipher[MAX_CIPHER_LEN], cipher_mode[MAX_CIPHER_LEN];
+	json_object *jobj2, *jobj_af, *jobj_area;
+	uint64_t area_offset;
+	size_t keyslot_key_len;
+	int r;
+
+	if (!json_object_object_get_ex(jobj_keyslot, "af", &jobj_af) ||
+	    !json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
+		return -EINVAL;
+
+	if (luks2_keyslot_get_pbkdf_params(jobj_keyslot, &pbkdf, salt))
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_af, "hash", &jobj2))
+		return -EINVAL;
+	af_hash = json_object_get_string(jobj2);
+
+	if (!json_object_object_get_ex(jobj_area, "offset", &jobj2))
+		return -EINVAL;
+	area_offset = json_object_get_uint64(jobj2);
+
+	if (!json_object_object_get_ex(jobj_area, "encryption", &jobj2))
+		return -EINVAL;
+	r = crypt_parse_name_and_mode(json_object_get_string(jobj2), cipher, NULL, cipher_mode);
+	if (r < 0)
+		return r;
+
+	if (!json_object_object_get_ex(jobj_area, "key_size", &jobj2))
+		return -EINVAL;
+	keyslot_key_len = json_object_get_int(jobj2);
+
+	/*
+	 * Allocate derived key storage space.
+	 */
+	derived_key = crypt_alloc_volume_key(keyslot_key_len, NULL);
+	if (!derived_key)
+		return -ENOMEM;
+
+	AFEKSize = AF_split_sectors(volume_key_len, LUKS_STRIPES) * SECTOR_SIZE;
+	AfKey = crypt_safe_alloc(AFEKSize);
+	if (!AfKey) {
+		crypt_free_volume_key(derived_key);
+		return -ENOMEM;
+	}
+	/*
+	 * Calculate derived key, decrypt keyslot content and merge it.
+	 */
+	r = crypt_pbkdf(pbkdf.type, pbkdf.hash, password, passwordLen,
+			salt, LUKS_SALTSIZE,
+			derived_key->key, derived_key->keylength,
+			pbkdf.iterations, pbkdf.max_memory_kb,
+			pbkdf.parallel_threads);
+
+	if (r == 0) {
+		log_dbg(cd, "Reading keyslot area [0x%04x].", (unsigned)area_offset);
+		/* FIXME: sector_offset should be size_t, fix LUKS_decrypt... accordingly */
+		r = luks2_decrypt_from_storage(AfKey, AFEKSize, cipher, cipher_mode,
+				      derived_key, (unsigned)(area_offset / SECTOR_SIZE), cd);
+	}
+
+	if (r == 0)
+		r = AF_merge(cd, AfKey, volume_key, volume_key_len, LUKS_STRIPES, af_hash);
+
+	crypt_free_volume_key(derived_key);
+	crypt_safe_free(AfKey);
+
+	return r;
+}
+
+/*
+ * currently we support update of only:
+ *
+ * - af hash function
+ * - kdf params
+ */
+static int luks2_keyslot_update_json(struct crypt_device *cd,
+	json_object *jobj_keyslot,
+	const struct luks2_keyslot_params *params)
+{
+	const struct crypt_pbkdf_type *pbkdf;
+	json_object *jobj_af, *jobj_area, *jobj_kdf;
+	char salt[LUKS_SALTSIZE], *salt_base64 = NULL;
+	int r;
+
+	/* jobj_keyslot is not yet validated */
+
+	if (!json_object_object_get_ex(jobj_keyslot, "af", &jobj_af) ||
+	    !json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
+		return -EINVAL;
+
+	/* update area encryption parameters */
+	json_object_object_add(jobj_area, "encryption", json_object_new_string(params->area.raw.encryption));
+	json_object_object_add(jobj_area, "key_size", json_object_new_int(params->area.raw.key_size));
+
+	pbkdf = crypt_get_pbkdf_type(cd);
+	if (!pbkdf)
+		return -EINVAL;
+
+	r = crypt_benchmark_pbkdf_internal(cd, CONST_CAST(struct crypt_pbkdf_type *)pbkdf, params->area.raw.key_size);
+	if (r < 0)
+		return r;
+
+	/* refresh whole 'kdf' object */
+	jobj_kdf = json_object_new_object();
+	if (!jobj_kdf)
+		return -ENOMEM;
+	json_object_object_add(jobj_kdf, "type", json_object_new_string(pbkdf->type));
+	if (!strcmp(pbkdf->type, CRYPT_KDF_PBKDF2)) {
+		json_object_object_add(jobj_kdf, "hash", json_object_new_string(pbkdf->hash));
+		json_object_object_add(jobj_kdf, "iterations", json_object_new_int(pbkdf->iterations));
+	} else {
+		json_object_object_add(jobj_kdf, "time", json_object_new_int(pbkdf->iterations));
+		json_object_object_add(jobj_kdf, "memory", json_object_new_int(pbkdf->max_memory_kb));
+		json_object_object_add(jobj_kdf, "cpus", json_object_new_int(pbkdf->parallel_threads));
+	}
+	json_object_object_add(jobj_keyslot, "kdf", jobj_kdf);
+
+	/*
+	 * Regenerate salt and add it in 'kdf' object
+	 */
+	r = crypt_random_get(cd, salt, LUKS_SALTSIZE, CRYPT_RND_SALT);
+	if (r < 0)
+		return r;
+	base64_encode_alloc(salt, LUKS_SALTSIZE, &salt_base64);
+	if (!salt_base64)
+		return -ENOMEM;
+	json_object_object_add(jobj_kdf, "salt", json_object_new_string(salt_base64));
+	free(salt_base64);
+
+	/* update 'af' hash */
+	json_object_object_add(jobj_af, "hash", json_object_new_string(params->af.luks1.hash));
+
+	JSON_DBG(cd, jobj_keyslot, "Keyslot JSON:");
+	return 0;
+}
+
+static int luks2_keyslot_alloc(struct crypt_device *cd,
+	int keyslot,
+	size_t volume_key_len,
+	const struct luks2_keyslot_params *params)
+{
+	struct luks2_hdr *hdr;
+	uint64_t area_offset, area_length;
+	json_object *jobj_keyslots, *jobj_keyslot, *jobj_af, *jobj_area;
+	int r;
+
+	log_dbg(cd, "Trying to allocate LUKS2 keyslot %d.", keyslot);
+
+	if (!params || params->area_type != LUKS2_KEYSLOT_AREA_RAW ||
+	    params->af_type != LUKS2_KEYSLOT_AF_LUKS1) {
+		log_dbg(cd, "Invalid LUKS2 keyslot parameters.");
+		return -EINVAL;
+	}
+
+	if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
+		return -EINVAL;
+
+	if (keyslot == CRYPT_ANY_SLOT)
+		keyslot = LUKS2_keyslot_find_empty(hdr, "luks2");
+
+	if (keyslot < 0 || keyslot >= LUKS2_KEYSLOTS_MAX)
+		return -ENOMEM;
+
+	if (LUKS2_get_keyslot_jobj(hdr, keyslot)) {
+		log_dbg(cd, "Cannot modify already active keyslot %d.", keyslot);
+		return -EINVAL;
+	}
+
+	if (!json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots))
+		return -EINVAL;
+
+	r = LUKS2_find_area_gap(cd, hdr, volume_key_len, &area_offset, &area_length);
+	if (r < 0)
+		return r;
+
+	jobj_keyslot = json_object_new_object();
+	json_object_object_add(jobj_keyslot, "type", json_object_new_string("luks2"));
+	json_object_object_add(jobj_keyslot, "key_size", json_object_new_int(volume_key_len));
+
+	/* AF object */
+	jobj_af = json_object_new_object();
+	json_object_object_add(jobj_af, "type", json_object_new_string("luks1"));
+	json_object_object_add(jobj_af, "stripes", json_object_new_int(params->af.luks1.stripes));
+	json_object_object_add(jobj_keyslot, "af", jobj_af);
+
+	/* Area object */
+	jobj_area = json_object_new_object();
+	json_object_object_add(jobj_area, "type", json_object_new_string("raw"));
+	json_object_object_add(jobj_area, "offset", json_object_new_uint64(area_offset));
+	json_object_object_add(jobj_area, "size", json_object_new_uint64(area_length));
+	json_object_object_add(jobj_keyslot, "area", jobj_area);
+
+	json_object_object_add_by_uint(jobj_keyslots, keyslot, jobj_keyslot);
+
+	r = luks2_keyslot_update_json(cd, jobj_keyslot, params);
+
+	if (!r && LUKS2_check_json_size(cd, hdr)) {
+		log_dbg(cd, "Not enough space in header json area for new keyslot.");
+		r = -ENOSPC;
+	}
+
+	if (r)
+		json_object_object_del_by_uint(jobj_keyslots, keyslot);
+
+	return r;
+}
+
+static int luks2_keyslot_open(struct crypt_device *cd,
+	int keyslot,
+	const char *password,
+	size_t password_len,
+	char *volume_key,
+	size_t volume_key_len)
+{
+	struct luks2_hdr *hdr;
+	json_object *jobj_keyslot;
+
+	log_dbg(cd, "Trying to open LUKS2 keyslot %d.", keyslot);
+
+	if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
+		return -EINVAL;
+
+	jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
+	if (!jobj_keyslot)
+		return -EINVAL;
+
+	return luks2_keyslot_get_key(cd, jobj_keyslot,
+				     password, password_len,
+				     volume_key, volume_key_len);
+}
+
+/*
+ * This function must not modify json.
+ * It's called after luks2 keyslot validation.
+ */
+static int luks2_keyslot_store(struct crypt_device *cd,
+	int keyslot,
+	const char *password,
+	size_t password_len,
+	const char *volume_key,
+	size_t volume_key_len)
+{
+	struct luks2_hdr *hdr;
+	json_object *jobj_keyslot;
+	int r;
+
+	log_dbg(cd, "Calculating attributes for LUKS2 keyslot %d.", keyslot);
+
+	if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
+		return -EINVAL;
+
+	jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
+	if (!jobj_keyslot)
+		return -EINVAL;
+
+	r = luks2_keyslot_set_key(cd, jobj_keyslot,
+				  password, password_len,
+				  volume_key, volume_key_len);
+	if (r < 0)
+		return r;
+
+	r = LUKS2_hdr_write(cd, hdr);
+	if (r < 0)
+		return r;
+
+	return keyslot;
+}
+
+static int luks2_keyslot_wipe(struct crypt_device *cd, int keyslot)
+{
+	struct luks2_hdr *hdr;
+
+	if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
+		return -EINVAL;
+
+	/* Remove any reference of deleted keyslot from digests and tokens */
+	LUKS2_digest_assign(cd, hdr, keyslot, CRYPT_ANY_DIGEST, 0, 0);
+	LUKS2_token_assign(cd, hdr, keyslot, CRYPT_ANY_TOKEN, 0, 0);
+
+	return 0;
+}
+
+static int luks2_keyslot_dump(struct crypt_device *cd, int keyslot)
+{
+	json_object *jobj_keyslot, *jobj1, *jobj_kdf, *jobj_af, *jobj_area;
+
+	jobj_keyslot = LUKS2_get_keyslot_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), keyslot);
+	if (!jobj_keyslot)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf) ||
+	    !json_object_object_get_ex(jobj_keyslot, "af", &jobj_af) ||
+	    !json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
+		return -EINVAL;
+
+	json_object_object_get_ex(jobj_area, "encryption", &jobj1);
+	log_std(cd, "\tCipher:     %s\n", json_object_get_string(jobj1));
+
+	json_object_object_get_ex(jobj_area, "key_size", &jobj1);
+	log_std(cd, "\tCipher key: %u bits\n", json_object_get_uint32(jobj1) * 8);
+
+	json_object_object_get_ex(jobj_kdf, "type", &jobj1);
+	log_std(cd, "\tPBKDF:      %s\n", json_object_get_string(jobj1));
+
+	if (!strcmp(json_object_get_string(jobj1), CRYPT_KDF_PBKDF2)) {
+		json_object_object_get_ex(jobj_kdf, "hash", &jobj1);
+		log_std(cd, "\tHash:       %s\n", json_object_get_string(jobj1));
+
+		json_object_object_get_ex(jobj_kdf, "iterations", &jobj1);
+		log_std(cd, "\tIterations: %" PRIu64 "\n", json_object_get_uint64(jobj1));
+	} else {
+		json_object_object_get_ex(jobj_kdf, "time", &jobj1);
+		log_std(cd, "\tTime cost:  %" PRIu64 "\n", json_object_get_int64(jobj1));
+
+		json_object_object_get_ex(jobj_kdf, "memory", &jobj1);
+		log_std(cd, "\tMemory:     %" PRIu64 "\n", json_object_get_int64(jobj1));
+
+		json_object_object_get_ex(jobj_kdf, "cpus", &jobj1);
+		log_std(cd, "\tThreads:    %" PRIu64 "\n", json_object_get_int64(jobj1));
+	}
+	json_object_object_get_ex(jobj_kdf, "salt", &jobj1);
+	log_std(cd, "\tSalt:       ");
+	hexprint_base64(cd, jobj1, " ", "            ");
+
+
+	json_object_object_get_ex(jobj_af, "stripes", &jobj1);
+	log_std(cd, "\tAF stripes: %u\n", json_object_get_int(jobj1));
+
+	json_object_object_get_ex(jobj_af, "hash", &jobj1);
+	log_std(cd, "\tAF hash:    %s\n", json_object_get_string(jobj1));
+
+	json_object_object_get_ex(jobj_area, "offset", &jobj1);
+	log_std(cd, "\tArea offset:%" PRIu64 " [bytes]\n", json_object_get_uint64(jobj1));
+
+	json_object_object_get_ex(jobj_area, "size", &jobj1);
+	log_std(cd, "\tArea length:%" PRIu64 " [bytes]\n", json_object_get_uint64(jobj1));
+
+	return 0;
+}
+
+static int luks2_keyslot_validate(struct crypt_device *cd, json_object *jobj_keyslot)
+{
+	json_object *jobj_kdf, *jobj_af, *jobj_area, *jobj1;
+	const char *type;
+	int count;
+
+	if (!jobj_keyslot)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf) ||
+	    !json_object_object_get_ex(jobj_keyslot, "af", &jobj_af) ||
+	    !json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
+		return -EINVAL;
+
+	count = json_object_object_length(jobj_kdf);
+
+	jobj1 = json_contains(cd, jobj_kdf, "", "kdf section", "type", json_type_string);
+	if (!jobj1)
+		return -EINVAL;
+	type = json_object_get_string(jobj1);
+
+	if (!strcmp(type, CRYPT_KDF_PBKDF2)) {
+		if (count != 4 || /* type, salt, hash, iterations only */
+		    !json_contains(cd, jobj_kdf, "kdf type", type, "hash", json_type_string) ||
+		    !json_contains(cd, jobj_kdf, "kdf type", type, "iterations", json_type_int) ||
+		    !json_contains(cd, jobj_kdf, "kdf type", type, "salt", json_type_string))
+			return -EINVAL;
+	} else if (!strcmp(type, CRYPT_KDF_ARGON2I) || !strcmp(type, CRYPT_KDF_ARGON2ID)) {
+		if (count != 5 || /* type, salt, time, memory, cpus only */
+		    !json_contains(cd, jobj_kdf, "kdf type", type, "time", json_type_int) ||
+		    !json_contains(cd, jobj_kdf, "kdf type", type, "memory", json_type_int) ||
+		    !json_contains(cd, jobj_kdf, "kdf type", type, "cpus", json_type_int) ||
+		    !json_contains(cd, jobj_kdf, "kdf type", type, "salt", json_type_string))
+			return -EINVAL;
+	}
+
+	if (!json_object_object_get_ex(jobj_af, "type", &jobj1))
+		return -EINVAL;
+	if (!strcmp(json_object_get_string(jobj1), "luks1")) {
+		if (!json_contains(cd, jobj_af, "", "luks1 af", "hash", json_type_string) ||
+		    !json_contains(cd, jobj_af, "", "luks1 af", "stripes", json_type_int))
+			return -EINVAL;
+	} else
+		return -EINVAL;
+
+	// FIXME check numbered
+	if (!json_object_object_get_ex(jobj_area, "type", &jobj1))
+		return -EINVAL;
+	if (!strcmp(json_object_get_string(jobj1), "raw")) {
+		if (!json_contains(cd, jobj_area, "area", "raw type", "encryption", json_type_string) ||
+		    !json_contains(cd, jobj_area, "area", "raw type", "key_size", json_type_int) ||
+		    !json_contains(cd, jobj_area, "area", "raw type", "offset", json_type_string) ||
+		    !json_contains(cd, jobj_area, "area", "raw type", "size", json_type_string))
+			return -EINVAL;
+	} else
+		return -EINVAL;
+
+	return 0;
+}
+
+static int luks2_keyslot_update(struct crypt_device *cd,
+	int keyslot,
+	const struct luks2_keyslot_params *params)
+{
+	struct luks2_hdr *hdr;
+	json_object *jobj_keyslot;
+	int r;
+
+	log_dbg(cd, "Updating LUKS2 keyslot %d.", keyslot);
+
+	if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
+		return -EINVAL;
+
+	jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
+	if (!jobj_keyslot)
+		return -EINVAL;
+
+	r = luks2_keyslot_update_json(cd, jobj_keyslot, params);
+
+	if (!r && LUKS2_check_json_size(cd, hdr)) {
+		log_dbg(cd, "Not enough space in header json area for updated keyslot %d.", keyslot);
+		r = -ENOSPC;
+	}
+
+	return r;
+}
+
+static void luks2_keyslot_repair(struct crypt_device *cd, json_object *jobj_keyslot)
+{
+	const char *type;
+	json_object *jobj_kdf, *jobj_type;
+
+	if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf) ||
+	    !json_object_is_type(jobj_kdf, json_type_object))
+		return;
+
+	if (!json_object_object_get_ex(jobj_kdf, "type", &jobj_type) ||
+	    !json_object_is_type(jobj_type, json_type_string))
+		return;
+
+	type = json_object_get_string(jobj_type);
+
+	if (!strcmp(type, CRYPT_KDF_PBKDF2)) {
+		/* type, salt, hash, iterations only */
+		json_object_object_foreach(jobj_kdf, key, val) {
+			UNUSED(val);
+			if (!strcmp(key, "type") || !strcmp(key, "salt") ||
+			    !strcmp(key, "hash") || !strcmp(key, "iterations"))
+					continue;
+			json_object_object_del(jobj_kdf, key);
+		}
+	} else if (!strcmp(type, CRYPT_KDF_ARGON2I) || !strcmp(type, CRYPT_KDF_ARGON2ID)) {
+		/* type, salt, time, memory, cpus only */
+		json_object_object_foreach(jobj_kdf, key, val) {
+			UNUSED(val);
+			if (!strcmp(key, "type") || !strcmp(key, "salt") ||
+			    !strcmp(key, "time") || !strcmp(key, "memory") ||
+			    !strcmp(key, "cpus"))
+					continue;
+			json_object_object_del(jobj_kdf, key);
+		}
+	}
+}
+
+const keyslot_handler luks2_keyslot = {
+	.name  = "luks2",
+	.alloc  = luks2_keyslot_alloc,
+	.update = luks2_keyslot_update,
+	.open  = luks2_keyslot_open,
+	.store = luks2_keyslot_store,
+	.wipe  = luks2_keyslot_wipe,
+	.dump  = luks2_keyslot_dump,
+	.validate = luks2_keyslot_validate,
+	.repair = luks2_keyslot_repair
+};
diff --git a/lib/luks2/luks2_luks1_convert.c b/lib/luks2/luks2_luks1_convert.c
new file mode 100644
index 0000000..7884de0
--- /dev/null
+++ b/lib/luks2/luks2_luks1_convert.c
@@ -0,0 +1,863 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, LUKS1 conversion code
+ *
+ * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2015-2019 Ondrej Kozina
+ * Copyright (C) 2015-2019 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"
+#include "../luks1/luks.h"
+#include "../luks1/af.h"
+
+static int json_luks1_keyslot(const struct luks_phdr *hdr_v1, int keyslot, struct json_object **keyslot_object)
+{
+	char *base64_str, cipher[LUKS_CIPHERNAME_L+LUKS_CIPHERMODE_L];
+	size_t base64_len;
+	struct json_object *keyslot_obj, *field, *jobj_kdf, *jobj_af, *jobj_area;
+	uint64_t offset, area_size, offs_a, offs_b, length;
+
+	keyslot_obj = json_object_new_object();
+	json_object_object_add(keyslot_obj, "type", json_object_new_string("luks2"));
+	json_object_object_add(keyslot_obj, "key_size", json_object_new_int64(hdr_v1->keyBytes));
+
+	/* KDF */
+	jobj_kdf = json_object_new_object();
+	json_object_object_add(jobj_kdf, "type", json_object_new_string(CRYPT_KDF_PBKDF2));
+	json_object_object_add(jobj_kdf, "hash", json_object_new_string(hdr_v1->hashSpec));
+	json_object_object_add(jobj_kdf, "iterations", json_object_new_int64(hdr_v1->keyblock[keyslot].passwordIterations));
+	/* salt field */
+	base64_len = base64_encode_alloc(hdr_v1->keyblock[keyslot].passwordSalt, LUKS_SALTSIZE, &base64_str);
+	if (!base64_str) {
+		json_object_put(keyslot_obj);
+		json_object_put(jobj_kdf);
+		if (!base64_len)
+			return -EINVAL;
+		return -ENOMEM;
+	}
+	field = json_object_new_string_len(base64_str, base64_len);
+	free(base64_str);
+	json_object_object_add(jobj_kdf, "salt", field);
+	json_object_object_add(keyslot_obj, "kdf", jobj_kdf);
+
+	/* AF */
+	jobj_af = json_object_new_object();
+	json_object_object_add(jobj_af, "type", json_object_new_string("luks1"));
+	json_object_object_add(jobj_af, "hash", json_object_new_string(hdr_v1->hashSpec));
+	/* stripes field ignored, fixed to LUKS_STRIPES (4000) */
+	json_object_object_add(jobj_af, "stripes", json_object_new_int(4000));
+	json_object_object_add(keyslot_obj, "af", jobj_af);
+
+	/* Area */
+	jobj_area = json_object_new_object();
+	json_object_object_add(jobj_area, "type", json_object_new_string("raw"));
+
+	/* encryption algorithm field */
+	if (*hdr_v1->cipherMode != '\0') {
+		(void) snprintf(cipher, sizeof(cipher), "%s-%s", hdr_v1->cipherName, hdr_v1->cipherMode);
+		json_object_object_add(jobj_area, "encryption", json_object_new_string(cipher));
+	} else
+		json_object_object_add(jobj_area, "encryption", json_object_new_string(hdr_v1->cipherName));
+
+	/* area */
+	if (LUKS_keyslot_area(hdr_v1, 0, &offs_a, &length) ||
+	    LUKS_keyslot_area(hdr_v1, 1, &offs_b, &length) ||
+	    LUKS_keyslot_area(hdr_v1, keyslot, &offset, &length)) {
+		json_object_put(keyslot_obj);
+		json_object_put(jobj_area);
+		return -EINVAL;
+	}
+	area_size = offs_b - offs_a;
+	json_object_object_add(jobj_area, "key_size", json_object_new_int(hdr_v1->keyBytes));
+	json_object_object_add(jobj_area, "offset", json_object_new_uint64(offset));
+	json_object_object_add(jobj_area, "size", json_object_new_uint64(area_size));
+	json_object_object_add(keyslot_obj, "area", jobj_area);
+
+	*keyslot_object = keyslot_obj;
+	return 0;
+}
+
+static int json_luks1_keyslots(const struct luks_phdr *hdr_v1, struct json_object **keyslots_object)
+{
+	int keyslot, r;
+	struct json_object *keyslot_obj, *field;
+
+	keyslot_obj = json_object_new_object();
+	if (!keyslot_obj)
+		return -ENOMEM;
+
+	for (keyslot = 0; keyslot < LUKS_NUMKEYS; keyslot++) {
+		if (hdr_v1->keyblock[keyslot].active != LUKS_KEY_ENABLED)
+			continue;
+		r = json_luks1_keyslot(hdr_v1, keyslot, &field);
+		if (r) {
+			json_object_put(keyslot_obj);
+			return r;
+		}
+		json_object_object_add_by_uint(keyslot_obj, keyslot, field);
+	}
+
+	*keyslots_object = keyslot_obj;
+	return 0;
+}
+
+static int json_luks1_segment(const struct luks_phdr *hdr_v1, struct json_object **segment_object)
+{
+	const char *c;
+	char cipher[LUKS_CIPHERNAME_L+LUKS_CIPHERMODE_L];
+	struct json_object *segment_obj, *field;
+	uint64_t number;
+
+	segment_obj = json_object_new_object();
+	if (!segment_obj)
+		return -ENOMEM;
+
+	/* type field */
+	field = json_object_new_string("crypt");
+	if (!field) {
+		json_object_put(segment_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(segment_obj, "type", field);
+
+	/* offset field */
+	number = (uint64_t)hdr_v1->payloadOffset * SECTOR_SIZE;
+
+	field = json_object_new_uint64(number);
+	if (!field) {
+		json_object_put(segment_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(segment_obj, "offset", field);
+
+	/* iv_tweak field */
+	field = json_object_new_string("0");
+	if (!field) {
+		json_object_put(segment_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(segment_obj, "iv_tweak", field);
+
+	/* length field */
+	field = json_object_new_string("dynamic");
+	if (!field) {
+		json_object_put(segment_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(segment_obj, "size", field);
+
+	/* cipher field */
+	if (*hdr_v1->cipherMode != '\0') {
+		(void) snprintf(cipher, sizeof(cipher), "%s-%s", hdr_v1->cipherName, hdr_v1->cipherMode);
+		c = cipher;
+	} else
+		c = hdr_v1->cipherName;
+
+	field = json_object_new_string(c);
+	if (!field) {
+		json_object_put(segment_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(segment_obj, "encryption", field);
+
+	/* block field */
+	field = json_object_new_int(SECTOR_SIZE);
+	if (!field) {
+		json_object_put(segment_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(segment_obj, "sector_size", field);
+
+	*segment_object = segment_obj;
+	return 0;
+}
+
+static int json_luks1_segments(const struct luks_phdr *hdr_v1, struct json_object **segments_object)
+{
+	int r;
+	struct json_object *segments_obj, *field;
+
+	segments_obj = json_object_new_object();
+	if (!segments_obj)
+		return -ENOMEM;
+
+	r = json_luks1_segment(hdr_v1, &field);
+	if (r) {
+		json_object_put(segments_obj);
+		return r;
+	}
+	json_object_object_add_by_uint(segments_obj, CRYPT_DEFAULT_SEGMENT, field);
+
+	*segments_object = segments_obj;
+	return 0;
+}
+
+static int json_luks1_digest(const struct luks_phdr *hdr_v1, struct json_object **digest_object)
+{
+	char keyslot_str[2], *base64_str;
+	int ks;
+	size_t base64_len;
+	struct json_object *digest_obj, *array, *field;
+
+	digest_obj = json_object_new_object();
+	if (!digest_obj)
+		return -ENOMEM;
+
+	/* type field */
+	field = json_object_new_string("pbkdf2");
+	if (!field) {
+		json_object_put(digest_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(digest_obj, "type", field);
+
+	/* keyslots array */
+	array = json_object_new_array();
+	if (!array) {
+		json_object_put(digest_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(digest_obj, "keyslots", json_object_get(array));
+
+	for (ks = 0; ks < LUKS_NUMKEYS; ks++) {
+		if (hdr_v1->keyblock[ks].active != LUKS_KEY_ENABLED)
+			continue;
+		(void) snprintf(keyslot_str, sizeof(keyslot_str), "%d", ks);
+
+		field = json_object_new_string(keyslot_str);
+		if (!field || json_object_array_add(array, field) < 0) {
+			json_object_put(field);
+			json_object_put(array);
+			json_object_put(digest_obj);
+			return -ENOMEM;
+		}
+	}
+
+	json_object_put(array);
+
+	/* segments array */
+	array = json_object_new_array();
+	if (!array) {
+		json_object_put(digest_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(digest_obj, "segments", json_object_get(array));
+
+	field = json_object_new_string("0");
+	if (!field || json_object_array_add(array, field) < 0) {
+		json_object_put(field);
+		json_object_put(array);
+		json_object_put(digest_obj);
+		return -ENOMEM;
+	}
+
+	json_object_put(array);
+
+	/* hash field */
+	field = json_object_new_string(hdr_v1->hashSpec);
+	if (!field) {
+		json_object_put(digest_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(digest_obj, "hash", field);
+
+	/* salt field */
+	base64_len = base64_encode_alloc(hdr_v1->mkDigestSalt, LUKS_SALTSIZE, &base64_str);
+	if (!base64_str) {
+		json_object_put(digest_obj);
+		if (!base64_len)
+			return -EINVAL;
+		return -ENOMEM;
+	}
+
+	field = json_object_new_string_len(base64_str, base64_len);
+	free(base64_str);
+	if (!field) {
+		json_object_put(digest_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(digest_obj, "salt", field);
+
+	/* digest field */
+	base64_len = base64_encode_alloc(hdr_v1->mkDigest, LUKS_DIGESTSIZE, &base64_str);
+	if (!base64_str) {
+		json_object_put(digest_obj);
+		if (!base64_len)
+			return -EINVAL;
+		return -ENOMEM;
+	}
+
+	field = json_object_new_string_len(base64_str, base64_len);
+	free(base64_str);
+	if (!field) {
+		json_object_put(digest_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(digest_obj, "digest", field);
+
+	/* iterations field */
+	field = json_object_new_int64(hdr_v1->mkDigestIterations);
+	if (!field) {
+		json_object_put(digest_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(digest_obj, "iterations", field);
+
+	*digest_object = digest_obj;
+	return 0;
+}
+
+static int json_luks1_digests(const struct luks_phdr *hdr_v1, struct json_object **digests_object)
+{
+	int r;
+	struct json_object *digests_obj, *field;
+
+	digests_obj = json_object_new_object();
+	if (!digests_obj)
+		return -ENOMEM;
+
+	r = json_luks1_digest(hdr_v1, &field);
+	if (r) {
+		json_object_put(digests_obj);
+		return r;
+	}
+	json_object_object_add(digests_obj, "0", field);
+
+	*digests_object = digests_obj;
+	return 0;
+}
+
+static int json_luks1_object(struct luks_phdr *hdr_v1, struct json_object **luks1_object, uint64_t keyslots_size)
+{
+	int r;
+	struct json_object *luks1_obj, *field;
+	uint64_t json_size;
+
+	luks1_obj = json_object_new_object();
+	if (!luks1_obj)
+		return -ENOMEM;
+
+	/* keyslots field */
+	r = json_luks1_keyslots(hdr_v1, &field);
+	if (r) {
+		json_object_put(luks1_obj);
+		return r;
+	}
+	json_object_object_add(luks1_obj, "keyslots", field);
+
+	/* tokens field */
+	field = json_object_new_object();
+	if (!field) {
+		json_object_put(luks1_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(luks1_obj, "tokens", field);
+
+	/* segments field */
+	r = json_luks1_segments(hdr_v1, &field);
+	if (r) {
+		json_object_put(luks1_obj);
+		return r;
+	}
+	json_object_object_add(luks1_obj, "segments", field);
+
+	/* digests field */
+	r = json_luks1_digests(hdr_v1, &field);
+	if (r) {
+		json_object_put(luks1_obj);
+		return r;
+	}
+	json_object_object_add(luks1_obj, "digests", field);
+
+	/* config field */
+	/* anything else? */
+	field = json_object_new_object();
+	if (!field) {
+		json_object_put(luks1_obj);
+		return -ENOMEM;
+	}
+	json_object_object_add(luks1_obj, "config", field);
+
+	json_size = LUKS2_HDR_16K_LEN - LUKS2_HDR_BIN_LEN;
+	json_object_object_add(field, "json_size", json_object_new_uint64(json_size));
+	json_object_object_add(field, "keyslots_size", json_object_new_uint64(keyslots_size));
+
+	*luks1_object = luks1_obj;
+	return 0;
+}
+
+static void move_keyslot_offset(json_object *jobj, int offset_add)
+{
+	json_object *jobj1, *jobj2, *jobj_area;
+	uint64_t offset = 0;
+
+	json_object_object_get_ex(jobj, "keyslots", &jobj1);
+	json_object_object_foreach(jobj1, key, val) {
+		UNUSED(key);
+		json_object_object_get_ex(val, "area", &jobj_area);
+		json_object_object_get_ex(jobj_area, "offset", &jobj2);
+		offset = json_object_get_uint64(jobj2) + offset_add;
+		json_object_object_add(jobj_area, "offset", json_object_new_uint64(offset));
+	}
+}
+
+/* FIXME: return specific error code for partial write error (aka keyslots are gone) */
+static int move_keyslot_areas(struct crypt_device *cd, off_t offset_from,
+			      off_t offset_to, size_t buf_size)
+{
+	struct device *device = crypt_metadata_device(cd);
+	void *buf = NULL;
+	int r = -EIO, devfd = -1;
+
+	log_dbg(cd, "Moving keyslot areas of size %zu from %jd to %jd.",
+		buf_size, (intmax_t)offset_from, (intmax_t)offset_to);
+
+	if (posix_memalign(&buf, crypt_getpagesize(), buf_size))
+		return -ENOMEM;
+
+	devfd = device_open(cd, device, O_RDWR);
+	if (devfd == -1) {
+		free(buf);
+		return -EIO;
+	}
+
+	/* This can safely fail (for block devices). It only allocates space if it is possible. */
+	if (posix_fallocate(devfd, offset_to, buf_size))
+		log_dbg(cd, "Preallocation (fallocate) of new keyslot area not available.");
+
+	/* Try to read *new* area to check that area is there (trimmed backup). */
+	if (read_lseek_blockwise(devfd, device_block_size(cd, device),
+				 device_alignment(device), buf, buf_size,
+				 offset_to)!= (ssize_t)buf_size)
+		goto out;
+
+	if (read_lseek_blockwise(devfd, device_block_size(cd, device),
+				 device_alignment(device), buf, buf_size,
+				 offset_from)!= (ssize_t)buf_size)
+		goto out;
+
+	if (write_lseek_blockwise(devfd, device_block_size(cd, device),
+				  device_alignment(device), buf, buf_size,
+				  offset_to) != (ssize_t)buf_size)
+		goto out;
+
+	r = 0;
+out:
+	device_sync(cd, device, devfd);
+	close(devfd);
+	crypt_memzero(buf, buf_size);
+	free(buf);
+
+	return r;
+}
+
+static int luks_header_in_use(struct crypt_device *cd)
+{
+	int r;
+
+	r = lookup_dm_dev_by_uuid(cd, crypt_get_uuid(cd), crypt_get_type(cd));
+	if (r < 0)
+		log_err(cd, _("Can not check status of device with uuid: %s."), crypt_get_uuid(cd));
+
+	return r;
+}
+
+/* Check if there is a luksmeta area (foreign metadata created by the luksmeta package) */
+static int luksmeta_header_present(struct crypt_device *cd, off_t luks1_size)
+{
+	static const uint8_t LM_MAGIC[] = { 'L', 'U', 'K', 'S', 'M', 'E', 'T', 'A' };
+	struct device *device = crypt_metadata_device(cd);
+	void *buf = NULL;
+	int devfd, r = 0;
+
+	if (posix_memalign(&buf, crypt_getpagesize(), sizeof(LM_MAGIC)))
+		return -ENOMEM;
+
+	devfd = device_open(cd, device, O_RDONLY);
+	if (devfd == -1) {
+		free(buf);
+		return -EIO;
+	}
+
+	/* Note: we must not detect failure as problem here, header can be trimmed. */
+	if (read_lseek_blockwise(devfd, device_block_size(cd, device), device_alignment(device),
+		buf, sizeof(LM_MAGIC), luks1_size) == (ssize_t)sizeof(LM_MAGIC) &&
+		!memcmp(LM_MAGIC, buf, sizeof(LM_MAGIC))) {
+			log_err(cd, _("Unable to convert header with LUKSMETA additional metadata."));
+			r = -EBUSY;
+	}
+
+	close(devfd);
+	free(buf);
+	return r;
+}
+
+/* Convert LUKS1 -> LUKS2 */
+int LUKS2_luks1_to_luks2(struct crypt_device *cd, struct luks_phdr *hdr1, struct luks2_hdr *hdr2)
+{
+	int r;
+	json_object *jobj = NULL;
+	size_t buf_size, buf_offset, luks1_size, luks1_shift = 2 * LUKS2_HDR_16K_LEN - LUKS_ALIGN_KEYSLOTS;
+	uint64_t max_size = crypt_get_data_offset(cd) * SECTOR_SIZE;
+
+	/* for detached headers max size == device size */
+	if (!max_size && (r = device_size(crypt_metadata_device(cd), &max_size)))
+		return r;
+
+	luks1_size = LUKS_device_sectors(hdr1) << SECTOR_SHIFT;
+	luks1_size = size_round_up(luks1_size, LUKS_ALIGN_KEYSLOTS);
+	if (!luks1_size)
+		return -EINVAL;
+
+	if (LUKS_keyslots_offset(hdr1) != (LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE)) {
+		log_dbg(cd, "Unsupported keyslots material offset: %zu.", LUKS_keyslots_offset(hdr1));
+		return -EINVAL;
+	}
+
+	if (luksmeta_header_present(cd, luks1_size))
+		return -EINVAL;
+
+	log_dbg(cd, "Max size: %" PRIu64 ", LUKS1 (full) header size %zu , required shift: %zu",
+		max_size, luks1_size, luks1_shift);
+	if ((max_size - luks1_size) < luks1_shift) {
+		log_err(cd, _("Unable to move keyslot area. Not enough space."));
+		return -EINVAL;
+	}
+
+	r = json_luks1_object(hdr1, &jobj, max_size - 2 * LUKS2_HDR_16K_LEN);
+	if (r < 0)
+		return r;
+
+	move_keyslot_offset(jobj, luks1_shift);
+
+	// fill hdr2
+	memset(hdr2, 0, sizeof(*hdr2));
+	hdr2->hdr_size = LUKS2_HDR_16K_LEN;
+	hdr2->seqid = 1;
+	hdr2->version = 2;
+	strncpy(hdr2->checksum_alg, "sha256", LUKS2_CHECKSUM_ALG_L);
+	crypt_random_get(cd, (char*)hdr2->salt1, sizeof(hdr2->salt1), CRYPT_RND_SALT);
+	crypt_random_get(cd, (char*)hdr2->salt2, sizeof(hdr2->salt2), CRYPT_RND_SALT);
+	strncpy(hdr2->uuid, crypt_get_uuid(cd), LUKS2_UUID_L-1); /* UUID should be max 36 chars */
+	hdr2->jobj = jobj;
+
+	/*
+	 * It duplicates check in LUKS2_hdr_write() but we don't want to move
+	 * keyslot areas in case it would fail later
+	 */
+	if (max_size < LUKS2_hdr_and_areas_size(hdr2->jobj)) {
+		r = -EINVAL;
+		goto out;
+	}
+
+	if ((r = luks_header_in_use(cd))) {
+		if (r > 0)
+			r = -EBUSY;
+		goto out;
+	}
+
+	// move keyslots 4k -> 32k offset
+	buf_offset = 2 * LUKS2_HDR_16K_LEN;
+	buf_size   = luks1_size - LUKS_ALIGN_KEYSLOTS;
+	if ((r = move_keyslot_areas(cd, 8 * SECTOR_SIZE, buf_offset, buf_size)) < 0) {
+		log_err(cd, _("Unable to move keyslot area."));
+		goto out;
+	}
+
+	// Write JSON hdr2
+	r = LUKS2_hdr_write(cd, hdr2);
+out:
+	LUKS2_hdr_free(cd, hdr2);
+
+	return r;
+}
+
+static int keyslot_LUKS1_compatible(struct crypt_device *cd, struct luks2_hdr *hdr,
+				    int keyslot, uint32_t key_size, const char *hash)
+{
+	json_object *jobj_keyslot, *jobj, *jobj_kdf, *jobj_af;
+	uint64_t l2_offset, l2_length;
+	size_t ks_key_size;
+	const char *ks_cipher, *data_cipher;
+
+	jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
+	if (!jobj_keyslot)
+		return 1;
+
+	if (!json_object_object_get_ex(jobj_keyslot, "type", &jobj) ||
+	    strcmp(json_object_get_string(jobj), "luks2"))
+		return 0;
+
+	/* Using PBKDF2, this implies memory and parallel is not used. */
+	jobj = NULL;
+	if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf) ||
+	    !json_object_object_get_ex(jobj_kdf, "type", &jobj) ||
+	    strcmp(json_object_get_string(jobj), CRYPT_KDF_PBKDF2) ||
+	    !json_object_object_get_ex(jobj_kdf, "hash", &jobj) ||
+	    strcmp(json_object_get_string(jobj), hash))
+		return 0;
+
+	jobj = NULL;
+	if (!json_object_object_get_ex(jobj_keyslot, "af", &jobj_af) ||
+	    !json_object_object_get_ex(jobj_af, "stripes", &jobj) ||
+	    json_object_get_int(jobj) != LUKS_STRIPES)
+		return 0;
+
+	jobj = NULL;
+	if (!json_object_object_get_ex(jobj_af, "hash", &jobj) ||
+	    (crypt_hash_size(json_object_get_string(jobj)) < 0) ||
+	    strcmp(json_object_get_string(jobj), hash))
+		return 0;
+
+	/* FIXME: should this go to validation code instead (aka invalid luks2 header if assigned to segment 0)? */
+	/* FIXME: check all keyslots are assigned to segment id 0, and segments count == 1 */
+	ks_cipher = LUKS2_get_keyslot_cipher(hdr, keyslot, &ks_key_size);
+	data_cipher = LUKS2_get_cipher(hdr, CRYPT_DEFAULT_SEGMENT);
+	if (!ks_cipher || !data_cipher || key_size != ks_key_size || strcmp(ks_cipher, data_cipher)) {
+		log_dbg(cd, "Cipher in keyslot %d is different from volume key encryption.", keyslot);
+		return 0;
+	}
+
+	if (LUKS2_keyslot_area(hdr, keyslot, &l2_offset, &l2_length))
+		return 0;
+
+	if (l2_length != (size_round_up(AF_split_sectors(key_size, LUKS_STRIPES) * SECTOR_SIZE, 4096))) {
+		log_dbg(cd, "Area length in LUKS2 keyslot (%d) is not compatible with LUKS1", keyslot);
+		return 0;
+	}
+
+	return 1;
+}
+
+/* Convert LUKS2 -> LUKS1 */
+int LUKS2_luks2_to_luks1(struct crypt_device *cd, struct luks2_hdr *hdr2, struct luks_phdr *hdr1)
+{
+	size_t buf_size, buf_offset;
+	char cipher[LUKS_CIPHERNAME_L-1], cipher_mode[LUKS_CIPHERMODE_L-1];
+	char digest[LUKS_DIGESTSIZE], digest_salt[LUKS_SALTSIZE];
+	const char *hash;
+	size_t len;
+	json_object *jobj_keyslot, *jobj_digest, *jobj_segment, *jobj_kdf, *jobj_area, *jobj1, *jobj2;
+	uint32_t key_size;
+	int i, r, last_active = 0;
+	uint64_t offset, area_length;
+	char buf[256], luksMagic[] = LUKS_MAGIC;
+
+	jobj_digest  = LUKS2_get_digest_jobj(hdr2, 0);
+	if (!jobj_digest)
+		return -EINVAL;
+
+	jobj_segment = LUKS2_get_segment_jobj(hdr2, CRYPT_DEFAULT_SEGMENT);
+	if (!jobj_segment)
+		return -EINVAL;
+
+	json_object_object_get_ex(hdr2->jobj, "digests", &jobj1);
+	if (!json_object_object_get_ex(jobj_digest, "type", &jobj2) ||
+	    strcmp(json_object_get_string(jobj2), "pbkdf2") ||
+	    json_object_object_length(jobj1) != 1) {
+		log_err(cd, _("Cannot convert to LUKS1 format - key slot digests are not LUKS1 compatible."));
+		return -EINVAL;
+	}
+	if (!json_object_object_get_ex(jobj_digest, "hash", &jobj2))
+		return -EINVAL;
+	hash = json_object_get_string(jobj2);
+
+	r = crypt_parse_name_and_mode(LUKS2_get_cipher(hdr2, CRYPT_DEFAULT_SEGMENT), cipher, NULL, cipher_mode);
+	if (r < 0)
+		return r;
+
+	if (crypt_cipher_wrapped_key(cipher, cipher_mode)) {
+		log_err(cd, _("Cannot convert to LUKS1 format - device uses wrapped key cipher %s."), cipher);
+		return -EINVAL;
+	}
+
+	r = LUKS2_tokens_count(hdr2);
+	if (r < 0)
+		return r;
+	if (r > 0) {
+		log_err(cd, _("Cannot convert to LUKS1 format - LUKS2 header contains %u token(s)."), r);
+		return -EINVAL;
+	}
+
+	r = LUKS2_get_volume_key_size(hdr2, 0);
+	if (r < 0)
+		return -EINVAL;
+	key_size = r;
+
+	for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++) {
+		if (LUKS2_keyslot_info(hdr2, i) == CRYPT_SLOT_INACTIVE)
+			continue;
+
+		if (LUKS2_keyslot_info(hdr2, i) == CRYPT_SLOT_INVALID) {
+			log_err(cd, _("Cannot convert to LUKS1 format - keyslot %u is in invalid state."), i);
+			return -EINVAL;
+		}
+
+		if (i >= LUKS_NUMKEYS) {
+			log_err(cd, _("Cannot convert to LUKS1 format - slot %u (over maximum slots) is still active."), i);
+			return -EINVAL;
+		}
+
+		if (!keyslot_LUKS1_compatible(cd, hdr2, i, key_size, hash)) {
+			log_err(cd, _("Cannot convert to LUKS1 format - keyslot %u is not LUKS1 compatible."), i);
+			return -EINVAL;
+		}
+	}
+
+	memset(hdr1, 0, sizeof(*hdr1));
+
+	for (i = 0; i < LUKS_NUMKEYS; i++) {
+		hdr1->keyblock[i].active = LUKS_KEY_DISABLED;
+		hdr1->keyblock[i].stripes = LUKS_STRIPES;
+
+		jobj_keyslot = LUKS2_get_keyslot_jobj(hdr2, i);
+
+		if (jobj_keyslot) {
+			if (!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
+				return -EINVAL;
+			if (!json_object_object_get_ex(jobj_area, "offset", &jobj1))
+				return -EINVAL;
+			offset = json_object_get_uint64(jobj1);
+		} else {
+			if (LUKS2_find_area_gap(cd, hdr2, key_size, &offset, &area_length))
+				return -EINVAL;
+			/*
+			 * We have to create placeholder luks2 keyslots in place of all
+			 * inactive keyslots. Otherwise we would allocate all
+			 * inactive luks1 keyslots over same binary keyslot area.
+			 */
+			if (placeholder_keyslot_alloc(cd, i, offset, area_length, key_size))
+				return -EINVAL;
+		}
+
+		offset /= SECTOR_SIZE;
+		if (offset > UINT32_MAX)
+			return -EINVAL;
+
+		hdr1->keyblock[i].keyMaterialOffset = offset;
+		hdr1->keyblock[i].keyMaterialOffset -=
+				((2 * LUKS2_HDR_16K_LEN - LUKS_ALIGN_KEYSLOTS) / SECTOR_SIZE);
+
+		if (!jobj_keyslot)
+			continue;
+
+		hdr1->keyblock[i].active = LUKS_KEY_ENABLED;
+		last_active = i;
+
+		if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf))
+			continue;
+
+		if (!json_object_object_get_ex(jobj_kdf, "iterations", &jobj1))
+			continue;
+		hdr1->keyblock[i].passwordIterations = json_object_get_uint32(jobj1);
+
+		if (!json_object_object_get_ex(jobj_kdf, "salt", &jobj1))
+			continue;
+		len = sizeof(buf);
+		memset(buf, 0, len);
+		if (!base64_decode(json_object_get_string(jobj1),
+				   json_object_get_string_len(jobj1), buf, &len))
+			continue;
+		if (len > 0 && len != LUKS_SALTSIZE)
+			continue;
+		memcpy(hdr1->keyblock[i].passwordSalt, buf, LUKS_SALTSIZE);
+	}
+
+	if (!jobj_keyslot) {
+		jobj_keyslot = LUKS2_get_keyslot_jobj(hdr2, last_active);
+		if (!jobj_keyslot)
+			return -EINVAL;
+	}
+
+	if (!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
+		return -EINVAL;
+	if (!json_object_object_get_ex(jobj_area, "encryption", &jobj1))
+		return -EINVAL;
+	r = crypt_parse_name_and_mode(json_object_get_string(jobj1), cipher, NULL, cipher_mode);
+	if (r < 0)
+		return r;
+
+	strncpy(hdr1->cipherName, cipher, sizeof(hdr1->cipherName) - 1);
+	strncpy(hdr1->cipherMode, cipher_mode, sizeof(hdr1->cipherMode) - 1);
+
+	if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf))
+		return -EINVAL;
+	if (!json_object_object_get_ex(jobj_kdf, "hash", &jobj1))
+		return -EINVAL;
+	strncpy(hdr1->hashSpec, json_object_get_string(jobj1), sizeof(hdr1->hashSpec) - 1);
+
+	hdr1->keyBytes = key_size;
+
+	if (!json_object_object_get_ex(jobj_digest, "iterations", &jobj1))
+		return -EINVAL;
+	hdr1->mkDigestIterations = json_object_get_uint32(jobj1);
+
+	if (!json_object_object_get_ex(jobj_digest, "digest", &jobj1))
+		return -EINVAL;
+	len = sizeof(digest);
+	if (!base64_decode(json_object_get_string(jobj1),
+			   json_object_get_string_len(jobj1), digest, &len))
+		return -EINVAL;
+	/* We can store full digest here, not only sha1 length */
+	if (len < LUKS_DIGESTSIZE)
+		return -EINVAL;
+	memcpy(hdr1->mkDigest, digest, LUKS_DIGESTSIZE);
+
+	if (!json_object_object_get_ex(jobj_digest, "salt", &jobj1))
+		return -EINVAL;
+	len = sizeof(digest_salt);
+	if (!base64_decode(json_object_get_string(jobj1),
+			   json_object_get_string_len(jobj1), digest_salt, &len))
+		return -EINVAL;
+	if (len != LUKS_SALTSIZE)
+		return -EINVAL;
+	memcpy(hdr1->mkDigestSalt, digest_salt, LUKS_SALTSIZE);
+
+	if (!json_object_object_get_ex(jobj_segment, "offset", &jobj1))
+		return -EINVAL;
+	offset = json_object_get_uint64(jobj1) / SECTOR_SIZE;
+	if (offset > UINT32_MAX)
+		return -EINVAL;
+	/* FIXME: LUKS1 requires offset == 0 || offset >= luks1_hdr_size */
+	hdr1->payloadOffset = offset;
+
+	strncpy(hdr1->uuid, hdr2->uuid, UUID_STRING_L); /* max 36 chars */
+	hdr1->uuid[UUID_STRING_L-1] = '\0';
+
+	memcpy(hdr1->magic, luksMagic, LUKS_MAGIC_L);
+
+	hdr1->version = 1;
+
+	r = luks_header_in_use(cd);
+	if (r)
+		return r > 0 ? -EBUSY : r;
+
+	// move keyslots 32k -> 4k offset
+	buf_offset = 2 * LUKS2_HDR_16K_LEN;
+	buf_size   = LUKS2_keyslots_size(hdr2->jobj);
+	r = move_keyslot_areas(cd, buf_offset, 8 * SECTOR_SIZE, buf_size);
+	if (r < 0) {
+		log_err(cd, _("Unable to move keyslot area."));
+		return r;
+	}
+
+	crypt_wipe_device(cd, crypt_metadata_device(cd), CRYPT_WIPE_ZERO, 0,
+			  8 * SECTOR_SIZE, 8 * SECTOR_SIZE, NULL, NULL);
+
+	// Write LUKS1 hdr
+	return LUKS_write_phdr(hdr1, cd);
+}
diff --git a/lib/luks2/luks2_token.c b/lib/luks2/luks2_token.c
new file mode 100644
index 0000000..58ba61d
--- /dev/null
+++ b/lib/luks2/luks2_token.c
@@ -0,0 +1,606 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, token handling
+ *
+ * Copyright (C) 2016-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2016-2019 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 <assert.h>
+
+#include "luks2_internal.h"
+
+/* Builtin tokens */
+extern const crypt_token_handler keyring_handler;
+
+static token_handler token_handlers[LUKS2_TOKENS_MAX] = {
+	/* keyring builtin token */
+	{
+	  .get = token_keyring_get,
+	  .set = token_keyring_set,
+	  .h = &keyring_handler
+	},
+};
+
+static int is_builtin_candidate(const char *type)
+{
+	return !strncmp(type, LUKS2_BUILTIN_TOKEN_PREFIX, LUKS2_BUILTIN_TOKEN_PREFIX_LEN);
+}
+
+int crypt_token_register(const crypt_token_handler *handler)
+{
+	int i;
+
+	if (is_builtin_candidate(handler->name)) {
+		log_dbg(NULL, "'" LUKS2_BUILTIN_TOKEN_PREFIX "' is reserved prefix for builtin tokens.");
+		return -EINVAL;
+	}
+
+	for (i = 0; i < LUKS2_TOKENS_MAX && token_handlers[i].h; i++) {
+		if (!strcmp(token_handlers[i].h->name, handler->name)) {
+			log_dbg(NULL, "Keyslot handler %s is already registered.", handler->name);
+			return -EINVAL;
+		}
+	}
+
+	if (i == LUKS2_TOKENS_MAX)
+		return -EINVAL;
+
+	token_handlers[i].h = handler;
+	return 0;
+}
+
+static const token_handler
+*LUKS2_token_handler_type_internal(struct crypt_device *cd, const char *type)
+{
+	int i;
+
+	for (i = 0; i < LUKS2_TOKENS_MAX && token_handlers[i].h; i++)
+		if (!strcmp(token_handlers[i].h->name, type))
+			return token_handlers + i;
+
+	return NULL;
+}
+
+static const crypt_token_handler
+*LUKS2_token_handler_type(struct crypt_device *cd, const char *type)
+{
+	const token_handler *th = LUKS2_token_handler_type_internal(cd, type);
+
+	return th ? th->h : NULL;
+}
+
+static const token_handler
+*LUKS2_token_handler_internal(struct crypt_device *cd, int token)
+{
+	struct luks2_hdr *hdr;
+	json_object *jobj1, *jobj2;
+
+	if (token < 0)
+		return NULL;
+
+	if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
+		return NULL;
+
+	if (!(jobj1 = LUKS2_get_token_jobj(hdr, token)))
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj1, "type", &jobj2))
+		return NULL;
+
+	return LUKS2_token_handler_type_internal(cd, json_object_get_string(jobj2));
+}
+
+static const crypt_token_handler
+*LUKS2_token_handler(struct crypt_device *cd, int token)
+{
+	const token_handler *th = LUKS2_token_handler_internal(cd, token);
+
+	return th ? th->h : NULL;
+}
+
+static int LUKS2_token_find_free(struct luks2_hdr *hdr)
+{
+	int i;
+
+	for (i = 0; i < LUKS2_TOKENS_MAX; i++)
+		if (!LUKS2_get_token_jobj(hdr, i))
+			return i;
+
+	return -EINVAL;
+}
+
+int LUKS2_token_create(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char *json,
+	int commit)
+{
+	const crypt_token_handler *h;
+	const token_handler *th;
+	json_object *jobj_tokens, *jobj_type, *jobj;
+	enum json_tokener_error jerr;
+	char num[16];
+
+	if (token == CRYPT_ANY_TOKEN) {
+		if (!json)
+			return -EINVAL;
+		token = LUKS2_token_find_free(hdr);
+	}
+
+	if (token < 0 || token >= LUKS2_TOKENS_MAX)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "tokens", &jobj_tokens))
+		return -EINVAL;
+
+	snprintf(num, sizeof(num), "%d", token);
+
+	/* Remove token */
+	if (!json)
+		json_object_object_del(jobj_tokens, num);
+	else {
+
+		jobj = json_tokener_parse_verbose(json, &jerr);
+		if (!jobj) {
+			log_dbg(cd, "Token JSON parse failed.");
+			return -EINVAL;
+		}
+
+		if (LUKS2_token_validate(cd, hdr->jobj, jobj, num)) {
+			json_object_put(jobj);
+			return -EINVAL;
+		}
+
+		json_object_object_get_ex(jobj, "type", &jobj_type);
+		if (is_builtin_candidate(json_object_get_string(jobj_type))) {
+			th = LUKS2_token_handler_type_internal(cd, json_object_get_string(jobj_type));
+			if (!th || !th->set) {
+				log_dbg(cd, "%s is builtin token candidate with missing handler", json_object_get_string(jobj_type));
+				json_object_put(jobj);
+				return -EINVAL;
+			}
+			h = th->h;
+		} else
+			h = LUKS2_token_handler_type(cd, json_object_get_string(jobj_type));
+
+		if (h && h->validate && h->validate(cd, json)) {
+			json_object_put(jobj);
+			log_dbg(cd, "Token type %s validation failed.", h->name);
+			return -EINVAL;
+		}
+
+		json_object_object_add(jobj_tokens, num, jobj);
+		if (LUKS2_check_json_size(cd, hdr)) {
+			log_dbg(cd, "Not enough space in header json area for new token.");
+			json_object_object_del(jobj_tokens, num);
+			return -ENOSPC;
+		}
+	}
+
+	if (commit)
+		return LUKS2_hdr_write(cd, hdr) ?: token;
+
+	return token;
+}
+
+crypt_token_info LUKS2_token_status(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char **type)
+{
+	const char *tmp;
+	const token_handler *th;
+	json_object *jobj_type, *jobj_token;
+
+	if (token < 0 || token >= LUKS2_TOKENS_MAX)
+		return CRYPT_TOKEN_INVALID;
+
+	if (!(jobj_token = LUKS2_get_token_jobj(hdr, token)))
+		return CRYPT_TOKEN_INACTIVE;
+
+	json_object_object_get_ex(jobj_token, "type", &jobj_type);
+	tmp = json_object_get_string(jobj_type);
+
+	if ((th = LUKS2_token_handler_type_internal(cd, tmp))) {
+		if (type)
+			*type = th->h->name;
+		return th->set ? CRYPT_TOKEN_INTERNAL : CRYPT_TOKEN_EXTERNAL;
+	}
+
+	if (type)
+		*type = tmp;
+
+	return is_builtin_candidate(tmp) ? CRYPT_TOKEN_INTERNAL_UNKNOWN : CRYPT_TOKEN_EXTERNAL_UNKNOWN;
+}
+
+int LUKS2_builtin_token_get(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char *type,
+	void *params)
+{
+	const token_handler *th = LUKS2_token_handler_type_internal(cd, type);
+
+	// internal error
+	assert(th && th->get);
+
+	return th->get(LUKS2_get_token_jobj(hdr, token), params) ?: token;
+}
+
+int LUKS2_builtin_token_create(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	const char *type,
+	const void *params,
+	int commit)
+{
+	const token_handler *th;
+	int r;
+	json_object *jobj_token, *jobj_tokens;
+
+	th = LUKS2_token_handler_type_internal(cd, type);
+
+	// at this point all builtin handlers must exist and have validate fn defined
+	assert(th && th->set && th->h->validate);
+
+	if (token == CRYPT_ANY_TOKEN) {
+		if ((token = LUKS2_token_find_free(hdr)) < 0)
+			log_err(cd, _("No free token slot."));
+	}
+	if (token < 0 || token >= LUKS2_TOKENS_MAX)
+		return -EINVAL;
+
+	r = th->set(&jobj_token, params);
+	if (r) {
+		log_err(cd, _("Failed to create builtin token %s."), type);
+		return r;
+	}
+
+	// builtin tokens must produce valid json
+	r = LUKS2_token_validate(cd, hdr->jobj, jobj_token, "new");
+	assert(!r);
+	r = th->h->validate(cd, json_object_to_json_string_ext(jobj_token,
+		JSON_C_TO_STRING_PLAIN | JSON_C_TO_STRING_NOSLASHESCAPE));
+	assert(!r);
+
+	json_object_object_get_ex(hdr->jobj, "tokens", &jobj_tokens);
+	json_object_object_add_by_uint(jobj_tokens, token, jobj_token);
+	if (LUKS2_check_json_size(cd, hdr)) {
+		log_dbg(cd, "Not enough space in header json area for new %s token.", type);
+		json_object_object_del_by_uint(jobj_tokens, token);
+		return -ENOSPC;
+	}
+
+	if (commit)
+		return LUKS2_hdr_write(cd, hdr) ?: token;
+
+	return token;
+}
+
+static int LUKS2_token_open(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	char **buffer,
+	size_t *buffer_len,
+	void *usrptr)
+{
+	const char *json;
+	const crypt_token_handler *h;
+	int r;
+
+	if (!(h = LUKS2_token_handler(cd, token)))
+		return -ENOENT;
+
+	if (h->validate) {
+		if (LUKS2_token_json_get(cd, hdr, token, &json))
+			return -EINVAL;
+
+		if (h->validate(cd, json)) {
+			log_dbg(cd, "Token %d (%s) validation failed.", token, h->name);
+			return -EINVAL;
+		}
+	}
+
+	r = h->open(cd, token, buffer, buffer_len, usrptr);
+	if (r < 0)
+		log_dbg(cd, "Token %d (%s) open failed with %d.", token, h->name, r);
+
+	return r;
+}
+
+static void LUKS2_token_buffer_free(struct crypt_device *cd,
+		int token,
+		void *buffer,
+		size_t buffer_len)
+{
+	const crypt_token_handler *h = LUKS2_token_handler(cd, token);
+
+	if (h->buffer_free)
+		h->buffer_free(buffer, buffer_len);
+	else {
+		crypt_memzero(buffer, buffer_len);
+		free(buffer);
+	}
+}
+
+static int LUKS2_keyslot_open_by_token(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	int token,
+	int segment,
+	const char *buffer,
+	size_t buffer_len,
+	struct volume_key **vk)
+{
+	const crypt_token_handler *h;
+	json_object *jobj_token, *jobj_token_keyslots, *jobj;
+	const char *num = NULL;
+	int i, r;
+
+	if (!(h = LUKS2_token_handler(cd, token)))
+		return -ENOENT;
+
+	jobj_token = LUKS2_get_token_jobj(hdr, token);
+	if (!jobj_token)
+		return -EINVAL;
+
+	json_object_object_get_ex(jobj_token, "keyslots", &jobj_token_keyslots);
+	if (!jobj_token_keyslots)
+		return -EINVAL;
+
+	/* Try to open keyslot referenced in token */
+	r = -EINVAL;
+	for (i = 0; i < (int) json_object_array_length(jobj_token_keyslots) && r < 0; i++) {
+		jobj = json_object_array_get_idx(jobj_token_keyslots, i);
+		num = json_object_get_string(jobj);
+		log_dbg(cd, "Trying to open keyslot %s with token %d (type %s).", num, token, h->name);
+		r = LUKS2_keyslot_open(cd, atoi(num), segment, buffer, buffer_len, vk);
+	}
+
+	if (r >= 0 && num)
+		return atoi(num);
+
+	return r;
+}
+
+int LUKS2_token_open_and_activate(struct crypt_device *cd,
+		struct luks2_hdr *hdr,
+		int token,
+		const char *name,
+		uint32_t flags,
+		void *usrptr)
+{
+	int keyslot, r;
+	char *buffer;
+	size_t buffer_len;
+	struct volume_key *vk = NULL;
+
+	r = LUKS2_token_open(cd, hdr, token, &buffer, &buffer_len, usrptr);
+	if (r < 0)
+		return r;
+
+	r = LUKS2_keyslot_open_by_token(cd, hdr, token,
+					(flags & CRYPT_ACTIVATE_ALLOW_UNBOUND_KEY) ?
+					CRYPT_ANY_SEGMENT : CRYPT_DEFAULT_SEGMENT,
+					buffer, buffer_len, &vk);
+
+	LUKS2_token_buffer_free(cd, token, buffer, buffer_len);
+
+	if (r < 0)
+		return r;
+
+	keyslot = r;
+
+	if ((name || (flags & CRYPT_ACTIVATE_KEYRING_KEY)) && crypt_use_keyring_for_vk(cd))
+		r = LUKS2_volume_key_load_in_keyring_by_keyslot(cd, hdr, vk, keyslot);
+
+	if (r >= 0 && name)
+		r = LUKS2_activate(cd, name, vk, flags);
+
+	if (r < 0 && vk)
+		crypt_drop_keyring_key(cd, vk->key_description);
+	crypt_free_volume_key(vk);
+
+	return r < 0 ? r : keyslot;
+}
+
+int LUKS2_token_open_and_activate_any(struct crypt_device *cd,
+	struct luks2_hdr *hdr,
+	const char *name,
+	uint32_t flags)
+{
+	char *buffer;
+	json_object *tokens_jobj;
+	size_t buffer_len;
+	int keyslot, token, r = -EINVAL;
+	struct volume_key *vk = NULL;
+
+	json_object_object_get_ex(hdr->jobj, "tokens", &tokens_jobj);
+
+	json_object_object_foreach(tokens_jobj, slot, val) {
+		UNUSED(val);
+		token = atoi(slot);
+
+		r = LUKS2_token_open(cd, hdr, token, &buffer, &buffer_len, NULL);
+		if (r < 0)
+			continue;
+
+		r = LUKS2_keyslot_open_by_token(cd, hdr, token,
+						(flags & CRYPT_ACTIVATE_ALLOW_UNBOUND_KEY) ?
+						CRYPT_ANY_SEGMENT : CRYPT_DEFAULT_SEGMENT,
+						buffer, buffer_len, &vk);
+		LUKS2_token_buffer_free(cd, token, buffer, buffer_len);
+		if (r >= 0)
+			break;
+	}
+
+	keyslot = r;
+
+	if (r >= 0 && (name || (flags & CRYPT_ACTIVATE_KEYRING_KEY)) && crypt_use_keyring_for_vk(cd))
+		r = LUKS2_volume_key_load_in_keyring_by_keyslot(cd, hdr, vk, keyslot);
+
+	if (r >= 0 && name)
+		r = LUKS2_activate(cd, name, vk, flags);
+
+	if (r < 0 && vk)
+		crypt_drop_keyring_key(cd, vk->key_description);
+	crypt_free_volume_key(vk);
+
+	return r < 0 ? r : keyslot;
+}
+
+void LUKS2_token_dump(struct crypt_device *cd, int token)
+{
+	const crypt_token_handler *h;
+	json_object *jobj_token;
+
+	h = LUKS2_token_handler(cd, token);
+	if (h && h->dump) {
+		jobj_token = LUKS2_get_token_jobj(crypt_get_hdr(cd, CRYPT_LUKS2), token);
+		if (jobj_token)
+			h->dump(cd, json_object_to_json_string_ext(jobj_token,
+				JSON_C_TO_STRING_PLAIN | JSON_C_TO_STRING_NOSLASHESCAPE));
+	}
+}
+
+int LUKS2_token_json_get(struct crypt_device *cd, struct luks2_hdr *hdr,
+			   int token, const char **json)
+{
+	json_object *jobj_token;
+
+	jobj_token = LUKS2_get_token_jobj(hdr, token);
+	if (!jobj_token)
+		return -EINVAL;
+
+	*json = json_object_to_json_string_ext(jobj_token,
+		JSON_C_TO_STRING_PLAIN | JSON_C_TO_STRING_NOSLASHESCAPE);
+	return 0;
+}
+
+static int assign_one_keyslot(struct crypt_device *cd, struct luks2_hdr *hdr,
+			      int token, int keyslot, int assign)
+{
+	json_object *jobj1, *jobj_token, *jobj_token_keyslots;
+	char num[16];
+
+	log_dbg(cd, "Keyslot %i %s token %i.", keyslot, assign ? "assigned to" : "unassigned from", token);
+
+	jobj_token = LUKS2_get_token_jobj(hdr, token);
+	if (!jobj_token)
+		return -EINVAL;
+
+	json_object_object_get_ex(jobj_token, "keyslots", &jobj_token_keyslots);
+	if (!jobj_token_keyslots)
+		return -EINVAL;
+
+	snprintf(num, sizeof(num), "%d", keyslot);
+	if (assign) {
+		jobj1 = LUKS2_array_jobj(jobj_token_keyslots, num);
+		if (!jobj1)
+			json_object_array_add(jobj_token_keyslots, json_object_new_string(num));
+	} else {
+		jobj1 = LUKS2_array_remove(jobj_token_keyslots, num);
+		if (jobj1)
+			json_object_object_add(jobj_token, "keyslots", jobj1);
+	}
+
+	return 0;
+}
+
+static int assign_one_token(struct crypt_device *cd, struct luks2_hdr *hdr,
+			    int keyslot, int token, int assign)
+{
+	json_object *jobj_keyslots;
+	int r = 0;
+
+	if (!LUKS2_get_token_jobj(hdr, token))
+		return -EINVAL;
+
+	if (keyslot == CRYPT_ANY_SLOT) {
+		json_object_object_get_ex(hdr->jobj, "keyslots", &jobj_keyslots);
+
+		json_object_object_foreach(jobj_keyslots, key, val) {
+			UNUSED(val);
+			r = assign_one_keyslot(cd, hdr, token, atoi(key), assign);
+			if (r < 0)
+				break;
+		}
+	} else
+		r = assign_one_keyslot(cd, hdr, token, keyslot, assign);
+
+	return r;
+}
+
+int LUKS2_token_assign(struct crypt_device *cd, struct luks2_hdr *hdr,
+			int keyslot, int token, int assign, int commit)
+{
+	json_object *jobj_tokens;
+	int r = 0;
+
+	if (token == CRYPT_ANY_TOKEN) {
+		json_object_object_get_ex(hdr->jobj, "tokens", &jobj_tokens);
+
+		json_object_object_foreach(jobj_tokens, key, val) {
+			UNUSED(val);
+			r = assign_one_token(cd, hdr, keyslot, atoi(key), assign);
+			if (r < 0)
+				break;
+		}
+	} else
+		r = assign_one_token(cd, hdr, keyslot, token, assign);
+
+	if (r < 0)
+		return r;
+
+	// FIXME: do not write header in nothing changed
+	if (commit)
+		return LUKS2_hdr_write(cd, hdr) ?: token;
+
+	return token;
+}
+
+int LUKS2_token_is_assigned(struct crypt_device *cd, struct luks2_hdr *hdr,
+			    int keyslot, int token)
+{
+	int i;
+	json_object *jobj_token, *jobj_token_keyslots, *jobj;
+
+	if (keyslot < 0 || keyslot >= LUKS2_KEYSLOTS_MAX || token < 0 || token >= LUKS2_TOKENS_MAX)
+		return -EINVAL;
+
+	jobj_token = LUKS2_get_token_jobj(hdr, token);
+	if (!jobj_token)
+		return -ENOENT;
+
+	json_object_object_get_ex(jobj_token, "keyslots", &jobj_token_keyslots);
+
+	for (i = 0; i < (int) json_object_array_length(jobj_token_keyslots); i++) {
+		jobj = json_object_array_get_idx(jobj_token_keyslots, i);
+		if (keyslot == atoi(json_object_get_string(jobj)))
+			return 0;
+	}
+
+	return -ENOENT;
+}
+
+int LUKS2_tokens_count(struct luks2_hdr *hdr)
+{
+	json_object *jobj_tokens = LUKS2_get_tokens_jobj(hdr);
+	if (!jobj_tokens)
+		return -EINVAL;
+
+	return json_object_object_length(jobj_tokens);
+}
diff --git a/lib/luks2/luks2_token_keyring.c b/lib/luks2/luks2_token_keyring.c
new file mode 100644
index 0000000..7f28607
--- /dev/null
+++ b/lib/luks2/luks2_token_keyring.c
@@ -0,0 +1,170 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, kernel keyring token
+ *
+ * Copyright (C) 2016-2019 Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2016-2019 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 <assert.h>
+
+#include "luks2_internal.h"
+
+static int keyring_open(struct crypt_device *cd,
+				int token,
+				char **buffer,
+				size_t *buffer_len,
+				void *usrptr __attribute__((unused)))
+{
+	json_object *jobj_token, *jobj_key;
+	struct luks2_hdr *hdr;
+	int r;
+
+	if (!(hdr = crypt_get_hdr(cd, CRYPT_LUKS2)))
+		return -EINVAL;
+
+	jobj_token = LUKS2_get_token_jobj(hdr, token);
+	if (!jobj_token)
+		return -EINVAL;
+
+	json_object_object_get_ex(jobj_token, "key_description", &jobj_key);
+
+	r = keyring_get_passphrase(json_object_get_string(jobj_key), buffer, buffer_len);
+	if (r == -ENOTSUP) {
+		log_dbg(cd, "Kernel keyring features disabled.");
+		return -EINVAL;
+	} else if (r < 0) {
+		log_dbg(cd, "keyring_get_passphrase failed (error %d)", r);
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static int keyring_validate(struct crypt_device *cd __attribute__((unused)),
+				    const char *json)
+{
+	enum json_tokener_error jerr;
+	json_object *jobj_token, *jobj_key;
+	int r = 1;
+
+	log_dbg(cd, "Validating keyring token json");
+
+	jobj_token = json_tokener_parse_verbose(json, &jerr);
+	if (!jobj_token) {
+		log_dbg(cd, "Keyring token JSON parse failed.");
+		return r;
+	}
+
+	if (json_object_object_length(jobj_token) != 3) {
+		log_dbg(cd, "Keyring token is expected to have exactly 3 fields.");
+		goto out;
+	}
+
+	if (!json_object_object_get_ex(jobj_token, "key_description", &jobj_key)) {
+		log_dbg(cd, "missing key_description field.");
+		goto out;
+	}
+
+	if (!json_object_is_type(jobj_key, json_type_string)) {
+		log_dbg(cd, "key_description is not a string.");
+		goto out;
+	}
+
+	/* TODO: perhaps check that key description is in '%s:%s'
+	 * format where both strings are not empty */
+	r = !strlen(json_object_get_string(jobj_key));
+out:
+	json_object_put(jobj_token);
+	return r;
+}
+
+static void keyring_dump(struct crypt_device *cd, const char *json)
+{
+	enum json_tokener_error jerr;
+	json_object *jobj_token, *jobj_key;
+
+	jobj_token = json_tokener_parse_verbose(json, &jerr);
+	if (!jobj_token)
+		return;
+
+	if (!json_object_object_get_ex(jobj_token, "key_description", &jobj_key)) {
+		json_object_put(jobj_token);
+		return;
+	}
+
+	log_std(cd, "\tKey description: %s\n", json_object_get_string(jobj_key));
+
+	json_object_put(jobj_token);
+}
+
+int token_keyring_set(json_object **jobj_builtin_token,
+	const void *params)
+{
+	json_object *jobj_token, *jobj;
+	const struct crypt_token_params_luks2_keyring *keyring_params = (const struct crypt_token_params_luks2_keyring *) params;
+
+	jobj_token = json_object_new_object();
+	if (!jobj_token)
+		return -ENOMEM;
+
+	jobj = json_object_new_string(LUKS2_TOKEN_KEYRING);
+	if (!jobj) {
+		json_object_put(jobj_token);
+		return -ENOMEM;
+	}
+	json_object_object_add(jobj_token, "type", jobj);
+
+	jobj = json_object_new_array();
+	if (!jobj) {
+		json_object_put(jobj_token);
+		return -ENOMEM;
+	}
+	json_object_object_add(jobj_token, "keyslots", jobj);
+
+	jobj = json_object_new_string(keyring_params->key_description);
+	if (!jobj) {
+		json_object_put(jobj_token);
+		return -ENOMEM;
+	}
+	json_object_object_add(jobj_token, "key_description", jobj);
+
+	*jobj_builtin_token = jobj_token;
+	return 0;
+}
+
+int token_keyring_get(json_object *jobj_token,
+	void *params)
+{
+	json_object *jobj;
+	struct crypt_token_params_luks2_keyring *keyring_params = (struct crypt_token_params_luks2_keyring *) params;
+
+	json_object_object_get_ex(jobj_token, "type", &jobj);
+	assert(!strcmp(json_object_get_string(jobj), LUKS2_TOKEN_KEYRING));
+
+	json_object_object_get_ex(jobj_token, "key_description", &jobj);
+
+	keyring_params->key_description = json_object_get_string(jobj);
+
+	return 0;
+}
+
+const crypt_token_handler keyring_handler = {
+	.name = LUKS2_TOKEN_KEYRING,
+	.open = keyring_open,
+	.validate = keyring_validate,
+	.dump = keyring_dump
+};