/src/cryptsetup/lib/luks2/luks2_reencrypt.c

Source
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * LUKS - Linux Unified Key Setup v2, reencryption helpers
 *
 * Copyright (C) 2015-2025 Red Hat, Inc. All rights reserved.
 * Copyright (C) 2015-2025 Ondrej Kozina
 */

#include "luks2_internal.h"
#include "utils_device_locking.h"
#include "keyslot_context.h"

struct luks2_reencrypt {
  /* reencryption window attributes */
  uint64_t offset;
  uint64_t progress;
  uint64_t length;
  uint64_t device_size;
  bool online;
  bool fixed_length;
  crypt_reencrypt_direction_info direction;
  crypt_reencrypt_mode_info mode;

  char *device_name;
  char *hotzone_name;
  char *overlay_name;
  uint32_t flags;

  /* reencryption window persistence attributes */
  struct reenc_protection rp;
  struct reenc_protection rp_moved_segment;

  int reenc_keyslot;

  /* already running reencryption */
  json_object *jobj_segs_hot;
  json_object *jobj_segs_post;

  /* backup segments */
  json_object *jobj_segment_new;
  int digest_new;
  json_object *jobj_segment_old;
  int digest_old;
  json_object *jobj_segment_moved;

  struct volume_key *vks;

  void *reenc_buffer;
  ssize_t read;

  struct crypt_storage_wrapper *cw1;
  struct crypt_storage_wrapper *cw2;

  uint32_t wflags1;
  uint32_t wflags2;

  struct device *hotzone_device;

  struct crypt_lock_handle *reenc_lock;
};
#if USE_LUKS2_REENCRYPTION
static uint64_t data_shift_value(struct reenc_protection *rp)
{
  return rp->type == REENC_PROTECTION_DATASHIFT ? rp->p.ds.data_shift : 0;
}

static json_object *reencrypt_segment(struct luks2_hdr *hdr, unsigned new)
{
  return LUKS2_get_segment_by_flag(hdr, new ? "backup-final" : "backup-previous");
}

static json_object *reencrypt_segment_new(struct luks2_hdr *hdr)
{
  return reencrypt_segment(hdr, 1);
}

static json_object *reencrypt_segment_old(struct luks2_hdr *hdr)
{
  return reencrypt_segment(hdr, 0);
}

static json_object *reencrypt_segments_old(struct luks2_hdr *hdr)
{
  json_object *jobj_segments, *jobj = NULL;

  if (json_object_copy(reencrypt_segment_old(hdr), &jobj))
    return NULL;

  json_segment_remove_flag(jobj, "backup-previous");

  jobj_segments = json_object_new_object();
  if (!jobj_segments) {
    json_object_put(jobj);
    return NULL;
  }

  if (json_object_object_add_by_uint(jobj_segments, 0, jobj)) {
    json_object_put(jobj);
    json_object_put(jobj_segments);
    return NULL;
  }

  return jobj_segments;
}

static const char *reencrypt_segment_cipher_new(struct luks2_hdr *hdr)
{
  return json_segment_get_cipher(reencrypt_segment(hdr, 1));
}

static const char *reencrypt_segment_cipher_old(struct luks2_hdr *hdr)
{
  return json_segment_get_cipher(reencrypt_segment(hdr, 0));
}

static uint32_t reencrypt_get_sector_size_new(struct luks2_hdr *hdr)
{
  return json_segment_get_sector_size(reencrypt_segment(hdr, 1));
}

static uint32_t reencrypt_get_sector_size_old(struct luks2_hdr *hdr)
{
  return json_segment_get_sector_size(reencrypt_segment(hdr, 0));
}

static uint64_t reencrypt_data_offset(struct luks2_hdr *hdr, unsigned new)
{
  json_object *jobj = reencrypt_segment(hdr, new);
  if (jobj)
    return json_segment_get_offset(jobj, 0);

  return LUKS2_get_data_offset(hdr) << SECTOR_SHIFT;
}

static uint64_t LUKS2_reencrypt_get_data_offset_moved(struct luks2_hdr *hdr)
{
  json_object *jobj_segment = LUKS2_get_segment_by_flag(hdr, "backup-moved-segment");

  if (!jobj_segment)
    return 0;

  return json_segment_get_offset(jobj_segment, 0);
}

static uint64_t reencrypt_get_data_offset_new(struct luks2_hdr *hdr)
{
  return reencrypt_data_offset(hdr, 1);
}

static uint64_t reencrypt_get_data_offset_old(struct luks2_hdr *hdr)
{
  return reencrypt_data_offset(hdr, 0);
}
#endif

static int reencrypt_digest(struct luks2_hdr *hdr, unsigned new)
{
  int segment = LUKS2_get_segment_id_by_flag(hdr, new ? "backup-final" : "backup-previous");

  if (segment < 0)
    return segment;

  return LUKS2_digest_by_segment(hdr, segment);
}

int LUKS2_reencrypt_digest_new(struct luks2_hdr *hdr)
{
  return reencrypt_digest(hdr, 1);
}

int LUKS2_reencrypt_digest_old(struct luks2_hdr *hdr)
{
  return reencrypt_digest(hdr, 0);
}

int LUKS2_reencrypt_segment_new(struct luks2_hdr *hdr)
{
  return LUKS2_get_segment_id_by_flag(hdr, "backup-final");
}

int LUKS2_reencrypt_segment_old(struct luks2_hdr *hdr)
{
  return LUKS2_get_segment_id_by_flag(hdr, "backup-previous");
}

unsigned LUKS2_reencrypt_vks_count(struct luks2_hdr *hdr)
{
  int digest_old, digest_new;
  unsigned vks_count = 0;

  if ((digest_new = LUKS2_reencrypt_digest_new(hdr)) >= 0)
    vks_count++;
  if ((digest_old = LUKS2_reencrypt_digest_old(hdr)) >= 0) {
    if (digest_old != digest_new)
      vks_count++;
  }

  return vks_count;
}

/* none, checksums, journal or shift */
static const char *reencrypt_resilience_type(struct luks2_hdr *hdr)
{
  json_object *jobj_keyslot, *jobj_area, *jobj_type;
  int ks = LUKS2_find_keyslot(hdr, "reencrypt");

  if (ks < 0)
    return NULL;

  jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, ks);

  json_object_object_get_ex(jobj_keyslot, "area", &jobj_area);
  if (!json_object_object_get_ex(jobj_area, "type", &jobj_type))
    return NULL;

  return json_object_get_string(jobj_type);
}

static const char *reencrypt_resilience_hash(struct luks2_hdr *hdr)
{
  json_object *jobj_keyslot, *jobj_area, *jobj_type, *jobj_hash;
  int ks = LUKS2_find_keyslot(hdr, "reencrypt");

  if (ks < 0)
    return NULL;

  jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, ks);

  json_object_object_get_ex(jobj_keyslot, "area", &jobj_area);
  if (!json_object_object_get_ex(jobj_area, "type", &jobj_type))
    return NULL;
  if (strcmp(json_object_get_string(jobj_type), "checksum"))
    return NULL;
  if (!json_object_object_get_ex(jobj_area, "hash", &jobj_hash))
    return NULL;

  return json_object_get_string(jobj_hash);
}
#if USE_LUKS2_REENCRYPTION
static json_object *_enc_create_segments_shift_after(struct luks2_reencrypt *rh, uint64_t data_offset)
{
  int reenc_seg, i = 0;
  json_object *jobj, *jobj_copy = NULL, *jobj_seg_new = NULL, *jobj_segs_post = json_object_new_object();
  uint64_t tmp;

  if (!rh->jobj_segs_hot || !jobj_segs_post)
    goto err;

  if (json_segments_count(rh->jobj_segs_hot) == 0)
    return jobj_segs_post;

  reenc_seg = json_segments_segment_in_reencrypt(rh->jobj_segs_hot);
  if (reenc_seg < 0)
    goto err;

  while (i < reenc_seg) {
    jobj_copy = json_segments_get_segment(rh->jobj_segs_hot, i);
    if (!jobj_copy || json_object_object_add_by_uint(jobj_segs_post, i++, json_object_get(jobj_copy)))
      goto err;
  }
  jobj_copy = NULL;

  jobj = json_segments_get_segment(rh->jobj_segs_hot, reenc_seg + 1);
  if (!jobj) {
    jobj = json_segments_get_segment(rh->jobj_segs_hot, reenc_seg);
    if (!jobj || json_object_copy(jobj, &jobj_seg_new))
      goto err;
    json_segment_remove_flag(jobj_seg_new, "in-reencryption");
    tmp = rh->length;
  } else {
    if (json_object_copy(jobj, &jobj_seg_new))
      goto err;
    json_object_object_add(jobj_seg_new, "offset", crypt_jobj_new_uint64(rh->offset + data_offset));
    json_object_object_add(jobj_seg_new, "iv_tweak", crypt_jobj_new_uint64(rh->offset >> SECTOR_SHIFT));
    tmp = json_segment_get_size(jobj_seg_new, 0) + rh->length;
  }

  /* alter size of new segment, reenc_seg == 0 we're finished */
  json_object_object_add(jobj_seg_new, "size", reenc_seg > 0 ? crypt_jobj_new_uint64(tmp) : json_object_new_string("dynamic"));
  if (!json_object_object_add_by_uint(jobj_segs_post, reenc_seg, jobj_seg_new))
    return jobj_segs_post;

err:
  json_object_put(jobj_seg_new);
  json_object_put(jobj_copy);
  json_object_put(jobj_segs_post);
  return NULL;
}

static json_object *reencrypt_make_hot_segments_encrypt_shift(struct luks2_hdr *hdr,
  struct luks2_reencrypt *rh,
  uint64_t data_offset)
{
  int sg, crypt_seg, i = 0;
  uint64_t segment_size;
  json_object *jobj_seg_shrunk = NULL, *jobj_seg_new = NULL, *jobj_copy = NULL, *jobj_enc_seg = NULL,
         *jobj_segs_hot = json_object_new_object();

  if (!jobj_segs_hot)
    return NULL;

  crypt_seg = LUKS2_segment_by_type(hdr, "crypt");

  /* FIXME: This is hack. Find proper way to fix it. */
  sg = LUKS2_last_segment_by_type(hdr, "linear");
  if (rh->offset && sg < 0)
    goto err;
  if (sg < 0)
    return jobj_segs_hot;

  jobj_enc_seg = json_segment_create_crypt(data_offset + rh->offset,
                  rh->offset >> SECTOR_SHIFT,
                  &rh->length,
                  reencrypt_segment_cipher_new(hdr),
                  NULL, 0, /* integrity */
                  reencrypt_get_sector_size_new(hdr),
                  1);

  while (i < sg) {
    jobj_copy = LUKS2_get_segment_jobj(hdr, i);
    if (!jobj_copy || json_object_object_add_by_uint(jobj_segs_hot, i++, json_object_get(jobj_copy)))
      goto err;
  }
  jobj_copy = NULL;

  segment_size = LUKS2_segment_size(hdr, sg, 0);
  if (segment_size > rh->length) {
    if (json_object_copy(LUKS2_get_segment_jobj(hdr, sg), &jobj_seg_shrunk))
      goto err;
    json_object_object_add(jobj_seg_shrunk, "size", crypt_jobj_new_uint64(segment_size - rh->length));
    if (json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_seg_shrunk))
      goto err;
  }

  if (json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_enc_seg))
    goto err;

  /* first crypt segment after encryption ? */
  if (crypt_seg >= 0) {
    jobj_seg_new = LUKS2_get_segment_jobj(hdr, crypt_seg);
    if (!jobj_seg_new || json_object_object_add_by_uint(jobj_segs_hot, sg, json_object_get(jobj_seg_new)))
      goto err;
  }

  return jobj_segs_hot;
err:
  json_object_put(jobj_copy);
  json_object_put(jobj_seg_new);
  json_object_put(jobj_seg_shrunk);
  json_object_put(jobj_enc_seg);
  json_object_put(jobj_segs_hot);

  return NULL;
}

static json_object *reencrypt_make_segment_new(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    const struct luks2_reencrypt *rh,
    uint64_t data_offset,
    uint64_t segment_offset,
    uint64_t iv_offset,
    const uint64_t *segment_length)
{
  switch (rh->mode) {
  case CRYPT_REENCRYPT_REENCRYPT:
  case CRYPT_REENCRYPT_ENCRYPT:
    return json_segment_create_crypt(data_offset + segment_offset,
              crypt_get_iv_offset(cd) + (iv_offset >> SECTOR_SHIFT),
              segment_length,
              reencrypt_segment_cipher_new(hdr),
              NULL, 0, /* integrity */
              reencrypt_get_sector_size_new(hdr), 0);
  case CRYPT_REENCRYPT_DECRYPT:
    return json_segment_create_linear(data_offset + segment_offset, segment_length, 0);
  }

  return NULL;
}

static json_object *reencrypt_make_post_segments_forward(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  struct luks2_reencrypt *rh,
  uint64_t data_offset)
{
  int reenc_seg;
  json_object *jobj_old_seg, *jobj_new_seg_after = NULL, *jobj_old_seg_copy = NULL,
        *jobj_segs_post = json_object_new_object();
  uint64_t fixed_length = rh->offset + rh->length;

  if (!rh->jobj_segs_hot || !jobj_segs_post)
    goto err;

  reenc_seg = json_segments_segment_in_reencrypt(rh->jobj_segs_hot);
  if (reenc_seg < 0)
    goto err;

  jobj_old_seg = json_segments_get_segment(rh->jobj_segs_hot, reenc_seg + 1);

  /*
   * if there's no old segment after reencryption, we're done.
   * Set size to 'dynamic' again.
   */
  jobj_new_seg_after = reencrypt_make_segment_new(cd, hdr, rh, data_offset, 0, 0, jobj_old_seg ? &fixed_length : NULL);
  if (!jobj_new_seg_after || json_object_object_add_by_uint_by_ref(jobj_segs_post, 0, &jobj_new_seg_after))
    goto err;

  if (jobj_old_seg) {
    if (rh->fixed_length) {
      if (json_object_copy(jobj_old_seg, &jobj_old_seg_copy))
        goto err;
      fixed_length = rh->device_size - fixed_length;
      json_object_object_add(jobj_old_seg_copy, "size", crypt_jobj_new_uint64(fixed_length));
    } else
      jobj_old_seg_copy = json_object_get(jobj_old_seg);

    if (json_object_object_add_by_uint_by_ref(jobj_segs_post, 1, &jobj_old_seg_copy))
      goto err;
  }

  return jobj_segs_post;
err:
  json_object_put(jobj_new_seg_after);
  json_object_put(jobj_old_seg_copy);
  json_object_put(jobj_segs_post);
  return NULL;
}

static json_object *reencrypt_make_post_segments_backward(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  struct luks2_reencrypt *rh,
  uint64_t data_offset)
{
  int reenc_seg;
  uint64_t fixed_length;

  json_object *jobj_new_seg_after = NULL, *jobj_old_seg = NULL,
        *jobj_segs_post = json_object_new_object();

  if (!rh->jobj_segs_hot || !jobj_segs_post)
    goto err;

  reenc_seg = json_segments_segment_in_reencrypt(rh->jobj_segs_hot);
  if (reenc_seg < 0)
    goto err;

  jobj_old_seg = json_segments_get_segment(rh->jobj_segs_hot, reenc_seg - 1);
  if (jobj_old_seg) {
    json_object_get(jobj_old_seg);
    if (json_object_object_add_by_uint_by_ref(jobj_segs_post, reenc_seg - 1, &jobj_old_seg))
      goto err;
  }

  if (rh->fixed_length && rh->offset) {
    fixed_length = rh->device_size - rh->offset;
    jobj_new_seg_after = reencrypt_make_segment_new(cd, hdr, rh, data_offset, rh->offset, rh->offset, &fixed_length);
  } else
    jobj_new_seg_after = reencrypt_make_segment_new(cd, hdr, rh, data_offset, rh->offset, rh->offset, NULL);

  if (jobj_new_seg_after && !json_object_object_add_by_uint(jobj_segs_post, reenc_seg, jobj_new_seg_after))
    return jobj_segs_post;
err:
  json_object_put(jobj_new_seg_after);
  json_object_put(jobj_old_seg);
  json_object_put(jobj_segs_post);
  return NULL;
}

static json_object *reencrypt_make_segment_reencrypt(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    const struct luks2_reencrypt *rh,
    uint64_t data_offset,
    uint64_t segment_offset,
    uint64_t iv_offset,
    const uint64_t *segment_length)
{
  switch (rh->mode) {
  case CRYPT_REENCRYPT_REENCRYPT:
  case CRYPT_REENCRYPT_ENCRYPT:
    return json_segment_create_crypt(data_offset + segment_offset,
        crypt_get_iv_offset(cd) + (iv_offset >> SECTOR_SHIFT),
        segment_length,
        reencrypt_segment_cipher_new(hdr),
              NULL, 0, /* integrity */
        reencrypt_get_sector_size_new(hdr), 1);
  case CRYPT_REENCRYPT_DECRYPT:
    return json_segment_create_linear(data_offset + segment_offset, segment_length, 1);
  }

  return NULL;
}

static json_object *reencrypt_make_segment_old(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    const struct luks2_reencrypt *rh,
    uint64_t data_offset,
    uint64_t segment_offset,
    const uint64_t *segment_length)
{
  json_object *jobj_old_seg = NULL;

  switch (rh->mode) {
  case CRYPT_REENCRYPT_REENCRYPT:
  case CRYPT_REENCRYPT_DECRYPT:
    jobj_old_seg = json_segment_create_crypt(data_offset + segment_offset,
                crypt_get_iv_offset(cd) + (segment_offset >> SECTOR_SHIFT),
                segment_length,
                reencrypt_segment_cipher_old(hdr),
                NULL, 0, /* integrity */
                reencrypt_get_sector_size_old(hdr),
                0);
    break;
  case CRYPT_REENCRYPT_ENCRYPT:
    jobj_old_seg = json_segment_create_linear(data_offset + segment_offset, segment_length, 0);
  }

  return jobj_old_seg;
}

static json_object *reencrypt_make_hot_segments_forward(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh,
    uint64_t device_size,
    uint64_t data_offset)
{
  uint64_t fixed_length, tmp = rh->offset + rh->length;
  json_object *jobj_segs_hot = json_object_new_object(), *jobj_reenc_seg = NULL,
        *jobj_old_seg = NULL, *jobj_new_seg = NULL;
  unsigned int sg = 0;

  if (!jobj_segs_hot)
    return NULL;

  if (rh->offset) {
    jobj_new_seg = reencrypt_make_segment_new(cd, hdr, rh, data_offset, 0, 0, &rh->offset);
    if (!jobj_new_seg || json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_new_seg))
      goto err;
  }

  jobj_reenc_seg = reencrypt_make_segment_reencrypt(cd, hdr, rh, data_offset, rh->offset, rh->offset, &rh->length);
  if (!jobj_reenc_seg)
    goto err;

  if (json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_reenc_seg))
    goto err;

  if (tmp < device_size) {
    fixed_length = device_size - tmp;
    jobj_old_seg = reencrypt_make_segment_old(cd, hdr, rh, data_offset + data_shift_value(&rh->rp),
                rh->offset + rh->length, rh->fixed_length ? &fixed_length : NULL);
    if (!jobj_old_seg || json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg, &jobj_old_seg))
      goto err;
  }

  return jobj_segs_hot;
err:
  json_object_put(jobj_reenc_seg);
  json_object_put(jobj_old_seg);
  json_object_put(jobj_new_seg);
  json_object_put(jobj_segs_hot);
  return NULL;
}

static json_object *reencrypt_make_hot_segments_decrypt_shift(struct crypt_device *cd,
  struct luks2_hdr *hdr, struct luks2_reencrypt *rh,
  uint64_t device_size, uint64_t data_offset)
{
  uint64_t fixed_length, tmp = rh->offset + rh->length, linear_length = rh->progress;
  json_object *jobj, *jobj_segs_hot = json_object_new_object(), *jobj_reenc_seg = NULL,
        *jobj_old_seg = NULL, *jobj_new_seg = NULL;
  unsigned int sg = 0;

  if (!jobj_segs_hot)
    return NULL;

  if (rh->offset) {
    jobj = LUKS2_get_segment_jobj(hdr, 0);
    if (!jobj)
      goto err;

    jobj_new_seg = json_object_get(jobj);
    if (json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_new_seg))
      goto err;

    if (linear_length) {
      jobj_new_seg = reencrypt_make_segment_new(cd, hdr, rh,
                  data_offset,
                  json_segment_get_size(jobj, 0),
                  0,
                  &linear_length);
      if (!jobj_new_seg || json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_new_seg))
        goto err;
    }
  }

  jobj_reenc_seg = reencrypt_make_segment_reencrypt(cd, hdr, rh, data_offset,
                rh->offset,
                rh->offset,
                &rh->length);
  if (!jobj_reenc_seg || json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_reenc_seg))
    goto err;

  if (!rh->offset && (jobj = LUKS2_get_segment_jobj(hdr, 1)) &&
      !json_segment_is_backup(jobj)) {
    jobj_new_seg = json_object_get(jobj);
    if (json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_new_seg))
      goto err;
  } else if (tmp < device_size) {
    fixed_length = device_size - tmp;
    jobj_old_seg = reencrypt_make_segment_old(cd, hdr, rh,
                data_offset + data_shift_value(&rh->rp),
                rh->offset + rh->length,
                rh->fixed_length ? &fixed_length : NULL);
    if (!jobj_old_seg || json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg, &jobj_old_seg))
      goto err;
  }

  return jobj_segs_hot;
err:
  json_object_put(jobj_reenc_seg);
  json_object_put(jobj_old_seg);
  json_object_put(jobj_new_seg);
  json_object_put(jobj_segs_hot);
  return NULL;
}

static json_object *_dec_create_segments_shift_after(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  struct luks2_reencrypt *rh,
  uint64_t data_offset)
{
  int reenc_seg, i = 0;
  json_object *jobj_seg_old, *jobj_copy = NULL, *jobj_seg_old_copy = NULL, *jobj_seg_new = NULL,
        *jobj_segs_post = json_object_new_object();
  unsigned segs;
  uint64_t tmp;

  if (!rh->jobj_segs_hot || !jobj_segs_post)
    goto err;

  segs = json_segments_count(rh->jobj_segs_hot);
  if (segs == 0)
    return jobj_segs_post;

  reenc_seg = json_segments_segment_in_reencrypt(rh->jobj_segs_hot);
  if (reenc_seg < 0)
    goto err;

  if (reenc_seg == 0) {
    jobj_seg_new = reencrypt_make_segment_new(cd, hdr, rh, data_offset, 0, 0, NULL);
    if (!jobj_seg_new || json_object_object_add_by_uint(jobj_segs_post, 0, jobj_seg_new))
      goto err;

    return jobj_segs_post;
  }

  jobj_copy = json_segments_get_segment(rh->jobj_segs_hot, 0);
  if (!jobj_copy)
    goto err;
  json_object_get(jobj_copy);
  if (json_object_object_add_by_uint_by_ref(jobj_segs_post, i++, &jobj_copy))
    goto err;

  if ((jobj_seg_old = json_segments_get_segment(rh->jobj_segs_hot, reenc_seg + 1)))
    jobj_seg_old_copy = json_object_get(jobj_seg_old);

  tmp = rh->length + rh->progress;
  jobj_seg_new = reencrypt_make_segment_new(cd, hdr, rh, data_offset,
              json_segment_get_size(rh->jobj_segment_moved, 0),
              data_shift_value(&rh->rp),
              jobj_seg_old ? &tmp : NULL);
  if (!jobj_seg_new || json_object_object_add_by_uint_by_ref(jobj_segs_post, i++, &jobj_seg_new))
    goto err;

  if (jobj_seg_old_copy && json_object_object_add_by_uint(jobj_segs_post, i, jobj_seg_old_copy))
    goto err;

  return jobj_segs_post;
err:
  json_object_put(jobj_copy);
  json_object_put(jobj_seg_old_copy);
  json_object_put(jobj_seg_new);
  json_object_put(jobj_segs_post);
  return NULL;
}

static json_object *reencrypt_make_hot_segments_backward(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh,
    uint64_t device_size,
    uint64_t data_offset)
{
  uint64_t fixed_length, tmp = rh->offset + rh->length;
  json_object *jobj_reenc_seg = NULL, *jobj_new_seg = NULL, *jobj_old_seg = NULL,
        *jobj_segs_hot = json_object_new_object();
  int sg = 0;

  if (!jobj_segs_hot)
    return NULL;

  if (rh->offset) {
    if (json_object_copy(LUKS2_get_segment_jobj(hdr, 0), &jobj_old_seg))
      goto err;
    json_object_object_add(jobj_old_seg, "size", crypt_jobj_new_uint64(rh->offset));

    if (json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_old_seg))
      goto err;
  }

  jobj_reenc_seg = reencrypt_make_segment_reencrypt(cd, hdr, rh, data_offset, rh->offset, rh->offset, &rh->length);
  if (!jobj_reenc_seg || json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg++, &jobj_reenc_seg))
    goto err;

  if (tmp < device_size) {
    fixed_length = device_size - tmp;
    jobj_new_seg = reencrypt_make_segment_new(cd, hdr, rh, data_offset, rh->offset + rh->length,
                rh->offset + rh->length, rh->fixed_length ? &fixed_length : NULL);
    if (!jobj_new_seg || json_object_object_add_by_uint_by_ref(jobj_segs_hot, sg, &jobj_new_seg))
      goto err;
  }

  return jobj_segs_hot;
err:
  json_object_put(jobj_reenc_seg);
  json_object_put(jobj_new_seg);
  json_object_put(jobj_old_seg);
  json_object_put(jobj_segs_hot);
  return NULL;
}

static int reencrypt_make_hot_segments(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh,
    uint64_t device_size,
    uint64_t data_offset)
{
  rh->jobj_segs_hot = NULL;

  if (rh->mode == CRYPT_REENCRYPT_ENCRYPT && rh->direction == CRYPT_REENCRYPT_BACKWARD &&
      rh->rp.type == REENC_PROTECTION_DATASHIFT && rh->jobj_segment_moved) {
    log_dbg(cd, "Calculating hot segments for encryption with data move.");
    rh->jobj_segs_hot = reencrypt_make_hot_segments_encrypt_shift(hdr, rh, data_offset);
  } else if (rh->mode == CRYPT_REENCRYPT_DECRYPT && rh->direction == CRYPT_REENCRYPT_FORWARD &&
       rh->rp.type == REENC_PROTECTION_DATASHIFT && rh->jobj_segment_moved) {
    log_dbg(cd, "Calculating hot segments for decryption with data move.");
    rh->jobj_segs_hot = reencrypt_make_hot_segments_decrypt_shift(cd, hdr, rh, device_size, data_offset);
  } else if (rh->direction == CRYPT_REENCRYPT_FORWARD) {
    log_dbg(cd, "Calculating hot segments (forward direction).");
    rh->jobj_segs_hot = reencrypt_make_hot_segments_forward(cd, hdr, rh, device_size, data_offset);
  } else if (rh->direction == CRYPT_REENCRYPT_BACKWARD) {
    log_dbg(cd, "Calculating hot segments (backward direction).");
    rh->jobj_segs_hot = reencrypt_make_hot_segments_backward(cd, hdr, rh, device_size, data_offset);
  }

  return rh->jobj_segs_hot ? 0 : -EINVAL;
}

static int reencrypt_make_post_segments(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh,
    uint64_t data_offset)
{
  rh->jobj_segs_post = NULL;

  if (rh->mode == CRYPT_REENCRYPT_ENCRYPT && rh->direction == CRYPT_REENCRYPT_BACKWARD &&
      rh->rp.type == REENC_PROTECTION_DATASHIFT && rh->jobj_segment_moved) {
    log_dbg(cd, "Calculating post segments for encryption with data move.");
    rh->jobj_segs_post = _enc_create_segments_shift_after(rh, data_offset);
  } else if (rh->mode == CRYPT_REENCRYPT_DECRYPT && rh->direction == CRYPT_REENCRYPT_FORWARD &&
       rh->rp.type == REENC_PROTECTION_DATASHIFT && rh->jobj_segment_moved) {
    log_dbg(cd, "Calculating post segments for decryption with data move.");
    rh->jobj_segs_post = _dec_create_segments_shift_after(cd, hdr, rh, data_offset);
  } else if (rh->direction == CRYPT_REENCRYPT_FORWARD) {
    log_dbg(cd, "Calculating post segments (forward direction).");
    rh->jobj_segs_post = reencrypt_make_post_segments_forward(cd, hdr, rh, data_offset);
  } else if (rh->direction == CRYPT_REENCRYPT_BACKWARD) {
    log_dbg(cd, "Calculating segments (backward direction).");
    rh->jobj_segs_post = reencrypt_make_post_segments_backward(cd, hdr, rh, data_offset);
  }

  return rh->jobj_segs_post ? 0 : -EINVAL;
}
#endif

static uint64_t reencrypt_data_shift(struct luks2_hdr *hdr)
{
  json_object *jobj_keyslot, *jobj_area, *jobj_data_shift;
  int ks = LUKS2_find_keyslot(hdr, "reencrypt");

  if (ks < 0)
    return 0;

  jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, ks);

  json_object_object_get_ex(jobj_keyslot, "area", &jobj_area);
  if (!json_object_object_get_ex(jobj_area, "shift_size", &jobj_data_shift))
    return 0;

  return crypt_jobj_get_uint64(jobj_data_shift);
}

static crypt_reencrypt_mode_info reencrypt_mode(struct luks2_hdr *hdr)
{
  const char *mode;
  crypt_reencrypt_mode_info mi = CRYPT_REENCRYPT_REENCRYPT;
  json_object *jobj_keyslot, *jobj_mode;

  jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, LUKS2_find_keyslot(hdr, "reencrypt"));
  if (!jobj_keyslot)
    return mi;

  json_object_object_get_ex(jobj_keyslot, "mode", &jobj_mode);
  mode = json_object_get_string(jobj_mode);

  /* validation enforces allowed values */
  if (!strcmp(mode, "encrypt"))
    mi = CRYPT_REENCRYPT_ENCRYPT;
  else if (!strcmp(mode, "decrypt"))
    mi = CRYPT_REENCRYPT_DECRYPT;

  return mi;
}

static crypt_reencrypt_direction_info reencrypt_direction(struct luks2_hdr *hdr)
{
  const char *value;
  json_object *jobj_keyslot, *jobj_mode;
  crypt_reencrypt_direction_info di = CRYPT_REENCRYPT_FORWARD;

  jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, LUKS2_find_keyslot(hdr, "reencrypt"));
  if (!jobj_keyslot)
    return di;

  json_object_object_get_ex(jobj_keyslot, "direction", &jobj_mode);
  value = json_object_get_string(jobj_mode);

  /* validation enforces allowed values */
  if (strcmp(value, "forward"))
    di = CRYPT_REENCRYPT_BACKWARD;

  return di;
}

typedef enum { REENC_OK = 0, REENC_ERR, REENC_ROLLBACK, REENC_FATAL } reenc_status_t;

void LUKS2_reencrypt_protection_erase(struct reenc_protection *rp)
{
  if (!rp || rp->type != REENC_PROTECTION_CHECKSUM)
    return;

  if (rp->p.csum.ch) {
    crypt_hash_destroy(rp->p.csum.ch);
    rp->p.csum.ch = NULL;
  }

  if (rp->p.csum.checksums) {
    crypt_safe_memzero(rp->p.csum.checksums, rp->p.csum.checksums_len);
    free(rp->p.csum.checksums);
    rp->p.csum.checksums = NULL;
  }
}

void LUKS2_reencrypt_free(struct crypt_device *cd, struct luks2_reencrypt *rh)
{
  if (!rh)
    return;

  LUKS2_reencrypt_protection_erase(&rh->rp);
  LUKS2_reencrypt_protection_erase(&rh->rp_moved_segment);

  json_object_put(rh->jobj_segs_hot);
  rh->jobj_segs_hot = NULL;
  json_object_put(rh->jobj_segs_post);
  rh->jobj_segs_post = NULL;
  json_object_put(rh->jobj_segment_old);
  rh->jobj_segment_old = NULL;
  json_object_put(rh->jobj_segment_new);
  rh->jobj_segment_new = NULL;
  json_object_put(rh->jobj_segment_moved);
  rh->jobj_segment_moved = NULL;

  free(rh->reenc_buffer);
  rh->reenc_buffer = NULL;
  crypt_storage_wrapper_destroy(rh->cw1);
  rh->cw1 = NULL;
  crypt_storage_wrapper_destroy(rh->cw2);
  rh->cw2 = NULL;
  device_free(cd, rh->hotzone_device);
  rh->hotzone_device = NULL;

  free(rh->device_name);
  free(rh->overlay_name);
  free(rh->hotzone_name);
  crypt_drop_uploaded_keyring_key(cd, rh->vks);
  crypt_free_volume_key(rh->vks);
  device_release_excl(cd, crypt_data_device(cd));
  crypt_unlock_internal(cd, rh->reenc_lock);
  free(rh);
}

#if USE_LUKS2_REENCRYPTION
int LUKS2_reencrypt_max_hotzone_size(struct crypt_device *cd __attribute__((unused)),
  struct luks2_hdr *hdr,
  const struct reenc_protection *rp,
  int reencrypt_keyslot,
  uint64_t *r_length)
{
  int r;
  uint64_t dummy, area_length;

  assert(hdr);
  assert(rp);
  assert(r_length);

  if (rp->type <= REENC_PROTECTION_NONE) {
    *r_length = LUKS2_REENCRYPT_MAX_HOTZONE_LENGTH;
    return 0;
  }

  if (rp->type == REENC_PROTECTION_DATASHIFT) {
    *r_length = rp->p.ds.data_shift;
    return 0;
  }

  r = LUKS2_keyslot_area(hdr, reencrypt_keyslot, &dummy, &area_length);
  if (r < 0)
    return -EINVAL;

  if (rp->type == REENC_PROTECTION_JOURNAL) {
    *r_length = area_length;
    return 0;
  }

  if (rp->type == REENC_PROTECTION_CHECKSUM) {
    *r_length = (area_length / rp->p.csum.hash_size) * rp->p.csum.block_size;
    return 0;
  }

  return -EINVAL;
}

static size_t reencrypt_get_alignment(struct crypt_device *cd,
    struct luks2_hdr *hdr)
{
  size_t ss, alignment = device_block_size(cd, crypt_data_device(cd));

  ss = reencrypt_get_sector_size_old(hdr);
  if (ss > alignment)
    alignment = ss;
  ss = reencrypt_get_sector_size_new(hdr);
  if (ss > alignment)
    alignment = ss;

  return alignment;
}

/* returns void because it must not fail on valid LUKS2 header */
static void _load_backup_segments(struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh)
{
  int segment = LUKS2_get_segment_id_by_flag(hdr, "backup-final");

  if (segment >= 0) {
    rh->jobj_segment_new = json_object_get(LUKS2_get_segment_jobj(hdr, segment));
    rh->digest_new = LUKS2_digest_by_segment(hdr, segment);
  } else {
    rh->jobj_segment_new = NULL;
    rh->digest_new = -ENOENT;
  }

  segment = LUKS2_get_segment_id_by_flag(hdr, "backup-previous");
  if (segment >= 0) {
    rh->jobj_segment_old = json_object_get(LUKS2_get_segment_jobj(hdr, segment));
    rh->digest_old = LUKS2_digest_by_segment(hdr, segment);
  } else {
    rh->jobj_segment_old = NULL;
    rh->digest_old = -ENOENT;
  }

  segment = LUKS2_get_segment_id_by_flag(hdr, "backup-moved-segment");
  if (segment >= 0)
    rh->jobj_segment_moved = json_object_get(LUKS2_get_segment_jobj(hdr, segment));
  else
    rh->jobj_segment_moved = NULL;
}

static int reencrypt_offset_backward_moved(struct luks2_hdr *hdr, json_object *jobj_segments,
             uint64_t *reencrypt_length, uint64_t data_shift, uint64_t *offset)
{
  uint64_t tmp, linear_length = 0;
  int sg, segs = json_segments_count(jobj_segments);

  /* find reencrypt offset with data shift */
  for (sg = 0; sg < segs; sg++)
    if (LUKS2_segment_is_type(hdr, sg, "linear"))
      linear_length += LUKS2_segment_size(hdr, sg, 0);

  /* all active linear segments length */
  if (linear_length && segs > 1) {
    if (linear_length < data_shift)
      return -EINVAL;
    tmp = linear_length - data_shift;
    if (tmp && tmp < data_shift) {
      *offset = data_shift;
      *reencrypt_length = tmp;
    } else
      *offset = tmp;
    return 0;
  }

  if (segs == 1) {
    *offset = 0;
    return 0;
  }

  /* should be unreachable */

  return -EINVAL;
}

static int reencrypt_offset_forward_moved(struct luks2_hdr *hdr,
  uint64_t data_shift,
  uint64_t *offset)
{
  int last_crypt = LUKS2_last_segment_by_type(hdr, "crypt");

  /* if last crypt segment exists and it's first one, just return offset = 0 */
  if (last_crypt <= 0) {
    *offset = 0;
    return 0;
  }

  *offset = LUKS2_segment_offset(hdr, last_crypt, 0) - data_shift;
  return 0;
}

static int _offset_forward(json_object *jobj_segments, uint64_t *offset)
{
  int segs = json_segments_count(jobj_segments);

  if (segs == 1)
    *offset = 0;
  else if (segs == 2) {
    *offset = json_segment_get_size(json_segments_get_segment(jobj_segments, 0), 0);
    if (!*offset)
      return -EINVAL;
  } else
    return -EINVAL;

  return 0;
}

static int _offset_backward(json_object *jobj_segments, uint64_t device_size, uint64_t *length, uint64_t *offset)
{
  int segs = json_segments_count(jobj_segments);
  uint64_t tmp;

  if (segs == 1) {
    if (device_size < *length)
      *length = device_size;
    *offset = device_size - *length;
  } else if (segs == 2) {
    tmp = json_segment_get_size(json_segments_get_segment(jobj_segments, 0), 0);
    if (tmp < *length)
      *length = tmp;
    *offset =  tmp - *length;
  } else
    return -EINVAL;

  return 0;
}

/* must be always relative to data offset */
/* the LUKS2 header MUST be valid */
static int reencrypt_offset(struct luks2_hdr *hdr,
    crypt_reencrypt_direction_info di,
    uint64_t device_size,
    uint64_t *reencrypt_length,
    uint64_t *offset)
{
  int r, sg;
  json_object *jobj_segments;
  uint64_t data_shift = reencrypt_data_shift(hdr);

  if (!offset)
    return -EINVAL;

  /* if there's segment in reencryption return directly offset of it */
  json_object_object_get_ex(hdr->jobj, "segments", &jobj_segments);
  sg = json_segments_segment_in_reencrypt(jobj_segments);
  if (sg >= 0) {
    *offset = LUKS2_segment_offset(hdr, sg, 0) - (reencrypt_get_data_offset_new(hdr));
    return 0;
  }

  if (di == CRYPT_REENCRYPT_FORWARD) {
    if (reencrypt_mode(hdr) == CRYPT_REENCRYPT_DECRYPT &&
        LUKS2_get_segment_id_by_flag(hdr, "backup-moved-segment") >= 0) {
      r = reencrypt_offset_forward_moved(hdr, data_shift, offset);
      if (!r && *offset > device_size)
        *offset = device_size;
      return r;
    }
    return _offset_forward(jobj_segments, offset);
  } else if (di == CRYPT_REENCRYPT_BACKWARD) {
    if (reencrypt_mode(hdr) == CRYPT_REENCRYPT_ENCRYPT &&
        LUKS2_get_segment_id_by_flag(hdr, "backup-moved-segment") >= 0)
      return reencrypt_offset_backward_moved(hdr, jobj_segments, reencrypt_length, data_shift, offset);
    return _offset_backward(jobj_segments, device_size, reencrypt_length, offset);
  }

  return -EINVAL;
}

static uint64_t reencrypt_length(struct crypt_device *cd,
    struct reenc_protection *rp,
    uint64_t keyslot_area_length,
    uint64_t length_max,
    size_t alignment)
{
  unsigned long dummy, optimal_alignment;
  uint64_t length, soft_mem_limit;

  if (rp->type == REENC_PROTECTION_NONE)
    length = length_max ?: LUKS2_DEFAULT_NONE_REENCRYPTION_LENGTH;
  else if (rp->type == REENC_PROTECTION_CHECKSUM)
    length = (keyslot_area_length / rp->p.csum.hash_size) * rp->p.csum.block_size;
  else if (rp->type == REENC_PROTECTION_DATASHIFT)
    return rp->p.ds.data_shift;
  else
    length = keyslot_area_length;

  /* hard limit */
  if (length > LUKS2_REENCRYPT_MAX_HOTZONE_LENGTH)
    length = LUKS2_REENCRYPT_MAX_HOTZONE_LENGTH;

  /* soft limit is 1/4 of system memory */
  soft_mem_limit = crypt_getphysmemory_kb() << 8; /* multiply by (1024/4) */

  if (soft_mem_limit && length > soft_mem_limit)
    length = soft_mem_limit;

  if (length_max && length > length_max)
    length = length_max;

  length -= (length % alignment);

  /* Emits error later */
  if (!length)
    return length;

  device_topology_alignment(cd, crypt_data_device(cd), &optimal_alignment, &dummy, length);

  /* we have to stick with encryption sector size alignment */
  if (optimal_alignment % alignment)
    return length;

  /* align to opt-io size only if remaining size allows it */
  if (length > optimal_alignment)
    length -= (length % optimal_alignment);

  return length;
}

static int reencrypt_context_init(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  struct luks2_reencrypt *rh,
  uint64_t device_size,
  uint64_t max_hotzone_size,
  uint64_t fixed_device_size)
{
  int r;
  size_t alignment;
  uint64_t dummy, area_length;

  rh->reenc_keyslot = LUKS2_find_keyslot(hdr, "reencrypt");
  if (rh->reenc_keyslot < 0)
    return -EINVAL;
  if (LUKS2_keyslot_area(hdr, rh->reenc_keyslot, &dummy, &area_length) < 0)
    return -EINVAL;

  rh->mode = reencrypt_mode(hdr);

  rh->direction = reencrypt_direction(hdr);

  r = LUKS2_keyslot_reencrypt_load(cd, hdr, rh->reenc_keyslot, &rh->rp, true);
  if (r < 0)
    return r;

  if (rh->rp.type == REENC_PROTECTION_CHECKSUM)
    alignment = rh->rp.p.csum.block_size;
  else
    alignment = reencrypt_get_alignment(cd, hdr);

  if (!alignment)
    return -EINVAL;

  if ((max_hotzone_size << SECTOR_SHIFT) % alignment) {
    log_err(cd, _("Hotzone size must be multiple of calculated zone alignment (%zu bytes)."), alignment);
    return -EINVAL;
  }

  if ((fixed_device_size << SECTOR_SHIFT) % alignment) {
    log_err(cd, _("Device size must be multiple of calculated zone alignment (%zu bytes)."), alignment);
    return -EINVAL;
  }

  if (fixed_device_size) {
    log_dbg(cd, "Switching reencryption to fixed size mode.");
    device_size = fixed_device_size << SECTOR_SHIFT;
    rh->fixed_length = true;
  } else
    rh->fixed_length = false;

  rh->length = reencrypt_length(cd, &rh->rp, area_length, max_hotzone_size << SECTOR_SHIFT, alignment);
  if (!rh->length) {
    log_dbg(cd, "Invalid reencryption length.");
    return -EINVAL;
  }

  if (reencrypt_offset(hdr, rh->direction, device_size, &rh->length, &rh->offset)) {
    log_dbg(cd, "Failed to get reencryption offset.");
    return -EINVAL;
  }

  if (rh->offset > device_size)
    return -EINVAL;
  if (rh->length > device_size - rh->offset)
    rh->length = device_size - rh->offset;

  _load_backup_segments(hdr, rh);

  r = LUKS2_keyslot_reencrypt_load(cd, hdr, rh->reenc_keyslot, &rh->rp_moved_segment, false);
  if (r < 0)
    return r;

  if (rh->rp_moved_segment.type == REENC_PROTECTION_NOT_SET)
    log_dbg(cd, "No moved segment resilience configured.");

  if (rh->direction == CRYPT_REENCRYPT_BACKWARD)
    rh->progress = device_size - rh->offset - rh->length;
  else if (rh->jobj_segment_moved && rh->direction == CRYPT_REENCRYPT_FORWARD) {
    if (rh->offset == json_segment_get_offset(LUKS2_get_segment_by_flag(hdr, "backup-moved-segment"), false))
      rh->progress = device_size - json_segment_get_size(LUKS2_get_segment_by_flag(hdr, "backup-moved-segment"), false);
    else
      rh->progress = rh->offset - json_segment_get_size(rh->jobj_segment_moved, 0);
  } else
    rh->progress = rh->offset;

  log_dbg(cd, "reencrypt-direction: %s", rh->direction == CRYPT_REENCRYPT_FORWARD ? "forward" : "backward");
  log_dbg(cd, "backup-previous digest id: %d", rh->digest_old);
  log_dbg(cd, "backup-final digest id: %d", rh->digest_new);
  log_dbg(cd, "reencrypt length: %" PRIu64, rh->length);
  log_dbg(cd, "reencrypt offset: %" PRIu64, rh->offset);
  log_dbg(cd, "reencrypt shift: %s%" PRIu64,
    (rh->rp.type == REENC_PROTECTION_DATASHIFT && rh->direction == CRYPT_REENCRYPT_BACKWARD ? "-" : ""),
    data_shift_value(&rh->rp));
  log_dbg(cd, "reencrypt alignment: %zu", alignment);
  log_dbg(cd, "reencrypt progress: %" PRIu64, rh->progress);

  rh->device_size = device_size;

  return rh->length < 512 ? -EINVAL : 0;
}

static size_t reencrypt_buffer_length(struct luks2_reencrypt *rh)
{
  if (rh->rp.type == REENC_PROTECTION_DATASHIFT)
    return data_shift_value(&rh->rp);
  return rh->length;
}

static int reencrypt_load_clean(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  uint64_t device_size,
  uint64_t max_hotzone_size,
  uint64_t fixed_device_size,
  struct luks2_reencrypt **rh)
{
  int r;
  struct luks2_reencrypt *tmp = crypt_zalloc(sizeof (*tmp));

  if (!tmp)
    return -ENOMEM;

  log_dbg(cd, "Loading stored reencryption context.");

  r = reencrypt_context_init(cd, hdr, tmp, device_size, max_hotzone_size, fixed_device_size);
  if (r)
    goto err;

  if (posix_memalign(&tmp->reenc_buffer, device_alignment(crypt_data_device(cd)),
         reencrypt_buffer_length(tmp))) {
    r = -ENOMEM;
    goto err;
  }

  *rh = tmp;

  return 0;
err:
  LUKS2_reencrypt_free(cd, tmp);

  return r;
}

static int reencrypt_make_segments(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  struct luks2_reencrypt *rh,
  uint64_t device_size)
{
  int r;
  uint64_t data_offset = reencrypt_get_data_offset_new(hdr);

  log_dbg(cd, "Calculating segments.");

  r = reencrypt_make_hot_segments(cd, hdr, rh, device_size, data_offset);
  if (!r) {
    r = reencrypt_make_post_segments(cd, hdr, rh, data_offset);
    if (r)
      json_object_put(rh->jobj_segs_hot);
  }

  if (r)
    log_dbg(cd, "Failed to make reencryption segments.");

  return r;
}

static int reencrypt_make_segments_crashed(struct crypt_device *cd,
        struct luks2_hdr *hdr,
              struct luks2_reencrypt *rh)
{
  int r;
  uint64_t data_offset = crypt_get_data_offset(cd) << SECTOR_SHIFT;

  if (!rh)
    return -EINVAL;

  rh->jobj_segs_hot = json_object_new_object();
  if (!rh->jobj_segs_hot)
    return -ENOMEM;

  json_object_object_foreach(LUKS2_get_segments_jobj(hdr), key, val) {
    if (json_segment_is_backup(val))
      continue;
    json_object_object_add(rh->jobj_segs_hot, key, json_object_get(val));
  }

  r = reencrypt_make_post_segments(cd, hdr, rh, data_offset);
  if (r) {
    json_object_put(rh->jobj_segs_hot);
    rh->jobj_segs_hot = NULL;
  }

  return r;
}

static int reencrypt_load_crashed(struct crypt_device *cd,
  struct luks2_hdr *hdr, uint64_t device_size, struct luks2_reencrypt **rh)
{
  bool dynamic;
  uint64_t required_device_size;
  int r, reenc_seg;

  if (LUKS2_get_data_size(hdr, &required_device_size, &dynamic))
    return -EINVAL;

  if (dynamic)
    required_device_size = 0;
  else
    required_device_size >>= SECTOR_SHIFT;

  r = reencrypt_load_clean(cd, hdr, device_size, 0, required_device_size, rh);

  if (!r) {
    reenc_seg = json_segments_segment_in_reencrypt(LUKS2_get_segments_jobj(hdr));
    if (reenc_seg < 0)
      r = -EINVAL;
    else
      (*rh)->length = LUKS2_segment_size(hdr, reenc_seg, 0);
  }

  if (!r)
    r = reencrypt_make_segments_crashed(cd, hdr, *rh);

  if (r) {
    LUKS2_reencrypt_free(cd, *rh);
    *rh = NULL;
  }
  return r;
}

static int reencrypt_init_storage_wrappers(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh,
    struct volume_key *vks)
{
  int r;
  struct volume_key *vk;
  uint32_t wrapper_flags = (getuid() || geteuid()) ? 0 : DISABLE_KCAPI;

  vk = crypt_volume_key_by_id(vks, rh->digest_old);
  r = crypt_storage_wrapper_init(cd, &rh->cw1, crypt_data_device(cd),
      reencrypt_get_data_offset_old(hdr),
      crypt_get_iv_offset(cd),
      reencrypt_get_sector_size_old(hdr),
      reencrypt_segment_cipher_old(hdr),
      vk, wrapper_flags | OPEN_READONLY);
  if (r) {
    log_err(cd, _("Failed to initialize old segment storage wrapper."));
    return r;
  }
  rh->wflags1 = wrapper_flags | OPEN_READONLY;
  log_dbg(cd, "Old cipher storage wrapper type: %d.", crypt_storage_wrapper_get_type(rh->cw1));

  vk = crypt_volume_key_by_id(vks, rh->digest_new);
  r = crypt_storage_wrapper_init(cd, &rh->cw2, crypt_data_device(cd),
      reencrypt_get_data_offset_new(hdr),
      crypt_get_iv_offset(cd),
      reencrypt_get_sector_size_new(hdr),
      reencrypt_segment_cipher_new(hdr),
      vk, wrapper_flags);
  if (r) {
    log_err(cd, _("Failed to initialize new segment storage wrapper."));
    return r;
  }
  rh->wflags2 = wrapper_flags;
  log_dbg(cd, "New cipher storage wrapper type: %d", crypt_storage_wrapper_get_type(rh->cw2));

  return 0;
}

static int reencrypt_context_set_names(struct luks2_reencrypt *rh, const char *name)
{
  if (!rh || !name)
    return -EINVAL;

  if (*name == '/') {
    if (!(rh->device_name = dm_device_name(name)))
      return -EINVAL;
  } else if (!(rh->device_name = strdup(name)))
    return -ENOMEM;

  if (asprintf(&rh->hotzone_name, "%s-hotzone-%s", rh->device_name,
         rh->direction == CRYPT_REENCRYPT_FORWARD ? "forward" : "backward") < 0) {
    rh->hotzone_name = NULL;
    return -ENOMEM;
  }
  if (asprintf(&rh->overlay_name, "%s-overlay", rh->device_name) < 0) {
    rh->overlay_name = NULL;
    return -ENOMEM;
  }

  rh->online = true;
  return 0;
}

static int modify_offset(uint64_t *offset, uint64_t data_shift, crypt_reencrypt_direction_info di)
{
  int r = -EINVAL;

  if (!offset)
    return r;

  if (di == CRYPT_REENCRYPT_FORWARD) {
    if (*offset >= data_shift) {
      *offset -= data_shift;
      r = 0;
    }
  } else if (di == CRYPT_REENCRYPT_BACKWARD) {
    *offset += data_shift;
    r = 0;
  }

  return r;
}

static int reencrypt_update_flag(struct crypt_device *cd, uint8_t version,
  bool enable, bool commit)
{
  uint32_t reqs;
  struct luks2_hdr *hdr = crypt_get_hdr(cd, CRYPT_LUKS2);

  if (enable) {
    log_dbg(cd, "Going to store reencryption requirement flag (version: %u).", version);
    return LUKS2_config_set_requirement_version(cd, hdr, CRYPT_REQUIREMENT_ONLINE_REENCRYPT, version, commit);
  }

  LUKS2_config_get_requirements(cd, hdr, &reqs);

  reqs &= ~CRYPT_REQUIREMENT_ONLINE_REENCRYPT;

  log_dbg(cd, "Going to wipe reencryption requirement flag.");

  return LUKS2_config_set_requirements(cd, hdr, reqs, commit);
}

static int reencrypt_hotzone_protect_ready(struct crypt_device *cd,
  struct reenc_protection *rp)
{
  assert(rp);

  if (rp->type == REENC_PROTECTION_NOT_SET)
    return -EINVAL;

  if (rp->type != REENC_PROTECTION_CHECKSUM)
    return 0;

  if (!rp->p.csum.checksums) {
    log_dbg(cd, "Allocating buffer for storing resilience checksums.");
    if (posix_memalign(&rp->p.csum.checksums, device_alignment(crypt_metadata_device(cd)),
           rp->p.csum.checksums_len))
      return -ENOMEM;
  }

  return 0;
}

static int reencrypt_recover_segment(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  struct luks2_reencrypt *rh,
  struct volume_key *vks)
{
  struct volume_key *vk_old, *vk_new;
  size_t count, s;
  ssize_t read, w;
  struct reenc_protection *rp;
  int devfd, r, new_sector_size, old_sector_size, rseg;
  uint64_t area_offset, area_length, area_length_read, crash_iv_offset,
     data_offset = crypt_get_data_offset(cd) << SECTOR_SHIFT;
  char *checksum_tmp = NULL, *data_buffer = NULL;
  struct crypt_storage_wrapper *cw1 = NULL, *cw2 = NULL;

  assert(hdr);
  assert(rh);
  assert(vks);

  rseg = json_segments_segment_in_reencrypt(rh->jobj_segs_hot);
  if (rh->offset == 0 && rh->rp_moved_segment.type > REENC_PROTECTION_NOT_SET) {
    log_dbg(cd, "Recovery using moved segment protection.");
    rp = &rh->rp_moved_segment;
  } else
    rp = &rh->rp;

  if (rseg < 0 || rh->length < 512)
    return -EINVAL;

  r = reencrypt_hotzone_protect_ready(cd, rp);
  if (r) {
    log_err(cd, _("Failed to initialize hotzone protection."));
    return -EINVAL;
  }

  vk_new = crypt_volume_key_by_id(vks, rh->digest_new);
  if (!vk_new && rh->mode != CRYPT_REENCRYPT_DECRYPT)
    return -EINVAL;
  vk_old = crypt_volume_key_by_id(vks, rh->digest_old);
  if (!vk_old && rh->mode != CRYPT_REENCRYPT_ENCRYPT)
    return -EINVAL;
  old_sector_size = json_segment_get_sector_size(reencrypt_segment_old(hdr));
  new_sector_size = json_segment_get_sector_size(reencrypt_segment_new(hdr));
  if (rh->mode == CRYPT_REENCRYPT_DECRYPT)
    crash_iv_offset = rh->offset >> SECTOR_SHIFT; /* TODO: + old iv_tweak */
  else
    crash_iv_offset = json_segment_get_iv_offset(json_segments_get_segment(rh->jobj_segs_hot, rseg));

  log_dbg(cd, "crash_offset: %" PRIu64 ", crash_length: %" PRIu64 ",  crash_iv_offset: %" PRIu64,
    data_offset + rh->offset, rh->length, crash_iv_offset);

  r = crypt_storage_wrapper_init(cd, &cw2, crypt_data_device(cd),
      data_offset + rh->offset, crash_iv_offset, new_sector_size,
      reencrypt_segment_cipher_new(hdr), vk_new, 0);
  if (r) {
    log_err(cd, _("Failed to initialize new segment storage wrapper."));
    return r;
  }

  if (LUKS2_keyslot_area(hdr, rh->reenc_keyslot, &area_offset, &area_length)) {
    r = -EINVAL;
    goto out;
  }

  if (posix_memalign((void**)&data_buffer, device_alignment(crypt_data_device(cd)), rh->length)) {
    r = -ENOMEM;
    goto out;
  }

  switch (rp->type) {
  case  REENC_PROTECTION_CHECKSUM:
    log_dbg(cd, "Checksums based recovery.");

    r = crypt_storage_wrapper_init(cd, &cw1, crypt_data_device(cd),
        data_offset + rh->offset, crash_iv_offset, old_sector_size,
        reencrypt_segment_cipher_old(hdr), vk_old, 0);
    if (r) {
      log_err(cd, _("Failed to initialize old segment storage wrapper."));
      goto out;
    }

    count = rh->length / rp->p.csum.block_size;
    area_length_read = count * rp->p.csum.hash_size;
    if (area_length_read > area_length) {
      log_dbg(cd, "Internal error in calculated area_length.");
      r = -EINVAL;
      goto out;
    }

    checksum_tmp = malloc(rp->p.csum.hash_size);
    if (!checksum_tmp) {
      r = -ENOMEM;
      goto out;
    }

    /* TODO: lock for read */
    devfd = device_open(cd, crypt_metadata_device(cd), O_RDONLY);
    if (devfd < 0)
      goto out;

    /* read old data checksums */
    read = read_lseek_blockwise(devfd, device_block_size(cd, crypt_metadata_device(cd)),
          device_alignment(crypt_metadata_device(cd)), rp->p.csum.checksums, area_length_read, area_offset);
    if (read < 0 || (size_t)read != area_length_read) {
      log_err(cd, _("Failed to read checksums for current hotzone."));
      r = -EINVAL;
      goto out;
    }

    read = crypt_storage_wrapper_read(cw2, 0, data_buffer, rh->length);
    if (read < 0 || (size_t)read != rh->length) {
      log_err(cd, _("Failed to read hotzone area starting at %" PRIu64 "."), rh->offset + data_offset);
      r = -EINVAL;
      goto out;
    }

    for (s = 0; s < count; s++) {
      if (crypt_hash_write(rp->p.csum.ch, data_buffer + (s * rp->p.csum.block_size), rp->p.csum.block_size)) {
        log_dbg(cd, "Failed to write hash.");
        r = EINVAL;
        goto out;
      }
      if (crypt_hash_final(rp->p.csum.ch, checksum_tmp, rp->p.csum.hash_size)) {
        log_dbg(cd, "Failed to finalize hash.");
        r = EINVAL;
        goto out;
      }
      if (!memcmp(checksum_tmp, (char *)rp->p.csum.checksums + (s * rp->p.csum.hash_size), rp->p.csum.hash_size)) {
        log_dbg(cd, "Sector %zu (size %zu, offset %zu) needs recovery", s, rp->p.csum.block_size, s * rp->p.csum.block_size);
        if (crypt_storage_wrapper_decrypt(cw1, s * rp->p.csum.block_size, data_buffer + (s * rp->p.csum.block_size), rp->p.csum.block_size)) {
          log_err(cd, _("Failed to decrypt sector %zu."), s);
          r = -EINVAL;
          goto out;
        }
        w = crypt_storage_wrapper_encrypt_write(cw2, s * rp->p.csum.block_size, data_buffer + (s * rp->p.csum.block_size), rp->p.csum.block_size);
        if (w < 0 || (size_t)w != rp->p.csum.block_size) {
          log_err(cd, _("Failed to recover sector %zu."), s);
          r = -EINVAL;
          goto out;
        }
      }
    }

    r = 0;
    break;
  case  REENC_PROTECTION_JOURNAL:
    log_dbg(cd, "Journal based recovery.");

    /* FIXME: validation candidate */
    if (rh->length > area_length) {
      r = -EINVAL;
      log_dbg(cd, "Invalid journal size.");
      goto out;
    }

    /* TODO locking */
    r = crypt_storage_wrapper_init(cd, &cw1, crypt_metadata_device(cd),
        area_offset, crash_iv_offset, old_sector_size,
        reencrypt_segment_cipher_old(hdr), vk_old, 0);
    if (r) {
      log_err(cd, _("Failed to initialize old segment storage wrapper."));
      goto out;
    }
    read = crypt_storage_wrapper_read_decrypt(cw1, 0, data_buffer, rh->length);
    if (read < 0 || (size_t)read != rh->length) {
      log_dbg(cd, "Failed to read journaled data.");
      r = -EIO;
      /* may content plaintext */
      crypt_safe_memzero(data_buffer, rh->length);
      goto out;
    }
    read = crypt_storage_wrapper_encrypt_write(cw2, 0, data_buffer, rh->length);
    /* may content plaintext */
    crypt_safe_memzero(data_buffer, rh->length);
    if (read < 0 || (size_t)read != rh->length) {
      log_dbg(cd, "recovery write failed.");
      r = -EINVAL;
      goto out;
    }

    r = 0;
    break;
  case  REENC_PROTECTION_DATASHIFT:
    log_dbg(cd, "Data shift based recovery.");

    if (rseg == 0) {
      r = crypt_storage_wrapper_init(cd, &cw1, crypt_data_device(cd),
          json_segment_get_offset(rh->jobj_segment_moved, 0), 0,
          reencrypt_get_sector_size_old(hdr),
          reencrypt_segment_cipher_old(hdr), vk_old, 0);
    } else {
      if (rh->direction == CRYPT_REENCRYPT_FORWARD)
        data_offset = data_offset + rh->offset + data_shift_value(rp);
      else
        data_offset = data_offset + rh->offset - data_shift_value(rp);
      r = crypt_storage_wrapper_init(cd, &cw1, crypt_data_device(cd),
          data_offset,
          crash_iv_offset,
          reencrypt_get_sector_size_old(hdr),
          reencrypt_segment_cipher_old(hdr), vk_old, 0);
    }
    if (r) {
      log_err(cd, _("Failed to initialize old segment storage wrapper."));
      goto out;
    }

    read = crypt_storage_wrapper_read_decrypt(cw1, 0, data_buffer, rh->length);
    if (read < 0 || (size_t)read != rh->length) {
      log_dbg(cd, "Failed to read data.");
      r = -EIO;
      /* may content plaintext */
      crypt_safe_memzero(data_buffer, rh->length);
      goto out;
    }

    read = crypt_storage_wrapper_encrypt_write(cw2, 0, data_buffer, rh->length);
    /* may content plaintext */
    crypt_safe_memzero(data_buffer, rh->length);
    if (read < 0 || (size_t)read != rh->length) {
      log_dbg(cd, "recovery write failed.");
      r = -EINVAL;
      goto out;
    }
    r = 0;
    break;
  default:
    r = -EINVAL;
  }

  if (!r)
    rh->read = rh->length;
out:
  free(data_buffer);
  free(checksum_tmp);
  crypt_storage_wrapper_destroy(cw1);
  crypt_storage_wrapper_destroy(cw2);

  return r;
}

static int reencrypt_add_moved_segment(struct crypt_device *cd, struct luks2_hdr *hdr, struct luks2_reencrypt *rh)
{
  int digest = rh->digest_old, s = LUKS2_segment_first_unused_id(hdr);

  if (!rh->jobj_segment_moved)
    return 0;

  if (s < 0)
    return s;

  if (json_object_object_add_by_uint(LUKS2_get_segments_jobj(hdr), s, json_object_get(rh->jobj_segment_moved))) {
    json_object_put(rh->jobj_segment_moved);
    return -EINVAL;
  }

  if (!strcmp(json_segment_type(rh->jobj_segment_moved), "crypt"))
    return LUKS2_digest_segment_assign(cd, hdr, s, digest, 1, 0);

  return 0;
}

static int reencrypt_add_backup_segment(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh,
    unsigned final)
{
  int digest, s = LUKS2_segment_first_unused_id(hdr);
  json_object *jobj;

  if (s < 0)
    return s;

  digest = final ? rh->digest_new : rh->digest_old;
  jobj = final ? rh->jobj_segment_new : rh->jobj_segment_old;

  if (json_object_object_add_by_uint(LUKS2_get_segments_jobj(hdr), s, json_object_get(jobj))) {
    json_object_put(jobj);
    return -EINVAL;
  }

  if (strcmp(json_segment_type(jobj), "crypt"))
    return 0;

  return LUKS2_digest_segment_assign(cd, hdr, s, digest, 1, 0);
}

static int reencrypt_assign_segments_simple(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  struct luks2_reencrypt *rh,
  unsigned hot,
  unsigned commit)
{
  int r, sg;

  if (hot && json_segments_count(rh->jobj_segs_hot) > 0) {
    log_dbg(cd, "Setting 'hot' segments.");

    r = LUKS2_segments_set(cd, hdr, rh->jobj_segs_hot, 0);
    if (!r)
      rh->jobj_segs_hot = NULL;
  } else if (!hot && json_segments_count(rh->jobj_segs_post) > 0) {
    log_dbg(cd, "Setting 'post' segments.");
    r = LUKS2_segments_set(cd, hdr, rh->jobj_segs_post, 0);
    if (!r)
      rh->jobj_segs_post = NULL;
  } else {
    log_dbg(cd, "No segments to set.");
    return -EINVAL;
  }

  if (r) {
    log_dbg(cd, "Failed to assign new enc segments.");
    return r;
  }

  r = reencrypt_add_backup_segment(cd, hdr, rh, 0);
  if (r) {
    log_dbg(cd, "Failed to assign reencryption previous backup segment.");
    return r;
  }

  r = reencrypt_add_backup_segment(cd, hdr, rh, 1);
  if (r) {
    log_dbg(cd, "Failed to assign reencryption final backup segment.");
    return r;
  }

  r = reencrypt_add_moved_segment(cd, hdr, rh);
  if (r) {
    log_dbg(cd, "Failed to assign reencryption moved backup segment.");
    return r;
  }

  for (sg = 0; sg < LUKS2_segments_count(hdr); sg++) {
    if (LUKS2_segment_is_type(hdr, sg, "crypt") &&
        LUKS2_digest_segment_assign(cd, hdr, sg, rh->mode == CRYPT_REENCRYPT_ENCRYPT ? rh->digest_new : rh->digest_old, 1, 0)) {
      log_dbg(cd, "Failed to assign digest %u to segment %u.", rh->digest_new, sg);
      return -EINVAL;
    }
  }

  return commit ? LUKS2_hdr_write(cd, hdr) : 0;
}

static int reencrypt_assign_segments(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh,
    unsigned hot,
    unsigned commit)
{
  bool forward;
  int rseg, scount, r = -EINVAL;

  /* FIXME: validate in reencrypt context load */
  if (rh->digest_new < 0 && rh->mode != CRYPT_REENCRYPT_DECRYPT)
    return -EINVAL;

  if (LUKS2_digest_segment_assign(cd, hdr, CRYPT_ANY_SEGMENT, CRYPT_ANY_DIGEST, 0, 0))
    return -EINVAL;

  if (rh->mode == CRYPT_REENCRYPT_ENCRYPT || rh->mode == CRYPT_REENCRYPT_DECRYPT)
    return reencrypt_assign_segments_simple(cd, hdr, rh, hot, commit);

  if (hot && rh->jobj_segs_hot) {
    log_dbg(cd, "Setting 'hot' segments.");

    r = LUKS2_segments_set(cd, hdr, rh->jobj_segs_hot, 0);
    if (!r)
      rh->jobj_segs_hot = NULL;
  } else if (!hot && rh->jobj_segs_post) {
    log_dbg(cd, "Setting 'post' segments.");
    r = LUKS2_segments_set(cd, hdr, rh->jobj_segs_post, 0);
    if (!r)
      rh->jobj_segs_post = NULL;
  }

  if (r)
    return r;

  scount = LUKS2_segments_count(hdr);

  /* segment in reencryption has to hold reference on both digests */
  rseg = json_segments_segment_in_reencrypt(LUKS2_get_segments_jobj(hdr));
  if (rseg < 0 && hot)
    return -EINVAL;

  if (rseg >= 0) {
    LUKS2_digest_segment_assign(cd, hdr, rseg, rh->digest_new, 1, 0);
    LUKS2_digest_segment_assign(cd, hdr, rseg, rh->digest_old, 1, 0);
  }

  forward = (rh->direction == CRYPT_REENCRYPT_FORWARD);
  if (hot) {
    if (rseg > 0)
      LUKS2_digest_segment_assign(cd, hdr, 0, forward ? rh->digest_new : rh->digest_old, 1, 0);
    if (scount > rseg + 1)
      LUKS2_digest_segment_assign(cd, hdr, rseg + 1, forward ? rh->digest_old : rh->digest_new, 1, 0);
  } else {
    LUKS2_digest_segment_assign(cd, hdr, 0, forward || scount == 1 ? rh->digest_new : rh->digest_old, 1, 0);
    if (scount > 1)
      LUKS2_digest_segment_assign(cd, hdr, 1, forward ? rh->digest_old : rh->digest_new, 1, 0);
  }

  r = reencrypt_add_backup_segment(cd, hdr, rh, 0);
  if (r) {
    log_dbg(cd, "Failed to assign hot reencryption backup segment.");
    return r;
  }
  r = reencrypt_add_backup_segment(cd, hdr, rh, 1);
  if (r) {
    log_dbg(cd, "Failed to assign post reencryption backup segment.");
    return r;
  }

  return commit ? LUKS2_hdr_write(cd, hdr) : 0;
}

static int reencrypt_set_encrypt_segments(struct crypt_device *cd, struct luks2_hdr *hdr,
            uint64_t dev_size, uint64_t data_size, uint64_t data_shift, bool move_first_segment,
            crypt_reencrypt_direction_info di)
{
  int r;
  uint64_t first_segment_offset, first_segment_length,
     second_segment_offset, second_segment_length,
     data_offset = LUKS2_get_data_offset(hdr) << SECTOR_SHIFT;
  json_object *jobj_segment_first = NULL, *jobj_segment_second = NULL, *jobj_segments;

  if (dev_size < data_shift)
    return -EINVAL;

  if (data_shift && (di == CRYPT_REENCRYPT_FORWARD))
    return -ENOTSUP;

  if (move_first_segment) {
    /*
     * future data_device layout:
     * [future LUKS2 header (data shift size)][second data segment][gap (data shift size)][first data segment (data shift size)]
     */
    first_segment_offset = dev_size;
    if (data_size < data_shift) {
      first_segment_length = data_size;
      second_segment_length = second_segment_offset = 0;
    } else {
      first_segment_length = data_shift;
      second_segment_offset = data_shift;
      second_segment_length = data_size - data_shift;
    }
  } else if (data_shift) {
    first_segment_offset = data_offset;
    first_segment_length = dev_size;
  } else {
    /* future data_device layout with detached header: [first data segment] */
    first_segment_offset = data_offset;
    first_segment_length = 0; /* dynamic */
  }

  jobj_segments = json_object_new_object();
  if (!jobj_segments)
    return -ENOMEM;

  r = -EINVAL;
  if (move_first_segment) {
    jobj_segment_first =  json_segment_create_linear(first_segment_offset, &first_segment_length, 0);
    if (second_segment_length &&
        !(jobj_segment_second = json_segment_create_linear(second_segment_offset, &second_segment_length, 0))) {
      log_dbg(cd, "Failed generate 2nd segment.");
      return r;
    }
  } else
    jobj_segment_first =  json_segment_create_linear(first_segment_offset, first_segment_length ? &first_segment_length : NULL, 0);

  if (!jobj_segment_first) {
    log_dbg(cd, "Failed generate 1st segment.");
    return r;
  }

  json_object_object_add(jobj_segments, "0", jobj_segment_first);
  if (jobj_segment_second)
    json_object_object_add(jobj_segments, "1", jobj_segment_second);

  r = LUKS2_digest_segment_assign(cd, hdr, CRYPT_ANY_SEGMENT, CRYPT_ANY_DIGEST, 0, 0);

  return r ?: LUKS2_segments_set(cd, hdr, jobj_segments, 0);
}

static int reencrypt_set_decrypt_shift_segments(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  uint64_t dev_size,
  uint64_t moved_segment_length,
  crypt_reencrypt_direction_info di)
{
  int digest, r;
  uint64_t data_offset = LUKS2_get_data_offset(hdr) << SECTOR_SHIFT;
  json_object *jobj_segment_first = NULL, *jobj_segment_second = NULL, *jobj_segments;

  if (di == CRYPT_REENCRYPT_BACKWARD)
    return -ENOTSUP;

  digest = LUKS2_digest_by_segment(hdr, CRYPT_DEFAULT_SEGMENT);
  if (digest < 0)
    return -EINVAL;

  /*
   * future data_device layout:
   * [encrypted first segment (max data shift size)][gap (data shift size)][second encrypted data segment]
   */
  jobj_segments = json_object_new_object();
  if (!jobj_segments)
    return -ENOMEM;

  r = -EINVAL;
  jobj_segment_first = json_segment_create_crypt(0, crypt_get_iv_offset(cd),
        &moved_segment_length, crypt_get_cipher_spec(cd),
        NULL, 0, crypt_get_sector_size(cd), 0);

  if (!jobj_segment_first) {
    log_dbg(cd, "Failed generate 1st segment.");
    goto err;
  }

  r = json_object_object_add_by_uint_by_ref(jobj_segments, 0, &jobj_segment_first);
  if (r)
    goto err;

  if (dev_size > moved_segment_length) {
    jobj_segment_second = json_segment_create_crypt(data_offset + moved_segment_length,
                crypt_get_iv_offset(cd) + (moved_segment_length >> SECTOR_SHIFT),
                NULL,
                crypt_get_cipher_spec(cd),
                NULL, 0, /* integrity */
                crypt_get_sector_size(cd), 0);
    if (!jobj_segment_second) {
      r = -EINVAL;
      log_dbg(cd, "Failed generate 2nd segment.");
      goto err;
    }

    r = json_object_object_add_by_uint_by_ref(jobj_segments, 1, &jobj_segment_second);
    if (r)
      goto err;
  }

  if (!(r = LUKS2_segments_set(cd, hdr, jobj_segments, 0)))
    return LUKS2_digest_segment_assign(cd, hdr, CRYPT_ANY_SEGMENT, digest, 1, 0);
err:
  json_object_put(jobj_segment_first);
  json_object_put(jobj_segment_second);
  json_object_put(jobj_segments);
  return r;
}

static int reencrypt_make_targets(struct crypt_device *cd,
        struct luks2_hdr *hdr,
        struct device *hz_device,
        struct volume_key *vks,
        struct dm_target *result,
        uint64_t size)
{
  bool reenc_seg;
  struct volume_key *vk;
  uint64_t segment_size, segment_offset, segment_start = 0;
  int r;
  int s = 0;
  json_object *jobj, *jobj_segments = LUKS2_get_segments_jobj(hdr);

  while (result) {
    jobj = json_segments_get_segment(jobj_segments, s);
    if (!jobj) {
      log_dbg(cd, "Internal error. Segment %u is null.", s);
      return -EINVAL;
    }

    reenc_seg = (s == json_segments_segment_in_reencrypt(jobj_segments));

    segment_offset = json_segment_get_offset(jobj, 1);
    segment_size = json_segment_get_size(jobj, 1);
    /* 'dynamic' length allowed in last segment only */
    if (!segment_size && !result->next)
      segment_size = (size >> SECTOR_SHIFT) - segment_start;
    if (!segment_size) {
      log_dbg(cd, "Internal error. Wrong segment size %u", s);
      return -EINVAL;
    }

    if (reenc_seg)
      segment_offset -= crypt_get_data_offset(cd);

    if (!strcmp(json_segment_type(jobj), "crypt")) {
      vk = crypt_volume_key_by_id(vks, reenc_seg ? LUKS2_reencrypt_digest_new(hdr) : LUKS2_digest_by_segment(hdr, s));
      if (!vk) {
        log_err(cd, _("Missing key for dm-crypt segment %u"), s);
        return -EINVAL;
      }

      r = dm_crypt_target_set(result, segment_start, segment_size,
            reenc_seg ? hz_device : crypt_data_device(cd),
            vk,
            json_segment_get_cipher(jobj),
            json_segment_get_iv_offset(jobj),
            segment_offset,
            "none", 0, 0,
            json_segment_get_sector_size(jobj));
      if (r) {
        log_err(cd, _("Failed to set dm-crypt segment."));
        return r;
      }
    } else if (!strcmp(json_segment_type(jobj), "linear")) {
      r = dm_linear_target_set(result, segment_start, segment_size, reenc_seg ? hz_device : crypt_data_device(cd), segment_offset);
      if (r) {
        log_err(cd, _("Failed to set dm-linear segment."));
        return r;
      }
    } else
      return EINVAL;

    segment_start += segment_size;
    s++;
    result = result->next;
  }

  return s;
}

/* GLOBAL FIXME: audit function names and parameters names */

/* FIXME:
 *  1) audit log routines
 *  2) can't we derive hotzone device name from crypt context? (unlocked name, device uuid, etc?)
 */
static int reencrypt_load_overlay_device(struct crypt_device *cd, struct luks2_hdr *hdr,
  const char *overlay, struct device *hotzone_device, struct volume_key *vks, uint64_t size,
  uint32_t flags)
{
  int r;

  struct crypt_dm_active_device dmd = {
    .flags = flags,
  };

  log_dbg(cd, "Loading new table for overlay device %s.", overlay);

  r = dm_targets_allocate(&dmd.segment, LUKS2_segments_count(hdr));
  if (r)
    goto out;

  r = reencrypt_make_targets(cd, hdr, hotzone_device, vks, &dmd.segment, size);
  if (r < 0)
    goto out;

  r = dm_reload_device(cd, overlay, &dmd, 0, 0);

  /* what else on error here ? */
out:
  dm_targets_free(cd, &dmd);

  return r;
}

static int reencrypt_replace_device(struct crypt_device *cd, const char *target, const char *source, uint32_t flags)
{
  int r, exists = 1;
  struct crypt_dm_active_device dmd_source, dmd_target = {};
  uint64_t dmflags = DM_SUSPEND_SKIP_LOCKFS | DM_SUSPEND_NOFLUSH;

  log_dbg(cd, "Replacing table in device %s with table from device %s.", target, source);

  /* check only whether target device exists */
  r = dm_status_device(cd, target);
  if (r < 0) {
    if (r == -ENODEV)
      exists = 0;
    else
      return r;
  }

  r = dm_query_device(cd, source, DM_ACTIVE_DEVICE | DM_ACTIVE_CRYPT_CIPHER |
          DM_ACTIVE_CRYPT_KEYSIZE | DM_ACTIVE_CRYPT_KEY, &dmd_source);

  if (r < 0)
    return r;

  if (exists && ((r = dm_query_device(cd, target, 0, &dmd_target)) < 0))
    goto out;

  dmd_source.flags |= flags;
  dmd_source.uuid = crypt_get_uuid(cd);

  if (exists) {
    if (dmd_target.size != dmd_source.size) {
      log_err(cd, _("Source and target device sizes don't match. Source %" PRIu64 ", target: %" PRIu64 "."),
        dmd_source.size, dmd_target.size);
      r = -EINVAL;
      goto out;
    }
    r = dm_reload_device(cd, target, &dmd_source, 0, 0);
    if (!r) {
      log_dbg(cd, "Resuming device %s", target);
      r = dm_resume_device(cd, target, dmflags | act2dmflags(dmd_source.flags));
    }
  } else
    r = dm_create_device(cd, target, CRYPT_SUBDEV, &dmd_source);
out:
  dm_targets_free(cd, &dmd_source);
  dm_targets_free(cd, &dmd_target);

  return r;
}

static int reencrypt_swap_backing_device(struct crypt_device *cd, const char *name,
            const char *new_backend_name)
{
  int r;
  struct device *overlay_dev = NULL;
  char overlay_path[PATH_MAX] = { 0 };
  struct crypt_dm_active_device dmd = {};

  log_dbg(cd, "Redirecting %s mapping to new backing device: %s.", name, new_backend_name);

  r = snprintf(overlay_path, PATH_MAX, "%s/%s", dm_get_dir(), new_backend_name);
  if (r < 0 || r >= PATH_MAX) {
    r = -EINVAL;
    goto out;
  }

  r = device_alloc(cd, &overlay_dev, overlay_path);
  if (r)
    goto out;

  r = device_block_adjust(cd, overlay_dev, DEV_OK,
        0, &dmd.size, &dmd.flags);
  if (r)
    goto out;

  r = dm_linear_target_set(&dmd.segment, 0, dmd.size, overlay_dev, 0);
  if (r)
    goto out;

  r = dm_reload_device(cd, name, &dmd, 0, 0);
  if (!r) {
    log_dbg(cd, "Resuming device %s", name);
    r = dm_resume_device(cd, name, DM_SUSPEND_SKIP_LOCKFS | DM_SUSPEND_NOFLUSH);
  }

out:
  dm_targets_free(cd, &dmd);
  device_free(cd, overlay_dev);

  return r;
}

static int reencrypt_activate_hotzone_device(struct crypt_device *cd, const char *name, uint64_t device_size, uint32_t flags)
{
  int r;
  uint64_t new_offset = reencrypt_get_data_offset_new(crypt_get_hdr(cd, CRYPT_LUKS2)) >> SECTOR_SHIFT;

  struct crypt_dm_active_device dmd = {
    .flags = flags,
    .uuid = crypt_get_uuid(cd),
    .size = device_size >> SECTOR_SHIFT
  };

  log_dbg(cd, "Activating hotzone device %s.", name);

  r = device_block_adjust(cd, crypt_data_device(cd), DEV_OK,
        new_offset, &dmd.size, &dmd.flags);
  if (r)
    goto out;

  r = dm_linear_target_set(&dmd.segment, 0, dmd.size, crypt_data_device(cd), new_offset);
  if (r)
    goto out;

  r = dm_create_device(cd, name, CRYPT_SUBDEV, &dmd);
out:
  dm_targets_free(cd, &dmd);

  return r;
}

static int reencrypt_init_device_stack(struct crypt_device *cd,
                         struct luks2_reencrypt *rh)
{
  int r;
  char hz_path[PATH_MAX];

  assert(rh);
  assert(!rh->hotzone_device);

  /* Activate hotzone device 1:1 linear mapping to data_device */
  r = reencrypt_activate_hotzone_device(cd, rh->hotzone_name, rh->device_size, CRYPT_ACTIVATE_PRIVATE);
  if (r) {
    log_err(cd, _("Failed to activate hotzone device %s."), rh->hotzone_name);
    return r;
  }

  r = snprintf(hz_path, PATH_MAX, "%s/%s", dm_get_dir(), rh->hotzone_name);
  if (r < 0 || r >= PATH_MAX) {
    r = -EINVAL;
    goto err;
  }

  r = device_alloc(cd, &rh->hotzone_device, hz_path);
  if (r) {
    log_err(cd, _("Failed to allocate hotzone device %s."), rh->hotzone_name);
    goto err;
  }

  /*
   * Activate overlay device with exactly same table as original 'name' mapping.
   * Note that within this step the 'name' device may already include a table
   * constructed from more than single dm-crypt segment. Therefore transfer
   * mapping as is.
   *
   * If we're about to resume reencryption orig mapping has to be already validated for
   * abrupt shutdown and rchunk_offset has to point on next chunk to reencrypt!
   *
   * TODO: in crypt_activate_by*
   */
  r = reencrypt_replace_device(cd, rh->overlay_name, rh->device_name, CRYPT_ACTIVATE_PRIVATE);
  if (r) {
    log_err(cd, _("Failed to activate overlay device %s with actual origin table."), rh->overlay_name);
    goto err;
  }

  /* swap origin mapping to overlay device */
  r = reencrypt_swap_backing_device(cd, rh->device_name, rh->overlay_name);
  if (r) {
    log_err(cd, _("Failed to load new mapping for device %s."), rh->device_name);
    goto err;
  }

  /*
   * Now the 'name' (unlocked luks) device is mapped via dm-linear to an overlay dev.
   * The overlay device has a original live table of 'name' device in-before the swap.
   */

  return 0;
err:
  /* TODO: force error helper devices on error path */
  dm_remove_device(cd, rh->overlay_name, 0);
  dm_remove_device(cd, rh->hotzone_name, 0);

  return r;
}

/* TODO:
 *  1) audit error path. any error in this routine is fatal and should be unlikely.
 *     usually it would hint some collision with another userspace process touching
 *     dm devices directly.
 */
static int reenc_refresh_helper_devices(struct crypt_device *cd, const char *overlay, const char *hotzone)
{
  int r;

  /*
   * we have to explicitly suspend the overlay device before suspending
   * the hotzone one. Resuming overlay device (aka switching tables) only
   * after suspending the hotzone may lead to deadlock.
   *
   * In other words: always suspend the stack from top to bottom!
   */
  r = dm_suspend_device(cd, overlay, DM_SUSPEND_SKIP_LOCKFS | DM_SUSPEND_NOFLUSH);
  if (r) {
    log_err(cd, _("Failed to suspend device %s."), overlay);
    return r;
  }

  /* suspend HZ device */
  r = dm_suspend_device(cd, hotzone, DM_SUSPEND_SKIP_LOCKFS | DM_SUSPEND_NOFLUSH);
  if (r) {
    log_err(cd, _("Failed to suspend device %s."), hotzone);
    return r;
  }

  /* resume overlay device: inactive table (with hotozne) -> live */
  r = dm_resume_device(cd, overlay, DM_RESUME_PRIVATE);
  if (r)
    log_err(cd, _("Failed to resume device %s."), overlay);

  return r;
}

static int reencrypt_refresh_overlay_devices(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    const char *overlay,
    const char *hotzone,
    struct device *hotzone_device,
    struct volume_key *vks,
    uint64_t device_size,
    uint32_t flags)
{
  int r = reencrypt_load_overlay_device(cd, hdr, overlay, hotzone_device, vks, device_size, flags);
  if (r) {
    log_err(cd, _("Failed to reload device %s."), overlay);
    return REENC_ERR;
  }

  r = reenc_refresh_helper_devices(cd, overlay, hotzone);
  if (r) {
    log_err(cd, _("Failed to refresh reencryption devices stack."));
    return REENC_ROLLBACK;
  }

  return REENC_OK;
}

static int reencrypt_move_data(struct crypt_device *cd,
  int devfd,
  uint64_t data_shift,
  crypt_reencrypt_mode_info mode)
{
  void *buffer;
  int r;
  ssize_t ret;
  uint64_t buffer_len, offset,
     read_offset = (mode == CRYPT_REENCRYPT_ENCRYPT ? 0 : data_shift);
  struct luks2_hdr *hdr = crypt_get_hdr(cd, CRYPT_LUKS2);

  offset = json_segment_get_offset(LUKS2_get_segment_jobj(hdr, 0), 0);
  buffer_len = json_segment_get_size(LUKS2_get_segment_jobj(hdr, 0), 0);
  if (!buffer_len || buffer_len > data_shift)
    return -EINVAL;

  if (posix_memalign(&buffer, device_alignment(crypt_data_device(cd)), buffer_len))
    return -ENOMEM;

  ret = read_lseek_blockwise(devfd,
      device_block_size(cd, crypt_data_device(cd)),
      device_alignment(crypt_data_device(cd)),
      buffer, buffer_len, read_offset);
  if (ret < 0 || (uint64_t)ret != buffer_len) {
    log_dbg(cd, "Failed to read data at offset %" PRIu64 " (size: %zu)",
      read_offset, buffer_len);
    r = -EIO;
    goto out;
  }

  log_dbg(cd, "Going to write %" PRIu64 " bytes read at offset %" PRIu64 " to new offset %" PRIu64,
    buffer_len, read_offset, offset);
  ret = write_lseek_blockwise(devfd,
      device_block_size(cd, crypt_data_device(cd)),
      device_alignment(crypt_data_device(cd)),
      buffer, buffer_len, offset);
  if (ret < 0 || (uint64_t)ret != buffer_len) {
    log_dbg(cd, "Failed to write data at offset %" PRIu64 " (size: %zu)",
      offset, buffer_len);
    r = -EIO;
    goto out;
  }

  r = 0;
out:
  crypt_safe_memzero(buffer, buffer_len);
  free(buffer);
  return r;
}

static int reencrypt_make_backup_segments(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    int digest_new,
    const char *cipher,
    uint64_t data_offset,
    const struct crypt_params_reencrypt *params)
{
  const char *type;
  int r, segment, moved_segment = -1, digest_old = -1;
  json_object *jobj_tmp, *jobj_segment_new = NULL, *jobj_segment_old = NULL, *jobj_segment_bcp = NULL;
  uint32_t sector_size = params->luks2 ? params->luks2->sector_size : SECTOR_SIZE;
  uint64_t segment_offset, tmp, data_shift = params->data_shift << SECTOR_SHIFT,
     device_size = params->device_size << SECTOR_SHIFT;

  if (params->mode != CRYPT_REENCRYPT_DECRYPT && digest_new < 0)
    return -EINVAL;

  if (params->mode != CRYPT_REENCRYPT_ENCRYPT) {
    digest_old = LUKS2_digest_by_segment(hdr, CRYPT_DEFAULT_SEGMENT);
    if (digest_old < 0)
      return -EINVAL;
  }

  segment = LUKS2_segment_first_unused_id(hdr);
  if (segment < 0)
    return -EINVAL;

  if (params->flags & CRYPT_REENCRYPT_MOVE_FIRST_SEGMENT) {
    if (json_object_copy(LUKS2_get_segment_jobj(hdr, 0), &jobj_segment_bcp)) {
      r = -EINVAL;
      goto err;
    }
    r = LUKS2_segment_set_flag(jobj_segment_bcp, "backup-moved-segment");
    if (r)
      goto err;
    moved_segment = segment++;
    r = json_object_object_add_by_uint_by_ref(LUKS2_get_segments_jobj(hdr), moved_segment, &jobj_segment_bcp);
    if (r)
      goto err;

    if (!(type = json_segment_type(LUKS2_get_segment_jobj(hdr, moved_segment)))) {
      r = -EINVAL;
      goto err;
    }

    if (!strcmp(type, "crypt") && ((r = LUKS2_digest_segment_assign(cd, hdr, moved_segment, digest_old, 1, 0))))
      goto err;
  }

  /* FIXME: Add detection for case (digest old == digest new && old segment == new segment) */
  if (digest_old >= 0) {
    if (params->flags & CRYPT_REENCRYPT_MOVE_FIRST_SEGMENT) {
      jobj_tmp = LUKS2_get_segment_jobj(hdr, 0);
      if (!jobj_tmp) {
        r = -EINVAL;
        goto err;
      }

      jobj_segment_old = json_segment_create_crypt(data_offset,
            json_segment_get_iv_offset(jobj_tmp),
            device_size ? &device_size : NULL,
            json_segment_get_cipher(jobj_tmp),
            NULL, 0, /* integrity */
            json_segment_get_sector_size(jobj_tmp),
            0);
    } else {
      if (json_object_copy(LUKS2_get_segment_jobj(hdr, CRYPT_DEFAULT_SEGMENT), &jobj_segment_old)) {
        r = -EINVAL;
        goto err;
      }
    }
  } else if (params->mode == CRYPT_REENCRYPT_ENCRYPT) {
    r = LUKS2_get_data_size(hdr, &tmp, NULL);
    if (r)
      goto err;

    if (params->flags & CRYPT_REENCRYPT_MOVE_FIRST_SEGMENT)
      jobj_segment_old = json_segment_create_linear(0, tmp ? &tmp : NULL, 0);
    else
      jobj_segment_old = json_segment_create_linear(data_offset, tmp ? &tmp : NULL, 0);
  }

  if (!jobj_segment_old) {
    r = -EINVAL;
    goto err;
  }

  r = LUKS2_segment_set_flag(jobj_segment_old, "backup-previous");
  if (r)
    goto err;

  r = json_object_object_add_by_uint_by_ref(LUKS2_get_segments_jobj(hdr), segment, &jobj_segment_old);
  if (r)
    goto err;

  if (digest_old >= 0 && (r = LUKS2_digest_segment_assign(cd, hdr, segment, digest_old, 1, 0)))
    goto err;

  segment++;

  if (digest_new >= 0) {
    segment_offset = data_offset;
    if (params->mode != CRYPT_REENCRYPT_ENCRYPT &&
        modify_offset(&segment_offset, data_shift, params->direction)) {
      r = -EINVAL;
      goto err;
    }
    jobj_segment_new = json_segment_create_crypt(segment_offset,
              crypt_get_iv_offset(cd),
              NULL, cipher, NULL, 0, sector_size, 0);
  } else if (params->mode == CRYPT_REENCRYPT_DECRYPT) {
    segment_offset = data_offset;
    if (modify_offset(&segment_offset, data_shift, params->direction)) {
      r = -EINVAL;
      goto err;
    }
    jobj_segment_new = json_segment_create_linear(segment_offset, NULL, 0);
  }

  if (!jobj_segment_new) {
    r = -EINVAL;
    goto err;
  }

  r = LUKS2_segment_set_flag(jobj_segment_new, "backup-final");
  if (r)
    goto err;

  r = json_object_object_add_by_uint_by_ref(LUKS2_get_segments_jobj(hdr), segment, &jobj_segment_new);
  if (r)
    goto err;

  if (digest_new >= 0 && (r = LUKS2_digest_segment_assign(cd, hdr, segment, digest_new, 1, 0)))
    goto err;

  /* FIXME: also check occupied space by keyslot in shrunk area */
  if (params->direction == CRYPT_REENCRYPT_FORWARD && data_shift &&
      crypt_metadata_device(cd) == crypt_data_device(cd) &&
      LUKS2_set_keyslots_size(hdr, json_segment_get_offset(reencrypt_segment_new(hdr), 0))) {
    log_err(cd, _("Failed to set new keyslots area size."));
    r = -EINVAL;
    goto err;
  }

  return 0;
err:
  json_object_put(jobj_segment_new);
  json_object_put(jobj_segment_old);
  json_object_put(jobj_segment_bcp);
  return r;
}

static int reencrypt_verify_single_key(struct crypt_device *cd, int digest, struct volume_key *vks)
{
  struct volume_key *vk;

  vk = crypt_volume_key_by_id(vks, digest);
  if (!vk)
    return -ENOENT;

  if (LUKS2_digest_verify_by_digest(cd, digest, vk) != digest)
    return -EINVAL;

  return 0;
}

static int reencrypt_verify_keys(struct crypt_device *cd,
  int digest_old,
  int digest_new,
  struct volume_key *vks)
{
  int r;

  if (digest_new >= 0 && (r = reencrypt_verify_single_key(cd, digest_new, vks)))
    return r;

  if (digest_old >= 0 && (r = reencrypt_verify_single_key(cd, digest_old, vks)))
    return r;

  return 0;
}

static int reencrypt_upload_single_key(struct crypt_device *cd,
  int digest,
  struct volume_key *vks)
{
  struct volume_key *vk;

  vk = crypt_volume_key_by_id(vks, digest);
  if (!vk)
    return -EINVAL;

  return LUKS2_volume_key_load_in_keyring_by_digest(cd, vk, digest);
}

static int reencrypt_upload_keys(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  int digest_old,
  int digest_new,
  struct volume_key *vks)
{
  int r;

  if (!crypt_use_keyring_for_vk(cd))
    return 0;

  if (digest_new >= 0 && !crypt_is_cipher_null(reencrypt_segment_cipher_new(hdr)) &&
      (r = reencrypt_upload_single_key(cd, digest_new, vks)))
    return r;

  if (digest_old >= 0 && !crypt_is_cipher_null(reencrypt_segment_cipher_old(hdr)) &&
      (r = reencrypt_upload_single_key(cd, digest_old, vks))) {
    crypt_drop_uploaded_keyring_key(cd, vks);
    return r;
  }

  return 0;
}

static int reencrypt_verify_and_upload_keys(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  int digest_old,
  int digest_new,
  struct volume_key *vks)
{
  int r;

  r = reencrypt_verify_keys(cd, digest_old, digest_new, vks);
  if (r)
    return r;

  r = reencrypt_upload_keys(cd, hdr, digest_old, digest_new, vks);
  if (r)
    return r;

  return 0;
}

static int reencrypt_verify_checksum_params(struct crypt_device *cd,
    const struct crypt_params_reencrypt *params)
{
  size_t len;
  struct crypt_hash *ch;

  assert(params);

  if (!params->hash)
    return -EINVAL;

  len = strlen(params->hash);
  if (!len || len > (LUKS2_CHECKSUM_ALG_L - 1))
    return -EINVAL;

  if (crypt_hash_size(params->hash) <= 0)
    return -EINVAL;

  if (crypt_hash_init(&ch, params->hash)) {
    log_err(cd, _("Hash algorithm %s is not available."), params->hash);
    return -EINVAL;
  }
  /* We just check for alg availability */
  crypt_hash_destroy(ch);

  return 0;
}

static int reencrypt_verify_datashift_params(struct crypt_device *cd,
    const struct crypt_params_reencrypt *params,
    uint32_t sector_size)
{
  assert(params);

  if (!params->data_shift)
    return -EINVAL;
  if (MISALIGNED(params->data_shift, sector_size >> SECTOR_SHIFT)) {
    log_err(cd, _("Data shift value is not aligned to encryption sector size (%" PRIu32 " bytes)."),
      sector_size);
    return -EINVAL;
  }

  return 0;
}

static int reencrypt_verify_resilience_params(struct crypt_device *cd,
    const struct crypt_params_reencrypt *params,
    uint32_t sector_size, bool move_first_segment)
{
  /* no change requested */
  if (!params || !params->resilience)
    return 0;

  if (!strcmp(params->resilience, "journal"))
    return (params->data_shift || move_first_segment) ? -EINVAL : 0;
  else if (!strcmp(params->resilience, "none"))
    return (params->data_shift || move_first_segment) ? -EINVAL : 0;
  else if (!strcmp(params->resilience, "datashift"))
    return reencrypt_verify_datashift_params(cd, params, sector_size);
  else if (!strcmp(params->resilience, "checksum")) {
    if (params->data_shift || move_first_segment)
      return -EINVAL;
    return reencrypt_verify_checksum_params(cd, params);
  } else if (!strcmp(params->resilience, "datashift-checksum")) {
    if (!move_first_segment ||
         reencrypt_verify_datashift_params(cd, params, sector_size))
      return -EINVAL;
    return reencrypt_verify_checksum_params(cd, params);
  } else if (!strcmp(params->resilience, "datashift-journal")) {
    if (!move_first_segment)
      return -EINVAL;
    return reencrypt_verify_datashift_params(cd, params, sector_size);
  }

  log_err(cd, _("Unsupported resilience mode %s"), params->resilience);
  return -EINVAL;
}

static int reencrypt_decrypt_with_datashift_init(struct crypt_device *cd,
    const char *name,
    struct luks2_hdr *hdr,
    int reencrypt_keyslot,
    uint32_t sector_size,
    uint64_t data_size,
    uint64_t data_offset,
    struct crypt_keyslot_context *kc_old,
    int keyslot_old,
    const struct crypt_params_reencrypt *params,
    struct volume_key **vks)
{
  bool clear_table = false;
  int r, devfd = -1;
  uint64_t data_shift, max_moved_segment_length, moved_segment_length;
  struct reenc_protection check_rp = {};
  struct crypt_dm_active_device dmd_target, dmd_source = {
    .uuid = crypt_get_uuid(cd),
    .flags = CRYPT_ACTIVATE_SHARED /* turn off exclusive open checks */
  };
  json_object *jobj_segments_old;

  assert(hdr);
  assert(params);
  assert(params->resilience);
  assert(params->data_shift);
  assert(vks);

  if (!data_offset)
    return -EINVAL;

  if (params->max_hotzone_size > params->data_shift) {
    log_err(cd, _("Moved segment size can not be greater than data shift value."));
    return -EINVAL;
  }

  log_dbg(cd, "Initializing decryption with datashift.");

  data_shift = params->data_shift << SECTOR_SHIFT;

  /*
   * In offline mode we must perform data move with exclusively opened data
   * device in order to exclude LUKS2 decryption process and filesystem mount.
   */
  if (name)
    devfd = device_open(cd, crypt_data_device(cd), O_RDWR);
  else
    devfd = device_open_excl(cd, crypt_data_device(cd), O_RDWR);
  if (devfd < 0)
    return -EINVAL;

  /* in-memory only */
  moved_segment_length = params->max_hotzone_size << SECTOR_SHIFT;
  if (!moved_segment_length)
    moved_segment_length = data_shift < LUKS2_DEFAULT_NONE_REENCRYPTION_LENGTH ?
               data_shift : LUKS2_DEFAULT_NONE_REENCRYPTION_LENGTH;

  if (moved_segment_length > data_size)
    moved_segment_length = data_size;

  r = reencrypt_set_decrypt_shift_segments(cd, hdr, data_size,
             moved_segment_length,
             params->direction);
  if (r)
    goto out;

  r = reencrypt_make_backup_segments(cd, hdr, CRYPT_ANY_DIGEST, NULL, data_offset, params);
  if (r) {
    log_dbg(cd, "Failed to create reencryption backup device segments.");
    goto out;
  }

  r = reencrypt_verify_resilience_params(cd, params, sector_size, true);
  if (r < 0) {
    log_err(cd, _("Invalid reencryption resilience parameters."));
    goto out;
  }

  r = LUKS2_keyslot_reencrypt_allocate(cd, hdr, reencrypt_keyslot,
             params, reencrypt_get_alignment(cd, hdr));
  if (r < 0)
    goto out;

  r = LUKS2_keyslot_reencrypt_load(cd, hdr, reencrypt_keyslot, &check_rp, false);
  if (r < 0)
    goto out;

  r = LUKS2_reencrypt_max_hotzone_size(cd, hdr, &check_rp,
               reencrypt_keyslot,
               &max_moved_segment_length);
  if (r < 0)
    goto out;

  LUKS2_reencrypt_protection_erase(&check_rp);

  if (moved_segment_length > max_moved_segment_length) {
    log_err(cd, _("Moved segment too large. Requested size %" PRIu64 ", available space for: %" PRIu64 "."),
      moved_segment_length, max_moved_segment_length);
    r = -EINVAL;
    goto out;
  }

  r = LUKS2_keyslot_context_open_all_segments(cd, keyslot_old, CRYPT_ANY_SLOT,
                kc_old, NULL, vks);
  if (r < 0)
    goto out;

  r = LUKS2_keyslot_reencrypt_digest_create(cd, hdr, LUKS2_DECRYPT_DATASHIFT_REQ_VERSION, *vks);
  if (r < 0)
    goto out;

  if (name) {
    r = reencrypt_verify_and_upload_keys(cd, hdr,
                 LUKS2_reencrypt_digest_old(hdr),
                 LUKS2_reencrypt_digest_new(hdr),
                 *vks);
    if (r)
      goto out;

    r = dm_query_device(cd, name, DM_ACTIVE_UUID | DM_ACTIVE_DEVICE |
            DM_ACTIVE_CRYPT_KEYSIZE | DM_ACTIVE_CRYPT_KEY |
            DM_ACTIVE_CRYPT_CIPHER, &dmd_target);
    if (r < 0)
      goto out;

    jobj_segments_old = reencrypt_segments_old(hdr);
    if (!jobj_segments_old) {
      dm_targets_free(cd, &dmd_target);
      free(CONST_CAST(void*)dmd_target.uuid);
      r = -EINVAL;
      goto out;
    }
    r = LUKS2_assembly_multisegment_dmd(cd, hdr, *vks, jobj_segments_old, &dmd_source);
    if (!r) {
      r = crypt_compare_dm_devices(cd, &dmd_source, &dmd_target);
      if (r)
        log_err(cd, _("Mismatching parameters on device %s."), name);
    }
    json_object_put(jobj_segments_old);

    dm_targets_free(cd, &dmd_source);
    dm_targets_free(cd, &dmd_target);
    free(CONST_CAST(void*)dmd_target.uuid);

    if (r)
      goto out;

    dmd_source.size = dmd_target.size;
    r = LUKS2_assembly_multisegment_dmd(cd, hdr, *vks, LUKS2_get_segments_jobj(hdr), &dmd_source);
    if (!r) {
      r = dm_reload_device(cd, name, &dmd_source, dmd_target.flags, 0);
      if (r)
        log_err(cd, _("Failed to reload device %s."), name);
      else
        clear_table = true;
    }

    dm_targets_free(cd, &dmd_source);

    if (r)
      goto out;
  }

  if (name) {
    r = dm_suspend_device(cd, name, DM_SUSPEND_SKIP_LOCKFS);
    if (r) {
      log_err(cd, _("Failed to suspend device %s."), name);
      goto out;
    }
  }

  if (reencrypt_move_data(cd, devfd, data_shift, params->mode)) {
    r = -EIO;
    goto out;
  }

  /* This must be first and only write in LUKS2 metadata during _reencrypt_init */
  r = reencrypt_update_flag(cd, LUKS2_DECRYPT_DATASHIFT_REQ_VERSION, true, true);
  if (r) {
    log_dbg(cd, "Failed to set online-reencryption requirement.");
    r = -EINVAL;
  } else
    r = reencrypt_keyslot;
out:
  if (r < 0 && clear_table && dm_clear_device(cd, name))
    log_err(cd, _("Failed to clear table."));
  else if (clear_table && dm_resume_device(cd, name, DM_SUSPEND_SKIP_LOCKFS))
    log_err(cd, _("Failed to resume device %s."), name);

  device_release_excl(cd, crypt_data_device(cd));
  if (r < 0 && LUKS2_hdr_rollback(cd, hdr) < 0)
    log_dbg(cd, "Failed to rollback LUKS2 metadata after failure.");

  return r;
}

/* This function must be called with metadata lock held */
static int reencrypt_init(struct crypt_device *cd,
    const char *name,
    struct luks2_hdr *hdr,
    struct crypt_keyslot_context *kc_old,
    struct crypt_keyslot_context *kc_new,
    int keyslot_old,
    int keyslot_new,
    const char *cipher,
    const char *cipher_mode,
    const struct crypt_params_reencrypt *params,
    struct volume_key **vks)
{
  bool move_first_segment;
  char _cipher[128];
  uint32_t check_sector_size, new_sector_size, old_sector_size;
  int digest_new, r, reencrypt_keyslot, devfd = -1;
  uint64_t data_offset_bytes, data_size_bytes, data_shift_bytes, device_size_bytes;
  struct volume_key *vk;
  struct crypt_dm_active_device dmd_target, dmd_source = {
    .uuid = crypt_get_uuid(cd),
    .flags = CRYPT_ACTIVATE_SHARED /* turn off exclusive open checks */
  };

  assert(cd);
  assert(hdr);

  if (!params || !params->resilience || params->mode > CRYPT_REENCRYPT_DECRYPT)
    return -EINVAL;

  if (params->mode != CRYPT_REENCRYPT_DECRYPT &&
      (!params->luks2 || !(cipher && cipher_mode) ||
       (keyslot_new < 0 && !(params->flags & CRYPT_REENCRYPT_CREATE_NEW_DIGEST))))
    return -EINVAL;

  log_dbg(cd, "Initializing reencryption (mode: %s) in LUKS2 metadata.",
        crypt_reencrypt_mode_to_str(params->mode));

  move_first_segment = (params->flags & CRYPT_REENCRYPT_MOVE_FIRST_SEGMENT);

  old_sector_size = LUKS2_get_sector_size(hdr);

  /* implicit sector size 512 for decryption */
  new_sector_size = params->luks2 ? params->luks2->sector_size : SECTOR_SIZE;
  if (new_sector_size < SECTOR_SIZE || new_sector_size > MAX_SECTOR_SIZE ||
      NOTPOW2(new_sector_size)) {
    log_err(cd, _("Unsupported encryption sector size."));
    return -EINVAL;
  }
  /* check the larger encryption sector size only */
  check_sector_size = new_sector_size > old_sector_size ? new_sector_size : old_sector_size;

  if (!cipher_mode || *cipher_mode == '\0')
    r = snprintf(_cipher, sizeof(_cipher), "%s", cipher);
  else
    r = snprintf(_cipher, sizeof(_cipher), "%s-%s", cipher, cipher_mode);
  if (r < 0 || (size_t)r >= sizeof(_cipher))
    return -EINVAL;

  data_offset_bytes = LUKS2_get_data_offset(hdr) << SECTOR_SHIFT;

  r = device_check_access(cd, crypt_data_device(cd), DEV_OK);
  if (r)
    return r;

  r = device_check_size(cd, crypt_data_device(cd), data_offset_bytes, 1);
  if (r)
    return r;

  r = device_size(crypt_data_device(cd), &device_size_bytes);
  if (r)
    return r;

  if (move_first_segment && params->mode == CRYPT_REENCRYPT_ENCRYPT &&
      params->data_shift < LUKS2_get_data_offset(hdr)) {
    log_err(cd, _("Data shift (%" PRIu64 " sectors) is less than future data offset (%" PRIu64 " sectors)."),
      params->data_shift, LUKS2_get_data_offset(hdr));
    return -EINVAL;
  }

  device_size_bytes -= data_offset_bytes;
  data_shift_bytes = params->data_shift << SECTOR_SHIFT;
  data_size_bytes = params->device_size << SECTOR_SHIFT;

  if (device_size_bytes < data_shift_bytes && params->direction == CRYPT_REENCRYPT_BACKWARD) {
    log_err(cd, _("Device %s is too small."), device_path(crypt_data_device(cd)));
    return -EINVAL;
  }

  if (data_size_bytes > device_size_bytes) {
    log_err(cd, _("Reduced data size is larger than real device size."));
    return -EINVAL;
  }

  if (data_size_bytes && params->mode == CRYPT_REENCRYPT_ENCRYPT &&
      move_first_segment && data_shift_bytes) {
    if (data_size_bytes > device_size_bytes - data_shift_bytes) {
      log_err(cd, _("Reduced data size is larger than real device size."));
      return -EINVAL;
    }
  } else if (!data_size_bytes && params->mode == CRYPT_REENCRYPT_ENCRYPT &&
      move_first_segment && data_shift_bytes)
    data_size_bytes = device_size_bytes - data_shift_bytes;
  else if (!data_size_bytes)
    data_size_bytes = device_size_bytes;

  if (MISALIGNED(data_size_bytes, check_sector_size)) {
    log_err(cd, _("Data device is not aligned to encryption sector size (%" PRIu32 " bytes)."), check_sector_size);
    return -EINVAL;
  }

  reencrypt_keyslot = LUKS2_keyslot_find_empty(cd, hdr, 0);
  if (reencrypt_keyslot < 0) {
    log_err(cd, _("All key slots full."));
    return -EINVAL;
  }

  if (params->mode == CRYPT_REENCRYPT_DECRYPT && data_shift_bytes && move_first_segment)
    return reencrypt_decrypt_with_datashift_init(cd, name, hdr,
                   reencrypt_keyslot,
                   check_sector_size,
                   data_size_bytes,
                   data_offset_bytes,
                   kc_old,
                   keyslot_old,
                   params,
                   vks);

  /*
   * We must perform data move with exclusive open data device
   * to exclude another cryptsetup process to colide with
   * encryption initialization (or mount)
   */
  if (move_first_segment) {
    devfd = device_open_excl(cd, crypt_data_device(cd), O_RDWR);
    if (devfd < 0) {
      if (devfd == -EBUSY)
        log_err(cd,_("Failed to open %s in exclusive mode (already mapped or mounted)."),
          device_path(crypt_data_device(cd)));
      return -EINVAL;
    }
  }

  if (params->mode == CRYPT_REENCRYPT_ENCRYPT) {
    /* in-memory only */
    r = reencrypt_set_encrypt_segments(cd, hdr, device_size_bytes, data_size_bytes,
               data_shift_bytes,
               move_first_segment,
               params->direction);
    if (r)
      goto out;
  }

  if (params->flags & CRYPT_REENCRYPT_CREATE_NEW_DIGEST) {
    assert(kc_new->get_luks2_key);
    r = kc_new->get_luks2_key(cd, kc_new, CRYPT_ANY_SLOT, CRYPT_ANY_SEGMENT, &vk);
    if (r < 0)
      goto out;

    /* do not create new digest in case it matches the current one */
    r = LUKS2_digest_verify_by_segment(cd, hdr, CRYPT_DEFAULT_SEGMENT, vk);
    if (r == -EPERM || r == -ENOENT)
      r = LUKS2_digest_create(cd, "pbkdf2", hdr, vk);

    crypt_free_volume_key(vk);
    if (r < 0)
      goto out;
    digest_new = r;
  } else
    digest_new = LUKS2_digest_by_keyslot(hdr, keyslot_new);

  r = reencrypt_make_backup_segments(cd, hdr, digest_new, _cipher, data_offset_bytes, params);
  if (r) {
    log_dbg(cd, "Failed to create reencryption backup device segments.");
    goto out;
  }

  r = reencrypt_verify_resilience_params(cd, params, check_sector_size, move_first_segment);
  if (r < 0)
    goto out;

  r = LUKS2_keyslot_reencrypt_allocate(cd, hdr, reencrypt_keyslot, params,
      reencrypt_get_alignment(cd, hdr));
  if (r < 0)
    goto out;

  r = LUKS2_keyslot_context_open_all_segments(cd, keyslot_old, keyslot_new, kc_old, kc_new, vks);
  if (r < 0)
    goto out;

  r = LUKS2_keyslot_reencrypt_digest_create(cd, hdr, LUKS2_REENCRYPT_REQ_VERSION, *vks);
  if (r < 0)
    goto out;

  if (name && params->mode != CRYPT_REENCRYPT_ENCRYPT) {
    r = reencrypt_verify_and_upload_keys(cd, hdr, LUKS2_reencrypt_digest_old(hdr), LUKS2_reencrypt_digest_new(hdr), *vks);
    if (r)
      goto out;

    r = dm_query_device(cd, name, DM_ACTIVE_UUID | DM_ACTIVE_DEVICE |
            DM_ACTIVE_CRYPT_KEYSIZE | DM_ACTIVE_CRYPT_KEY |
            DM_ACTIVE_CRYPT_CIPHER, &dmd_target);
    if (r < 0)
      goto out;

    r = LUKS2_assembly_multisegment_dmd(cd, hdr, *vks, LUKS2_get_segments_jobj(hdr), &dmd_source);
    if (!r) {
      r = crypt_compare_dm_devices(cd, &dmd_source, &dmd_target);
      if (r)
        log_err(cd, _("Mismatching parameters on device %s."), name);
    }

    dm_targets_free(cd, &dmd_source);
    dm_targets_free(cd, &dmd_target);
    free(CONST_CAST(void*)dmd_target.uuid);

    if (r)
      goto out;
  }

  if (move_first_segment && reencrypt_move_data(cd, devfd, data_shift_bytes, params->mode)) {
    r = -EIO;
    goto out;
  }

  /* This must be first and only write in LUKS2 metadata during reencrypt_init */
  r = reencrypt_update_flag(cd, LUKS2_REENCRYPT_REQ_VERSION, true, true);
  if (r) {
    log_dbg(cd, "Failed to set online-reencryption requirement.");
    r = -EINVAL;
  } else
    r = reencrypt_keyslot;
out:
  device_release_excl(cd, crypt_data_device(cd));
  if (r < 0 && LUKS2_hdr_rollback(cd, hdr) < 0)
    log_dbg(cd, "Failed to rollback LUKS2 metadata after failure.");

  return r;
}

static int reencrypt_hotzone_protect_final(struct crypt_device *cd,
  struct luks2_hdr *hdr, int reencrypt_keyslot,
  const struct reenc_protection *rp,
  const void *buffer, size_t buffer_len)
{
  const void *pbuffer;
  size_t data_offset, len;
  int r;

  assert(hdr);
  assert(rp);

  if (rp->type == REENC_PROTECTION_NONE)
    return 0;

  if (rp->type == REENC_PROTECTION_CHECKSUM) {
    log_dbg(cd, "Checksums hotzone resilience.");

    for (data_offset = 0, len = 0; data_offset < buffer_len; data_offset += rp->p.csum.block_size, len += rp->p.csum.hash_size) {
      if (crypt_hash_write(rp->p.csum.ch, (const char *)buffer + data_offset, rp->p.csum.block_size)) {
        log_dbg(cd, "Failed to hash sector at offset %zu.", data_offset);
        return -EINVAL;
      }
      if (crypt_hash_final(rp->p.csum.ch, (char *)rp->p.csum.checksums + len, rp->p.csum.hash_size)) {
        log_dbg(cd, "Failed to finalize hash.");
        return -EINVAL;
      }
    }
    pbuffer = rp->p.csum.checksums;
  } else if (rp->type == REENC_PROTECTION_JOURNAL) {
    log_dbg(cd, "Journal hotzone resilience.");
    len = buffer_len;
    pbuffer = buffer;
  } else if (rp->type == REENC_PROTECTION_DATASHIFT) {
    log_dbg(cd, "Data shift hotzone resilience.");
    return LUKS2_hdr_write(cd, hdr);
  } else
    return -EINVAL;

  log_dbg(cd, "Going to store %zu bytes in reencrypt keyslot.", len);

  r = LUKS2_keyslot_reencrypt_store(cd, hdr, reencrypt_keyslot, pbuffer, len);

  return r > 0 ? 0 : r;
}

static int reencrypt_context_update(struct crypt_device *cd,
  struct luks2_reencrypt *rh)
{
  if (rh->read < 0)
    return -EINVAL;

  if (rh->direction == CRYPT_REENCRYPT_BACKWARD) {
    if (rh->rp.type == REENC_PROTECTION_DATASHIFT && rh->mode == CRYPT_REENCRYPT_ENCRYPT) {
      if (rh->offset)
        rh->offset -= data_shift_value(&rh->rp);
      if (rh->offset && (rh->offset < data_shift_value(&rh->rp))) {
        rh->length = rh->offset;
        rh->offset = data_shift_value(&rh->rp);
      }
      if (!rh->offset)
        rh->length = data_shift_value(&rh->rp);
    } else {
      if (rh->offset < rh->length)
        rh->length = rh->offset;
      rh->offset -= rh->length;
    }
  } else if (rh->direction == CRYPT_REENCRYPT_FORWARD) {
    rh->offset += (uint64_t)rh->read;
    if (rh->device_size == rh->offset &&
        rh->jobj_segment_moved &&
        rh->mode == CRYPT_REENCRYPT_DECRYPT &&
        rh->rp.type == REENC_PROTECTION_DATASHIFT) {
      rh->offset = 0;
      rh->length = json_segment_get_size(rh->jobj_segment_moved, 0);
    }
    /* it fails in-case of device_size < rh->offset later */
    else if (rh->device_size - rh->offset < rh->length)
      rh->length = rh->device_size - rh->offset;
  } else
    return -EINVAL;

  if (rh->device_size < rh->offset) {
    log_dbg(cd, "Calculated reencryption offset %" PRIu64 " is beyond device size %" PRIu64 ".", rh->offset, rh->device_size);
    return -EINVAL;
  }

  rh->progress += (uint64_t)rh->read;

  return 0;
}

static int reencrypt_load(struct crypt_device *cd, struct luks2_hdr *hdr,
    uint64_t device_size,
    uint64_t max_hotzone_size,
    uint64_t required_device_size,
    struct volume_key *vks,
    struct luks2_reencrypt **rh)
{
  int r;
  struct luks2_reencrypt *tmp = NULL;
  crypt_reencrypt_info ri = LUKS2_reencrypt_status(hdr);

  if (ri == CRYPT_REENCRYPT_NONE) {
    log_err(cd, _("Device not marked for LUKS2 reencryption."));
    return -EINVAL;
  } else if (ri == CRYPT_REENCRYPT_INVALID)
    return -EINVAL;

  r = LUKS2_reencrypt_digest_verify(cd, hdr, vks);
  if (r < 0)
    return r;

  if (ri == CRYPT_REENCRYPT_CLEAN)
    r = reencrypt_load_clean(cd, hdr, device_size, max_hotzone_size, required_device_size, &tmp);
  else if (ri == CRYPT_REENCRYPT_CRASH)
    r = reencrypt_load_crashed(cd, hdr, device_size, &tmp);
  else
    r = -EINVAL;

  if (r < 0 || !tmp) {
    log_err(cd, _("Failed to load LUKS2 reencryption context."));
    return r < 0 ? r : -EINVAL;
  }

  *rh = tmp;

  return 0;
}
#else
int LUKS2_reencrypt_max_hotzone_size(struct crypt_device *cd __attribute__((unused)),
  struct luks2_hdr *hdr __attribute__((unused)),
  const struct reenc_protection *rp __attribute__((unused)),
  int reencrypt_keyslot __attribute__((unused)),
  uint64_t *r_length __attribute__((unused)))
{
  return -ENOTSUP;
}
#endif

static int reencrypt_lock_internal(struct crypt_device *cd, const char *uuid, struct crypt_lock_handle **reencrypt_lock)
{
  int r;
  char *lock_resource;

  if (!crypt_metadata_locking_enabled()) {
    *reencrypt_lock = NULL;
    return 0;
  }

  r = asprintf(&lock_resource, "LUKS2-reencryption-%s", uuid);
  if (r < 0)
    return -ENOMEM;
  if (r < 20) {
    free(lock_resource);
    return -EINVAL;
  }

  r = crypt_write_lock(cd, lock_resource, false, reencrypt_lock);

  free(lock_resource);

  return r;
}

/* internal only */
int LUKS2_reencrypt_lock_by_dm_uuid(struct crypt_device *cd, const char *dm_uuid,
  struct crypt_lock_handle **reencrypt_lock)
{
  int r;
  char hdr_uuid[37];
  const char *uuid = crypt_get_uuid(cd);

  if (!dm_uuid)
    return -EINVAL;

  if (!uuid) {
    r = snprintf(hdr_uuid, sizeof(hdr_uuid), "%.8s-%.4s-%.4s-%.4s-%.12s",
       dm_uuid + 6, dm_uuid + 14, dm_uuid + 18, dm_uuid + 22, dm_uuid + 26);
    if (r < 0 || (size_t)r != (sizeof(hdr_uuid) - 1))
      return -EINVAL;
  } else if (dm_uuid_cmp(dm_uuid, uuid))
    return -EINVAL;

  return reencrypt_lock_internal(cd, uuid, reencrypt_lock);
}

/* internal only */
int LUKS2_reencrypt_lock(struct crypt_device *cd, struct crypt_lock_handle **reencrypt_lock)
{
  if (!cd || !crypt_get_type(cd) || strcmp(crypt_get_type(cd), CRYPT_LUKS2))
    return -EINVAL;

  return reencrypt_lock_internal(cd, crypt_get_uuid(cd), reencrypt_lock);
}

/* internal only */
void LUKS2_reencrypt_unlock(struct crypt_device *cd, struct crypt_lock_handle *reencrypt_lock)
{
  crypt_unlock_internal(cd, reencrypt_lock);
}
#if USE_LUKS2_REENCRYPTION
static int reencrypt_lock_and_verify(struct crypt_device *cd, struct luks2_hdr *hdr,
    struct crypt_lock_handle **reencrypt_lock)
{
  int r;
  crypt_reencrypt_info ri;
  struct crypt_lock_handle *h;

  ri = LUKS2_reencrypt_status(hdr);
  if (ri == CRYPT_REENCRYPT_INVALID)
    return -EINVAL;
  if (ri < CRYPT_REENCRYPT_CLEAN) {
    log_err(cd, _("Device is not in reencryption."));
    return -EINVAL;
  }

  r = LUKS2_reencrypt_lock(cd, &h);
  if (r < 0) {
    if (r == -EBUSY)
      log_err(cd, _("Reencryption process is already running."));
    else
      log_err(cd, _("Failed to acquire reencryption lock."));
    return r;
  }

  /* With reencryption lock held, reload device context and verify metadata state */
  r = crypt_load(cd, CRYPT_LUKS2, NULL);
  if (r) {
    LUKS2_reencrypt_unlock(cd, h);
    return r;
  }

  ri = LUKS2_reencrypt_status(hdr);
  if (ri == CRYPT_REENCRYPT_CLEAN) {
    *reencrypt_lock = h;
    return 0;
  }

  LUKS2_reencrypt_unlock(cd, h);
  log_err(cd, _("Cannot proceed with reencryption. Run reencryption recovery first."));
  return -EINVAL;
}

static int reencrypt_load_by_keyslot_context(struct crypt_device *cd,
    const char *name,
    struct crypt_keyslot_context *kc_old,
    struct crypt_keyslot_context *kc_new,
    int keyslot_old,
    int keyslot_new,
    struct volume_key **vks,
    const struct crypt_params_reencrypt *params)
{
  int r, reencrypt_slot;
  struct luks2_hdr *hdr;
  struct crypt_lock_handle *reencrypt_lock;
  struct luks2_reencrypt *rh;
  const struct volume_key *vk;
  size_t alignment;
  uint32_t old_sector_size, new_sector_size, sector_size;
  struct crypt_dm_active_device dmd_target, dmd_source = {
    .uuid = crypt_get_uuid(cd),
    .flags = CRYPT_ACTIVATE_SHARED /* turn off exclusive open checks */
  };
  uint64_t minimal_size, device_size, mapping_size = 0, required_size = 0,
     max_hotzone_size = 0;
  bool dynamic;
  uint32_t flags = 0;

  assert(cd);

  hdr = crypt_get_hdr(cd, CRYPT_LUKS2);
  if (!hdr)
    return -EINVAL;

  log_dbg(cd, "Loading LUKS2 reencryption context.");

  old_sector_size = reencrypt_get_sector_size_old(hdr);
  new_sector_size = reencrypt_get_sector_size_new(hdr);
  sector_size = new_sector_size > old_sector_size ? new_sector_size : old_sector_size;

  r = reencrypt_verify_resilience_params(cd, params, sector_size,
                 LUKS2_get_segment_id_by_flag(hdr, "backup-moved-segment") >= 0);
  if (r < 0)
    return r;

  if (params) {
    required_size = params->device_size;
    max_hotzone_size = params->max_hotzone_size;
  }

  rh = crypt_get_luks2_reencrypt(cd);
  if (rh) {
    LUKS2_reencrypt_free(cd, rh);
    crypt_set_luks2_reencrypt(cd, NULL);
    rh = NULL;
  }

  r = reencrypt_lock_and_verify(cd, hdr, &reencrypt_lock);
  if (r)
    return r;

  reencrypt_slot = LUKS2_find_keyslot(hdr, "reencrypt");
  if (reencrypt_slot < 0) {
    r = -EINVAL;
    goto err;
  }

  /* From now on we hold reencryption lock */

  if (LUKS2_get_data_size(hdr, &minimal_size, &dynamic)) {
    r = -EINVAL;
    goto err;
  }

  /* some configurations provides fixed device size */
  r = LUKS2_reencrypt_check_device_size(cd, hdr, minimal_size, &device_size, false, dynamic);
  if (r) {
    r = -EINVAL;
    goto err;
  }

  minimal_size >>= SECTOR_SHIFT;

  r = reencrypt_verify_keys(cd, LUKS2_reencrypt_digest_old(hdr), LUKS2_reencrypt_digest_new(hdr), *vks);
  if (r == -ENOENT) {
    log_dbg(cd, "Keys are not ready. Unlocking all volume keys.");
    r = LUKS2_keyslot_context_open_all_segments(cd, keyslot_old, keyslot_new,
                  kc_old, kc_new, vks);
  }

  if (r < 0)
    goto err;

  if (name) {
    r = reencrypt_upload_keys(cd, hdr, LUKS2_reencrypt_digest_old(hdr), LUKS2_reencrypt_digest_new(hdr), *vks);
    if (r < 0)
      goto err;

    r = dm_query_device(cd, name, DM_ACTIVE_UUID | DM_ACTIVE_DEVICE |
            DM_ACTIVE_CRYPT_KEYSIZE | DM_ACTIVE_CRYPT_KEY |
            DM_ACTIVE_CRYPT_CIPHER, &dmd_target);
    if (r < 0)
      goto err;
    flags = dmd_target.flags;

    /*
     * By default reencryption code aims to retain flags from existing dm device.
     * The keyring activation flag can not be inherited if original cipher is null.
     *
     * In this case override the flag based on decision made in reencrypt_upload_keys
     * above. The code checks if new VK is eligible for keyring.
     */
    vk = crypt_volume_key_by_id(*vks, LUKS2_reencrypt_digest_new(hdr));
    if (vk && crypt_volume_key_description(vk) && crypt_is_cipher_null(reencrypt_segment_cipher_old(hdr))) {
      flags |= CRYPT_ACTIVATE_KEYRING_KEY;
      dmd_source.flags |= CRYPT_ACTIVATE_KEYRING_KEY;
    }

    r = LUKS2_assembly_multisegment_dmd(cd, hdr, *vks, LUKS2_get_segments_jobj(hdr), &dmd_source);
    if (!r) {
      r = crypt_compare_dm_devices(cd, &dmd_source, &dmd_target);
      if (r)
        log_err(cd, _("Mismatching parameters on device %s."), name);
    }

    dm_targets_free(cd, &dmd_source);
    dm_targets_free(cd, &dmd_target);
    free(CONST_CAST(void*)dmd_target.uuid);
    if (r)
      goto err;
    mapping_size = dmd_target.size;
  }

  r = -EINVAL;
  if (required_size && mapping_size && (required_size != mapping_size)) {
    log_err(cd, _("Active device size and requested reencryption size don't match."));
    goto err;
  }

  if (mapping_size)
    required_size = mapping_size;

  if (required_size) {
    /* TODO: Add support for changing fixed minimal size in reencryption mda where possible */
    if ((minimal_size && (required_size < minimal_size)) ||
        (required_size > (device_size >> SECTOR_SHIFT)) ||
        (!dynamic && (required_size != minimal_size)) ||
        (old_sector_size > 0 && MISALIGNED(required_size, old_sector_size >> SECTOR_SHIFT)) ||
        (new_sector_size > 0 && MISALIGNED(required_size, new_sector_size >> SECTOR_SHIFT))) {
      log_err(cd, _("Illegal device size requested in reencryption parameters."));
      goto err;
    }
  }

  alignment = reencrypt_get_alignment(cd, hdr);

  r = LUKS2_keyslot_reencrypt_update_needed(cd, hdr, reencrypt_slot, params, alignment);
  if (r > 0) /* metadata update needed */
    r = LUKS2_keyslot_reencrypt_update(cd, hdr, reencrypt_slot, params, alignment, *vks);
  if (r < 0)
    goto err;

  r = reencrypt_load(cd, hdr, device_size, max_hotzone_size, required_size, *vks, &rh);
  if (r < 0 || !rh)
    goto err;

  if (name && (r = reencrypt_context_set_names(rh, name)))
    goto err;

  /* Reassure device is not mounted and there's no dm mapping active */
  if (!name && (device_open_excl(cd, crypt_data_device(cd), O_RDONLY) < 0)) {
    log_err(cd,_("Failed to open %s in exclusive mode (already mapped or mounted)."), device_path(crypt_data_device(cd)));
    r = -EBUSY;
    goto err;
  }
  device_release_excl(cd, crypt_data_device(cd));

  /* There's a race for dm device activation not managed by cryptsetup.
   *
   * 1) excl close
   * 2) rogue dm device activation
   * 3) one or more dm-crypt based wrapper activation
   * 4) next excl open gets skipped due to 3) device from 2) remains undetected.
   */
  r = reencrypt_init_storage_wrappers(cd, hdr, rh, *vks);
  if (r)
    goto err;

  /* If one of wrappers is based on dmcrypt fallback it already blocked mount */
  if (!name && crypt_storage_wrapper_get_type(rh->cw1) != DMCRYPT &&
      crypt_storage_wrapper_get_type(rh->cw2) != DMCRYPT) {
    if (device_open_excl(cd, crypt_data_device(cd), O_RDONLY) < 0) {
      log_err(cd,_("Failed to open %s in exclusive mode (already mapped or mounted)."), device_path(crypt_data_device(cd)));
      r = -EBUSY;
      goto err;
    }
  }

  rh->flags = flags;

  MOVE_REF(rh->vks, *vks);
  MOVE_REF(rh->reenc_lock, reencrypt_lock);

  crypt_set_luks2_reencrypt(cd, rh);

  return 0;
err:
  LUKS2_reencrypt_unlock(cd, reencrypt_lock);
  LUKS2_reencrypt_free(cd, rh);
  return r;
}

static int reencrypt_locked_recovery(struct crypt_device *cd,
  int keyslot_old,
  int keyslot_new,
  struct crypt_keyslot_context *kc_old,
  struct crypt_keyslot_context *kc_new,
  struct volume_key **r_vks)
{
  int keyslot, r = -EINVAL;
  struct volume_key *_vks = NULL;

  r = LUKS2_keyslot_context_open_all_segments(cd, keyslot_old, keyslot_new,
                kc_old, kc_new, &_vks);
  if (r < 0)
    return r;
  keyslot = r;

  r = LUKS2_reencrypt_locked_recovery_by_vks(cd, _vks);
  if (!r && r_vks)
    MOVE_REF(*r_vks, _vks);

  crypt_free_volume_key(_vks);

  return r < 0 ? r : keyslot;
}

static int reencrypt_recovery_by_keyslot_context(struct crypt_device *cd,
  struct luks2_hdr *hdr,
  int keyslot_old,
  int keyslot_new,
  struct crypt_keyslot_context *kc_old,
  struct crypt_keyslot_context *kc_new)
{
  int r;
  crypt_reencrypt_info ri;
  struct crypt_lock_handle *reencrypt_lock;

  r = LUKS2_reencrypt_lock(cd, &reencrypt_lock);
  if (r) {
    if (r == -EBUSY)
      log_err(cd, _("Reencryption in-progress. Cannot perform recovery."));
    else
      log_err(cd, _("Failed to get reencryption lock."));
    return r;
  }

  if ((r = crypt_load(cd, CRYPT_LUKS2, NULL))) {
    LUKS2_reencrypt_unlock(cd, reencrypt_lock);
    return r;
  }

  ri = LUKS2_reencrypt_status(hdr);
  if (ri == CRYPT_REENCRYPT_INVALID) {
    LUKS2_reencrypt_unlock(cd, reencrypt_lock);
    return -EINVAL;
  }

  if (ri == CRYPT_REENCRYPT_CRASH) {
    r = reencrypt_locked_recovery(cd, keyslot_old, keyslot_new,
                kc_old, kc_new, NULL);
    if (r < 0)
      log_err(cd, _("LUKS2 reencryption recovery failed."));
  } else {
    log_dbg(cd, "No LUKS2 reencryption recovery needed.");
    r = 0;
  }

  LUKS2_reencrypt_unlock(cd, reencrypt_lock);
  return r;
}

static int reencrypt_repair(
    struct crypt_device *cd,
    struct luks2_hdr *hdr,
    int keyslot_old,
    int keyslot_new,
    struct crypt_keyslot_context *kc_old,
    struct crypt_keyslot_context *kc_new)
{
  int r;
  struct crypt_lock_handle *reencrypt_lock;
  struct luks2_reencrypt *rh;
  crypt_reencrypt_info ri;
  uint8_t requirement_version;
  const char *resilience;
  struct volume_key *vks = NULL;

  log_dbg(cd, "Loading LUKS2 reencryption context for metadata repair.");

  rh = crypt_get_luks2_reencrypt(cd);
  if (rh) {
    LUKS2_reencrypt_free(cd, rh);
    crypt_set_luks2_reencrypt(cd, NULL);
    rh = NULL;
  }

  ri = LUKS2_reencrypt_status(hdr);
  if (ri == CRYPT_REENCRYPT_INVALID)
    return -EINVAL;

  if (ri < CRYPT_REENCRYPT_CLEAN) {
    log_err(cd, _("Device is not in reencryption."));
    return -EINVAL;
  }

  r = LUKS2_reencrypt_lock(cd, &reencrypt_lock);
  if (r < 0) {
    if (r == -EBUSY)
      log_err(cd, _("Reencryption process is already running."));
    else
      log_err(cd, _("Failed to acquire reencryption lock."));
    return r;
  }

  /* With reencryption lock held, reload device context and verify metadata state */
  r = crypt_load(cd, CRYPT_LUKS2, NULL);
  if (r)
    goto out;

  ri = LUKS2_reencrypt_status(hdr);
  if (ri == CRYPT_REENCRYPT_INVALID) {
    r = -EINVAL;
    goto out;
  }
  if (ri == CRYPT_REENCRYPT_NONE) {
    r = 0;
    goto out;
  }

  resilience = reencrypt_resilience_type(hdr);
  if (!resilience) {
    r = -EINVAL;
    goto out;
  }

  if (reencrypt_mode(hdr) == CRYPT_REENCRYPT_DECRYPT &&
      !strncmp(resilience, "datashift-", 10) &&
      LUKS2_get_segment_id_by_flag(hdr, "backup-moved-segment") >= 0)
    requirement_version = LUKS2_DECRYPT_DATASHIFT_REQ_VERSION;
  else
    requirement_version = LUKS2_REENCRYPT_REQ_VERSION;

  r = LUKS2_keyslot_context_open_all_segments(cd, keyslot_old, keyslot_new, kc_old, kc_new, &vks);
  if (r < 0)
    goto out;

  r = LUKS2_keyslot_reencrypt_digest_create(cd, hdr, requirement_version, vks);
  crypt_free_volume_key(vks);
  vks = NULL;
  if (r < 0)
    goto out;

  /* replaces old online-reencrypt flag with updated version and commits metadata */
  r = reencrypt_update_flag(cd, requirement_version, true, true);
out:
  LUKS2_reencrypt_unlock(cd, reencrypt_lock);
  crypt_free_volume_key(vks);
  return r;

}

static int reencrypt_init_by_keyslot_context(struct crypt_device *cd,
  const char *name,
  struct crypt_keyslot_context *kc_old,
  struct crypt_keyslot_context *kc_new,
  int keyslot_old,
  int keyslot_new,
  const char *cipher,
  const char *cipher_mode,
  const struct crypt_params_reencrypt *params)
{
  int r;
  crypt_reencrypt_info ri;
  size_t key_length;
  struct volume_key *vks = NULL;
  uint32_t flags = params ? params->flags : 0;
  struct luks2_hdr *hdr = crypt_get_hdr(cd, CRYPT_LUKS2);

  if (params && (params->flags & CRYPT_REENCRYPT_CREATE_NEW_DIGEST) &&
      (!kc_new || !kc_new->get_luks2_key || !kc_new->get_key_size ||
       (params->flags & CRYPT_REENCRYPT_RESUME_ONLY)))
    return -EINVAL;

  /* short-circuit in reencryption metadata update and finish immediately. */
  if (flags & CRYPT_REENCRYPT_REPAIR_NEEDED)
    return reencrypt_repair(cd, hdr, keyslot_old, keyslot_new, kc_old, kc_new);

  /* short-circuit in recovery and finish immediately. */
  if (flags & CRYPT_REENCRYPT_RECOVERY)
    return reencrypt_recovery_by_keyslot_context(cd, hdr, keyslot_old, keyslot_new, kc_old, kc_new);

  if (name && !device_direct_io(crypt_data_device(cd))) {
    log_dbg(cd, "Device %s does not support direct I/O.", device_path(crypt_data_device(cd)));
    /* FIXME: Add more specific error message for translation later. */
    log_err(cd, _("Failed to initialize reencryption device stack."));
    return -EINVAL;
  }

  if (cipher && !crypt_cipher_wrapped_key(cipher, cipher_mode)) {
    if (keyslot_new == CRYPT_ANY_SLOT && kc_new && kc_new->get_key_size)
      r = kc_new->get_key_size(cd, kc_new, &key_length);
    else {
      r = crypt_keyslot_get_key_size(cd, keyslot_new);
      if (r >= 0)
        key_length = r;
    }
    if (r < 0)
      return r;
    r = LUKS2_check_cipher(cd, key_length, cipher, cipher_mode);
    if (r < 0) {
      log_err(cd, _("Unable to use cipher specification %s-%s for LUKS2."), cipher, cipher_mode);
      return r;
    }
  }

  r = LUKS2_device_write_lock(cd, hdr, crypt_metadata_device(cd));
  if (r)
    return r;

  ri = LUKS2_reencrypt_status(hdr);
  if (ri == CRYPT_REENCRYPT_INVALID) {
    device_write_unlock(cd, crypt_metadata_device(cd));
    return -EINVAL;
  }

  if ((ri > CRYPT_REENCRYPT_NONE) && (flags & CRYPT_REENCRYPT_INITIALIZE_ONLY)) {
    device_write_unlock(cd, crypt_metadata_device(cd));
    log_err(cd, _("LUKS2 reencryption already initialized in metadata."));
    return -EBUSY;
  }

  if (ri == CRYPT_REENCRYPT_NONE && !(flags & CRYPT_REENCRYPT_RESUME_ONLY)) {
    r = reencrypt_init(cd, name, hdr, kc_old, kc_new, keyslot_old,
           keyslot_new, cipher, cipher_mode, params, &vks);
    if (r < 0)
      log_err(cd, _("Failed to initialize LUKS2 reencryption in metadata."));
  } else if (ri > CRYPT_REENCRYPT_NONE) {
    log_dbg(cd, "LUKS2 reencryption already initialized.");
    r = 0;
  }

  device_write_unlock(cd, crypt_metadata_device(cd));

  if (r < 0 || (flags & CRYPT_REENCRYPT_INITIALIZE_ONLY))
    goto out;

  r = reencrypt_load_by_keyslot_context(cd, name, kc_old, kc_new, keyslot_old,
                keyslot_new, &vks, params);
out:
  if (r < 0)
    crypt_drop_uploaded_keyring_key(cd, vks);
  crypt_free_volume_key(vks);
  return r < 0 ? r : LUKS2_find_keyslot(hdr, "reencrypt");
}
#else
static int reencrypt_init_by_keyslot_context(struct crypt_device *cd,
  const char *name __attribute__((unused)),
  struct crypt_keyslot_context *kc_old __attribute__((unused)),
  struct crypt_keyslot_context *kc_new __attribute__((unused)),
  int keyslot_old __attribute__((unused)),
  int keyslot_new __attribute__((unused)),
  const char *cipher __attribute__((unused)),
  const char *cipher_mode __attribute__((unused)),
  const struct crypt_params_reencrypt *params __attribute__((unused)))
{
  log_err(cd, _("This operation is not supported for this device type."));
  return -ENOTSUP;
}
#endif

int crypt_reencrypt_init_by_keyring(struct crypt_device *cd,
  const char *name,
  const char *passphrase_description,
  int keyslot_old,
  int keyslot_new,
  const char *cipher,
  const char *cipher_mode,
  const struct crypt_params_reencrypt *params)
{
  int r;
  struct crypt_keyslot_context kc = {0};

  if (onlyLUKS2reencrypt(cd) || !passphrase_description)
    return -EINVAL;
  if (params && (params->flags & CRYPT_REENCRYPT_INITIALIZE_ONLY) && (params->flags & CRYPT_REENCRYPT_RESUME_ONLY))
    return -EINVAL;

  if (device_is_dax(crypt_data_device(cd)) > 0) {
    log_err(cd, _("Reencryption is not supported for DAX (persistent memory) devices."));
    return -EINVAL;
  }

  crypt_keyslot_context_init_by_keyring_internal(&kc, passphrase_description);
  r = reencrypt_init_by_keyslot_context(cd, name, &kc, &kc, keyslot_old,
                keyslot_new, cipher, cipher_mode, params);

  crypt_keyslot_context_destroy_internal(&kc);

  return r;
}

int crypt_reencrypt_init_by_passphrase(struct crypt_device *cd,
  const char *name,
  const char *passphrase,
  size_t passphrase_size,
  int keyslot_old,
  int keyslot_new,
  const char *cipher,
  const char *cipher_mode,
  const struct crypt_params_reencrypt *params)
{
  int r;
  struct crypt_keyslot_context kc = {0};

  if (onlyLUKS2reencrypt(cd) || !passphrase)
    return -EINVAL;
  if (params && (params->flags & CRYPT_REENCRYPT_INITIALIZE_ONLY) && (params->flags & CRYPT_REENCRYPT_RESUME_ONLY))
    return -EINVAL;

  if (device_is_dax(crypt_data_device(cd)) > 0) {
    log_err(cd, _("Reencryption is not supported for DAX (persistent memory) devices."));
    return -EINVAL;
  }

  crypt_keyslot_context_init_by_passphrase_internal(&kc, passphrase, passphrase_size);

  r = reencrypt_init_by_keyslot_context(cd, name, &kc, &kc, keyslot_old,
                keyslot_new, cipher, cipher_mode, params);

  crypt_keyslot_context_destroy_internal(&kc);

  return r;
}

int crypt_reencrypt_init_by_keyslot_context(struct crypt_device *cd,
  const char *name,
  struct crypt_keyslot_context *kc_old,
  struct crypt_keyslot_context *kc_new,
  int keyslot_old,
  int keyslot_new,
  const char *cipher,
  const char *cipher_mode,
  const struct crypt_params_reencrypt *params)
{
  if (onlyLUKS2reencrypt(cd) || (!kc_old && !kc_new))
    return -EINVAL;
  if (params && (params->flags & CRYPT_REENCRYPT_INITIALIZE_ONLY) && (params->flags & CRYPT_REENCRYPT_RESUME_ONLY))
    return -EINVAL;

  if (device_is_dax(crypt_data_device(cd)) > 0) {
    log_err(cd, _("Reencryption is not supported for DAX (persistent memory) devices."));
    return -EINVAL;
  }

  return reencrypt_init_by_keyslot_context(cd, name, kc_old, kc_new, keyslot_old, keyslot_new, cipher, cipher_mode, params);
}

#if USE_LUKS2_REENCRYPTION
static reenc_status_t reencrypt_step(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh,
    uint64_t device_size,
    bool online)
{
  int r;
  struct reenc_protection *rp;

  assert(hdr);
  assert(rh);

  rp = &rh->rp;

  /* in memory only */
  r = reencrypt_make_segments(cd, hdr, rh, device_size);
  if (r)
    return REENC_ERR;

  r = reencrypt_assign_segments(cd, hdr, rh, 1, 0);
  if (r) {
    log_err(cd, _("Failed to set device segments for next reencryption hotzone."));
    return REENC_ERR;
  }

  log_dbg(cd, "Reencrypting chunk starting at offset: %" PRIu64 ", size :%" PRIu64 ".", rh->offset, rh->length);
  log_dbg(cd, "data_offset: %" PRIu64, crypt_get_data_offset(cd) << SECTOR_SHIFT);

  if (!rh->offset && rp->type == REENC_PROTECTION_DATASHIFT && rh->jobj_segment_moved) {
    crypt_storage_wrapper_destroy(rh->cw1);
    log_dbg(cd, "Reinitializing old segment storage wrapper for moved segment.");
    r = crypt_storage_wrapper_init(cd, &rh->cw1, crypt_data_device(cd),
        LUKS2_reencrypt_get_data_offset_moved(hdr),
        crypt_get_iv_offset(cd),
        reencrypt_get_sector_size_old(hdr),
        reencrypt_segment_cipher_old(hdr),
        crypt_volume_key_by_id(rh->vks, rh->digest_old),
        rh->wflags1);
    if (r) {
      log_err(cd, _("Failed to initialize old segment storage wrapper."));
      return REENC_ROLLBACK;
    }

    if (rh->rp_moved_segment.type != REENC_PROTECTION_NOT_SET) {
      log_dbg(cd, "Switching to moved segment resilience type.");
      rp = &rh->rp_moved_segment;
    }
  }

  r = reencrypt_hotzone_protect_ready(cd, rp);
  if (r) {
    log_err(cd, _("Failed to initialize hotzone protection."));
    return REENC_ROLLBACK;
  }

  if (online) {
    r = reencrypt_refresh_overlay_devices(cd, hdr, rh->overlay_name, rh->hotzone_name,
                  rh->hotzone_device, rh->vks, rh->device_size, rh->flags);
    /* Teardown overlay devices with dm-error. None bio shall pass! */
    if (r != REENC_OK)
      return r;
  }

  rh->read = crypt_storage_wrapper_read(rh->cw1, rh->offset, rh->reenc_buffer, rh->length);
  if (rh->read < 0) {
    /* severity normal */
    log_err(cd, _("Failed to read hotzone area starting at %" PRIu64 "."), rh->offset);
    return REENC_ROLLBACK;
  }

  /* metadata commit point */
  r = reencrypt_hotzone_protect_final(cd, hdr, rh->reenc_keyslot, rp, rh->reenc_buffer, rh->read);
  if (r < 0) {
    /* severity normal */
    log_err(cd, _("Failed to write reencryption resilience metadata."));
    return REENC_ROLLBACK;
  }

  r = crypt_storage_wrapper_decrypt(rh->cw1, rh->offset, rh->reenc_buffer, rh->read);
  if (r) {
    /* severity normal */
    log_err(cd, _("Decryption failed."));
    return REENC_ROLLBACK;
  }
  if (rh->read != crypt_storage_wrapper_encrypt_write(rh->cw2, rh->offset, rh->reenc_buffer, rh->read)) {
    /* severity fatal */
    log_err(cd, _("Failed to write hotzone area starting at %" PRIu64 "."), rh->offset);
    return REENC_FATAL;
  }

  if (rp->type != REENC_PROTECTION_NONE && crypt_storage_wrapper_datasync(rh->cw2)) {
    log_err(cd, _("Failed to sync data."));
    return REENC_FATAL;
  }

  /* metadata commit safe point */
  r = reencrypt_assign_segments(cd, hdr, rh, 0, rp->type != REENC_PROTECTION_NONE);
  if (r) {
    /* severity fatal */
    log_err(cd, _("Failed to update metadata after current reencryption hotzone completed."));
    return REENC_FATAL;
  }

  if (online) {
    /* severity normal */
    log_dbg(cd, "Resuming device %s", rh->hotzone_name);
    r = dm_resume_device(cd, rh->hotzone_name, DM_RESUME_PRIVATE);
    if (r) {
      log_err(cd, _("Failed to resume device %s."), rh->hotzone_name);
      return REENC_ERR;
    }
  }

  return REENC_OK;
}

static int reencrypt_erase_backup_segments(struct crypt_device *cd,
    struct luks2_hdr *hdr)
{
  int segment = LUKS2_get_segment_id_by_flag(hdr, "backup-previous");
  if (segment >= 0) {
    if (LUKS2_digest_segment_assign(cd, hdr, segment, CRYPT_ANY_DIGEST, 0, 0))
      return -EINVAL;
    json_object_object_del_by_uint(LUKS2_get_segments_jobj(hdr), segment);
  }
  segment = LUKS2_get_segment_id_by_flag(hdr, "backup-final");
  if (segment >= 0) {
    if (LUKS2_digest_segment_assign(cd, hdr, segment, CRYPT_ANY_DIGEST, 0, 0))
      return -EINVAL;
    json_object_object_del_by_uint(LUKS2_get_segments_jobj(hdr), segment);
  }
  segment = LUKS2_get_segment_id_by_flag(hdr, "backup-moved-segment");
  if (segment >= 0) {
    if (LUKS2_digest_segment_assign(cd, hdr, segment, CRYPT_ANY_DIGEST, 0, 0))
      return -EINVAL;
    json_object_object_del_by_uint(LUKS2_get_segments_jobj(hdr), segment);
  }

  return 0;
}

static int reencrypt_wipe_unused_device_area(struct crypt_device *cd, struct luks2_reencrypt *rh)
{
  uint64_t offset, length, dev_size;
  int r = 0;

  assert(cd);
  assert(rh);

  if (rh->jobj_segment_moved && rh->mode == CRYPT_REENCRYPT_ENCRYPT) {
    offset = json_segment_get_offset(rh->jobj_segment_moved, 0);
    length = json_segment_get_size(rh->jobj_segment_moved, 0);
    log_dbg(cd, "Wiping %" PRIu64 " bytes of backup segment data at offset %" PRIu64,
      length, offset);
    r = crypt_wipe_device(cd, crypt_data_device(cd), CRYPT_WIPE_RANDOM,
        offset, length, 1024 * 1024, NULL, NULL);
  }

  if (r < 0)
    return r;

  if (rh->rp.type == REENC_PROTECTION_DATASHIFT && rh->direction == CRYPT_REENCRYPT_FORWARD) {
    r = device_size(crypt_data_device(cd), &dev_size);
    if (r < 0)
      return r;

    if (dev_size < data_shift_value(&rh->rp))
      return -EINVAL;

    offset = dev_size - data_shift_value(&rh->rp);
    length = data_shift_value(&rh->rp);
    log_dbg(cd, "Wiping %" PRIu64 " bytes of data at offset %" PRIu64,
      length, offset);
    r = crypt_wipe_device(cd, crypt_data_device(cd), CRYPT_WIPE_RANDOM,
        offset, length, 1024 * 1024, NULL, NULL);
  }

  return r;
}

static int reencrypt_teardown_ok(struct crypt_device *cd, struct luks2_hdr *hdr, struct luks2_reencrypt *rh)
{
  int i, r;
  uint64_t dmt_flags;
  bool finished = !(rh->device_size > rh->progress);

  if (rh->rp.type == REENC_PROTECTION_NONE &&
      LUKS2_hdr_write(cd, hdr)) {
    log_err(cd, _("Failed to write LUKS2 metadata."));
    return -EINVAL;
  }

  if (rh->online) {
    r = LUKS2_reload(cd, rh->device_name, rh->vks, rh->device_size, rh->flags);
    if (r)
      log_err(cd, _("Failed to reload device %s."), rh->device_name);
    if (!r) {
      r = dm_resume_device(cd, rh->device_name, DM_SUSPEND_SKIP_LOCKFS | DM_SUSPEND_NOFLUSH);
      if (r)
        log_err(cd, _("Failed to resume device %s."), rh->device_name);
    }
    dm_remove_device(cd, rh->overlay_name, 0);
    dm_remove_device(cd, rh->hotzone_name, 0);

    if (!r && finished && rh->mode == CRYPT_REENCRYPT_DECRYPT &&
        !dm_flags(cd, DM_LINEAR, &dmt_flags) && (dmt_flags & DM_DEFERRED_SUPPORTED))
        dm_remove_device(cd, rh->device_name, CRYPT_DEACTIVATE_DEFERRED);
  }

  if (finished) {
    if (reencrypt_wipe_unused_device_area(cd, rh))
      log_err(cd, _("Failed to wipe unused data device area."));
    if (reencrypt_get_data_offset_new(hdr) && LUKS2_set_keyslots_size(hdr, reencrypt_get_data_offset_new(hdr)))
      log_dbg(cd, "Failed to set new keyslots area size.");
    if (rh->digest_old >= 0 && rh->digest_new != rh->digest_old)
      for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++)
        if (LUKS2_digest_by_keyslot(hdr, i) == rh->digest_old && crypt_keyslot_destroy(cd, i))
          log_err(cd, _("Failed to remove unused (unbound) keyslot %d."), i);

    if (reencrypt_erase_backup_segments(cd, hdr))
      log_dbg(cd, "Failed to erase backup segments");

    if (reencrypt_update_flag(cd, 0, false, false))
      log_dbg(cd, "Failed to disable reencryption requirement flag.");

    /* metadata commit point also removing reencryption flag on-disk */
    if (crypt_keyslot_destroy(cd, rh->reenc_keyslot)) {
      log_err(cd, _("Failed to remove reencryption keyslot."));
      return -EINVAL;
    }
  }

  return 0;
}

static void reencrypt_teardown_fatal(struct crypt_device *cd, struct luks2_reencrypt *rh)
{
  log_err(cd, _("Fatal error while reencrypting chunk starting at %" PRIu64 ", %" PRIu64 " sectors long."),
    (rh->offset >> SECTOR_SHIFT) + crypt_get_data_offset(cd), rh->length >> SECTOR_SHIFT);

  if (rh->online) {
    log_err(cd, _("Online reencryption failed."));
    if (dm_status_suspended(cd, rh->hotzone_name) > 0) {
      log_dbg(cd, "Hotzone device %s suspended, replacing with dm-error.", rh->hotzone_name);
      if (dm_error_device(cd, rh->hotzone_name)) {
        log_err(cd, _("Failed to replace suspended device %s with dm-error target."), rh->hotzone_name);
        log_err(cd, _("Do not resume the device unless replaced with error target manually."));
      }
    }
  }
}

static int reencrypt_teardown(struct crypt_device *cd, struct luks2_hdr *hdr,
    struct luks2_reencrypt *rh, reenc_status_t rs, bool interrupted,
    int (*progress)(uint64_t size, uint64_t offset, void *usrptr),
    void *usrptr)
{
  int r;

  switch (rs) {
  case REENC_OK:
    if (progress && !interrupted)
      progress(rh->device_size, rh->progress, usrptr);
    r = reencrypt_teardown_ok(cd, hdr, rh);
    break;
  case REENC_FATAL:
    reencrypt_teardown_fatal(cd, rh);
    /* fall-through */
  default:
    r = -EIO;
  }

  /* this frees reencryption lock */
  LUKS2_reencrypt_free(cd, rh);
  crypt_set_luks2_reencrypt(cd, NULL);

  return r;
}

int crypt_reencrypt_run(
  struct crypt_device *cd,
  int (*progress)(uint64_t size, uint64_t offset, void *usrptr),
  void *usrptr)
{
  int r;
  crypt_reencrypt_info ri;
  struct luks2_hdr *hdr;
  struct luks2_reencrypt *rh;
  reenc_status_t rs;
  bool quit = false;

  if (onlyLUKS2reencrypt(cd))
    return -EINVAL;

  hdr = crypt_get_hdr(cd, CRYPT_LUKS2);

  ri = LUKS2_reencrypt_status(hdr);
  if (ri > CRYPT_REENCRYPT_CLEAN) {
    log_err(cd, _("Cannot proceed with reencryption. Unexpected reencryption status."));
    return -EINVAL;
  }

  rh = crypt_get_luks2_reencrypt(cd);
  if (!rh || (!rh->reenc_lock && crypt_metadata_locking_enabled())) {
    log_err(cd, _("Missing or invalid reencrypt context."));
    return -EINVAL;
  }

  log_dbg(cd, "Resuming LUKS2 reencryption.");

  if (rh->online) {
    /* This is last resort to avoid data corruption. Abort is justified here. */
    assert(device_direct_io(crypt_data_device(cd)));

    if (reencrypt_init_device_stack(cd, rh)) {
      log_err(cd, _("Failed to initialize reencryption device stack."));
      return -EINVAL;
    }
  }

  log_dbg(cd, "Progress %" PRIu64 ", device_size %" PRIu64, rh->progress, rh->device_size);

  rs = REENC_OK;

  if (progress && progress(rh->device_size, rh->progress, usrptr))
    quit = true;

  while (!quit && (rh->device_size > rh->progress)) {
    rs = reencrypt_step(cd, hdr, rh, rh->device_size, rh->online);
    if (rs != REENC_OK)
      break;

    log_dbg(cd, "Progress %" PRIu64 ", device_size %" PRIu64, rh->progress, rh->device_size);
    if (progress && progress(rh->device_size, rh->progress, usrptr))
      quit = true;

    r = reencrypt_context_update(cd, rh);
    if (r) {
      log_err(cd, _("Failed to update reencryption context."));
      rs = REENC_ERR;
      break;
    }

    log_dbg(cd, "Next reencryption offset will be %" PRIu64 " sectors.", rh->offset);
    log_dbg(cd, "Next reencryption chunk size will be %" PRIu64 " sectors).", rh->length);
  }

  r = reencrypt_teardown(cd, hdr, rh, rs, quit, progress, usrptr);
  return r;
}


static int reencrypt_recovery(struct crypt_device *cd,
    struct luks2_hdr *hdr,
    uint64_t device_size,
    struct volume_key *vks)
{
  int r;
  struct luks2_reencrypt *rh = NULL;

  r = reencrypt_load(cd, hdr, device_size, 0, 0, vks, &rh);
  if (r < 0) {
    log_err(cd, _("Failed to load LUKS2 reencryption context."));
    return r;
  }

  r = reencrypt_recover_segment(cd, hdr, rh, vks);
  if (r < 0)
    goto out;

  if ((r = reencrypt_assign_segments(cd, hdr, rh, 0, 0)))
    goto out;

  r = reencrypt_context_update(cd, rh);
  if (r) {
    log_err(cd, _("Failed to update reencryption context."));
    goto out;
  }

  r = reencrypt_teardown_ok(cd, hdr, rh);
  if (!r)
    r = LUKS2_hdr_write(cd, hdr);
out:
  LUKS2_reencrypt_free(cd, rh);

  return r;
}
#else /* USE_LUKS2_REENCRYPTION */
int crypt_reencrypt_run(
  struct crypt_device *cd,
  int (*progress)(uint64_t size, uint64_t offset, void *usrptr),
  void *usrptr)
{
  UNUSED(progress);
  UNUSED(usrptr);

  log_err(cd, _("This operation is not supported for this device type."));
  return -ENOTSUP;
}
#endif

int crypt_reencrypt(
  struct crypt_device *cd,
  int (*progress)(uint64_t size, uint64_t offset, void *usrptr))
{
  return crypt_reencrypt_run(cd, progress, NULL);
}

/*
 * use only for calculation of minimal data device size.
 * The real data offset is taken directly from segments!
 */
int LUKS2_reencrypt_data_offset(struct luks2_hdr *hdr, bool blockwise)
{
  crypt_reencrypt_info ri = LUKS2_reencrypt_status(hdr);
  uint64_t data_offset = LUKS2_get_data_offset(hdr);

  if (ri == CRYPT_REENCRYPT_CLEAN && reencrypt_direction(hdr) == CRYPT_REENCRYPT_FORWARD)
    data_offset += reencrypt_data_shift(hdr) >> SECTOR_SHIFT;

  return blockwise ? data_offset : data_offset << SECTOR_SHIFT;
}

/* internal only */
int LUKS2_reencrypt_check_device_size(struct crypt_device *cd, struct luks2_hdr *hdr,
  uint64_t check_size, uint64_t *dev_size, bool device_exclusive_check, bool dynamic)
{
  int r;
  uint64_t data_offset, real_size = 0;

  if (reencrypt_direction(hdr) == CRYPT_REENCRYPT_BACKWARD &&
      (LUKS2_get_segment_by_flag(hdr, "backup-moved-segment") || dynamic))
    check_size += reencrypt_data_shift(hdr);

  r = device_check_access(cd, crypt_data_device(cd),
        device_exclusive_check ? DEV_EXCL : DEV_OK);
  if (r)
    return r;

  data_offset = LUKS2_reencrypt_data_offset(hdr, false);

  r = device_check_size(cd, crypt_data_device(cd), data_offset, 1);
  if (r)
    return r;

  r = device_size(crypt_data_device(cd), &real_size);
  if (r)
    return r;

  log_dbg(cd, "Required minimal device size: %" PRIu64 " (%" PRIu64 " sectors)"
        ", real device size: %" PRIu64 " (%" PRIu64 " sectors) "
        "calculated device size: %" PRIu64 " (%" PRIu64 " sectors)",
        check_size, check_size >> SECTOR_SHIFT, real_size, real_size >> SECTOR_SHIFT,
        real_size - data_offset, (real_size - data_offset) >> SECTOR_SHIFT);

  if (real_size < data_offset || (check_size && real_size < check_size)) {
    log_err(cd, _("Device %s is too small."), device_path(crypt_data_device(cd)));
    return -EINVAL;
  }

  *dev_size = real_size - data_offset;

  return 0;
}
#if USE_LUKS2_REENCRYPTION
/* returns keyslot number on success (>= 0) or negative errnor otherwise */
int LUKS2_reencrypt_locked_recovery_by_vks(struct crypt_device *cd,
  struct volume_key *vks)
{
  uint64_t minimal_size, device_size;
  int r = -EINVAL;
  struct luks2_hdr *hdr = crypt_get_hdr(cd, CRYPT_LUKS2);

  log_dbg(cd, "Entering reencryption crash recovery.");

  if (LUKS2_get_data_size(hdr, &minimal_size, NULL))
    return r;
  if (LUKS2_reencrypt_check_device_size(cd, hdr, minimal_size, &device_size, true, false))
    goto out;

  r = reencrypt_recovery(cd, hdr, device_size, vks);

out:
  if (r < 0)
    crypt_drop_uploaded_keyring_key(cd, vks);
  return r;
}
#endif
crypt_reencrypt_info LUKS2_reencrypt_get_params(struct luks2_hdr *hdr,
  struct crypt_params_reencrypt *params)
{
  crypt_reencrypt_info ri;
  int digest;
  uint8_t version;

  if (params)
    memset(params, 0, sizeof(*params));

  ri = LUKS2_reencrypt_status(hdr);
  if (ri == CRYPT_REENCRYPT_NONE || ri == CRYPT_REENCRYPT_INVALID || !params)
    return ri;

  digest = LUKS2_digest_by_keyslot(hdr, LUKS2_find_keyslot(hdr, "reencrypt"));
  if (digest < 0 && digest != -ENOENT)
    return CRYPT_REENCRYPT_INVALID;

  /*
   * In case there's an old "online-reencrypt" requirement or reencryption
   * keyslot digest is missing inform caller reencryption metadata requires repair.
   */
  if (!LUKS2_config_get_reencrypt_version(hdr, &version) &&
      (version < 2 || digest == -ENOENT)) {
    params->flags |= CRYPT_REENCRYPT_REPAIR_NEEDED;
    return ri;
  }

  params->mode = reencrypt_mode(hdr);
  params->direction = reencrypt_direction(hdr);
  params->resilience = reencrypt_resilience_type(hdr);
  params->hash = reencrypt_resilience_hash(hdr);
  params->data_shift = reencrypt_data_shift(hdr) >> SECTOR_SHIFT;
  params->max_hotzone_size = 0;
  if (LUKS2_get_segment_id_by_flag(hdr, "backup-moved-segment") >= 0)
    params->flags |= CRYPT_REENCRYPT_MOVE_FIRST_SEGMENT;

  return ri;
}

Coverage Report

Created: 2025-11-25 07:00