/src/cryptsetup/lib/luks2/luks2_luks1_convert.c

Source (jump to first uncovered line)
/*
 * LUKS - Linux Unified Key Setup v2, LUKS1 conversion code
 *
 * Copyright (C) 2015-2024 Red Hat, Inc. All rights reserved.
 * Copyright (C) 2015-2024 Ondrej Kozina
 * Copyright (C) 2015-2024 Milan Broz
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include "luks2_internal.h"
#include "../luks1/luks.h"
#include "../luks1/af.h"

/* This differs from LUKS_check_cipher() that it does not check dm-crypt fallback. */
int LUKS2_check_cipher(struct crypt_device *cd,
          size_t keylength,
          const char *cipher,
          const char *cipher_mode)
{
  int r;
  struct crypt_storage *s;
  char buf[SECTOR_SIZE], *empty_key;

  log_dbg(cd, "Checking if cipher %s-%s is usable (storage wrapper).", cipher, cipher_mode);

  empty_key = crypt_safe_alloc(keylength);
  if (!empty_key)
    return -ENOMEM;

  /* No need to get KEY quality random but it must avoid known weak keys. */
  r = crypt_random_get(cd, empty_key, keylength, CRYPT_RND_NORMAL);
  if (r < 0)
    goto out;

  r = crypt_storage_init(&s, SECTOR_SIZE, cipher, cipher_mode, empty_key, keylength, false);
  if (r < 0)
    goto out;

  memset(buf, 0, sizeof(buf));
  r = crypt_storage_decrypt(s, 0, sizeof(buf), buf);
  crypt_storage_destroy(s);
out:
  crypt_safe_free(empty_key);
  crypt_safe_memzero(buf, sizeof(buf));
  return r;
}

static int json_luks1_keyslot(const struct luks_phdr *hdr_v1, int keyslot, struct json_object **keyslot_object)
{
  char *base64_str, cipher[LUKS_CIPHERNAME_L+LUKS_CIPHERMODE_L];
  size_t base64_len;
  struct json_object *keyslot_obj, *field, *jobj_kdf, *jobj_af, *jobj_area;
  uint64_t offset, area_size, length;
  int r;

  keyslot_obj = json_object_new_object();
  if (!keyslot_obj) {
    r = -ENOMEM;
    goto err;
  }

  json_object_object_add(keyslot_obj, "type", json_object_new_string("luks2"));
  json_object_object_add(keyslot_obj, "key_size", json_object_new_int64(hdr_v1->keyBytes));

  /* KDF */
  jobj_kdf = json_object_new_object();
  if (!jobj_kdf) {
    r = -ENOMEM;
    goto err;
  }

  json_object_object_add(jobj_kdf, "type", json_object_new_string(CRYPT_KDF_PBKDF2));
  json_object_object_add(jobj_kdf, "hash", json_object_new_string(hdr_v1->hashSpec));
  json_object_object_add(jobj_kdf, "iterations", json_object_new_int64(hdr_v1->keyblock[keyslot].passwordIterations));
  /* salt field */
  r = crypt_base64_encode(&base64_str, &base64_len, hdr_v1->keyblock[keyslot].passwordSalt, LUKS_SALTSIZE);
  if (r < 0) {
    json_object_put(keyslot_obj);
    json_object_put(jobj_kdf);
    return r;
  }
  field = json_object_new_string_len(base64_str, base64_len);
  free(base64_str);
  json_object_object_add(jobj_kdf, "salt", field);
  json_object_object_add(keyslot_obj, "kdf", jobj_kdf);

  /* AF */
  jobj_af = json_object_new_object();
  if (!jobj_af) {
    r = -ENOMEM;
    goto err;
  }

  json_object_object_add(jobj_af, "type", json_object_new_string("luks1"));
  json_object_object_add(jobj_af, "hash", json_object_new_string(hdr_v1->hashSpec));
  /* stripes field ignored, fixed to LUKS_STRIPES (4000) */
  json_object_object_add(jobj_af, "stripes", json_object_new_int(LUKS_STRIPES));
  json_object_object_add(keyslot_obj, "af", jobj_af);

  /* Area */
  jobj_area = json_object_new_object();
  if (!jobj_area) {
    r = -ENOMEM;
    goto err;
  }

  json_object_object_add(jobj_area, "type", json_object_new_string("raw"));

  /* encryption algorithm field */
  if (*hdr_v1->cipherMode != '\0') {
    if (snprintf(cipher, sizeof(cipher), "%s-%s", hdr_v1->cipherName, hdr_v1->cipherMode) < 0) {
      json_object_put(keyslot_obj);
      json_object_put(jobj_area);
      return -EINVAL;
    }
    json_object_object_add(jobj_area, "encryption", json_object_new_string(cipher));
  } else
    json_object_object_add(jobj_area, "encryption", json_object_new_string(hdr_v1->cipherName));

  /* area */
  if (LUKS_keyslot_area(hdr_v1, keyslot, &offset, &length)) {
    json_object_put(keyslot_obj);
    json_object_put(jobj_area);
    return -EINVAL;
  }
  area_size = size_round_up(length, 4096);
  json_object_object_add(jobj_area, "key_size", json_object_new_int(hdr_v1->keyBytes));
  json_object_object_add(jobj_area, "offset", crypt_jobj_new_uint64(offset));
  json_object_object_add(jobj_area, "size", crypt_jobj_new_uint64(area_size));
  json_object_object_add(keyslot_obj, "area", jobj_area);

  *keyslot_object = keyslot_obj;
  return 0;
err:
  json_object_put(keyslot_obj);
  return r;
}

static int json_luks1_keyslots(const struct luks_phdr *hdr_v1, struct json_object **keyslots_object)
{
  int keyslot, r;
  struct json_object *keyslot_obj, *field;

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

  for (keyslot = 0; keyslot < LUKS_NUMKEYS; keyslot++) {
    if (hdr_v1->keyblock[keyslot].active != LUKS_KEY_ENABLED)
      continue;
    r = json_luks1_keyslot(hdr_v1, keyslot, &field);
    if (r) {
      json_object_put(keyslot_obj);
      return r;
    }
    r = json_object_object_add_by_uint(keyslot_obj, keyslot, field);
    if (r) {
      json_object_put(field);
      json_object_put(keyslot_obj);
      return r;
    }
  }

  *keyslots_object = keyslot_obj;
  return 0;
}

static int json_luks1_segment(const struct luks_phdr *hdr_v1, struct json_object **segment_object)
{
  const char *c;
  char cipher[LUKS_CIPHERNAME_L+LUKS_CIPHERMODE_L];
  struct json_object *segment_obj, *field;
  uint64_t number;

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

  /* type field */
  field = json_object_new_string("crypt");
  if (!field) {
    json_object_put(segment_obj);
    return -ENOMEM;
  }
  json_object_object_add(segment_obj, "type", field);

  /* offset field */
  number = (uint64_t)hdr_v1->payloadOffset * SECTOR_SIZE;

  field = crypt_jobj_new_uint64(number);
  if (!field) {
    json_object_put(segment_obj);
    return -ENOMEM;
  }
  json_object_object_add(segment_obj, "offset", field);

  /* iv_tweak field */
  field = json_object_new_string("0");
  if (!field) {
    json_object_put(segment_obj);
    return -ENOMEM;
  }
  json_object_object_add(segment_obj, "iv_tweak", field);

  /* length field */
  field = json_object_new_string("dynamic");
  if (!field) {
    json_object_put(segment_obj);
    return -ENOMEM;
  }
  json_object_object_add(segment_obj, "size", field);

  /* cipher field */
  if (*hdr_v1->cipherMode != '\0') {
    if (snprintf(cipher, sizeof(cipher), "%s-%s", hdr_v1->cipherName, hdr_v1->cipherMode) < 0) {
      json_object_put(segment_obj);
      return -EINVAL;
    }
    c = cipher;
  } else
    c = hdr_v1->cipherName;

  field = json_object_new_string(c);
  if (!field) {
    json_object_put(segment_obj);
    return -ENOMEM;
  }
  json_object_object_add(segment_obj, "encryption", field);

  /* block field */
  field = json_object_new_int(SECTOR_SIZE);
  if (!field) {
    json_object_put(segment_obj);
    return -ENOMEM;
  }
  json_object_object_add(segment_obj, "sector_size", field);

  *segment_object = segment_obj;
  return 0;
}

static int json_luks1_segments(const struct luks_phdr *hdr_v1, struct json_object **segments_object)
{
  int r;
  struct json_object *segments_obj, *field;

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

  r = json_luks1_segment(hdr_v1, &field);
  if (r) {
    json_object_put(segments_obj);
    return r;
  }
  r = json_object_object_add_by_uint(segments_obj, 0, field);
  if (r) {
    json_object_put(field);
    json_object_put(segments_obj);
    return r;
  }

  *segments_object = segments_obj;
  return 0;
}

static int json_luks1_digest(const struct luks_phdr *hdr_v1, struct json_object **digest_object)
{
  char keyslot_str[16], *base64_str;
  int r, ks;
  size_t base64_len;
  struct json_object *digest_obj, *array, *field;

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

  /* type field */
  field = json_object_new_string("pbkdf2");
  if (!field) {
    json_object_put(digest_obj);
    return -ENOMEM;
  }
  json_object_object_add(digest_obj, "type", field);

  /* keyslots array */
  array = json_object_new_array();
  if (!array) {
    json_object_put(digest_obj);
    return -ENOMEM;
  }
  json_object_object_add(digest_obj, "keyslots", json_object_get(array));

  for (ks = 0; ks < LUKS_NUMKEYS; ks++) {
    if (hdr_v1->keyblock[ks].active != LUKS_KEY_ENABLED)
      continue;
    if (snprintf(keyslot_str, sizeof(keyslot_str), "%d", ks) < 0) {
      json_object_put(field);
      json_object_put(array);
      json_object_put(digest_obj);
      return -EINVAL;
    }

    field = json_object_new_string(keyslot_str);
    if (!field || json_object_array_add(array, field) < 0) {
      json_object_put(field);
      json_object_put(array);
      json_object_put(digest_obj);
      return -ENOMEM;
    }
  }

  json_object_put(array);

  /* segments array */
  array = json_object_new_array();
  if (!array) {
    json_object_put(digest_obj);
    return -ENOMEM;
  }
  json_object_object_add(digest_obj, "segments", json_object_get(array));

  field = json_object_new_string("0");
  if (!field || json_object_array_add(array, field) < 0) {
    json_object_put(field);
    json_object_put(array);
    json_object_put(digest_obj);
    return -ENOMEM;
  }

  json_object_put(array);

  /* hash field */
  field = json_object_new_string(hdr_v1->hashSpec);
  if (!field) {
    json_object_put(digest_obj);
    return -ENOMEM;
  }
  json_object_object_add(digest_obj, "hash", field);

  /* salt field */
  r = crypt_base64_encode(&base64_str, &base64_len, hdr_v1->mkDigestSalt, LUKS_SALTSIZE);
  if (r < 0) {
    json_object_put(digest_obj);
    return r;
  }

  field = json_object_new_string_len(base64_str, base64_len);
  free(base64_str);
  if (!field) {
    json_object_put(digest_obj);
    return -ENOMEM;
  }
  json_object_object_add(digest_obj, "salt", field);

  /* digest field */
  r = crypt_base64_encode(&base64_str, &base64_len, hdr_v1->mkDigest, LUKS_DIGESTSIZE);
  if (r < 0) {
    json_object_put(digest_obj);
    return r;
  }

  field = json_object_new_string_len(base64_str, base64_len);
  free(base64_str);
  if (!field) {
    json_object_put(digest_obj);
    return -ENOMEM;
  }
  json_object_object_add(digest_obj, "digest", field);

  /* iterations field */
  field = json_object_new_int64(hdr_v1->mkDigestIterations);
  if (!field) {
    json_object_put(digest_obj);
    return -ENOMEM;
  }
  json_object_object_add(digest_obj, "iterations", field);

  *digest_object = digest_obj;
  return 0;
}

static int json_luks1_digests(const struct luks_phdr *hdr_v1, struct json_object **digests_object)
{
  int r;
  struct json_object *digests_obj, *field;

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

  r = json_luks1_digest(hdr_v1, &field);
  if (r) {
    json_object_put(digests_obj);
    return r;
  }
  json_object_object_add(digests_obj, "0", field);

  *digests_object = digests_obj;
  return 0;
}

static int json_luks1_object(struct luks_phdr *hdr_v1, struct json_object **luks1_object, uint64_t keyslots_size)
{
  int r;
  struct json_object *luks1_obj, *field;
  uint64_t json_size;

  luks1_obj = json_object_new_object();
  if (!luks1_obj)
    return -ENOMEM;

  /* keyslots field */
  r = json_luks1_keyslots(hdr_v1, &field);
  if (r) {
    json_object_put(luks1_obj);
    return r;
  }
  json_object_object_add(luks1_obj, "keyslots", field);

  /* tokens field */
  field = json_object_new_object();
  if (!field) {
    json_object_put(luks1_obj);
    return -ENOMEM;
  }
  json_object_object_add(luks1_obj, "tokens", field);

  /* segments field */
  r = json_luks1_segments(hdr_v1, &field);
  if (r) {
    json_object_put(luks1_obj);
    return r;
  }
  json_object_object_add(luks1_obj, "segments", field);

  /* digests field */
  r = json_luks1_digests(hdr_v1, &field);
  if (r) {
    json_object_put(luks1_obj);
    return r;
  }
  json_object_object_add(luks1_obj, "digests", field);

  /* config field */
  /* anything else? */
  field = json_object_new_object();
  if (!field) {
    json_object_put(luks1_obj);
    return -ENOMEM;
  }
  json_object_object_add(luks1_obj, "config", field);

  json_size = LUKS2_HDR_16K_LEN - LUKS2_HDR_BIN_LEN;
  json_object_object_add(field, "json_size", crypt_jobj_new_uint64(json_size));
  keyslots_size -= (keyslots_size % 4096);
  json_object_object_add(field, "keyslots_size", crypt_jobj_new_uint64(keyslots_size));

  *luks1_object = luks1_obj;
  return 0;
}

static void move_keyslot_offset(json_object *jobj, int offset_add)
{
  json_object *jobj1, *jobj2, *jobj_area;
  uint64_t offset = 0;

  json_object_object_get_ex(jobj, "keyslots", &jobj1);
  json_object_object_foreach(jobj1, key, val) {
    UNUSED(key);
    json_object_object_get_ex(val, "area", &jobj_area);
    json_object_object_get_ex(jobj_area, "offset", &jobj2);
    offset = crypt_jobj_get_uint64(jobj2) + offset_add;
    json_object_object_add(jobj_area, "offset", crypt_jobj_new_uint64(offset));
  }
}

static int move_keyslot_areas(struct crypt_device *cd, off_t offset_from,
            off_t offset_to, size_t buf_size)
{
  int devfd, r = -EIO;
  struct device *device = crypt_metadata_device(cd);
  void *buf = NULL;

  log_dbg(cd, "Moving keyslot areas of size %zu from %jd to %jd.",
    buf_size, (intmax_t)offset_from, (intmax_t)offset_to);

  if (posix_memalign(&buf, crypt_getpagesize(), buf_size))
    return -ENOMEM;

  devfd = device_open(cd, device, O_RDWR);
  if (devfd < 0) {
    free(buf);
    return -EIO;
  }

  /* This can safely fail (for block devices). It only allocates space if it is possible. */
  if (posix_fallocate(devfd, offset_to, buf_size))
    log_dbg(cd, "Preallocation (fallocate) of new keyslot area not available.");

  /* Try to read *new* area to check that area is there (trimmed backup). */
  if (read_lseek_blockwise(devfd, device_block_size(cd, device),
         device_alignment(device), buf, buf_size,
         offset_to)!= (ssize_t)buf_size)
    goto out;

  if (read_lseek_blockwise(devfd, device_block_size(cd, device),
         device_alignment(device), buf, buf_size,
         offset_from)!= (ssize_t)buf_size)
    goto out;

  if (write_lseek_blockwise(devfd, device_block_size(cd, device),
          device_alignment(device), buf, buf_size,
          offset_to) != (ssize_t)buf_size)
    goto out;

  r = 0;
out:
  device_sync(cd, device);
  crypt_safe_memzero(buf, buf_size);
  free(buf);

  return r;
}

static int luks_header_in_use(struct crypt_device *cd)
{
  int r;

  r = lookup_dm_dev_by_uuid(cd, crypt_get_uuid(cd), crypt_get_type(cd));
  if (r < 0)
    log_err(cd, _("Cannot check status of device with uuid: %s."), crypt_get_uuid(cd));

  return r;
}

/* Check if there is a luksmeta area (foreign metadata created by the luksmeta package) */
static int luksmeta_header_present(struct crypt_device *cd, off_t luks1_size)
{
  int devfd, r = 0;
  static const uint8_t LM_MAGIC[] = { 'L', 'U', 'K', 'S', 'M', 'E', 'T', 'A' };
  struct device *device = crypt_metadata_device(cd);
  void *buf = NULL;

  if (posix_memalign(&buf, crypt_getpagesize(), sizeof(LM_MAGIC)))
    return -ENOMEM;

  devfd = device_open(cd, device, O_RDONLY);
  if (devfd < 0) {
    free(buf);
    return -EIO;
  }

  /* Note: we must not detect failure as problem here, header can be trimmed. */
  if (read_lseek_blockwise(devfd, device_block_size(cd, device), device_alignment(device),
    buf, sizeof(LM_MAGIC), luks1_size) == (ssize_t)sizeof(LM_MAGIC) &&
    !memcmp(LM_MAGIC, buf, sizeof(LM_MAGIC))) {
      log_err(cd, _("Unable to convert header with LUKSMETA additional metadata."));
      r = -EBUSY;
  }

  free(buf);
  return r;
}

/* Convert LUKS1 -> LUKS2 */
int LUKS2_luks1_to_luks2(struct crypt_device *cd, struct luks_phdr *hdr1, struct luks2_hdr *hdr2)
{
  int r;
  json_object *jobj = NULL;
  size_t buf_size, buf_offset, luks1_size, luks1_shift = 2 * LUKS2_HDR_16K_LEN - LUKS_ALIGN_KEYSLOTS;
  uint64_t required_size, max_size = crypt_get_data_offset(cd) * SECTOR_SIZE;

  /* for detached headers max size == device size */
  if (!max_size && (r = device_size(crypt_metadata_device(cd), &max_size)))
    return r;

  luks1_size = LUKS_device_sectors(hdr1) << SECTOR_SHIFT;
  luks1_size = size_round_up(luks1_size, LUKS_ALIGN_KEYSLOTS);
  if (!luks1_size)
    return -EINVAL;

  if (LUKS_keyslots_offset(hdr1) != (LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE)) {
    log_dbg(cd, "Unsupported keyslots material offset: %zu.", LUKS_keyslots_offset(hdr1));
    return -EINVAL;
  }

  if (LUKS2_check_cipher(cd, hdr1->keyBytes, hdr1->cipherName, hdr1->cipherMode)) {
    log_err(cd, _("Unable to use cipher specification %s-%s for LUKS2."),
      hdr1->cipherName, hdr1->cipherMode);
    return -EINVAL;
  }

  if (luksmeta_header_present(cd, luks1_size))
    return -EINVAL;

  log_dbg(cd, "Max size: %" PRIu64 ", LUKS1 (full) header size %zu , required shift: %zu",
    max_size, luks1_size, luks1_shift);

  required_size = luks1_size + luks1_shift;

  if ((max_size < required_size) &&
      device_fallocate(crypt_metadata_device(cd), required_size)) {
    log_err(cd, _("Unable to move keyslot area. Not enough space."));
    return -EINVAL;
  }

  if (max_size < required_size)
    max_size = required_size;

  /* fix coverity false positive integer underflow */
  if (max_size < 2 * LUKS2_HDR_16K_LEN)
    return -EINVAL;

  r = json_luks1_object(hdr1, &jobj, max_size - 2 * LUKS2_HDR_16K_LEN);
  if (r < 0)
    return r;

  move_keyslot_offset(jobj, luks1_shift);

  /* Create and fill LUKS2 hdr */
  memset(hdr2, 0, sizeof(*hdr2));
  hdr2->hdr_size = LUKS2_HDR_16K_LEN;
  hdr2->seqid = 1;
  hdr2->version = 2;
  strncpy(hdr2->checksum_alg, "sha256", LUKS2_CHECKSUM_ALG_L);
  crypt_random_get(cd, (char*)hdr2->salt1, sizeof(hdr2->salt1), CRYPT_RND_SALT);
  crypt_random_get(cd, (char*)hdr2->salt2, sizeof(hdr2->salt2), CRYPT_RND_SALT);
  strncpy(hdr2->uuid, crypt_get_uuid(cd), LUKS2_UUID_L-1); /* UUID should be max 36 chars */
  hdr2->jobj = jobj;

  /*
   * It duplicates check in LUKS2_hdr_write() but we don't want to move
   * keyslot areas in case it would fail later
   */
  if (max_size < LUKS2_hdr_and_areas_size(hdr2)) {
    r = -EINVAL;
    goto out;
  }

  /* check future LUKS2 metadata before moving keyslots area */
  if (LUKS2_hdr_validate(cd, hdr2->jobj, hdr2->hdr_size - LUKS2_HDR_BIN_LEN)) {
    log_err(cd, _("Cannot convert to LUKS2 format - invalid metadata."));
    r = -EINVAL;
    goto out;
  }

  if ((r = luks_header_in_use(cd))) {
    if (r > 0)
      r = -EBUSY;
    goto out;
  }

  /* move keyslots 4k -> 32k offset */
  buf_offset = 2 * LUKS2_HDR_16K_LEN;
  buf_size   = luks1_size - LUKS_ALIGN_KEYSLOTS;

  /* check future LUKS2 keyslots area is at least as large as LUKS1 keyslots area */
  if (buf_size > LUKS2_keyslots_size(hdr2)) {
    log_err(cd, _("Unable to move keyslot area. LUKS2 keyslots area too small."));
    r = -EINVAL;
    goto out;
  }

  if ((r = move_keyslot_areas(cd, 8 * SECTOR_SIZE, buf_offset, buf_size)) < 0) {
    log_err(cd, _("Unable to move keyslot area."));
    goto out;
  }

  /* Write new LUKS2 JSON */
  r = LUKS2_hdr_write(cd, hdr2);
out:
  LUKS2_hdr_free(cd, hdr2);

  return r;
}

static int keyslot_LUKS1_compatible(struct crypt_device *cd, struct luks2_hdr *hdr,
            int keyslot, uint32_t key_size, const char *hash)
{
  json_object *jobj_keyslot, *jobj, *jobj_kdf, *jobj_af;
  uint64_t l2_offset, l2_length;
  size_t ks_key_size;
  const char *ks_cipher, *data_cipher;

  jobj_keyslot = LUKS2_get_keyslot_jobj(hdr, keyslot);
  if (!jobj_keyslot)
    return 1;

  if (!json_object_object_get_ex(jobj_keyslot, "type", &jobj) ||
      strcmp(json_object_get_string(jobj), "luks2"))
    return 0;

  /* Using PBKDF2, this implies memory and parallel is not used. */
  jobj = NULL;
  if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf) ||
      !json_object_object_get_ex(jobj_kdf, "type", &jobj) ||
      strcmp(json_object_get_string(jobj), CRYPT_KDF_PBKDF2) ||
      !json_object_object_get_ex(jobj_kdf, "hash", &jobj) ||
      strcmp(json_object_get_string(jobj), hash))
    return 0;

  jobj = NULL;
  if (!json_object_object_get_ex(jobj_keyslot, "af", &jobj_af) ||
      !json_object_object_get_ex(jobj_af, "stripes", &jobj) ||
      json_object_get_int(jobj) != LUKS_STRIPES)
    return 0;

  jobj = NULL;
  if (!json_object_object_get_ex(jobj_af, "hash", &jobj) ||
      (crypt_hash_size(json_object_get_string(jobj)) < 0) ||
      strcmp(json_object_get_string(jobj), hash))
    return 0;

  ks_cipher = LUKS2_get_keyslot_cipher(hdr, keyslot, &ks_key_size);
  data_cipher = LUKS2_get_cipher(hdr, CRYPT_DEFAULT_SEGMENT);
  if (!ks_cipher || !data_cipher || key_size != ks_key_size || strcmp(ks_cipher, data_cipher)) {
    log_dbg(cd, "Cipher in keyslot %d is different from volume key encryption.", keyslot);
    return 0;
  }

  if (LUKS2_keyslot_area(hdr, keyslot, &l2_offset, &l2_length))
    return 0;

  if (l2_length != (size_round_up(AF_split_sectors(key_size, LUKS_STRIPES) * SECTOR_SIZE, 4096))) {
    log_dbg(cd, "Area length in LUKS2 keyslot (%d) is not compatible with LUKS1", keyslot);
    return 0;
  }

  return 1;
}

/* Convert LUKS2 -> LUKS1 */
int LUKS2_luks2_to_luks1(struct crypt_device *cd, struct luks2_hdr *hdr2, struct luks_phdr *hdr1)
{
  size_t buf_size, buf_offset;
  char cipher[LUKS_CIPHERNAME_L], cipher_mode[LUKS_CIPHERMODE_L];
  char *digest, *digest_salt;
  const char *hash;
  size_t len;
  json_object *jobj_keyslot, *jobj_digest, *jobj_segment, *jobj_kdf, *jobj_area, *jobj1, *jobj2;
  uint32_t key_size;
  int i, r, last_active = 0;
  uint64_t offset, area_length;
  char *buf, luksMagic[] = LUKS_MAGIC;

  jobj_digest  = LUKS2_get_digest_jobj(hdr2, 0);
  if (!jobj_digest)
    return -EINVAL;

  jobj_segment = LUKS2_get_segment_jobj(hdr2, CRYPT_DEFAULT_SEGMENT);
  if (!jobj_segment)
    return -EINVAL;

  if (json_segment_get_sector_size(jobj_segment) != SECTOR_SIZE) {
    log_err(cd, _("Cannot convert to LUKS1 format - default segment encryption sector size is not 512 bytes."));
    return -EINVAL;
  }

  json_object_object_get_ex(hdr2->jobj, "digests", &jobj1);
  if (!json_object_object_get_ex(jobj_digest, "type", &jobj2) ||
      strcmp(json_object_get_string(jobj2), "pbkdf2") ||
      json_object_object_length(jobj1) != 1) {
    log_err(cd, _("Cannot convert to LUKS1 format - key slot digests are not LUKS1 compatible."));
    return -EINVAL;
  }
  if (!json_object_object_get_ex(jobj_digest, "hash", &jobj2))
    return -EINVAL;
  hash = json_object_get_string(jobj2);

  r = crypt_parse_name_and_mode(LUKS2_get_cipher(hdr2, CRYPT_DEFAULT_SEGMENT), cipher, NULL, cipher_mode);
  if (r < 0)
    return r;

  if (crypt_cipher_wrapped_key(cipher, cipher_mode)) {
    log_err(cd, _("Cannot convert to LUKS1 format - device uses wrapped key cipher %s."), cipher);
    return -EINVAL;
  }

  if (json_segments_count(LUKS2_get_segments_jobj(hdr2)) != 1) {
    log_err(cd, _("Cannot convert to LUKS1 format - device uses more segments."));
    return -EINVAL;
  }

  r = LUKS2_tokens_count(hdr2);
  if (r < 0)
    return r;
  if (r > 0) {
    log_err(cd, _("Cannot convert to LUKS1 format - LUKS2 header contains %u token(s)."), r);
    return -EINVAL;
  }

  r = LUKS2_get_volume_key_size(hdr2, 0);
  if (r < 0)
    return -EINVAL;
  key_size = r;

  for (i = 0; i < LUKS2_KEYSLOTS_MAX; i++) {
    if (LUKS2_keyslot_info(hdr2, i) == CRYPT_SLOT_INACTIVE)
      continue;

    if (LUKS2_keyslot_info(hdr2, i) == CRYPT_SLOT_INVALID) {
      log_err(cd, _("Cannot convert to LUKS1 format - keyslot %u is in invalid state."), i);
      return -EINVAL;
    }

    if (i >= LUKS_NUMKEYS) {
      log_err(cd, _("Cannot convert to LUKS1 format - slot %u (over maximum slots) is still active."), i);
      return -EINVAL;
    }

    if (!keyslot_LUKS1_compatible(cd, hdr2, i, key_size, hash)) {
      log_err(cd, _("Cannot convert to LUKS1 format - keyslot %u is not LUKS1 compatible."), i);
      return -EINVAL;
    }
  }

  memset(hdr1, 0, sizeof(*hdr1));

  for (i = 0; i < LUKS_NUMKEYS; i++) {
    hdr1->keyblock[i].active = LUKS_KEY_DISABLED;
    hdr1->keyblock[i].stripes = LUKS_STRIPES;

    jobj_keyslot = LUKS2_get_keyslot_jobj(hdr2, i);

    if (jobj_keyslot) {
      if (!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
        return -EINVAL;
      if (!json_object_object_get_ex(jobj_area, "offset", &jobj1))
        return -EINVAL;
      offset = crypt_jobj_get_uint64(jobj1);
    } else {
      if (LUKS2_find_area_gap(cd, hdr2, key_size, &offset, &area_length))
        return -EINVAL;
      /*
       * We have to create placeholder luks2 keyslots in place of all
       * inactive keyslots. Otherwise we would allocate all
       * inactive luks1 keyslots over same binary keyslot area.
       */
      if (placeholder_keyslot_alloc(cd, i, offset, area_length))
        return -EINVAL;
    }

    offset /= SECTOR_SIZE;
    if (offset > UINT32_MAX)
      return -EINVAL;

    hdr1->keyblock[i].keyMaterialOffset = offset;
    hdr1->keyblock[i].keyMaterialOffset -=
        ((2 * LUKS2_HDR_16K_LEN - LUKS_ALIGN_KEYSLOTS) / SECTOR_SIZE);

    if (!jobj_keyslot)
      continue;

    hdr1->keyblock[i].active = LUKS_KEY_ENABLED;
    last_active = i;

    if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf))
      continue;

    if (!json_object_object_get_ex(jobj_kdf, "iterations", &jobj1))
      continue;
    hdr1->keyblock[i].passwordIterations = crypt_jobj_get_uint32(jobj1);

    if (!json_object_object_get_ex(jobj_kdf, "salt", &jobj1))
      continue;

    if (crypt_base64_decode(&buf, &len, json_object_get_string(jobj1),
          json_object_get_string_len(jobj1)))
      continue;
    if (len > 0 && len != LUKS_SALTSIZE) {
      free(buf);
      continue;
    }
    memcpy(hdr1->keyblock[i].passwordSalt, buf, LUKS_SALTSIZE);
    free(buf);
  }

  if (!jobj_keyslot) {
    jobj_keyslot = LUKS2_get_keyslot_jobj(hdr2, last_active);
    if (!jobj_keyslot)
      return -EINVAL;
  }

  if (!json_object_object_get_ex(jobj_keyslot, "area", &jobj_area))
    return -EINVAL;
  if (!json_object_object_get_ex(jobj_area, "encryption", &jobj1))
    return -EINVAL;
  r = crypt_parse_name_and_mode(json_object_get_string(jobj1), cipher, NULL, cipher_mode);
  if (r < 0)
    return r;

  strncpy(hdr1->cipherName, cipher, LUKS_CIPHERNAME_L - 1);
  hdr1->cipherName[LUKS_CIPHERNAME_L-1] = '\0';
  strncpy(hdr1->cipherMode, cipher_mode, LUKS_CIPHERMODE_L - 1);
  hdr1->cipherMode[LUKS_CIPHERMODE_L-1] = '\0';

  if (!json_object_object_get_ex(jobj_keyslot, "kdf", &jobj_kdf))
    return -EINVAL;
  if (!json_object_object_get_ex(jobj_kdf, "hash", &jobj1))
    return -EINVAL;
  strncpy(hdr1->hashSpec, json_object_get_string(jobj1), sizeof(hdr1->hashSpec) - 1);

  hdr1->keyBytes = key_size;

  if (!json_object_object_get_ex(jobj_digest, "iterations", &jobj1))
    return -EINVAL;
  hdr1->mkDigestIterations = crypt_jobj_get_uint32(jobj1);

  if (!json_object_object_get_ex(jobj_digest, "digest", &jobj1))
    return -EINVAL;
  r = crypt_base64_decode(&digest, &len, json_object_get_string(jobj1),
        json_object_get_string_len(jobj1));
  if (r < 0)
    return r;
  /* We can store full digest here, not only sha1 length */
  if (len < LUKS_DIGESTSIZE) {
    free(digest);
    return -EINVAL;
  }
  memcpy(hdr1->mkDigest, digest, LUKS_DIGESTSIZE);
  free(digest);

  if (!json_object_object_get_ex(jobj_digest, "salt", &jobj1))
    return -EINVAL;
  r = crypt_base64_decode(&digest_salt, &len, json_object_get_string(jobj1),
        json_object_get_string_len(jobj1));
  if (r < 0)
    return r;
  if (len != LUKS_SALTSIZE) {
    free(digest_salt);
    return -EINVAL;
  }
  memcpy(hdr1->mkDigestSalt, digest_salt, LUKS_SALTSIZE);
  free(digest_salt);

  if (!json_object_object_get_ex(jobj_segment, "offset", &jobj1))
    return -EINVAL;
  offset = crypt_jobj_get_uint64(jobj1) / SECTOR_SIZE;
  if (offset > UINT32_MAX)
    return -EINVAL;
  hdr1->payloadOffset = offset;

  strncpy(hdr1->uuid, hdr2->uuid, UUID_STRING_L); /* max 36 chars */
  hdr1->uuid[UUID_STRING_L-1] = '\0';

  memcpy(hdr1->magic, luksMagic, LUKS_MAGIC_L);

  hdr1->version = 1;

  r = luks_header_in_use(cd);
  if (r)
    return r > 0 ? -EBUSY : r;

  /* move keyslots 32k -> 4k offset */
  buf_offset = 2 * LUKS2_HDR_16K_LEN;
  buf_size   = LUKS2_keyslots_size(hdr2);
  r = move_keyslot_areas(cd, buf_offset, 8 * SECTOR_SIZE, buf_size);
  if (r < 0) {
    log_err(cd, _("Unable to move keyslot area."));
    return r;
  }

  crypt_wipe_device(cd, crypt_metadata_device(cd), CRYPT_WIPE_ZERO, 0,
        8 * SECTOR_SIZE, 8 * SECTOR_SIZE, NULL, NULL);

  /* Write new LUKS1 hdr */
  return LUKS_write_phdr(hdr1, cd);
}

Coverage Report

Created: 2024-05-21 06:33