diff options
Diffstat (limited to '')
| -rw-r--r-- | lib/luks2/luks2_disk_metadata.c | 769 |
1 files changed, 769 insertions, 0 deletions
diff --git a/lib/luks2/luks2_disk_metadata.c b/lib/luks2/luks2_disk_metadata.c new file mode 100644 index 0000000..c6a121a --- /dev/null +++ b/lib/luks2/luks2_disk_metadata.c @@ -0,0 +1,769 @@ +/* + * LUKS - Linux Unified Key Setup v2 + * + * Copyright (C) 2015-2019 Red Hat, Inc. All rights reserved. + * Copyright (C) 2015-2019 Milan Broz + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version 2 + * of the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <assert.h> + +#include "luks2_internal.h" + +/* + * Helper functions + */ +json_object *parse_json_len(struct crypt_device *cd, const char *json_area, + uint64_t max_length, int *json_len) +{ + json_object *jobj; + struct json_tokener *jtok; + + /* INT32_MAX is internal (json-c) json_tokener_parse_ex() limit */ + if (!json_area || max_length > INT32_MAX) + return NULL; + + jtok = json_tokener_new(); + if (!jtok) { + log_dbg(cd, "ERROR: Failed to init json tokener"); + return NULL; + } + + jobj = json_tokener_parse_ex(jtok, json_area, max_length); + if (!jobj) + log_dbg(cd, "ERROR: Failed to parse json data (%d): %s", + json_tokener_get_error(jtok), + json_tokener_error_desc(json_tokener_get_error(jtok))); + else + *json_len = jtok->char_offset; + + json_tokener_free(jtok); + + return jobj; +} + +static void log_dbg_checksum(struct crypt_device *cd, + const uint8_t *csum, const char *csum_alg, const char *info) +{ + char csum_txt[2*LUKS2_CHECKSUM_L+1]; + int i; + + for (i = 0; i < crypt_hash_size(csum_alg); i++) + snprintf(&csum_txt[i*2], 3, "%02hhx", (const char)csum[i]); + csum_txt[i*2+1] = '\0'; /* Just to be safe, sprintf should write \0 there. */ + + log_dbg(cd, "Checksum:%s (%s)", &csum_txt[0], info); +} + +/* + * Calculate hash (checksum) of |LUKS2_bin|LUKS2_JSON_area| from in-memory structs. + * LUKS2 on-disk header contains uniques salt both for primary and secondary header. + * Checksum is always calculated with zeroed checksum field in binary header. + */ +static int hdr_checksum_calculate(const char *alg, struct luks2_hdr_disk *hdr_disk, + const char *json_area, size_t json_len) +{ + struct crypt_hash *hd = NULL; + int hash_size, r; + + hash_size = crypt_hash_size(alg); + if (hash_size <= 0 || crypt_hash_init(&hd, alg)) + return -EINVAL; + + /* Binary header, csum zeroed. */ + r = crypt_hash_write(hd, (char*)hdr_disk, LUKS2_HDR_BIN_LEN); + + /* JSON area (including unused space) */ + if (!r) + r = crypt_hash_write(hd, json_area, json_len); + + if (!r) + r = crypt_hash_final(hd, (char*)hdr_disk->csum, (size_t)hash_size); + + crypt_hash_destroy(hd); + return r; +} + +/* + * Compare hash (checksum) of on-disk and in-memory header. + */ +static int hdr_checksum_check(struct crypt_device *cd, + const char *alg, struct luks2_hdr_disk *hdr_disk, + const char *json_area, size_t json_len) +{ + struct luks2_hdr_disk hdr_tmp; + int hash_size, r; + + hash_size = crypt_hash_size(alg); + if (hash_size <= 0) + return -EINVAL; + + /* Copy header and zero checksum. */ + memcpy(&hdr_tmp, hdr_disk, LUKS2_HDR_BIN_LEN); + memset(&hdr_tmp.csum, 0, sizeof(hdr_tmp.csum)); + + r = hdr_checksum_calculate(alg, &hdr_tmp, json_area, json_len); + if (r < 0) + return r; + + log_dbg_checksum(cd, hdr_disk->csum, alg, "on-disk"); + log_dbg_checksum(cd, hdr_tmp.csum, alg, "in-memory"); + + if (memcmp(hdr_tmp.csum, hdr_disk->csum, (size_t)hash_size)) + return -EINVAL; + + return 0; +} + +/* + * Convert header from on-disk format to in-memory struct + */ +static void hdr_from_disk(struct luks2_hdr_disk *hdr_disk1, + struct luks2_hdr_disk *hdr_disk2, + struct luks2_hdr *hdr, + int secondary) +{ + hdr->version = be16_to_cpu(hdr_disk1->version); + hdr->hdr_size = be64_to_cpu(hdr_disk1->hdr_size); + hdr->seqid = be64_to_cpu(hdr_disk1->seqid); + + memcpy(hdr->label, hdr_disk1->label, LUKS2_LABEL_L); + hdr->label[LUKS2_LABEL_L - 1] = '\0'; + memcpy(hdr->subsystem, hdr_disk1->subsystem, LUKS2_LABEL_L); + hdr->subsystem[LUKS2_LABEL_L - 1] = '\0'; + memcpy(hdr->checksum_alg, hdr_disk1->checksum_alg, LUKS2_CHECKSUM_ALG_L); + hdr->checksum_alg[LUKS2_CHECKSUM_ALG_L - 1] = '\0'; + memcpy(hdr->uuid, hdr_disk1->uuid, LUKS2_UUID_L); + hdr->uuid[LUKS2_UUID_L - 1] = '\0'; + + if (secondary) { + memcpy(hdr->salt1, hdr_disk2->salt, LUKS2_SALT_L); + memcpy(hdr->salt2, hdr_disk1->salt, LUKS2_SALT_L); + } else { + memcpy(hdr->salt1, hdr_disk1->salt, LUKS2_SALT_L); + memcpy(hdr->salt2, hdr_disk2->salt, LUKS2_SALT_L); + } +} + +/* + * Convert header from in-memory struct to on-disk format + */ +static void hdr_to_disk(struct luks2_hdr *hdr, + struct luks2_hdr_disk *hdr_disk, + int secondary, uint64_t offset) +{ + assert(((char*)&(hdr_disk->_padding4096) - (char*)&(hdr_disk->magic)) == 512); + + memset(hdr_disk, 0, LUKS2_HDR_BIN_LEN); + + memcpy(&hdr_disk->magic, secondary ? LUKS2_MAGIC_2ND : LUKS2_MAGIC_1ST, LUKS2_MAGIC_L); + hdr_disk->version = cpu_to_be16(hdr->version); + hdr_disk->hdr_size = cpu_to_be64(hdr->hdr_size); + hdr_disk->hdr_offset = cpu_to_be64(offset); + hdr_disk->seqid = cpu_to_be64(hdr->seqid); + + strncpy(hdr_disk->label, hdr->label, LUKS2_LABEL_L); + hdr_disk->label[LUKS2_LABEL_L - 1] = '\0'; + strncpy(hdr_disk->subsystem, hdr->subsystem, LUKS2_LABEL_L); + hdr_disk->subsystem[LUKS2_LABEL_L - 1] = '\0'; + strncpy(hdr_disk->checksum_alg, hdr->checksum_alg, LUKS2_CHECKSUM_ALG_L); + hdr_disk->checksum_alg[LUKS2_CHECKSUM_ALG_L - 1] = '\0'; + strncpy(hdr_disk->uuid, hdr->uuid, LUKS2_UUID_L); + hdr_disk->uuid[LUKS2_UUID_L - 1] = '\0'; + + memcpy(hdr_disk->salt, secondary ? hdr->salt2 : hdr->salt1, LUKS2_SALT_L); +} + +/* + * Sanity checks before checksum is validated + */ +static int hdr_disk_sanity_check_pre(struct crypt_device *cd, + struct luks2_hdr_disk *hdr, + size_t *hdr_json_size, int secondary, + uint64_t offset) +{ + if (memcmp(hdr->magic, secondary ? LUKS2_MAGIC_2ND : LUKS2_MAGIC_1ST, LUKS2_MAGIC_L)) + return -EINVAL; + + if (be16_to_cpu(hdr->version) != 2) { + log_dbg(cd, "Unsupported LUKS2 header version %u.", be16_to_cpu(hdr->version)); + return -EINVAL; + } + + if (offset != be64_to_cpu(hdr->hdr_offset)) { + log_dbg(cd, "LUKS2 offset 0x%04x on device differs to expected offset 0x%04x.", + (unsigned)be64_to_cpu(hdr->hdr_offset), (unsigned)offset); + return -EINVAL; + } + + if (secondary && (offset != be64_to_cpu(hdr->hdr_size))) { + log_dbg(cd, "LUKS2 offset 0x%04x in secondary header doesn't match size 0x%04x.", + (unsigned)offset, (unsigned)be64_to_cpu(hdr->hdr_size)); + return -EINVAL; + } + + /* FIXME: sanity check checksum alg. */ + + log_dbg(cd, "LUKS2 header version %u of size %u bytes, checksum %s.", + (unsigned)be16_to_cpu(hdr->version), (unsigned)be64_to_cpu(hdr->hdr_size), + hdr->checksum_alg); + + *hdr_json_size = be64_to_cpu(hdr->hdr_size) - LUKS2_HDR_BIN_LEN; + return 0; +} + +/* + * Read LUKS2 header from disk at specific offset. + */ +static int hdr_read_disk(struct crypt_device *cd, + struct device *device, struct luks2_hdr_disk *hdr_disk, + char **json_area, uint64_t offset, int secondary) +{ + size_t hdr_json_size = 0; + int devfd = -1, r; + + log_dbg(cd, "Trying to read %s LUKS2 header at offset 0x%" PRIx64 ".", + secondary ? "secondary" : "primary", offset); + + devfd = device_open_locked(cd, device, O_RDONLY); + if (devfd < 0) + return devfd == -1 ? -EIO : devfd; + + /* + * Read binary header and run sanity check before reading + * JSON area and validating checksum. + */ + if (read_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), hdr_disk, + LUKS2_HDR_BIN_LEN, offset) != LUKS2_HDR_BIN_LEN) { + close(devfd); + return -EIO; + } + + r = hdr_disk_sanity_check_pre(cd, hdr_disk, &hdr_json_size, secondary, offset); + if (r < 0) { + close(devfd); + return r; + } + + /* + * Allocate and read JSON area. Always the whole area must be read. + */ + *json_area = malloc(hdr_json_size); + if (!*json_area) { + close(devfd); + return -ENOMEM; + } + + if (read_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), *json_area, hdr_json_size, + offset + LUKS2_HDR_BIN_LEN) != (ssize_t)hdr_json_size) { + close(devfd); + free(*json_area); + *json_area = NULL; + return -EIO; + } + + close(devfd); + + /* + * Calculate and validate checksum and zero it afterwards. + */ + if (hdr_checksum_check(cd, hdr_disk->checksum_alg, hdr_disk, + *json_area, hdr_json_size)) { + log_dbg(cd, "LUKS2 header checksum error (offset %" PRIu64 ").", offset); + r = -EINVAL; + } + memset(hdr_disk->csum, 0, LUKS2_CHECKSUM_L); + + return r; +} + +/* + * Write LUKS2 header to disk at specific offset. + */ +static int hdr_write_disk(struct crypt_device *cd, + struct device *device, struct luks2_hdr *hdr, + const char *json_area, int secondary) +{ + struct luks2_hdr_disk hdr_disk; + uint64_t offset = secondary ? hdr->hdr_size : 0; + size_t hdr_json_len; + int devfd = -1, r; + + log_dbg(cd, "Trying to write LUKS2 header (%zu bytes) at offset %" PRIu64 ".", + hdr->hdr_size, offset); + + /* FIXME: read-only device silent fail? */ + + devfd = device_open_locked(cd, device, O_RDWR); + if (devfd < 0) + return devfd == -1 ? -EINVAL : devfd; + + hdr_json_len = hdr->hdr_size - LUKS2_HDR_BIN_LEN; + + hdr_to_disk(hdr, &hdr_disk, secondary, offset); + + /* + * Write header without checksum but with proper seqid. + */ + if (write_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), (char *)&hdr_disk, + LUKS2_HDR_BIN_LEN, offset) < (ssize_t)LUKS2_HDR_BIN_LEN) { + close(devfd); + return -EIO; + } + + /* + * Write json area. + */ + if (write_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), + CONST_CAST(char*)json_area, hdr_json_len, + LUKS2_HDR_BIN_LEN + offset) < (ssize_t)hdr_json_len) { + close(devfd); + return -EIO; + } + + /* + * Calculate checksum and write header with checksum. + */ + r = hdr_checksum_calculate(hdr_disk.checksum_alg, &hdr_disk, + json_area, hdr_json_len); + if (r < 0) { + close(devfd); + return r; + } + log_dbg_checksum(cd, hdr_disk.csum, hdr_disk.checksum_alg, "in-memory"); + + if (write_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), (char *)&hdr_disk, + LUKS2_HDR_BIN_LEN, offset) < (ssize_t)LUKS2_HDR_BIN_LEN) + r = -EIO; + + device_sync(cd, device, devfd); + close(devfd); + return r; +} + +/* + * Convert in-memory LUKS2 header and write it to disk. + * This will increase sequence id, write both header copies and calculate checksum. + */ +int LUKS2_disk_hdr_write(struct crypt_device *cd, struct luks2_hdr *hdr, struct device *device) +{ + char *json_area; + const char *json_text; + size_t json_area_len; + int r; + + if (hdr->version != 2) { + log_dbg(cd, "Unsupported LUKS2 header version (%u).", hdr->version); + return -EINVAL; + } + + r = device_check_size(cd, crypt_metadata_device(cd), LUKS2_hdr_and_areas_size(hdr->jobj), 1); + if (r) + return r; + + /* + * Allocate and zero JSON area (of proper header size). + */ + json_area_len = hdr->hdr_size - LUKS2_HDR_BIN_LEN; + json_area = malloc(json_area_len); + if (!json_area) + return -ENOMEM; + memset(json_area, 0, json_area_len); + + /* + * Generate text space-efficient JSON representation to json area. + */ + json_text = json_object_to_json_string_ext(hdr->jobj, + JSON_C_TO_STRING_PLAIN | JSON_C_TO_STRING_NOSLASHESCAPE); + if (!json_text || !*json_text) { + log_dbg(cd, "Cannot parse JSON object to text representation."); + free(json_area); + return -ENOMEM; + } + if (strlen(json_text) > (json_area_len - 1)) { + log_dbg(cd, "JSON is too large (%zu > %zu).", strlen(json_text), json_area_len); + free(json_area); + return -EINVAL; + } + strncpy(json_area, json_text, json_area_len); + + /* Increase sequence id before writing it to disk. */ + hdr->seqid++; + + r = device_write_lock(cd, device); + if (r) { + log_err(cd, _("Failed to acquire write device lock.")); + free(json_area); + return r; + } + + /* Write primary and secondary header */ + r = hdr_write_disk(cd, device, hdr, json_area, 0); + if (!r) + r = hdr_write_disk(cd, device, hdr, json_area, 1); + + if (r) + log_dbg(cd, "LUKS2 header write failed (%d).", r); + + device_write_unlock(cd, device); + + /* FIXME: try recovery here? */ + + free(json_area); + return r; +} +static int validate_json_area(struct crypt_device *cd, const char *json_area, + uint64_t json_len, uint64_t max_length) +{ + char c; + + /* Enforce there are no needless opening bytes */ + if (*json_area != '{') { + log_dbg(cd, "ERROR: Opening character must be left curly bracket: '{'."); + return -EINVAL; + } + + if (json_len >= max_length) { + log_dbg(cd, "ERROR: Missing trailing null byte beyond parsed json data string."); + return -EINVAL; + } + + /* + * TODO: + * validate there are legal json format characters between + * 'json_area' and 'json_area + json_len' + */ + + do { + c = *(json_area + json_len); + if (c != '\0') { + log_dbg(cd, "ERROR: Forbidden ascii code 0x%02hhx found beyond json data string at offset %" PRIu64, + c, json_len); + return -EINVAL; + } + } while (++json_len < max_length); + + return 0; +} + +static int validate_luks2_json_object(struct crypt_device *cd, json_object *jobj_hdr, uint64_t length) +{ + int r; + + /* we require top level object to be of json_type_object */ + r = !json_object_is_type(jobj_hdr, json_type_object); + if (r) { + log_dbg(cd, "ERROR: Resulting object is not a json object type"); + return r; + } + + r = LUKS2_hdr_validate(cd, jobj_hdr, length); + if (r) { + log_dbg(cd, "Repairing JSON metadata."); + /* try to correct known glitches */ + LUKS2_hdr_repair(cd, jobj_hdr); + + /* run validation again */ + r = LUKS2_hdr_validate(cd, jobj_hdr, length); + } + + if (r) + log_dbg(cd, "ERROR: LUKS2 validation failed"); + + return r; +} + +static json_object *parse_and_validate_json(struct crypt_device *cd, + const char *json_area, uint64_t max_length) +{ + int json_len, r; + json_object *jobj = parse_json_len(cd, json_area, max_length, &json_len); + + if (!jobj) + return NULL; + + /* successful parse_json_len must not return offset <= 0 */ + assert(json_len > 0); + + r = validate_json_area(cd, json_area, json_len, max_length); + if (!r) + r = validate_luks2_json_object(cd, jobj, max_length); + + if (r) { + json_object_put(jobj); + jobj = NULL; + } + + return jobj; +} + +static int detect_device_signatures(struct crypt_device *cd, const char *path) +{ + blk_probe_status prb_state; + int r; + struct blkid_handle *h; + + if (!blk_supported()) { + log_dbg(cd, "Blkid probing of device signatures disabled."); + return 0; + } + + if ((r = blk_init_by_path(&h, path))) { + log_dbg(cd, "Failed to initialize blkid_handle by path."); + return -EINVAL; + } + + /* We don't care about details. Be fast. */ + blk_set_chains_for_fast_detection(h); + + /* Filter out crypto_LUKS. we don't care now */ + blk_superblocks_filter_luks(h); + + prb_state = blk_safeprobe(h); + + switch (prb_state) { + case PRB_AMBIGUOUS: + log_dbg(cd, "Blkid probe couldn't decide device type unambiguously."); + /* fall through */ + case PRB_FAIL: + log_dbg(cd, "Blkid probe failed."); + r = -EINVAL; + break; + case PRB_OK: /* crypto_LUKS type is filtered out */ + r = -EINVAL; + + if (blk_is_partition(h)) + log_dbg(cd, "Blkid probe detected partition type '%s'", blk_get_partition_type(h)); + else if (blk_is_superblock(h)) + log_dbg(cd, "blkid probe detected superblock type '%s'", blk_get_superblock_type(h)); + break; + case PRB_EMPTY: + log_dbg(cd, "Blkid probe detected no foreign device signature."); + } + blk_free(h); + return r; +} + +/* + * Read and convert on-disk LUKS2 header to in-memory representation.. + * Try to do recovery if on-disk state is not consistent. + */ +int LUKS2_disk_hdr_read(struct crypt_device *cd, struct luks2_hdr *hdr, + struct device *device, int do_recovery, int do_blkprobe) +{ + enum { HDR_OK, HDR_OBSOLETE, HDR_FAIL, HDR_FAIL_IO } state_hdr1, state_hdr2; + struct luks2_hdr_disk hdr_disk1, hdr_disk2; + char *json_area1 = NULL, *json_area2 = NULL; + json_object *jobj_hdr1 = NULL, *jobj_hdr2 = NULL; + unsigned int i; + int r; + uint64_t hdr_size; + uint64_t hdr2_offsets[] = LUKS2_HDR2_OFFSETS; + + /* Skip auto-recovery if locks are disabled and we're not doing LUKS2 explicit repair */ + if (do_recovery && do_blkprobe && !crypt_metadata_locking_enabled()) { + do_recovery = 0; + log_dbg(cd, "Disabling header auto-recovery due to locking being disabled."); + } + + /* + * Read primary LUKS2 header (offset 0). + */ + state_hdr1 = HDR_FAIL; + r = hdr_read_disk(cd, device, &hdr_disk1, &json_area1, 0, 0); + if (r == 0) { + jobj_hdr1 = parse_and_validate_json(cd, json_area1, be64_to_cpu(hdr_disk1.hdr_size) - LUKS2_HDR_BIN_LEN); + state_hdr1 = jobj_hdr1 ? HDR_OK : HDR_OBSOLETE; + } else if (r == -EIO) + state_hdr1 = HDR_FAIL_IO; + + /* + * Read secondary LUKS2 header (follows primary). + */ + state_hdr2 = HDR_FAIL; + if (state_hdr1 != HDR_FAIL && state_hdr1 != HDR_FAIL_IO) { + r = hdr_read_disk(cd, device, &hdr_disk2, &json_area2, be64_to_cpu(hdr_disk1.hdr_size), 1); + if (r == 0) { + jobj_hdr2 = parse_and_validate_json(cd, json_area2, be64_to_cpu(hdr_disk2.hdr_size) - LUKS2_HDR_BIN_LEN); + state_hdr2 = jobj_hdr2 ? HDR_OK : HDR_OBSOLETE; + } else if (r == -EIO) + state_hdr2 = HDR_FAIL_IO; + } else { + /* + * No header size, check all known offsets. + */ + for (r = -EINVAL,i = 0; r < 0 && i < ARRAY_SIZE(hdr2_offsets); i++) + r = hdr_read_disk(cd, device, &hdr_disk2, &json_area2, hdr2_offsets[i], 1); + + if (r == 0) { + jobj_hdr2 = parse_and_validate_json(cd, json_area2, be64_to_cpu(hdr_disk2.hdr_size) - LUKS2_HDR_BIN_LEN); + state_hdr2 = jobj_hdr2 ? HDR_OK : HDR_OBSOLETE; + } else if (r == -EIO) + state_hdr2 = HDR_FAIL_IO; + } + + /* + * Check sequence id if both headers are read correctly. + */ + if (state_hdr1 == HDR_OK && state_hdr2 == HDR_OK) { + if (be64_to_cpu(hdr_disk1.seqid) > be64_to_cpu(hdr_disk2.seqid)) + state_hdr2 = HDR_OBSOLETE; + else if (be64_to_cpu(hdr_disk1.seqid) < be64_to_cpu(hdr_disk2.seqid)) + state_hdr1 = HDR_OBSOLETE; + } + + /* check header with keyslots to fit the device */ + if (state_hdr1 == HDR_OK) + hdr_size = LUKS2_hdr_and_areas_size(jobj_hdr1); + else if (state_hdr2 == HDR_OK) + hdr_size = LUKS2_hdr_and_areas_size(jobj_hdr2); + else { + r = (state_hdr1 == HDR_FAIL_IO && state_hdr2 == HDR_FAIL_IO) ? -EIO : -EINVAL; + goto err; + } + + r = device_check_size(cd, device, hdr_size, 0); + if (r) + goto err; + + /* + * Try to rewrite (recover) bad header. Always regenerate salt for bad header. + */ + if (state_hdr1 == HDR_OK && state_hdr2 != HDR_OK) { + log_dbg(cd, "Secondary LUKS2 header requires recovery."); + + if (do_blkprobe && (r = detect_device_signatures(cd, device_path(device)))) { + log_err(cd, _("Device contains ambiguous signatures, cannot auto-recover LUKS2.\n" + "Please run \"cryptsetup repair\" for recovery.")); + goto err; + } + + if (do_recovery) { + memcpy(&hdr_disk2, &hdr_disk1, LUKS2_HDR_BIN_LEN); + r = crypt_random_get(cd, (char*)hdr_disk2.salt, sizeof(hdr_disk2.salt), CRYPT_RND_SALT); + if (r) + log_dbg(cd, "Cannot generate master salt."); + else { + hdr_from_disk(&hdr_disk1, &hdr_disk2, hdr, 0); + r = hdr_write_disk(cd, device, hdr, json_area1, 1); + } + if (r) + log_dbg(cd, "Secondary LUKS2 header recovery failed."); + } + } else if (state_hdr1 != HDR_OK && state_hdr2 == HDR_OK) { + log_dbg(cd, "Primary LUKS2 header requires recovery."); + + if (do_blkprobe && (r = detect_device_signatures(cd, device_path(device)))) { + log_err(cd, _("Device contains ambiguous signatures, cannot auto-recover LUKS2.\n" + "Please run \"cryptsetup repair\" for recovery.")); + goto err; + } + + if (do_recovery) { + memcpy(&hdr_disk1, &hdr_disk2, LUKS2_HDR_BIN_LEN); + r = crypt_random_get(cd, (char*)hdr_disk1.salt, sizeof(hdr_disk1.salt), CRYPT_RND_SALT); + if (r) + log_dbg(cd, "Cannot generate master salt."); + else { + hdr_from_disk(&hdr_disk2, &hdr_disk1, hdr, 1); + r = hdr_write_disk(cd, device, hdr, json_area2, 0); + } + if (r) + log_dbg(cd, "Primary LUKS2 header recovery failed."); + } + } + + free(json_area1); + json_area1 = NULL; + free(json_area2); + json_area2 = NULL; + + /* wrong lock for write mode during recovery attempt */ + if (r == -EAGAIN) + goto err; + + /* + * Even if status is failed, the second header includes salt. + */ + if (state_hdr1 == HDR_OK) { + hdr_from_disk(&hdr_disk1, &hdr_disk2, hdr, 0); + hdr->jobj = jobj_hdr1; + json_object_put(jobj_hdr2); + } else if (state_hdr2 == HDR_OK) { + hdr_from_disk(&hdr_disk2, &hdr_disk1, hdr, 1); + hdr->jobj = jobj_hdr2; + json_object_put(jobj_hdr1); + } + + /* + * FIXME: should this fail? At least one header was read correctly. + * r = (state_hdr1 == HDR_FAIL_IO || state_hdr2 == HDR_FAIL_IO) ? -EIO : -EINVAL; + */ + return 0; +err: + log_dbg(cd, "LUKS2 header read failed (%d).", r); + + free(json_area1); + free(json_area2); + json_object_put(jobj_hdr1); + json_object_put(jobj_hdr2); + hdr->jobj = NULL; + return r; +} + +int LUKS2_hdr_version_unlocked(struct crypt_device *cd, const char *backup_file) +{ + struct { + char magic[LUKS2_MAGIC_L]; + uint16_t version; + } __attribute__ ((packed)) hdr; + struct device *device = NULL; + int r = 0, devfd = -1, flags; + + if (!backup_file) + device = crypt_metadata_device(cd); + else if (device_alloc(cd, &device, backup_file) < 0) + return 0; + + if (!device) + return 0; + + flags = O_RDONLY; + if (device_direct_io(device)) + flags |= O_DIRECT; + + devfd = open(device_path(device), flags); + if (devfd < 0) + goto err; + + if ((read_lseek_blockwise(devfd, device_block_size(cd, device), + device_alignment(device), &hdr, sizeof(hdr), 0) == sizeof(hdr)) && + !memcmp(hdr.magic, LUKS2_MAGIC_1ST, LUKS2_MAGIC_L)) + r = (int)be16_to_cpu(hdr.version); +err: + if (devfd != -1) + close(devfd); + + if (backup_file) + device_free(cd, device); + + return r; +} |