/*
* dm-verity volume handling
*
- * Copyright (C) 2012, Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2012-2021 Red Hat, Inc. All rights reserved.
*
- * This program is free software; you can redistribute it and/or
- * modify it under the terms of the GNU General Public License
- * version 2 as published by the Free Software Foundation.
+ * This file is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
*
- * This program is distributed in the hope that it will be useful,
+ * This file 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.
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser 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
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this file; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
+#include <ctype.h>
#include <sys/types.h>
#include <sys/stat.h>
-#include <fcntl.h>
#include <netinet/in.h>
#include <uuid/uuid.h>
#include "verity.h"
#include "internal.h"
-#define NEW_SB 1
+#define VERITY_SIGNATURE "verity\0\0"
-#ifndef NEW_SB
-struct verity_sb {
- uint8_t signature[8];
- uint8_t version;
- uint8_t data_block_bits;
- uint8_t hash_block_bits;
- uint8_t pad1[1];
- uint16_t salt_size;
- uint8_t pad2[2];
- uint32_t data_blocks_hi;
- uint32_t data_blocks_lo;
- uint8_t algorithm[16];
- uint8_t salt[384];
- uint8_t pad3[88];
-};
-
-#else
+/* https://gitlab.com/cryptsetup/cryptsetup/wikis/DMVerity#verity-superblock-format */
struct verity_sb {
uint8_t signature[8]; /* "verity\0\0" */
uint32_t version; /* superblock version */
uint32_t hash_type; /* 0 - Chrome OS, 1 - normal */
uint8_t uuid[16]; /* UUID of hash device */
uint8_t algorithm[32];/* hash algorithm name */
- uint64_t data_block_size; /* data block in bytes */
- uint64_t hash_block_size; /* hash block in bytes */
+ uint32_t data_block_size; /* data block in bytes */
+ uint32_t hash_block_size; /* hash block in bytes */
uint64_t data_blocks; /* number of data blocks */
- uint64_t salt_size; /* salt size */
+ uint16_t salt_size; /* salt size */
+ uint8_t _pad1[6];
uint8_t salt[256]; /* salt */
- uint8_t _pad[160];
+ uint8_t _pad2[168];
} __attribute__((packed));
-#endif
/* Read verity superblock from disk */
int VERITY_read_sb(struct crypt_device *cd,
- const char *device,
uint64_t sb_offset,
char **uuid_string,
struct crypt_params_verity *params)
{
+ struct device *device = crypt_metadata_device(cd);
struct verity_sb sb = {};
ssize_t hdr_size = sizeof(struct verity_sb);
- int devfd = 0, sb_version;
- uint64_t sb_data_blocks;
+ int devfd, sb_version;
- log_dbg("Reading VERITY header of size %u on device %s, offset %" PRIu64 ".",
- sizeof(struct verity_sb), device, sb_offset);
+ log_dbg(cd, "Reading VERITY header of size %zu on device %s, offset %" PRIu64 ".",
+ sizeof(struct verity_sb), device_path(device), sb_offset);
if (params->flags & CRYPT_VERITY_NO_HEADER) {
- log_err(cd, _("Verity device doesn't use on-disk header.\n"), device);
+ log_err(cd, _("Verity device %s does not use on-disk header."),
+ device_path(device));
return -EINVAL;
}
- devfd = open(device ,O_RDONLY | O_DIRECT);
- if(devfd == -1) {
- log_err(cd, _("Cannot open device %s.\n"), device);
+ if (MISALIGNED_512(sb_offset)) {
+ log_err(cd, _("Unsupported VERITY hash offset."));
return -EINVAL;
}
- if(lseek(devfd, sb_offset, SEEK_SET) < 0 ||
- read_blockwise(devfd, &sb, hdr_size) < hdr_size) {
- close(devfd);
- return -EIO;
- }
- close(devfd);
-
- if (memcmp(sb.signature, VERITY_SIGNATURE, sizeof(sb.signature))) {
- log_err(cd, _("Device %s is not a valid VERITY device.\n"), device);
- return -EINVAL;
- }
-#ifndef NEW_SB
- if (sb.version > 1) {
- log_err(cd, _("Unsupported VERITY version %d.\n"), sb.version);
+ devfd = device_open(cd, device, O_RDONLY);
+ if (devfd < 0) {
+ log_err(cd, _("Cannot open device %s."), device_path(device));
return -EINVAL;
}
- if (sb.data_block_bits < 9 || sb.data_block_bits >= 31 ||
- sb.hash_block_bits < 9 || sb.hash_block_bits >= 31 ||
- !memchr(sb.algorithm, 0, sizeof(sb.algorithm)) ||
- ntohs(sb.salt_size) > 256) {
- log_err(cd, _("VERITY header corrupted.\n"));
+ if (read_lseek_blockwise(devfd, device_block_size(cd, device),
+ device_alignment(device), &sb, hdr_size,
+ sb_offset) < hdr_size)
+ return -EIO;
+
+ if (memcmp(sb.signature, VERITY_SIGNATURE, sizeof(sb.signature))) {
+ log_err(cd, _("Device %s is not a valid VERITY device."),
+ device_path(device));
return -EINVAL;
}
- sb_data_blocks = ((uint64_t)ntohl(sb.data_blocks_hi) << 31 << 1) |
- ntohl(sb.data_blocks_lo);
-
- params->hash_name = strdup((const char*)sb.algorithm);
- if (!params->hash_name)
- return -ENOMEM;
- params->data_block_size = 1 << sb.data_block_bits;
- params->hash_block_size = 1 << sb.hash_block_bits;
- params->data_size = sb_data_blocks;
- params->salt_size = ntohs(sb.salt_size);
- params->salt = malloc(params->salt_size);
- if (!params->salt)
- return -ENOMEM;
- memcpy(CONST_CAST(char*)params->salt, sb.salt, params->salt_size);
- params->hash_type = sb.version;
-#else
sb_version = le32_to_cpu(sb.version);
if (sb_version != 1) {
- log_err(cd, _("Unsupported VERITY version %d.\n"), sb_version);
+ log_err(cd, _("Unsupported VERITY version %d."), sb_version);
return -EINVAL;
}
params->hash_type = le32_to_cpu(sb.hash_type);
- if (params->hash_type > 1) {
- log_err(cd, _("Unsupported VERITY hash type %d.\n"), params->hash_type);
+ if (params->hash_type > VERITY_MAX_HASH_TYPE) {
+ log_err(cd, _("Unsupported VERITY hash type %d."), params->hash_type);
return -EINVAL;
}
- params->data_block_size = le64_to_cpu(sb.data_block_size);
- params->hash_block_size = le64_to_cpu(sb.hash_block_size);
- if (params->data_block_size % 512 || params->hash_block_size % 512) {
- log_err(cd, _("Unsupported VERITY block size.\n"));
+ params->data_block_size = le32_to_cpu(sb.data_block_size);
+ params->hash_block_size = le32_to_cpu(sb.hash_block_size);
+ if (VERITY_BLOCK_SIZE_OK(params->data_block_size) ||
+ VERITY_BLOCK_SIZE_OK(params->hash_block_size)) {
+ log_err(cd, _("Unsupported VERITY block size."));
return -EINVAL;
}
params->data_size = le64_to_cpu(sb.data_blocks);
params->hash_name = strndup((const char*)sb.algorithm, sizeof(sb.algorithm));
if (!params->hash_name)
return -ENOMEM;
+ if (crypt_hash_size(params->hash_name) <= 0) {
+ log_err(cd, _("Hash algorithm %s not supported."),
+ params->hash_name);
+ free(CONST_CAST(char*)params->hash_name);
+ params->hash_name = NULL;
+ return -EINVAL;
+ }
- params->salt_size = le64_to_cpu(sb.salt_size);
+ params->salt_size = le16_to_cpu(sb.salt_size);
if (params->salt_size > sizeof(sb.salt)) {
- log_err(cd, _("VERITY header corrupted.\n"));
+ log_err(cd, _("VERITY header corrupted."));
free(CONST_CAST(char*)params->hash_name);
+ params->hash_name = NULL;
return -EINVAL;
}
params->salt = malloc(params->salt_size);
if (!params->salt) {
free(CONST_CAST(char*)params->hash_name);
+ params->hash_name = NULL;
return -ENOMEM;
}
memcpy(CONST_CAST(char*)params->salt, sb.salt, params->salt_size);
if ((*uuid_string = malloc(40)))
uuid_unparse(sb.uuid, *uuid_string);
-#endif
+
params->hash_area_offset = sb_offset;
return 0;
}
+static void _to_lower(char *str)
+{
+ for(; *str; str++)
+ if (isupper(*str))
+ *str = tolower(*str);
+}
+
/* Write verity superblock to disk */
int VERITY_write_sb(struct crypt_device *cd,
- const char *device,
uint64_t sb_offset,
const char *uuid_string,
struct crypt_params_verity *params)
{
+ struct device *device = crypt_metadata_device(cd);
struct verity_sb sb = {};
ssize_t hdr_size = sizeof(struct verity_sb);
+ size_t block_size;
+ char *algorithm;
uuid_t uuid;
- int r, devfd = 0;
+ int r, devfd;
- log_dbg("Updating VERITY header of size %u on device %s, offset %" PRIu64 ".",
- sizeof(struct verity_sb), device, sb_offset);
+ log_dbg(cd, "Updating VERITY header of size %zu on device %s, offset %" PRIu64 ".",
+ sizeof(struct verity_sb), device_path(device), sb_offset);
if (!uuid_string || uuid_parse(uuid_string, uuid) == -1) {
- log_err(cd, _("Wrong VERITY UUID format provided.\n"), device);
+ log_err(cd, _("Wrong VERITY UUID format provided on device %s."),
+ device_path(device));
return -EINVAL;
}
if (params->flags & CRYPT_VERITY_NO_HEADER) {
- log_err(cd, _("Verity device doesn't use on-disk header.\n"), device);
+ log_err(cd, _("Verity device %s does not use on-disk header."),
+ device_path(device));
return -EINVAL;
}
- devfd = open(device, O_RDWR | O_DIRECT);
- if(devfd == -1) {
- log_err(cd, _("Cannot open device %s.\n"), device);
+ /* Avoid possible increasing of image size - FEC could fail later because of it */
+ block_size = device_block_size(cd, device);
+ if (block_size > params->hash_block_size) {
+ device_disable_direct_io(device);
+ block_size = params->hash_block_size;
+ }
+
+ devfd = device_open(cd, device, O_RDWR);
+ if (devfd < 0) {
+ log_err(cd, _("Cannot open device %s."), device_path(device));
return -EINVAL;
}
memcpy(&sb.signature, VERITY_SIGNATURE, sizeof(sb.signature));
-#ifndef NEW_SB
- sb.version = params->hash_type;
- sb.data_block_bits = ffs(params->data_block_size) - 1;
- sb.hash_block_bits = ffs(params->hash_block_size) - 1;
- sb.salt_size = htons(params->salt_size);
- sb.data_blocks_hi = htonl(params->data_size >> 31 >> 1);
- sb.data_blocks_lo = htonl(params->data_size & 0xFFFFFFFF);
- strncpy((char *)sb.algorithm, params->hash_name, sizeof(sb.algorithm));
- memcpy(sb.salt, params->salt, params->salt_size);
-#else
sb.version = cpu_to_le32(1);
sb.hash_type = cpu_to_le32(params->hash_type);
- sb.data_block_size = cpu_to_le64(params->data_block_size);
- sb.hash_block_size = cpu_to_le64(params->hash_block_size);
- sb.salt_size = cpu_to_le64(params->salt_size);
+ sb.data_block_size = cpu_to_le32(params->data_block_size);
+ sb.hash_block_size = cpu_to_le32(params->hash_block_size);
+ sb.salt_size = cpu_to_le16(params->salt_size);
sb.data_blocks = cpu_to_le64(params->data_size);
- strncpy((char *)sb.algorithm, params->hash_name, sizeof(sb.algorithm));
+
+ /* Kernel always use lower-case */
+ algorithm = (char *)sb.algorithm;
+ strncpy(algorithm, params->hash_name, sizeof(sb.algorithm)-1);
+ algorithm[sizeof(sb.algorithm)-1] = '\0';
+ _to_lower(algorithm);
+
memcpy(sb.salt, params->salt, params->salt_size);
memcpy(sb.uuid, uuid, sizeof(sb.uuid));
-#endif
- r = write_lseek_blockwise(devfd, (char*)&sb, hdr_size, sb_offset) < hdr_size ? -EIO : 0;
+
+ r = write_lseek_blockwise(devfd, block_size, device_alignment(device),
+ (char*)&sb, hdr_size, sb_offset) < hdr_size ? -EIO : 0;
if (r)
- log_err(cd, _("Error during update of verity header on device %s.\n"), device);
- close(devfd);
+ log_err(cd, _("Error during update of verity header on device %s."),
+ device_path(device));
+
+ device_sync(cd, device);
return r;
}
{
uuid_t uuid;
- if (!(*uuid_string = malloc(40)))
+ *uuid_string = malloc(40);
+ if (!*uuid_string)
return -ENOMEM;
uuid_generate(uuid);
uuid_unparse(uuid, *uuid_string);
/* Activate verity device in kernel device-mapper */
int VERITY_activate(struct crypt_device *cd,
const char *name,
- const char *hash_device,
const char *root_hash,
size_t root_hash_size,
+ const char *signature_description,
+ struct device *fec_device,
struct crypt_params_verity *verity_hdr,
uint32_t activation_flags)
{
- struct crypt_dm_active_device dmd;
- uint64_t offset = 0;
- int r;
-
- log_dbg("Trying to activate VERITY device %s using hash %s.",
+ uint32_t dmv_flags;
+ unsigned int fec_errors = 0;
+ int r, v;
+ struct crypt_dm_active_device dmd = {
+ .size = verity_hdr->data_size * verity_hdr->data_block_size / 512,
+ .flags = activation_flags,
+ .uuid = crypt_get_uuid(cd),
+ };
+
+ log_dbg(cd, "Trying to activate VERITY device %s using hash %s.",
name ?: "[none]", verity_hdr->hash_name);
if (verity_hdr->flags & CRYPT_VERITY_CHECK_HASH) {
- r = VERITY_verify(cd, verity_hdr,
- crypt_get_device_name(cd), hash_device,
- root_hash, root_hash_size);
+ if (signature_description) {
+ log_err(cd, _("Root hash signature verification is not supported."));
+ return -EINVAL;
+ }
+
+ log_dbg(cd, "Verification of data in userspace required.");
+ r = VERITY_verify(cd, verity_hdr, root_hash, root_hash_size);
+
+ if ((r == -EPERM || r == -EFAULT) && fec_device) {
+ v = r;
+ log_dbg(cd, "Verification failed, trying to repair with FEC device.");
+ r = VERITY_FEC_process(cd, verity_hdr, fec_device, 1, &fec_errors);
+ if (r < 0)
+ log_err(cd, _("Errors cannot be repaired with FEC device."));
+ else if (fec_errors) {
+ log_err(cd, _("Found %u repairable errors with FEC device."),
+ fec_errors);
+ /* If root hash failed, we cannot be sure it was properly repaired */
+ }
+ if (v == -EFAULT)
+ r = -EPERM;
+ }
+
if (r < 0)
return r;
}
if (!name)
return 0;
- dmd.target = DM_VERITY;
- dmd.data_device = crypt_get_device_name(cd);
- dmd.u.verity.hash_device = hash_device;
- dmd.u.verity.root_hash = root_hash;
- dmd.u.verity.root_hash_size = root_hash_size;
- dmd.u.verity.hash_offset = VERITY_hash_offset_block(verity_hdr),
- dmd.flags = activation_flags;
- dmd.size = verity_hdr->data_size * verity_hdr->data_block_size / 512;
- dmd.uuid = crypt_get_uuid(cd);
- dmd.u.verity.vp = verity_hdr;
-
- r = device_check_and_adjust(cd, dmd.data_device, DEV_EXCL,
- &dmd.size, &offset, &dmd.flags);
+ r = device_block_adjust(cd, crypt_metadata_device(cd), DEV_OK,
+ 0, NULL, NULL);
+ if (r)
+ return r;
+
+ r = device_block_adjust(cd, crypt_data_device(cd), DEV_EXCL,
+ 0, &dmd.size, &dmd.flags);
+ if (r)
+ return r;
+
+ if (fec_device) {
+ r = device_block_adjust(cd, fec_device, DEV_OK,
+ 0, NULL, NULL);
+ if (r)
+ return r;
+ }
+
+ r = dm_verity_target_set(&dmd.segment, 0, dmd.size, crypt_data_device(cd),
+ crypt_metadata_device(cd), fec_device, root_hash,
+ root_hash_size, signature_description,
+ VERITY_hash_offset_block(verity_hdr),
+ VERITY_FEC_blocks(cd, fec_device, verity_hdr), verity_hdr);
+
if (r)
return r;
- r = dm_create_device(name, CRYPT_VERITY, &dmd, 0);
- if (!r && !(dm_flags() & DM_VERITY_SUPPORTED)) {
- log_err(cd, _("Kernel doesn't support dm-verity mapping.\n"));
- return -ENOTSUP;
+ r = dm_create_device(cd, name, CRYPT_VERITY, &dmd);
+ if (r < 0 && (dm_flags(cd, DM_VERITY, &dmv_flags) || !(dmv_flags & DM_VERITY_SUPPORTED))) {
+ log_err(cd, _("Kernel does not support dm-verity mapping."));
+ r = -ENOTSUP;
+ }
+ if (r < 0 && signature_description && !(dmv_flags & DM_VERITY_SIGNATURE_SUPPORTED)) {
+ log_err(cd, _("Kernel does not support dm-verity signature option."));
+ r = -ENOTSUP;
}
if (r < 0)
- return r;
+ goto out;
- r = dm_status_verity_ok(name);
+ r = dm_status_verity_ok(cd, name);
if (r < 0)
- return r;
+ goto out;
if (!r)
- log_err(cd, _("Verity device detected corruption after activation.\n"));
- return 0;
+ log_err(cd, _("Verity device detected corruption after activation."));
+
+ r = 0;
+out:
+ dm_targets_free(cd, &dmd);
+ return r;
}