Adding upstream version 2:2.3.7.upstream/2%2.3.7upstream

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

1 files changed, 354 insertions, 0 deletions

diff --git a/lib/verity/verity.c b/lib/verity/verity.c
new file mode 100644
index 0000000..278f34a
--- /dev/null
+++ b/lib/verity/verity.c
@@ -0,0 +1,354 @@
+/*
+ * dm-verity volume handling
+ *
+ * Copyright (C) 2012-2021 Red Hat, Inc. All rights reserved.
+ *
+ * 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 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
+ * Lesser General Public License for more details.
+ *
+ * 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 <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <ctype.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <netinet/in.h>
+#include <uuid/uuid.h>
+
+#include "libcryptsetup.h"
+#include "verity.h"
+#include "internal.h"
+
+#define VERITY_SIGNATURE "verity\0\0"
+
+/* 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 */
+	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 */
+	uint16_t salt_size;	/* salt size */
+	uint8_t  _pad1[6];
+	uint8_t  salt[256];	/* salt */
+	uint8_t  _pad2[168];
+} __attribute__((packed));
+
+/* Read verity superblock from disk */
+int VERITY_read_sb(struct crypt_device *cd,
+		   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, sb_version;
+
+	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 %s does not use on-disk header."),
+			device_path(device));
+		return -EINVAL;
+	}
+
+	if (MISALIGNED_512(sb_offset)) {
+		log_err(cd, _("Unsupported VERITY hash offset."));
+		return -EINVAL;
+	}
+
+	devfd = device_open(cd, device, O_RDONLY);
+	if (devfd < 0) {
+		log_err(cd, _("Cannot open device %s."), device_path(device));
+		return -EINVAL;
+	}
+
+	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_version = le32_to_cpu(sb.version);
+	if (sb_version != 1) {
+		log_err(cd, _("Unsupported VERITY version %d."), sb_version);
+		return -EINVAL;
+	}
+	params->hash_type = le32_to_cpu(sb.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 = 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 = le16_to_cpu(sb.salt_size);
+	if (params->salt_size > sizeof(sb.salt)) {
+		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);
+
+	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,
+		   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;
+
+	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 on device %s."),
+			device_path(device));
+		return -EINVAL;
+	}
+
+	if (params->flags & CRYPT_VERITY_NO_HEADER) {
+		log_err(cd, _("Verity device %s does not use on-disk header."),
+			device_path(device));
+		return -EINVAL;
+	}
+
+	/* 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));
+	sb.version         = cpu_to_le32(1);
+	sb.hash_type       = cpu_to_le32(params->hash_type);
+	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);
+
+	/* 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));
+
+	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."),
+			device_path(device));
+
+	device_sync(cd, device);
+
+	return r;
+}
+
+/* Calculate hash offset in hash blocks */
+uint64_t VERITY_hash_offset_block(struct crypt_params_verity *params)
+{
+	uint64_t hash_offset = params->hash_area_offset;
+
+	if (params->flags & CRYPT_VERITY_NO_HEADER)
+		return hash_offset / params->hash_block_size;
+
+	hash_offset += sizeof(struct verity_sb);
+	hash_offset += params->hash_block_size - 1;
+
+	return hash_offset / params->hash_block_size;
+}
+
+int VERITY_UUID_generate(struct crypt_device *cd, char **uuid_string)
+{
+	uuid_t uuid;
+
+	*uuid_string = malloc(40);
+	if (!*uuid_string)
+		return -ENOMEM;
+	uuid_generate(uuid);
+	uuid_unparse(uuid, *uuid_string);
+	return 0;
+}
+
+/* Activate verity device in kernel device-mapper */
+int VERITY_activate(struct crypt_device *cd,
+		     const char *name,
+		     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)
+{
+	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) {
+		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;
+
+	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(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)
+		goto out;
+
+	r = dm_status_verity_ok(cd, name);
+	if (r < 0)
+		goto out;
+
+	if (!r)
+		log_err(cd, _("Verity device detected corruption after activation."));
+
+	r = 0;
+out:
+	dm_targets_free(cd, &dmd);
+	return r;
+}