1 files changed, 327 insertions, 0 deletions
diff --git a/lib/integrity/integrity.c b/lib/integrity/integrity.c
new file mode 100644
index 0000000..c4c3f56
--- /dev/null
+++ b/lib/integrity/integrity.c
@@ -0,0 +1,327 @@
+/*
+ * Integrity volume handling
+ *
+ * Copyright (C) 2016-2019 Milan Broz
+ *
+ * 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 <fcntl.h>
+#include <uuid/uuid.h>
+
+#include "integrity.h"
+#include "internal.h"
+
+static int INTEGRITY_read_superblock(struct crypt_device *cd,
+				     struct device *device,
+				     uint64_t offset, struct superblock *sb)
+{
+	int devfd, r;
+
+	devfd = device_open(cd, device, O_RDONLY);
+	if(devfd < 0) {
+		return -EINVAL;
+	}
+
+	if (read_lseek_blockwise(devfd, device_block_size(cd, device),
+		device_alignment(device), sb, sizeof(*sb), offset) != sizeof(*sb) ||
+	    memcmp(sb->magic, SB_MAGIC, sizeof(sb->magic)) ||
+	    (sb->version != SB_VERSION_1 && sb->version != SB_VERSION_2)) {
+		log_std(cd, "No integrity superblock detected on %s.\n",
+			device_path(device));
+		r = -EINVAL;
+	} else {
+		sb->integrity_tag_size = le16toh(sb->integrity_tag_size);
+		sb->journal_sections = le32toh(sb->journal_sections);
+		sb->provided_data_sectors = le64toh(sb->provided_data_sectors);
+		sb->recalc_sector = le64toh(sb->recalc_sector);
+		sb->flags = le32toh(sb->flags);
+		r = 0;
+	}
+
+	close(devfd);
+	return r;
+}
+
+int INTEGRITY_read_sb(struct crypt_device *cd, struct crypt_params_integrity *params)
+{
+	struct superblock sb;
+	int r;
+
+	r = INTEGRITY_read_superblock(cd, crypt_metadata_device(cd), 0, &sb);
+	if (r)
+		return r;
+
+	params->sector_size = SECTOR_SIZE << sb.log2_sectors_per_block;
+	params->tag_size = sb.integrity_tag_size;
+
+	return 0;
+}
+
+int INTEGRITY_dump(struct crypt_device *cd, struct device *device, uint64_t offset)
+{
+	struct superblock sb;
+	int r;
+
+	r = INTEGRITY_read_superblock(cd, device, offset, &sb);
+	if (r)
+		return r;
+
+	log_std(cd, "Info for integrity device %s.\n", device_path(device));
+	log_std(cd, "superblock_version %d\n", (unsigned)sb.version);
+	log_std(cd, "log2_interleave_sectors %d\n", sb.log2_interleave_sectors);
+	log_std(cd, "integrity_tag_size %u\n", sb.integrity_tag_size);
+	log_std(cd, "journal_sections %u\n", sb.journal_sections);
+	log_std(cd, "provided_data_sectors %" PRIu64 "\n", sb.provided_data_sectors);
+	log_std(cd, "sector_size %u\n", SECTOR_SIZE << sb.log2_sectors_per_block);
+	if (sb.version == SB_VERSION_2 && (sb.flags & SB_FLAG_RECALCULATING))
+		log_std(cd, "recalc_sector %" PRIu64 "\n", sb.recalc_sector);
+	log_std(cd, "flags %s%s\n",
+		sb.flags & SB_FLAG_HAVE_JOURNAL_MAC ? "have_journal_mac " : "",
+		sb.flags & SB_FLAG_RECALCULATING ? "recalculating " : "");
+
+	return 0;
+}
+
+int INTEGRITY_data_sectors(struct crypt_device *cd,
+			   struct device *device, uint64_t offset,
+			   uint64_t *data_sectors)
+{
+	struct superblock sb;
+	int r;
+
+	r = INTEGRITY_read_superblock(cd, device, offset, &sb);
+	if (r)
+		return r;
+
+	*data_sectors = sb.provided_data_sectors;
+	return 0;
+}
+
+int INTEGRITY_key_size(struct crypt_device *cd, const char *integrity)
+{
+	if (!integrity)
+		return 0;
+
+	//FIXME: use crypto backend hash size
+	if (!strcmp(integrity, "aead"))
+		return 0;
+	else if (!strcmp(integrity, "hmac(sha1)"))
+		return 20;
+	else if (!strcmp(integrity, "hmac(sha256)"))
+		return 32;
+	else if (!strcmp(integrity, "hmac(sha512)"))
+		return 64;
+	else if (!strcmp(integrity, "poly1305"))
+		return 0;
+	else if (!strcmp(integrity, "none"))
+		return 0;
+
+	return -EINVAL;
+}
+
+int INTEGRITY_tag_size(struct crypt_device *cd,
+		       const char *integrity,
+		       const char *cipher,
+		       const char *cipher_mode)
+{
+	int iv_tag_size = 0, auth_tag_size = 0;
+
+	if (!cipher_mode)
+		iv_tag_size = 0;
+	else if (!strcmp(cipher_mode, "xts-random"))
+		iv_tag_size = 16;
+	else if (!strcmp(cipher_mode, "gcm-random"))
+		iv_tag_size = 12;
+	else if (!strcmp(cipher_mode, "ccm-random"))
+		iv_tag_size = 8;
+	else if (!strcmp(cipher_mode, "ctr-random"))
+		iv_tag_size = 16;
+	else if (!strcmp(cipher, "aegis256") && !strcmp(cipher_mode, "random"))
+		iv_tag_size = 32;
+	else if (!strcmp(cipher_mode, "random"))
+		iv_tag_size = 16;
+
+	//FIXME: use crypto backend hash size
+	if (!integrity || !strcmp(integrity, "none"))
+		auth_tag_size = 0;
+	else if (!strcmp(integrity, "aead"))
+		auth_tag_size = 16; //FIXME gcm- mode only
+	else if (!strcmp(integrity, "cmac(aes)"))
+		auth_tag_size = 16;
+	else if (!strcmp(integrity, "hmac(sha1)"))
+		auth_tag_size = 20;
+	else if (!strcmp(integrity, "hmac(sha256)"))
+		auth_tag_size = 32;
+	else if (!strcmp(integrity, "hmac(sha512)"))
+		auth_tag_size = 64;
+	else if (!strcmp(integrity, "poly1305")) {
+		if (iv_tag_size)
+			iv_tag_size = 12;
+		auth_tag_size = 16;
+	}
+
+	return iv_tag_size + auth_tag_size;
+}
+
+int INTEGRITY_create_dmd_device(struct crypt_device *cd,
+		       const struct crypt_params_integrity *params,
+		       struct volume_key *vk,
+		       struct volume_key *journal_crypt_key,
+		       struct volume_key *journal_mac_key,
+		       struct crypt_dm_active_device *dmd,
+		       uint32_t flags)
+{
+	int r;
+
+	if (!dmd)
+		return -EINVAL;
+
+	*dmd = (struct crypt_dm_active_device) {
+		.flags = flags,
+	};
+
+	r = INTEGRITY_data_sectors(cd, crypt_metadata_device(cd),
+				   crypt_get_data_offset(cd) * SECTOR_SIZE, &dmd->size);
+	if (r < 0)
+		return r;
+
+	return dm_integrity_target_set(&dmd->segment, 0, dmd->size,
+			crypt_metadata_device(cd), crypt_data_device(cd),
+			crypt_get_integrity_tag_size(cd), crypt_get_data_offset(cd),
+			crypt_get_sector_size(cd), vk, journal_crypt_key,
+			journal_mac_key, params);
+}
+
+int INTEGRITY_activate_dmd_device(struct crypt_device *cd,
+		       const char *name,
+		       struct crypt_dm_active_device *dmd)
+{
+	int r;
+	uint32_t dmi_flags;
+	struct dm_target *tgt = &dmd->segment;
+
+	if (!single_segment(dmd) || tgt->type != DM_INTEGRITY)
+		return -EINVAL;
+
+	log_dbg(cd, "Trying to activate INTEGRITY device on top of %s, using name %s, tag size %d, provided sectors %" PRIu64".",
+		device_path(tgt->data_device), name, tgt->u.integrity.tag_size, dmd->size);
+
+	r = device_block_adjust(cd, tgt->data_device, DEV_EXCL,
+				tgt->u.integrity.offset, NULL, &dmd->flags);
+	if (r)
+		return r;
+
+	if (tgt->u.integrity.meta_device) {
+		r = device_block_adjust(cd, tgt->u.integrity.meta_device, DEV_EXCL, 0, NULL, NULL);
+		if (r)
+			return r;
+	}
+
+	r = dm_create_device(cd, name, "INTEGRITY", dmd);
+	if (r < 0 && (dm_flags(cd, DM_INTEGRITY, &dmi_flags) || !(dmi_flags & DM_INTEGRITY_SUPPORTED))) {
+		log_err(cd, _("Kernel doesn't support dm-integrity mapping."));
+		return -ENOTSUP;
+	}
+
+	return r;
+}
+
+int INTEGRITY_activate(struct crypt_device *cd,
+		       const char *name,
+		       const struct crypt_params_integrity *params,
+		       struct volume_key *vk,
+		       struct volume_key *journal_crypt_key,
+		       struct volume_key *journal_mac_key,
+		       uint32_t flags)
+{
+	struct crypt_dm_active_device dmd = {};
+	int r = INTEGRITY_create_dmd_device(cd, params, vk, journal_crypt_key, journal_mac_key, &dmd, flags);
+
+	if (r < 0)
+		return r;
+
+	r = INTEGRITY_activate_dmd_device(cd, name, &dmd);
+	dm_targets_free(cd, &dmd);
+	return r;
+}
+
+int INTEGRITY_format(struct crypt_device *cd,
+		     const struct crypt_params_integrity *params,
+		     struct volume_key *journal_crypt_key,
+		     struct volume_key *journal_mac_key)
+{
+	uint32_t dmi_flags;
+	char tmp_name[64], tmp_uuid[40];
+	struct crypt_dm_active_device dmdi = {
+		.size = 8,
+		.flags = CRYPT_ACTIVATE_PRIVATE, /* We always create journal but it can be unused later */
+	};
+	struct dm_target *tgt = &dmdi.segment;
+	int r;
+	uuid_t tmp_uuid_bin;
+	struct volume_key *vk = NULL;
+
+	uuid_generate(tmp_uuid_bin);
+	uuid_unparse(tmp_uuid_bin, tmp_uuid);
+
+	snprintf(tmp_name, sizeof(tmp_name), "temporary-cryptsetup-%s", tmp_uuid);
+
+	/* There is no data area, we can actually use fake zeroed key */
+	if (params && params->integrity_key_size)
+		vk = crypt_alloc_volume_key(params->integrity_key_size, NULL);
+
+	r = dm_integrity_target_set(tgt, 0, dmdi.size, crypt_metadata_device(cd),
+			crypt_data_device(cd), crypt_get_integrity_tag_size(cd),
+			crypt_get_data_offset(cd), crypt_get_sector_size(cd), vk,
+			journal_crypt_key, journal_mac_key, params);
+	if (r < 0) {
+		crypt_free_volume_key(vk);
+		return r;
+	}
+
+	log_dbg(cd, "Trying to format INTEGRITY device on top of %s, tmp name %s, tag size %d.",
+		device_path(tgt->data_device), tmp_name, tgt->u.integrity.tag_size);
+
+	r = device_block_adjust(cd, tgt->data_device, DEV_EXCL, tgt->u.integrity.offset, NULL, NULL);
+	if (r < 0 && (dm_flags(cd, DM_INTEGRITY, &dmi_flags) || !(dmi_flags & DM_INTEGRITY_SUPPORTED))) {
+		log_err(cd, _("Kernel doesn't support dm-integrity mapping."));
+		r = -ENOTSUP;
+	}
+	if (r) {
+		dm_targets_free(cd, &dmdi);
+		return r;
+	}
+
+	if (tgt->u.integrity.meta_device) {
+		r = device_block_adjust(cd, tgt->u.integrity.meta_device, DEV_EXCL, 0, NULL, NULL);
+		if (r) {
+			dm_targets_free(cd, &dmdi);
+			return r;
+		}
+	}
+
+	r = dm_create_device(cd, tmp_name, "INTEGRITY", &dmdi);
+	crypt_free_volume_key(vk);
+	dm_targets_free(cd, &dmdi);
+	if (r)
+		return r;
+
+	return dm_remove_device(cd, tmp_name, CRYPT_DEACTIVATE_FORCE);
+}