1 files changed, 432 insertions, 0 deletions
diff --git a/lib/luks2/luks2_segment.c b/lib/luks2/luks2_segment.c
new file mode 100644
index 0000000..46a524d
--- /dev/null
+++ b/lib/luks2/luks2_segment.c
@@ -0,0 +1,432 @@
+/*
+ * LUKS - Linux Unified Key Setup v2, internal segment handling
+ *
+ * Copyright (C) 2018-2021, Red Hat, Inc. All rights reserved.
+ * Copyright (C) 2018-2021, Ondrej Kozina
+ *
+ * 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"
+
+/* use only on already validated 'segments' object */
+uint64_t json_segments_get_minimal_offset(json_object *jobj_segments, unsigned blockwise)
+{
+	uint64_t tmp, min = blockwise ? UINT64_MAX >> SECTOR_SHIFT : UINT64_MAX;
+
+	if (!jobj_segments)
+		return 0;
+
+	json_object_object_foreach(jobj_segments, key, val) {
+		UNUSED(key);
+
+		if (json_segment_is_backup(val))
+			continue;
+
+		tmp = json_segment_get_offset(val, blockwise);
+
+		if (!tmp)
+			return tmp;
+
+		if (tmp < min)
+			min = tmp;
+	}
+
+	return min;
+}
+
+uint64_t json_segment_get_offset(json_object *jobj_segment, unsigned blockwise)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "offset", &jobj))
+		return 0;
+
+	return blockwise ? crypt_jobj_get_uint64(jobj) >> SECTOR_SHIFT : crypt_jobj_get_uint64(jobj);
+}
+
+const char *json_segment_type(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "type", &jobj))
+		return NULL;
+
+	return json_object_get_string(jobj);
+}
+
+uint64_t json_segment_get_iv_offset(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "iv_tweak", &jobj))
+		return 0;
+
+	return crypt_jobj_get_uint64(jobj);
+}
+
+uint64_t json_segment_get_size(json_object *jobj_segment, unsigned blockwise)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "size", &jobj))
+		return 0;
+
+	return blockwise ? crypt_jobj_get_uint64(jobj) >> SECTOR_SHIFT : crypt_jobj_get_uint64(jobj);
+}
+
+const char *json_segment_get_cipher(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	/* FIXME: Pseudo "null" cipher should be handled elsewhere */
+	if (!jobj_segment ||
+	    !json_object_object_get_ex(jobj_segment, "encryption", &jobj))
+		return "null";
+
+	return json_object_get_string(jobj);
+}
+
+int json_segment_get_sector_size(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	if (!jobj_segment ||
+            !json_object_object_get_ex(jobj_segment, "sector_size", &jobj))
+		return -1;
+
+	return json_object_get_int(jobj);
+}
+
+static json_object *json_segment_get_flags(json_object *jobj_segment)
+{
+	json_object *jobj;
+
+	if (!jobj_segment || !(json_object_object_get_ex(jobj_segment, "flags", &jobj)))
+		return NULL;
+	return jobj;
+}
+
+bool json_segment_contains_flag(json_object *jobj_segment, const char *flag_str, size_t len)
+{
+	int r, i;
+	json_object *jobj, *jobj_flags = json_segment_get_flags(jobj_segment);
+
+	if (!jobj_flags)
+		return false;
+
+	for (i = 0; i < (int)json_object_array_length(jobj_flags); i++) {
+		jobj = json_object_array_get_idx(jobj_flags, i);
+		if (len)
+			r = strncmp(json_object_get_string(jobj), flag_str, len);
+		else
+			r = strcmp(json_object_get_string(jobj), flag_str);
+		if (!r)
+			return true;
+	}
+
+	return false;
+}
+
+bool json_segment_is_backup(json_object *jobj_segment)
+{
+	return json_segment_contains_flag(jobj_segment, "backup-", 7);
+}
+
+json_object *json_segments_get_segment(json_object *jobj_segments, int segment)
+{
+	json_object *jobj;
+	char segment_name[16];
+
+	if (snprintf(segment_name, sizeof(segment_name), "%u", segment) < 1)
+		return NULL;
+
+	if (!json_object_object_get_ex(jobj_segments, segment_name, &jobj))
+		return NULL;
+
+	return jobj;
+}
+
+unsigned json_segments_count(json_object *jobj_segments)
+{
+	unsigned count = 0;
+
+	if (!jobj_segments)
+		return 0;
+
+	json_object_object_foreach(jobj_segments, slot, val) {
+		UNUSED(slot);
+		if (!json_segment_is_backup(val))
+			count++;
+	}
+
+	return count;
+}
+
+static void _get_segment_or_id_by_flag(json_object *jobj_segments, const char *flag, unsigned id, void *retval)
+{
+	json_object *jobj_flags, **jobj_ret = (json_object **)retval;
+	int *ret = (int *)retval;
+
+	if (!flag)
+		return;
+
+	json_object_object_foreach(jobj_segments, key, value) {
+		if (!json_object_object_get_ex(value, "flags", &jobj_flags))
+			continue;
+		if (LUKS2_array_jobj(jobj_flags, flag)) {
+			if (id)
+				*ret = atoi(key);
+			else
+				*jobj_ret = value;
+			return;
+		}
+	}
+}
+
+void json_segment_remove_flag(json_object *jobj_segment, const char *flag)
+{
+	json_object *jobj_flags, *jobj_flags_new;
+
+	if (!jobj_segment)
+		return;
+
+	jobj_flags = json_segment_get_flags(jobj_segment);
+	if (!jobj_flags)
+		return;
+
+	jobj_flags_new = LUKS2_array_remove(jobj_flags, flag);
+	if (!jobj_flags_new)
+		return;
+
+	if (json_object_array_length(jobj_flags_new) <= 0) {
+		json_object_put(jobj_flags_new);
+		json_object_object_del(jobj_segment, "flags");
+	} else
+		json_object_object_add(jobj_segment, "flags", jobj_flags_new);
+}
+
+static json_object *_segment_create_generic(const char *type, uint64_t offset, const uint64_t *length)
+{
+	json_object *jobj = json_object_new_object();
+	if (!jobj)
+		return NULL;
+
+	json_object_object_add(jobj, "type",		json_object_new_string(type));
+	json_object_object_add(jobj, "offset",		crypt_jobj_new_uint64(offset));
+	json_object_object_add(jobj, "size",		length ? crypt_jobj_new_uint64(*length) : json_object_new_string("dynamic"));
+
+	return jobj;
+}
+
+json_object *json_segment_create_linear(uint64_t offset, const uint64_t *length, unsigned reencryption)
+{
+	json_object *jobj = _segment_create_generic("linear", offset, length);
+	if (reencryption)
+		LUKS2_segment_set_flag(jobj, "in-reencryption");
+	return jobj;
+}
+
+json_object *json_segment_create_crypt(uint64_t offset,
+				  uint64_t iv_offset, const uint64_t *length,
+				  const char *cipher, uint32_t sector_size,
+				  unsigned reencryption)
+{
+	json_object *jobj = _segment_create_generic("crypt", offset, length);
+	if (!jobj)
+		return NULL;
+
+	json_object_object_add(jobj, "iv_tweak",	crypt_jobj_new_uint64(iv_offset));
+	json_object_object_add(jobj, "encryption",	json_object_new_string(cipher));
+	json_object_object_add(jobj, "sector_size",	json_object_new_int(sector_size));
+	if (reencryption)
+		LUKS2_segment_set_flag(jobj, "in-reencryption");
+
+	return jobj;
+}
+
+uint64_t LUKS2_segment_offset(struct luks2_hdr *hdr, int segment, unsigned blockwise)
+{
+	return json_segment_get_offset(LUKS2_get_segment_jobj(hdr, segment), blockwise);
+}
+
+int json_segments_segment_in_reencrypt(json_object *jobj_segments)
+{
+	json_object *jobj_flags;
+
+	json_object_object_foreach(jobj_segments, slot, val) {
+		if (!json_object_object_get_ex(val, "flags", &jobj_flags) ||
+		    !LUKS2_array_jobj(jobj_flags, "in-reencryption"))
+			continue;
+
+		return atoi(slot);
+	}
+
+	return -1;
+}
+
+uint64_t LUKS2_segment_size(struct luks2_hdr *hdr, int segment, unsigned blockwise)
+{
+	return json_segment_get_size(LUKS2_get_segment_jobj(hdr, segment), blockwise);
+}
+
+int LUKS2_segment_is_type(struct luks2_hdr *hdr, int segment, const char *type)
+{
+	return !strcmp(json_segment_type(LUKS2_get_segment_jobj(hdr, segment)) ?: "", type);
+}
+
+int LUKS2_last_segment_by_type(struct luks2_hdr *hdr, const char *type)
+{
+	json_object *jobj_segments;
+	int last_found = -1;
+
+	if (!type)
+		return -1;
+
+	if (!json_object_object_get_ex(hdr->jobj, "segments", &jobj_segments))
+		return -1;
+
+	json_object_object_foreach(jobj_segments, slot, val) {
+		if (json_segment_is_backup(val))
+			continue;
+		if (strcmp(type, json_segment_type(val) ?: ""))
+			continue;
+
+		if (atoi(slot) > last_found)
+			last_found = atoi(slot);
+	}
+
+	return last_found;
+}
+
+int LUKS2_segment_by_type(struct luks2_hdr *hdr, const char *type)
+{
+	json_object *jobj_segments;
+	int first_found = -1;
+
+	if (!type)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(hdr->jobj, "segments", &jobj_segments))
+		return -EINVAL;
+
+	json_object_object_foreach(jobj_segments, slot, val) {
+		if (json_segment_is_backup(val))
+			continue;
+		if (strcmp(type, json_segment_type(val) ?: ""))
+			continue;
+
+		if (first_found < 0)
+			first_found = atoi(slot);
+		else if (atoi(slot) < first_found)
+			first_found = atoi(slot);
+	}
+
+	return first_found;
+}
+
+int LUKS2_segment_first_unused_id(struct luks2_hdr *hdr)
+{
+	json_object *jobj_segments;
+	int id, last_id = -1;
+
+	if (!json_object_object_get_ex(hdr->jobj, "segments", &jobj_segments))
+		return -EINVAL;
+
+	json_object_object_foreach(jobj_segments, slot, val) {
+		UNUSED(val);
+		id = atoi(slot);
+		if (id > last_id)
+			last_id = id;
+	}
+
+	return last_id + 1;
+}
+
+int LUKS2_segment_set_flag(json_object *jobj_segment, const char *flag)
+{
+	json_object *jobj_flags;
+
+	if (!jobj_segment || !flag)
+		return -EINVAL;
+
+	if (!json_object_object_get_ex(jobj_segment, "flags", &jobj_flags)) {
+		jobj_flags = json_object_new_array();
+		if (!jobj_flags)
+			return -ENOMEM;
+		json_object_object_add(jobj_segment, "flags", jobj_flags);
+	}
+
+	if (LUKS2_array_jobj(jobj_flags, flag))
+		return 0;
+
+	json_object_array_add(jobj_flags, json_object_new_string(flag));
+
+	return 0;
+}
+
+int LUKS2_segments_set(struct crypt_device *cd, struct luks2_hdr *hdr,
+		       json_object *jobj_segments, int commit)
+{
+	json_object_object_add(hdr->jobj, "segments", jobj_segments);
+
+	return commit ? LUKS2_hdr_write(cd, hdr) : 0;
+}
+
+int LUKS2_get_segment_id_by_flag(struct luks2_hdr *hdr, const char *flag)
+{
+	int ret = -ENOENT;
+	json_object *jobj_segments = LUKS2_get_segments_jobj(hdr);
+
+	if (jobj_segments)
+		_get_segment_or_id_by_flag(jobj_segments, flag, 1, &ret);
+
+	return ret;
+}
+
+json_object *LUKS2_get_segment_by_flag(struct luks2_hdr *hdr, const char *flag)
+{
+	json_object *jobj_segment = NULL,
+		    *jobj_segments = LUKS2_get_segments_jobj(hdr);
+
+	if (jobj_segments)
+		_get_segment_or_id_by_flag(jobj_segments, flag, 0, &jobj_segment);
+
+	return jobj_segment;
+}
+
+/* compares key characteristics of both segments */
+bool json_segment_cmp(json_object *jobj_segment_1, json_object *jobj_segment_2)
+{
+	const char *type = json_segment_type(jobj_segment_1);
+	const char *type2 = json_segment_type(jobj_segment_2);
+
+	if (!type || !type2)
+		return false;
+
+	if (strcmp(type, type2))
+		return false;
+
+	if (!strcmp(type, "crypt"))
+		return (json_segment_get_sector_size(jobj_segment_1) == json_segment_get_sector_size(jobj_segment_2) &&
+			!strcmp(json_segment_get_cipher(jobj_segment_1),
+			        json_segment_get_cipher(jobj_segment_2)));
+
+	return true;
+}