1 /*
2 * Copyright (C) 2018 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include "build_verity_tree_utils.h"
18
19 #include <limits>
20
21 #include <android-base/logging.h>
22
verity_tree_blocks(uint64_t data_size,size_t block_size,size_t hash_size,size_t level)23 size_t verity_tree_blocks(uint64_t data_size, size_t block_size,
24 size_t hash_size, size_t level) {
25 uint64_t level_blocks = div_round_up(data_size, block_size);
26 uint64_t hashes_per_block = div_round_up(block_size, hash_size);
27
28 do {
29 level_blocks = div_round_up(level_blocks, hashes_per_block);
30 } while (level--);
31
32 CHECK_LE(level_blocks, std::numeric_limits<size_t>::max());
33 return level_blocks;
34 }