1/*
2 * Copyright (C) 2016 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 <errno.h>
18#include <stdio.h>
19#include <stdlib.h>
20
21#include <memory>
22#include <string>
23
24#include <android-base/file.h>
25#include <android-base/test_utils.h>
26#include <android-base/unique_fd.h>
27#include <crypto_utils/android_pubkey.h>
28#include <fec/io.h>
29#include <openssl/obj_mac.h>
30#include <openssl/rsa.h>
31#include <openssl/sha.h>
32#include <sparse/sparse.h>
33
34static RSA* load_key(const char* path) {
35  std::string content;
36  if (!android::base::ReadFileToString(path, &content) ||
37      content.size() < ANDROID_PUBKEY_ENCODED_SIZE) {
38    fprintf(stderr, "Failed to load key from %s\n", path);
39    return nullptr;
40  }
41
42  RSA* key = nullptr;
43  if (!android_pubkey_decode(reinterpret_cast<const uint8_t*>(content.c_str()),
44                             ANDROID_PUBKEY_ENCODED_SIZE, &key)) {
45    fprintf(stderr, "Failed to parse key!\n");
46    return nullptr;
47  }
48
49  return key;
50}
51
52static int verify_table(const char* key_path, const uint8_t* signature, size_t signature_size,
53                        const char* table, uint32_t table_length) {
54  // Hash the table
55  uint8_t hash_buf[SHA256_DIGEST_LENGTH];
56  SHA256(const_cast<uint8_t*>(reinterpret_cast<const uint8_t*>(table)), table_length, hash_buf);
57
58  // Now get the public key from the keyfile
59  std::unique_ptr<RSA, decltype(&RSA_free)> key(load_key(key_path), RSA_free);
60  if (!key) {
61    fprintf(stderr, "Couldn't load verity keys\n");
62    return -1;
63  }
64
65  // Verify the result
66  if (!RSA_verify(NID_sha256, hash_buf, sizeof(hash_buf), signature, signature_size, key.get())) {
67    fprintf(stderr, "Couldn't verify table\n");
68    return -1;
69  }
70
71  return 0;
72}
73
74int main(int argc, char* argv[]) {
75  if (argc != 4 || strcmp(argv[2], "-mincrypt") != 0) {
76    printf("Usage: %s <image> -mincrypt <verity_key>\n"
77           "  image       the image file (raw or sparse image) to be verified\n"
78           "  verity_key  the verity key in mincrypt format (/verity_key on device)\n", argv[0]);
79    return 2;
80  }
81
82  // Get the raw image.
83  android::base::unique_fd fd(open(argv[1], O_RDONLY));
84  if (!fd) {
85    fprintf(stderr, "failed to open %s: %s\n", argv[1], strerror(errno));
86    return 1;
87  }
88
89  struct sparse_file* file = sparse_file_import_auto(fd, false, false);
90  if (file == nullptr) {
91    fprintf(stderr, "failed to read file %s\n", argv[1]);
92    return 1;
93  }
94
95  TemporaryFile tf;
96  if (sparse_file_write(file, tf.fd, false, false, false) < 0) {
97    fprintf(stderr, "failed to write output file\n");
98    return 1;
99  }
100  sparse_file_destroy(file);
101
102  // Verify.
103  fec::io input(tf.path);
104  if (!input) {
105    return 1;
106  }
107
108  fec_verity_metadata verity;
109  if (!input.get_verity_metadata(verity)) {
110    fprintf(stderr, "failed to get verity metadata\n");
111    return 1;
112  }
113
114  int ret = verify_table(argv[3], verity.signature, sizeof(verity.signature),
115                         verity.table, verity.table_length);
116  printf("%s\n", ret == 0 ? "VERIFIED" : "FAILED");
117  return ret;
118}
119