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/*
* Copyright (C) 2016 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <memory>
#include <string>
#include <android-base/file.h>
#include <android-base/unique_fd.h>
#include <crypto_utils/android_pubkey.h>
#include <fec/io.h>
#include <openssl/obj_mac.h>
#include <openssl/rsa.h>
#include <openssl/sha.h>
#include <sparse/sparse.h>
static RSA* load_key(const char* path) {
std::string content;
if (!android::base::ReadFileToString(path, &content) ||
content.size() < ANDROID_PUBKEY_ENCODED_SIZE) {
fprintf(stderr, "Failed to load key from %s\n", path);
return nullptr;
}
RSA* key = nullptr;
if (!android_pubkey_decode(reinterpret_cast<const uint8_t*>(content.c_str()),
ANDROID_PUBKEY_ENCODED_SIZE, &key)) {
fprintf(stderr, "Failed to parse key!\n");
return nullptr;
}
return key;
}
static int verify_table(const char* key_path, const uint8_t* signature, size_t signature_size,
const char* table, uint32_t table_length) {
// Hash the table
uint8_t hash_buf[SHA256_DIGEST_LENGTH];
SHA256(const_cast<uint8_t*>(reinterpret_cast<const uint8_t*>(table)), table_length, hash_buf);
// Now get the public key from the keyfile
std::unique_ptr<RSA, decltype(&RSA_free)> key(load_key(key_path), RSA_free);
if (!key) {
fprintf(stderr, "Couldn't load verity keys\n");
return -1;
}
// Verify the result
if (!RSA_verify(NID_sha256, hash_buf, sizeof(hash_buf), signature, signature_size, key.get())) {
fprintf(stderr, "Couldn't verify table\n");
return -1;
}
return 0;
}
int main(int argc, char* argv[]) {
if (argc != 4 || strcmp(argv[2], "-mincrypt") != 0) {
printf("Usage: %s <image> -mincrypt <verity_key>\n"
" image the image file (raw or sparse image) to be verified\n"
" verity_key the verity key in mincrypt format (/verity_key on device)\n", argv[0]);
return 2;
}
// Get the raw image.
android::base::unique_fd fd(open(argv[1], O_RDONLY));
if (fd == -1) {
fprintf(stderr, "failed to open %s: %s\n", argv[1], strerror(errno));
return 1;
}
struct sparse_file* file = sparse_file_import_auto(fd, false, false);
if (file == nullptr) {
fprintf(stderr, "failed to read file %s\n", argv[1]);
return 1;
}
TemporaryFile tf;
if (sparse_file_write(file, tf.fd, false, false, false) < 0) {
fprintf(stderr, "failed to write output file\n");
return 1;
}
sparse_file_destroy(file);
// Verify.
fec::io input(tf.path);
if (!input) {
return 1;
}
fec_verity_metadata verity;
if (!input.get_verity_metadata(verity)) {
fprintf(stderr, "failed to get verity metadata\n");
return 1;
}
int ret = verify_table(argv[3], verity.signature, sizeof(verity.signature),
verity.table, verity.table_length);
printf("%s\n", ret == 0 ? "VERIFIED" : "FAILED");
return ret;
}
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