| /* |
| * Copyright (C) 2019 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. |
| */ |
| |
| #define LOG_TAG "fsverity_init" |
| |
| #include <sys/types.h> |
| |
| #include <filesystem> |
| #include <memory> |
| #include <string> |
| #include <vector> |
| |
| #include <android-base/file.h> |
| #include <android-base/logging.h> |
| #include <android-base/properties.h> |
| #include <android-base/strings.h> |
| #include <keystore/keystore_client.h> |
| #include <keystore/keystore_client_impl.h> |
| #include <keystore/keystore_get.h> |
| #include <log/log.h> |
| #include <mini_keyctl_utils.h> |
| #include <private/android_filesystem_config.h> |
| |
| bool LoadKeyToKeyring(key_serial_t keyring_id, const char* desc, const char* data, size_t size) { |
| key_serial_t key = add_key("asymmetric", desc, data, size, keyring_id); |
| if (key < 0) { |
| PLOG(ERROR) << "Failed to add key"; |
| return false; |
| } |
| return true; |
| } |
| |
| void LoadKeyFromVerifiedPartitions(key_serial_t keyring_id) { |
| const char* dir = "/product/etc/security/fsverity"; |
| if (!std::filesystem::exists(dir)) { |
| LOG(ERROR) << "no such dir: " << dir; |
| return; |
| } |
| for (const auto& entry : std::filesystem::directory_iterator(dir)) { |
| if (!android::base::EndsWithIgnoreCase(entry.path().c_str(), ".der")) continue; |
| std::string content; |
| if (!android::base::ReadFileToString(entry.path(), &content)) { |
| continue; |
| } |
| if (!LoadKeyToKeyring(keyring_id, "fsv_system", content.c_str(), content.size())) { |
| LOG(ERROR) << "Failed to load key from " << entry.path(); |
| } |
| } |
| } |
| |
| std::unique_ptr<keystore::KeystoreClient> CreateKeystoreInstance() { |
| return std::unique_ptr<keystore::KeystoreClient>( |
| static_cast<keystore::KeystoreClient*>(new keystore::KeystoreClientImpl)); |
| } |
| |
| void LoadKeysFromKeystore(key_serial_t keyring_id) { |
| auto client = CreateKeystoreInstance(); |
| |
| std::vector<std::string> aliases; |
| if (client == nullptr || !client->listKeysOfUid("FSV_", AID_FSVERITY_CERT, &aliases)) { |
| LOG(ERROR) << "Failed to list key"; |
| return; |
| } |
| |
| // Always try to load all keys even if some fails to load. The rest may still |
| // be important to have. |
| for (auto& alias : aliases) { |
| auto blob = client->getKey(alias, AID_FSVERITY_CERT); |
| if (!LoadKeyToKeyring(keyring_id, "fsv_user", reinterpret_cast<char*>(blob->data()), |
| blob->size())) { |
| LOG(ERROR) << "Failed to load key " << alias << " from keyring"; |
| } |
| } |
| } |
| |
| int main(int /*argc*/, const char** /*argv*/) { |
| key_serial_t keyring_id = android::GetKeyringId(".fs-verity"); |
| if (keyring_id < 0) { |
| LOG(ERROR) << "Failed to find .fs-verity keyring id"; |
| return -1; |
| } |
| |
| // Requires files backed by fs-verity to be verified with a key in .fs-verity |
| // keyring. |
| if (!android::base::WriteStringToFile("1", "/proc/sys/fs/verity/require_signatures")) { |
| PLOG(ERROR) << "Failed to enforce fs-verity signature"; |
| } |
| |
| LoadKeyFromVerifiedPartitions(keyring_id); |
| LoadKeysFromKeystore(keyring_id); |
| |
| if (!android::base::GetBoolProperty("ro.debuggable", false)) { |
| if (keyctl_restrict_keyring(keyring_id, nullptr, nullptr) < 0) { |
| PLOG(ERROR) << "Cannot restrict .fs-verity keyring"; |
| } |
| } |
| return 0; |
| } |