2 * Copyright (C) 2016 The Android Open Source Project
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
8 * http://www.apache.org/licenses/LICENSE-2.0
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.
17 #ifndef ANDROID_VOLD_KEYSTORAGE_H
18 #define ANDROID_VOLD_KEYSTORAGE_H
20 #include "KeyBuffer.h"
29 // Represents the information needed to decrypt a disk encryption key.
30 class KeyAuthentication {
32 KeyAuthentication(const std::string& s) : secret{s} {};
34 bool usesKeymaster() const { return secret.empty(); };
36 const std::string secret;
39 extern const KeyAuthentication kEmptyAuthentication;
41 bool createSecdiscardable(const std::string& path, std::string* hash);
42 bool readSecdiscardable(const std::string& path, std::string* hash);
44 // Create a directory at the named path, and store "key" in it,
45 // in such a way that it can only be retrieved via Keymaster and
46 // can be securely deleted.
47 // It's safe to move/rename the directory after creation.
48 bool storeKey(const std::string& dir, const KeyAuthentication& auth, const KeyBuffer& key);
50 // Create a directory at the named path, and store "key" in it as storeKey
51 // This version creates the key in "tmp_path" then atomically renames "tmp_path"
52 // to "key_path" thereby ensuring that the key is either stored entirely or
53 // not at all. All the needed files and directories are also fsync'ed to ensure
54 // that the key is actually persisted to disk.
55 bool storeKeyAtomically(const std::string& key_path, const std::string& tmp_path,
56 const KeyAuthentication& auth, const KeyBuffer& key);
58 // Retrieve the key from the named directory.
59 bool retrieveKey(const std::string& dir, const KeyAuthentication& auth, KeyBuffer* key);
61 // Securely destroy the key stored in the named directory and delete the directory.
62 bool destroyKey(const std::string& dir);
64 bool runSecdiscardSingle(const std::string& file);
66 // Generate wrapped storage key using keymaster. Uses STORAGE_KEY tag in keymaster.
67 bool generateWrappedStorageKey(KeyBuffer* key);
68 // Export the per-boot boot wrapped storage key using keymaster.
69 bool exportWrappedStorageKey(const KeyBuffer& kmKey, KeyBuffer* key);
71 // Set a seed to be mixed into all key storage encryption keys.
72 bool setKeyStorageBindingSeed(const std::vector<uint8_t>& seed);
74 } // namespace android