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
25 // Represents the information needed to decrypt a disk encryption key.
26 // If "token" is nonempty, it is passed in as a required Gatekeeper auth token.
27 // If "token" and "secret" are nonempty, "secret" is appended to the application-specific
28 // binary needed to unlock.
29 // If only "secret" is nonempty, it is used to decrypt in a non-Keymaster process.
30 class KeyAuthentication {
32 KeyAuthentication(std::string t, std::string s) : token{t}, secret{s} {};
34 bool usesKeymaster() const { return !token.empty() || secret.empty(); };
36 const std::string token;
37 const std::string secret;
40 extern const KeyAuthentication kEmptyAuthentication;
42 // Checks if path "path" exists.
43 bool pathExists(const std::string& path);
45 // Create a directory at the named path, and store "key" in it,
46 // in such a way that it can only be retrieved via Keymaster and
47 // can be securely deleted.
48 // It's safe to move/rename the directory after creation.
49 bool storeKey(const std::string& dir, const KeyAuthentication& auth, const std::string& key);
51 // Create a directory at the named path, and store "key" in it as storeKey
52 // This version creates the key in "tmp_path" then atomically renames "tmp_path"
53 // to "key_path" thereby ensuring that the key is either stored entirely or
55 bool storeKeyAtomically(const std::string& key_path, const std::string& tmp_path,
56 const KeyAuthentication& auth, const std::string& key);
58 // Retrieve the key from the named directory.
59 bool retrieveKey(const std::string& dir, const KeyAuthentication& auth, std::string* 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 } // namespace android