Paul Crowley | 1ef2558 | 2016-01-21 20:26:12 +0000 | [diff] [blame] | 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 | #ifndef ANDROID_VOLD_KEYSTORAGE_H |
| 18 | #define ANDROID_VOLD_KEYSTORAGE_H |
| 19 | |
Pavel Grafov | e2e2d30 | 2017-08-01 17:15:53 +0100 | [diff] [blame] | 20 | #include "KeyBuffer.h" |
Bill Peckham | 08e5bd0 | 2020-02-25 16:23:13 -0800 | [diff] [blame] | 21 | |
Paul Crowley | 1ef2558 | 2016-01-21 20:26:12 +0000 | [diff] [blame] | 22 | #include <string> |
| 23 | |
| 24 | namespace android { |
| 25 | namespace vold { |
| 26 | |
Paul Crowley | 0572080 | 2016-02-08 15:55:41 +0000 | [diff] [blame] | 27 | // Represents the information needed to decrypt a disk encryption key. |
| 28 | // If "token" is nonempty, it is passed in as a required Gatekeeper auth token. |
Paul Crowley | 6ab2cab | 2017-01-04 22:32:40 -0800 | [diff] [blame] | 29 | // If "token" and "secret" are nonempty, "secret" is appended to the application-specific |
Paul Crowley | 0572080 | 2016-02-08 15:55:41 +0000 | [diff] [blame] | 30 | // binary needed to unlock. |
Paul Crowley | 6ab2cab | 2017-01-04 22:32:40 -0800 | [diff] [blame] | 31 | // If only "secret" is nonempty, it is used to decrypt in a non-Keymaster process. |
Paul Crowley | 0572080 | 2016-02-08 15:55:41 +0000 | [diff] [blame] | 32 | class KeyAuthentication { |
Paul Crowley | df528a7 | 2016-03-09 09:31:37 -0800 | [diff] [blame] | 33 | public: |
Greg Kaiser | fef650f | 2018-12-18 11:10:31 -0800 | [diff] [blame] | 34 | KeyAuthentication(const std::string& t, const std::string& s) : token{t}, secret{s} {}; |
Paul Crowley | 6ab2cab | 2017-01-04 22:32:40 -0800 | [diff] [blame] | 35 | |
| 36 | bool usesKeymaster() const { return !token.empty() || secret.empty(); }; |
| 37 | |
Paul Crowley | 0572080 | 2016-02-08 15:55:41 +0000 | [diff] [blame] | 38 | const std::string token; |
| 39 | const std::string secret; |
| 40 | }; |
| 41 | |
Shivaprasad Hongal | 9229262 | 2018-07-05 14:49:12 -0700 | [diff] [blame] | 42 | enum class KeyType { |
| 43 | DE_SYS, |
| 44 | DE_USER, |
Neeraj Soni | c480f91 | 2018-12-14 15:18:15 +0530 | [diff] [blame] | 45 | CE_USER, |
| 46 | ME, |
Shivaprasad Hongal | 9229262 | 2018-07-05 14:49:12 -0700 | [diff] [blame] | 47 | }; |
| 48 | |
Paul Crowley | 0572080 | 2016-02-08 15:55:41 +0000 | [diff] [blame] | 49 | extern const KeyAuthentication kEmptyAuthentication; |
| 50 | |
Paul Crowley | f71ace3 | 2016-06-02 11:01:19 -0700 | [diff] [blame] | 51 | // Checks if path "path" exists. |
| 52 | bool pathExists(const std::string& path); |
| 53 | |
Paul Crowley | 26a5388 | 2017-10-26 11:16:39 -0700 | [diff] [blame] | 54 | bool createSecdiscardable(const std::string& path, std::string* hash); |
| 55 | bool readSecdiscardable(const std::string& path, std::string* hash); |
| 56 | |
Paul Crowley | 1ef2558 | 2016-01-21 20:26:12 +0000 | [diff] [blame] | 57 | // Create a directory at the named path, and store "key" in it, |
| 58 | // in such a way that it can only be retrieved via Keymaster and |
| 59 | // can be securely deleted. |
| 60 | // It's safe to move/rename the directory after creation. |
Pavel Grafov | e2e2d30 | 2017-08-01 17:15:53 +0100 | [diff] [blame] | 61 | bool storeKey(const std::string& dir, const KeyAuthentication& auth, const KeyBuffer& key); |
Paul Crowley | 1ef2558 | 2016-01-21 20:26:12 +0000 | [diff] [blame] | 62 | |
Paul Crowley | f71ace3 | 2016-06-02 11:01:19 -0700 | [diff] [blame] | 63 | // Create a directory at the named path, and store "key" in it as storeKey |
| 64 | // This version creates the key in "tmp_path" then atomically renames "tmp_path" |
| 65 | // to "key_path" thereby ensuring that the key is either stored entirely or |
| 66 | // not at all. |
| 67 | bool storeKeyAtomically(const std::string& key_path, const std::string& tmp_path, |
Pavel Grafov | e2e2d30 | 2017-08-01 17:15:53 +0100 | [diff] [blame] | 68 | const KeyAuthentication& auth, const KeyBuffer& key); |
Paul Crowley | f71ace3 | 2016-06-02 11:01:19 -0700 | [diff] [blame] | 69 | |
Paul Crowley | 1ef2558 | 2016-01-21 20:26:12 +0000 | [diff] [blame] | 70 | // Retrieve the key from the named directory. |
Eric Biggers | 2c9d6d6 | 2020-10-29 12:59:28 -0700 | [diff] [blame] | 71 | // |
| 72 | // If the key is wrapped by a Keymaster key that requires an upgrade, then that |
| 73 | // Keymaster key is upgraded. If |keepOld| is false, then the upgraded |
| 74 | // Keymaster key replaces the original one. As part of this, the original is |
| 75 | // deleted from Keymaster; however, if a user data checkpoint is active, this |
| 76 | // part is delayed until the checkpoint is committed. |
| 77 | // |
| 78 | // If instead |keepOld| is true, then the upgraded key doesn't actually replace |
| 79 | // the original one. This is needed *only* if |dir| isn't located in /data and |
| 80 | // a user data checkpoint is active. In this case the caller must handle |
| 81 | // replacing the original key if the checkpoint is committed, and deleting the |
| 82 | // upgraded key if the checkpoint is rolled back. |
Daniel Rosenberg | 690d6de | 2018-12-14 01:08:10 -0800 | [diff] [blame] | 83 | bool retrieveKey(const std::string& dir, const KeyAuthentication& auth, KeyBuffer* key, |
Eric Biggers | 2c9d6d6 | 2020-10-29 12:59:28 -0700 | [diff] [blame] | 84 | bool keepOld); |
Paul Crowley | 1ef2558 | 2016-01-21 20:26:12 +0000 | [diff] [blame] | 85 | |
| 86 | // Securely destroy the key stored in the named directory and delete the directory. |
Paul Crowley | df528a7 | 2016-03-09 09:31:37 -0800 | [diff] [blame] | 87 | bool destroyKey(const std::string& dir); |
Paul Crowley | 1ef2558 | 2016-01-21 20:26:12 +0000 | [diff] [blame] | 88 | |
Rubin Xu | 2436e27 | 2017-04-27 20:43:10 +0100 | [diff] [blame] | 89 | bool runSecdiscardSingle(const std::string& file); |
Barani Muthukumaran | 3dfb094 | 2020-02-03 13:06:45 -0800 | [diff] [blame] | 90 | |
| 91 | // Generate wrapped storage key using keymaster. Uses STORAGE_KEY tag in keymaster. |
| 92 | bool generateWrappedStorageKey(KeyBuffer* key); |
| 93 | // Export the per-boot boot wrapped storage key using keymaster. |
| 94 | bool exportWrappedStorageKey(const KeyBuffer& kmKey, KeyBuffer* key); |
Paul Crowley | 1ef2558 | 2016-01-21 20:26:12 +0000 | [diff] [blame] | 95 | } // namespace vold |
| 96 | } // namespace android |
| 97 | |
| 98 | #endif |