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 KEYSTORE_USER_STATE_H_
18#define KEYSTORE_USER_STATE_H_
19
20#include <sys/types.h>
21
22#include <openssl/aes.h>
23
24#include <utils/String8.h>
25
26#include <keystore/keystore.h>
27
28#include "entropy.h"
29
30class UserState {
31  public:
32    UserState(uid_t userId);
33    ~UserState();
34
35    bool initialize();
36
37    uid_t getUserId() const { return mUserId; }
38    const char* getUserDirName() const { return mUserDir; }
39
40    const char* getMasterKeyFileName() const { return mMasterKeyFile; }
41
42    void setState(State state);
43    State getState() const { return mState; }
44
45    int8_t getRetry() const { return mRetry; }
46
47    void zeroizeMasterKeysInMemory();
48    bool deleteMasterKey();
49
50    ResponseCode initialize(const android::String8& pw, Entropy* entropy);
51
52    ResponseCode copyMasterKey(UserState* src);
53    ResponseCode copyMasterKeyFile(UserState* src);
54    ResponseCode writeMasterKey(const android::String8& pw, Entropy* entropy);
55    ResponseCode readMasterKey(const android::String8& pw, Entropy* entropy);
56
57    AES_KEY* getEncryptionKey() { return &mMasterKeyEncryption; }
58    AES_KEY* getDecryptionKey() { return &mMasterKeyDecryption; }
59
60    bool reset();
61
62  private:
63    static const int MASTER_KEY_SIZE_BYTES = 16;
64    static const int MASTER_KEY_SIZE_BITS = MASTER_KEY_SIZE_BYTES * 8;
65
66    static const int MAX_RETRY = 4;
67    static const size_t SALT_SIZE = 16;
68
69    void generateKeyFromPassword(uint8_t* key, ssize_t keySize, const android::String8& pw,
70                                 uint8_t* salt);
71    bool generateSalt(Entropy* entropy);
72    bool generateMasterKey(Entropy* entropy);
73    void setupMasterKeys();
74
75    uid_t mUserId;
76
77    char* mUserDir;
78    char* mMasterKeyFile;
79
80    State mState;
81    int8_t mRetry;
82
83    uint8_t mMasterKey[MASTER_KEY_SIZE_BYTES];
84    uint8_t mSalt[SALT_SIZE];
85
86    AES_KEY mMasterKeyEncryption;
87    AES_KEY mMasterKeyDecryption;
88};
89
90#endif  // KEYSTORE_USER_STATE_H_
91