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_KEYSTORE_SERVICE_H_
18 #define KEYSTORE_KEYSTORE_SERVICE_H_
19 
20 #include <android/security/keystore/BnKeystoreService.h>
21 
22 #include "auth_token_table.h"
23 #include "confirmation_manager.h"
24 
25 #include "KeyStore.h"
26 #include "keystore_keymaster_enforcement.h"
27 #include "operation.h"
28 #include "permissions.h"
29 
30 #include <keystore/ExportResult.h>
31 #include <keystore/KeyCharacteristics.h>
32 #include <keystore/KeymasterArguments.h>
33 #include <keystore/KeymasterBlob.h>
34 #include <keystore/KeymasterCertificateChain.h>
35 #include <keystore/OperationResult.h>
36 #include <keystore/keystore_return_types.h>
37 
38 #include <mutex>
39 
40 namespace keystore {
41 
42 // Class provides implementation for generated BnKeystoreService.h based on
43 // gen/aidl/android/security/BnKeystoreService.h generated from
44 // java/android/security/IKeystoreService.aidl Note that all generated methods return binder::Status
45 // and use last arguments to send actual result to the caller. Private methods don't need to handle
46 // binder::Status. Input parameters cannot be null unless annotated with @nullable in .aidl file.
47 class KeyStoreService : public android::security::keystore::BnKeystoreService {
48   public:
KeyStoreService(sp<KeyStore> keyStore)49     explicit KeyStoreService(sp<KeyStore> keyStore) : mKeyStore(keyStore) {}
50     virtual ~KeyStoreService() = default;
51 
52     void binderDied(const android::wp<android::IBinder>& who);
53 
54     ::android::binder::Status getState(int32_t userId, int32_t* _aidl_return) override;
55     ::android::binder::Status get(const ::android::String16& name, int32_t uid,
56                                   ::std::vector<uint8_t>* _aidl_return) override;
57     ::android::binder::Status insert(const ::android::String16& name,
58                                      const ::std::vector<uint8_t>& item, int32_t uid, int32_t flags,
59                                      int32_t* _aidl_return) override;
60     ::android::binder::Status del(const ::android::String16& name, int32_t uid,
61                                   int32_t* _aidl_return) override;
62     ::android::binder::Status exist(const ::android::String16& name, int32_t uid,
63                                     int32_t* _aidl_return) override;
64     ::android::binder::Status list(const ::android::String16& namePrefix, int32_t uid,
65                                    ::std::vector<::android::String16>* _aidl_return) override;
66     ::android::binder::Status listUidsOfAuthBoundKeys(std::vector<::std::string>* uids,
67                                                       int32_t* _aidl_return) override;
68 
69     ::android::binder::Status onUserPasswordChanged(int32_t userId,
70                                                     const ::android::String16& newPassword,
71                                                     int32_t* _aidl_return) override;
72     ::android::binder::Status lock(int32_t userId, int32_t* _aidl_return) override;
73     ::android::binder::Status unlock(int32_t userId, const ::android::String16& userPassword,
74                                      int32_t* _aidl_return) override;
75     ::android::binder::Status isEmpty(int32_t userId, int32_t* _aidl_return) override;
76     ::android::binder::Status grant(const ::android::String16& name, int32_t granteeUid,
77                                     ::android::String16* _aidl_return) override;
78     ::android::binder::Status ungrant(const ::android::String16& name, int32_t granteeUid,
79                                       int32_t* _aidl_return) override;
80     ::android::binder::Status getmtime(const ::android::String16& name, int32_t uid,
81                                        int64_t* _aidl_return) override;
82     ::android::binder::Status is_hardware_backed(const ::android::String16& string,
83                                                  int32_t* _aidl_return) override;
84     ::android::binder::Status clear_uid(int64_t uid, int32_t* _aidl_return) override;
85     ::android::binder::Status
86     addRngEntropy(const ::android::sp<::android::security::keystore::IKeystoreResponseCallback>& cb,
87                   const ::std::vector<uint8_t>& data, int32_t flags,
88                   int32_t* _aidl_return) override;
89     ::android::binder::Status generateKey(
90         const ::android::sp<::android::security::keystore::IKeystoreKeyCharacteristicsCallback>& cb,
91         const ::android::String16& alias,
92         const ::android::security::keymaster::KeymasterArguments& arguments,
93         const ::std::vector<uint8_t>& entropy, int32_t uid, int32_t flags,
94         int32_t* _aidl_return) override;
95     ::android::binder::Status getKeyCharacteristics(
96         const ::android::sp<::android::security::keystore::IKeystoreKeyCharacteristicsCallback>& cb,
97         const ::android::String16& alias,
98         const ::android::security::keymaster::KeymasterBlob& clientId,
99         const ::android::security::keymaster::KeymasterBlob& appId, int32_t uid,
100         int32_t* _aidl_return) override;
101     ::android::binder::Status importKey(
102         const ::android::sp<::android::security::keystore::IKeystoreKeyCharacteristicsCallback>& cb,
103         const ::android::String16& alias,
104         const ::android::security::keymaster::KeymasterArguments& arguments, int32_t format,
105         const ::std::vector<uint8_t>& keyData, int32_t uid, int32_t flags,
106         int32_t* _aidl_return) override;
107     ::android::binder::Status
108     exportKey(const ::android::sp<::android::security::keystore::IKeystoreExportKeyCallback>& cb,
109               const ::android::String16& alias, int32_t format,
110               const ::android::security::keymaster::KeymasterBlob& clientId,
111               const ::android::security::keymaster::KeymasterBlob& appId, int32_t uid,
112               int32_t* _aidl_return) override;
113     ::android::binder::Status
114     begin(const ::android::sp<::android::security::keystore::IKeystoreOperationResultCallback>& cb,
115           const ::android::sp<::android::IBinder>& appToken, const ::android::String16& alias,
116           int32_t purpose, bool pruneable,
117           const ::android::security::keymaster::KeymasterArguments& params,
118           const ::std::vector<uint8_t>& entropy, int32_t uid, int32_t* _aidl_return) override;
119     ::android::binder::Status
120     update(const ::android::sp<::android::security::keystore::IKeystoreOperationResultCallback>& cb,
121            const ::android::sp<::android::IBinder>& token,
122            const ::android::security::keymaster::KeymasterArguments& params,
123            const ::std::vector<uint8_t>& input, int32_t* _aidl_return) override;
124     ::android::binder::Status
125     finish(const ::android::sp<::android::security::keystore::IKeystoreOperationResultCallback>& cb,
126            const ::android::sp<::android::IBinder>& token,
127            const ::android::security::keymaster::KeymasterArguments& params,
128            const ::std::vector<uint8_t>& input, const ::std::vector<uint8_t>& signature,
129            const ::std::vector<uint8_t>& entropy, int32_t* _aidl_return) override;
130     ::android::binder::Status
131     abort(const ::android::sp<::android::security::keystore::IKeystoreResponseCallback>& cb,
132           const ::android::sp<::android::IBinder>& token, int32_t* _aidl_return) override;
133     ::android::binder::Status addAuthToken(const ::std::vector<uint8_t>& authToken,
134                                            int32_t* _aidl_return) override;
135     ::android::binder::Status getTokensForCredstore(
136         int64_t challenge, int64_t secureUserId, int32_t authTokenMaxAge,
137         const ::android::sp<::android::security::keystore::ICredstoreTokenCallback>& cb) override;
138     ::android::binder::Status onUserAdded(int32_t userId, int32_t parentId,
139                                           int32_t* _aidl_return) override;
140     ::android::binder::Status onUserRemoved(int32_t userId, int32_t* _aidl_return) override;
141     ::android::binder::Status attestKey(
142         const ::android::sp<::android::security::keystore::IKeystoreCertificateChainCallback>& cb,
143         const ::android::String16& alias,
144         const ::android::security::keymaster::KeymasterArguments& params,
145         int32_t* _aidl_return) override;
146     ::android::binder::Status attestDeviceIds(
147         const ::android::sp<::android::security::keystore::IKeystoreCertificateChainCallback>& cb,
148         const ::android::security::keymaster::KeymasterArguments& params,
149         int32_t* _aidl_return) override;
150     ::android::binder::Status onDeviceOffBody(int32_t* _aidl_return) override;
151 
152     ::android::binder::Status importWrappedKey(
153         const ::android::sp<::android::security::keystore::IKeystoreKeyCharacteristicsCallback>& cb,
154         const ::android::String16& wrappedKeyAlias, const ::std::vector<uint8_t>& wrappedKey,
155         const ::android::String16& wrappingKeyAlias, const ::std::vector<uint8_t>& maskingKey,
156         const ::android::security::keymaster::KeymasterArguments& params, int64_t rootSid,
157         int64_t fingerprintSid, int32_t* _aidl_return) override;
158 
159     ::android::binder::Status presentConfirmationPrompt(
160         const ::android::sp<::android::IBinder>& listener, const ::android::String16& promptText,
161         const ::std::vector<uint8_t>& extraData, const ::android::String16& locale,
162         int32_t uiOptionsAsFlags, int32_t* _aidl_return) override;
163     ::android::binder::Status
164     cancelConfirmationPrompt(const ::android::sp<::android::IBinder>& listener,
165                              int32_t* _aidl_return) override;
166     ::android::binder::Status isConfirmationPromptSupported(bool* _aidl_return) override;
167 
168     ::android::binder::Status onKeyguardVisibilityChanged(bool isShowing, int32_t userId,
169                                                           int32_t* _aidl_return) override;
170 
171   private:
172     static const int32_t UID_SELF = -1;
173 
174     /**
175      * Get the effective target uid for a binder operation that takes an
176      * optional uid as the target.
177      */
178     uid_t getEffectiveUid(int32_t targetUid);
179 
180     /**
181      * Check if the caller of the current binder method has the required
182      * permission and if acting on other uids the grants to do so.
183      */
184     bool checkBinderPermission(perm_t permission, int32_t targetUid = UID_SELF);
185 
186     /**
187      * Check if the caller of the current binder method has the required
188      * permission and the target uid is the caller or the caller is system.
189      */
190     bool checkBinderPermissionSelfOrSystem(perm_t permission, int32_t targetUid);
191 
192     /**
193      * Check if the caller of the current binder method has the required
194      * permission or the target of the operation is the caller's uid. This is
195      * for operation where the permission is only for cross-uid activity and all
196      * uids are allowed to act on their own (ie: clearing all entries for a
197      * given uid).
198      */
199     bool checkBinderPermissionOrSelfTarget(perm_t permission, int32_t targetUid);
200 
201     /**
202      * Helper method to check that the caller has the required permission as
203      * well as the keystore is in the unlocked state if checkUnlocked is true.
204      *
205      * Returns NO_ERROR on success, PERMISSION_DENIED on a permission error and
206      * otherwise the state of keystore when not unlocked and checkUnlocked is
207      * true.
208      */
209     KeyStoreServiceReturnCode checkBinderPermissionAndKeystoreState(perm_t permission,
210                                                                     int32_t targetUid = -1,
211                                                                     bool checkUnlocked = true);
212 
213     bool isKeystoreUnlocked(State state);
214 
215     /**
216      * Check that all keymaster_key_param_t's provided by the application are
217      * allowed. Any parameter that keystore adds itself should be disallowed here.
218      */
219     bool checkAllowedOperationParams(const hidl_vec<KeyParameter>& params);
220 
221     void addLegacyBeginParams(const android::String16& name, AuthorizationSet* params);
222 
223     KeyStoreServiceReturnCode doLegacySignVerify(const android::String16& name,
224                                                  const hidl_vec<uint8_t>& data,
225                                                  hidl_vec<uint8_t>* out,
226                                                  const hidl_vec<uint8_t>& signature,
227                                                  KeyPurpose purpose);
228 
229     /**
230      * Adds a Confirmation Token to the key parameters if needed.
231      */
232     void appendConfirmationTokenIfNeeded(const KeyCharacteristics& keyCharacteristics,
233                                          std::vector<KeyParameter>* params);
234 
235     sp<KeyStore> mKeyStore;
236 };
237 
238 };  // namespace keystore
239 
240 #endif  // KEYSTORE_KEYSTORE_SERVICE_H_
241