| /* |
| * Copyright (C) 2018 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package android.security.keystore; |
| |
| import java.security.SecureRandom; |
| |
| /** |
| * Session to recover a {@link KeychainSnapshot} from the remote trusted hardware, initiated by a |
| * recovery agent. |
| * |
| * @hide |
| */ |
| public class RecoverySession implements AutoCloseable { |
| |
| private static final int SESSION_ID_LENGTH_BYTES = 16; |
| |
| private final String mSessionId; |
| private final RecoveryController mRecoveryController; |
| |
| private RecoverySession(RecoveryController recoveryController, String sessionId) { |
| mRecoveryController = recoveryController; |
| mSessionId = sessionId; |
| } |
| |
| /** |
| * A new session, started by {@code recoveryManager}. |
| */ |
| static RecoverySession newInstance(RecoveryController recoveryController) { |
| return new RecoverySession(recoveryController, newSessionId()); |
| } |
| |
| /** |
| * Returns a new random session ID. |
| */ |
| private static String newSessionId() { |
| SecureRandom secureRandom = new SecureRandom(); |
| byte[] sessionId = new byte[SESSION_ID_LENGTH_BYTES]; |
| secureRandom.nextBytes(sessionId); |
| StringBuilder sb = new StringBuilder(); |
| for (byte b : sessionId) { |
| sb.append(Byte.toHexString(b, /*upperCase=*/ false)); |
| } |
| return sb.toString(); |
| } |
| |
| /** |
| * An internal session ID, used by the framework to match recovery claims to snapshot responses. |
| */ |
| String getSessionId() { |
| return mSessionId; |
| } |
| |
| @Override |
| public void close() { |
| mRecoveryController.closeSession(this); |
| } |
| } |