| /* |
| * Copyright (C) 2020 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 com.android.server.locksettings; |
| |
| import java.io.IOException; |
| import java.security.NoSuchAlgorithmException; |
| import java.security.SecureRandom; |
| |
| import javax.crypto.KeyGenerator; |
| import javax.crypto.SecretKey; |
| import javax.crypto.spec.SecretKeySpec; |
| |
| /** |
| * Key used to encrypt and decrypt the {@link RebootEscrowData}. |
| */ |
| class RebootEscrowKey { |
| |
| /** The secret key will be of this format. */ |
| private static final String KEY_ALGO = "AES"; |
| |
| /** The key size used for encrypting the reboot escrow data. */ |
| private static final int KEY_SIZE_BITS = 256; |
| |
| private final SecretKey mKey; |
| |
| private RebootEscrowKey(SecretKey key) { |
| mKey = key; |
| } |
| |
| static RebootEscrowKey fromKeyBytes(byte[] keyBytes) { |
| return new RebootEscrowKey(new SecretKeySpec(keyBytes, KEY_ALGO)); |
| } |
| |
| static RebootEscrowKey generate() throws IOException { |
| final SecretKey secretKey; |
| try { |
| KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_ALGO); |
| keyGenerator.init(KEY_SIZE_BITS, new SecureRandom()); |
| secretKey = keyGenerator.generateKey(); |
| } catch (NoSuchAlgorithmException e) { |
| throw new IOException("Could not generate new secret key", e); |
| } |
| return new RebootEscrowKey(secretKey); |
| } |
| |
| SecretKey getKey() { |
| return mKey; |
| } |
| |
| byte[] getKeyBytes() { |
| return mKey.getEncoded(); |
| } |
| } |