/*
 * Copyright (C) 2017 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.recoverablekeystore;

import static android.security.keystore.recovery.KeyChainProtectionParams.TYPE_LOCKSCREEN;
import static android.security.keystore.recovery.KeyChainProtectionParams.UI_FORMAT_PASSWORD;

import static com.google.common.truth.Truth.assertThat;
import static org.junit.Assert.assertArrayEquals;
import static org.junit.Assert.assertEquals;
import static org.junit.Assert.fail;
import static org.mockito.ArgumentMatchers.any;
import static org.mockito.ArgumentMatchers.anyInt;
import static org.mockito.ArgumentMatchers.anyString;
import static org.mockito.ArgumentMatchers.eq;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;
import static org.mockito.Mockito.when;

import android.app.KeyguardManager;
import android.app.PendingIntent;
import android.content.Context;
import android.content.Intent;
import android.Manifest;
import android.os.Binder;
import android.os.ServiceSpecificException;
import android.os.UserHandle;
import android.security.KeyStore;
import android.security.keystore.AndroidKeyStoreProvider;
import android.security.keystore.AndroidKeyStoreSecretKey;
import android.security.keystore.KeyGenParameterSpec;
import android.security.keystore.KeyProperties;
import android.security.keystore.recovery.KeyDerivationParams;
import android.security.keystore.recovery.KeyChainProtectionParams;
import android.security.keystore.recovery.RecoveryCertPath;
import android.security.keystore.recovery.WrappedApplicationKey;
import android.support.test.filters.SmallTest;
import android.support.test.InstrumentationRegistry;
import android.support.test.runner.AndroidJUnit4;

import com.android.server.locksettings.recoverablekeystore.storage.ApplicationKeyStorage;
import com.android.server.locksettings.recoverablekeystore.storage.RecoverableKeyStoreDb;
import com.android.server.locksettings.recoverablekeystore.storage.RecoverySessionStorage;
import com.android.server.locksettings.recoverablekeystore.storage.RecoverySnapshotStorage;

import com.google.common.collect.ImmutableList;
import com.google.common.collect.ImmutableMap;

import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import org.junit.runner.RunWith;
import org.mockito.Mock;
import org.mockito.MockitoAnnotations;

import java.io.File;
import java.nio.charset.StandardCharsets;
import java.security.UnrecoverableKeyException;
import java.security.cert.CertPath;
import java.security.cert.CertificateFactory;
import java.security.cert.X509Certificate;
import java.util.ArrayList;
import java.util.concurrent.Executors;
import java.util.Map;
import java.util.Random;

import javax.crypto.Cipher;
import javax.crypto.KeyGenerator;
import javax.crypto.SecretKey;
import javax.crypto.spec.GCMParameterSpec;
import javax.crypto.spec.SecretKeySpec;

@SmallTest
@RunWith(AndroidJUnit4.class)
public class RecoverableKeyStoreManagerTest {
    private static final String DATABASE_FILE_NAME = "recoverablekeystore.db";

    private static final String ROOT_CERTIFICATE_ALIAS = "";
    private static final String TEST_SESSION_ID = "karlin";
    private static final byte[] TEST_PUBLIC_KEY = new byte[] {
        (byte) 0x30, (byte) 0x59, (byte) 0x30, (byte) 0x13, (byte) 0x06, (byte) 0x07, (byte) 0x2a,
        (byte) 0x86, (byte) 0x48, (byte) 0xce, (byte) 0x3d, (byte) 0x02, (byte) 0x01, (byte) 0x06,
        (byte) 0x08, (byte) 0x2a, (byte) 0x86, (byte) 0x48, (byte) 0xce, (byte) 0x3d, (byte) 0x03,
        (byte) 0x01, (byte) 0x07, (byte) 0x03, (byte) 0x42, (byte) 0x00, (byte) 0x04, (byte) 0xb8,
        (byte) 0x00, (byte) 0x11, (byte) 0x18, (byte) 0x98, (byte) 0x1d, (byte) 0xf0, (byte) 0x6e,
        (byte) 0xb4, (byte) 0x94, (byte) 0xfe, (byte) 0x86, (byte) 0xda, (byte) 0x1c, (byte) 0x07,
        (byte) 0x8d, (byte) 0x01, (byte) 0xb4, (byte) 0x3a, (byte) 0xf6, (byte) 0x8d, (byte) 0xdc,
        (byte) 0x61, (byte) 0xd0, (byte) 0x46, (byte) 0x49, (byte) 0x95, (byte) 0x0f, (byte) 0x10,
        (byte) 0x86, (byte) 0x93, (byte) 0x24, (byte) 0x66, (byte) 0xe0, (byte) 0x3f, (byte) 0xd2,
        (byte) 0xdf, (byte) 0xf3, (byte) 0x79, (byte) 0x20, (byte) 0x1d, (byte) 0x91, (byte) 0x55,
        (byte) 0xb0, (byte) 0xe5, (byte) 0xbd, (byte) 0x7a, (byte) 0x8b, (byte) 0x32, (byte) 0x7d,
        (byte) 0x25, (byte) 0x53, (byte) 0xa2, (byte) 0xfc, (byte) 0xa5, (byte) 0x65, (byte) 0xe1,
        (byte) 0xbd, (byte) 0x21, (byte) 0x44, (byte) 0x7e, (byte) 0x78, (byte) 0x52, (byte) 0xfa};
    private static final byte[] TEST_SALT = getUtf8Bytes("salt");
    private static final byte[] TEST_SECRET = getUtf8Bytes("password1234");
    private static final byte[] TEST_VAULT_CHALLENGE = getUtf8Bytes("vault_challenge");
    private static final byte[] TEST_VAULT_PARAMS = new byte[] {
        // backend_key
        (byte) 0x04, (byte) 0xb8, (byte) 0x00, (byte) 0x11, (byte) 0x18, (byte) 0x98, (byte) 0x1d,
        (byte) 0xf0, (byte) 0x6e, (byte) 0xb4, (byte) 0x94, (byte) 0xfe, (byte) 0x86, (byte) 0xda,
        (byte) 0x1c, (byte) 0x07, (byte) 0x8d, (byte) 0x01, (byte) 0xb4, (byte) 0x3a, (byte) 0xf6,
        (byte) 0x8d, (byte) 0xdc, (byte) 0x61, (byte) 0xd0, (byte) 0x46, (byte) 0x49, (byte) 0x95,
        (byte) 0x0f, (byte) 0x10, (byte) 0x86, (byte) 0x93, (byte) 0x24, (byte) 0x66, (byte) 0xe0,
        (byte) 0x3f, (byte) 0xd2, (byte) 0xdf, (byte) 0xf3, (byte) 0x79, (byte) 0x20, (byte) 0x1d,
        (byte) 0x91, (byte) 0x55, (byte) 0xb0, (byte) 0xe5, (byte) 0xbd, (byte) 0x7a, (byte) 0x8b,
        (byte) 0x32, (byte) 0x7d, (byte) 0x25, (byte) 0x53, (byte) 0xa2, (byte) 0xfc, (byte) 0xa5,
        (byte) 0x65, (byte) 0xe1, (byte) 0xbd, (byte) 0x21, (byte) 0x44, (byte) 0x7e, (byte) 0x78,
        (byte) 0x52, (byte) 0xfa,
        // counter_id
        (byte) 0x31, (byte) 0x32, (byte) 0x33, (byte) 0x34, (byte) 0x00, (byte) 0x00, (byte) 0x00,
        (byte) 0x00,
        // device_parameter
        (byte) 0x78, (byte) 0x56, (byte) 0x34, (byte) 0x12, (byte) 0x00, (byte) 0x00, (byte) 0x00,
        (byte) 0x0,
        // max_attempts
        (byte) 0x0a, (byte) 0x00, (byte) 0x00, (byte) 0x00};
    private static final int TEST_GENERATION_ID = 2;
    private static final int TEST_USER_ID = 10009;
    private static final int KEY_CLAIMANT_LENGTH_BYTES = 16;
    private static final byte[] RECOVERY_RESPONSE_HEADER =
            "V1 reencrypted_recovery_key".getBytes(StandardCharsets.UTF_8);
    private static final String TEST_ALIAS = "nick";
    private static final String TEST_ALIAS2 = "bob";
    private static final int RECOVERABLE_KEY_SIZE_BYTES = 32;
    private static final int APPLICATION_KEY_SIZE_BYTES = 32;
    private static final int GENERATION_ID = 1;
    private static final byte[] NONCE = getUtf8Bytes("nonce");
    private static final byte[] KEY_MATERIAL = getUtf8Bytes("keymaterial");
    private static final String KEY_ALGORITHM = "AES";
    private static final String ANDROID_KEY_STORE_PROVIDER = "AndroidKeyStore";
    private static final String WRAPPING_KEY_ALIAS = "RecoverableKeyStoreManagerTest/WrappingKey";
    private static final String TEST_ROOT_CERT_ALIAS = "";

    @Mock private Context mMockContext;
    @Mock private RecoverySnapshotListenersStorage mMockListenersStorage;
    @Mock private KeyguardManager mKeyguardManager;
    @Mock private PlatformKeyManager mPlatformKeyManager;
    @Mock private ApplicationKeyStorage mApplicationKeyStorage;

    private RecoverableKeyStoreDb mRecoverableKeyStoreDb;
    private File mDatabaseFile;
    private RecoverableKeyStoreManager mRecoverableKeyStoreManager;
    private RecoverySessionStorage mRecoverySessionStorage;
    private RecoverySnapshotStorage mRecoverySnapshotStorage;
    private PlatformEncryptionKey mPlatformEncryptionKey;

    @Before
    public void setUp() throws Exception {
        MockitoAnnotations.initMocks(this);

        Context context = InstrumentationRegistry.getTargetContext();
        mDatabaseFile = context.getDatabasePath(DATABASE_FILE_NAME);
        mRecoverableKeyStoreDb = RecoverableKeyStoreDb.newInstance(context);

        mRecoverySessionStorage = new RecoverySessionStorage();

        when(mMockContext.getSystemService(anyString())).thenReturn(mKeyguardManager);
        when(mMockContext.getSystemServiceName(any())).thenReturn("test");
        when(mMockContext.getApplicationContext()).thenReturn(mMockContext);
        when(mKeyguardManager.isDeviceSecure(TEST_USER_ID)).thenReturn(true);

        mPlatformEncryptionKey =
                new PlatformEncryptionKey(TEST_GENERATION_ID, generateAndroidKeyStoreKey());
        when(mPlatformKeyManager.getEncryptKey(anyInt())).thenReturn(mPlatformEncryptionKey);

        mRecoverableKeyStoreManager = new RecoverableKeyStoreManager(
                mMockContext,
                KeyStore.getInstance(),
                mRecoverableKeyStoreDb,
                mRecoverySessionStorage,
                Executors.newSingleThreadExecutor(),
                mRecoverySnapshotStorage,
                mMockListenersStorage,
                mPlatformKeyManager,
                mApplicationKeyStorage);
    }

    @After
    public void tearDown() {
        mRecoverableKeyStoreDb.close();
        mDatabaseFile.delete();
    }

    @Test
    public void generateAndStoreKey_storesTheKey() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();

        mRecoverableKeyStoreManager.generateAndStoreKey(TEST_ALIAS);

        assertThat(mRecoverableKeyStoreDb.getKey(uid, TEST_ALIAS)).isNotNull();

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isTrue();
    }

    @Test
    public void generateAndStoreKey_returnsAKeyOfAppropriateSize() throws Exception {
        assertThat(mRecoverableKeyStoreManager.generateAndStoreKey(TEST_ALIAS))
                .hasLength(RECOVERABLE_KEY_SIZE_BYTES);
    }

    @Test
    public void importKey_storesTheKey() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        byte[] keyMaterial = randomBytes(APPLICATION_KEY_SIZE_BYTES);

        mRecoverableKeyStoreManager.importKey(TEST_ALIAS, keyMaterial);

        assertThat(mRecoverableKeyStoreDb.getKey(uid, TEST_ALIAS)).isNotNull();
        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isTrue();
        // TODO(76083050) Test the grant mechanism for the keys.
    }

    @Test
    public void importKey_throwsIfInvalidLength() throws Exception {
        byte[] keyMaterial = randomBytes(APPLICATION_KEY_SIZE_BYTES - 1);
        try {
            mRecoverableKeyStoreManager.importKey(TEST_ALIAS, keyMaterial);
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            assertThat(e.getMessage()).contains("not contain 256 bits");
        }
    }

    @Test
    public void importKey_throwsIfNullKey() throws Exception {
        try {
            mRecoverableKeyStoreManager.importKey(TEST_ALIAS, /*keyBytes=*/ null);
            fail("should have thrown");
        } catch (NullPointerException e) {
            assertThat(e.getMessage()).contains("is null");
        }
    }

    @Test
    public void removeKey_removesAKey() throws Exception {
        int uid = Binder.getCallingUid();
        mRecoverableKeyStoreManager.generateAndStoreKey(TEST_ALIAS);

        mRecoverableKeyStoreManager.removeKey(TEST_ALIAS);

        assertThat(mRecoverableKeyStoreDb.getKey(uid, TEST_ALIAS)).isNull();
    }

    @Test
    public void removeKey_updatesShouldCreateSnapshot() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        mRecoverableKeyStoreManager.generateAndStoreKey(TEST_ALIAS);
        // Pretend that key was synced
        mRecoverableKeyStoreDb.setShouldCreateSnapshot(userId, uid, false);

        mRecoverableKeyStoreManager.removeKey(TEST_ALIAS);

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isTrue();
    }

    @Test
    public void removeKey_failureDoesNotUpdateShouldCreateSnapshot() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        mRecoverableKeyStoreDb.setShouldCreateSnapshot(userId, uid, false);
        // Key did not exist
        mRecoverableKeyStoreManager.removeKey(TEST_ALIAS);

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isFalse();
    }

    @Test
    public void initRecoveryService_succeedsWithCertFile() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        long certSerial = 1000L;
        mRecoverableKeyStoreDb.setShouldCreateSnapshot(userId, uid, false);

        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS,
                TestData.getCertXmlWithSerial(certSerial));

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isTrue();
        assertThat(mRecoverableKeyStoreDb.getRecoveryServiceCertPath(userId, uid)).isEqualTo(
                TestData.CERT_PATH_1);
        assertThat(mRecoverableKeyStoreDb.getRecoveryServiceCertSerial(userId, uid)).isEqualTo(
                certSerial);
        assertThat(mRecoverableKeyStoreDb.getRecoveryServicePublicKey(userId, uid)).isNull();
    }

    @Test
    public void initRecoveryService_regeneratesCounterId() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        long certSerial = 1000L;

        Long counterId0 = mRecoverableKeyStoreDb.getCounterId(userId, uid);
        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS,
                TestData.getCertXmlWithSerial(certSerial));
        Long counterId1 = mRecoverableKeyStoreDb.getCounterId(userId, uid);
        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS,
                TestData.getCertXmlWithSerial(certSerial + 1));
        Long counterId2 = mRecoverableKeyStoreDb.getCounterId(userId, uid);

        assertThat(!counterId1.equals(counterId0) || !counterId2.equals(counterId1)).isTrue();
    }

    @Test
    public void initRecoveryService_throwsIfInvalidCert() throws Exception {
        byte[] modifiedCertXml = TestData.getCertXml();
        modifiedCertXml[modifiedCertXml.length - 50] ^= 1;  // Flip a bit in the certificate
        try {
            mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS, modifiedCertXml);
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            assertThat(e.getMessage()).contains("validate cert");
        }
    }

    @Test
    public void initRecoveryService_updatesWithLargerSerial() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        long certSerial = 1000L;

        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS,
                TestData.getCertXmlWithSerial(certSerial));
        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS,
                TestData.getCertXmlWithSerial(certSerial + 1));

        assertThat(mRecoverableKeyStoreDb.getRecoveryServiceCertSerial(userId, uid))
                .isEqualTo(certSerial + 1);
    }

    @Test
    public void initRecoveryService_ignoresSmallerSerial() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        long certSerial = 1000L;

        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS,
                TestData.getCertXmlWithSerial(certSerial));
        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS,
                TestData.getCertXmlWithSerial(certSerial - 1));

        assertThat(mRecoverableKeyStoreDb.getRecoveryServiceCertSerial(userId, uid))
                .isEqualTo(certSerial);
    }

    @Test
    public void initRecoveryService_ignoresTheSameSerial() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        long certSerial = 1000L;

        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS,
                TestData.getCertXmlWithSerial(certSerial));
        mRecoverableKeyStoreDb.setShouldCreateSnapshot(userId, uid, false);
        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS,
                TestData.getCertXmlWithSerial(certSerial));

        // If the second update succeeds, getShouldCreateSnapshot() will return true.
        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isFalse();
    }

    @Test
    public void initRecoveryService_succeedsWithRawPublicKey() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        mRecoverableKeyStoreDb.setShouldCreateSnapshot(userId, uid, false);

        mRecoverableKeyStoreManager.initRecoveryService(ROOT_CERTIFICATE_ALIAS, TEST_PUBLIC_KEY);

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isTrue();
        assertThat(mRecoverableKeyStoreDb.getRecoveryServiceCertPath(userId, uid)).isNull();
        assertThat(mRecoverableKeyStoreDb.getRecoveryServiceCertSerial(userId, uid)).isNull();
        assertThat(mRecoverableKeyStoreDb.getRecoveryServicePublicKey(userId, uid)).isNotNull();
    }

    @Test
    public void initRecoveryServiceWithSigFile_succeeds() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        mRecoverableKeyStoreDb.setShouldCreateSnapshot(userId, uid, false);

        mRecoverableKeyStoreManager.initRecoveryServiceWithSigFile(
                ROOT_CERTIFICATE_ALIAS, TestData.getCertXml(), TestData.getSigXml());

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isTrue();
        assertThat(mRecoverableKeyStoreDb.getRecoveryServiceCertPath(userId, uid)).isEqualTo(
                TestData.CERT_PATH_1);
        assertThat(mRecoverableKeyStoreDb.getRecoveryServicePublicKey(userId, uid)).isNull();
    }

    @Test
    public void initRecoveryServiceWithSigFile_throwsIfNullCertFile() throws Exception {
        try {
            mRecoverableKeyStoreManager.initRecoveryServiceWithSigFile(
                    ROOT_CERTIFICATE_ALIAS, /*recoveryServiceCertFile=*/ null,
                    TestData.getSigXml());
            fail("should have thrown");
        } catch (NullPointerException e) {
            assertThat(e.getMessage()).contains("is null");
        }
    }

    @Test
    public void initRecoveryServiceWithSigFile_throwsIfNullSigFile() throws Exception {
        try {
            mRecoverableKeyStoreManager.initRecoveryServiceWithSigFile(
                    ROOT_CERTIFICATE_ALIAS, TestData.getCertXml(),
                    /*recoveryServiceSigFile=*/ null);
            fail("should have thrown");
        } catch (NullPointerException e) {
            assertThat(e.getMessage()).contains("is null");
        }
    }

    @Test
    public void initRecoveryServiceWithSigFile_throwsIfWrongSigFileFormat() throws Exception {
        try {
            mRecoverableKeyStoreManager.initRecoveryServiceWithSigFile(
                    ROOT_CERTIFICATE_ALIAS, TestData.getCertXml(),
                    getUtf8Bytes("wrong-sig-file-format"));
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            assertThat(e.getMessage()).contains("parse the sig file");
        }
    }

    @Test
    public void initRecoveryServiceWithSigFile_throwsIfInvalidFileSignature() throws Exception {
        byte[] modifiedCertXml = TestData.getCertXml();
        modifiedCertXml[modifiedCertXml.length - 1] = 0;  // Change the last new line char to a zero
        try {
            mRecoverableKeyStoreManager.initRecoveryServiceWithSigFile(
                    ROOT_CERTIFICATE_ALIAS, modifiedCertXml, TestData.getSigXml());
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            assertThat(e.getMessage()).contains("is invalid");
        }
    }

    @Test
    public void startRecoverySession_checksPermissionFirst() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySession(
                TEST_SESSION_ID,
                TEST_PUBLIC_KEY,
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(
                        new KeyChainProtectionParams(
                                TYPE_LOCKSCREEN,
                                UI_FORMAT_PASSWORD,
                                KeyDerivationParams.createSha256Params(TEST_SALT),
                                TEST_SECRET)));

        verify(mMockContext, times(1))
                .enforceCallingOrSelfPermission(
                        eq(Manifest.permission.RECOVER_KEYSTORE), any());
    }

    // TODO: Add tests for non-existing cert alias

    @Test
    public void startRecoverySessionWithCertPath_storesTheSessionInfo() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySessionWithCertPath(
                TEST_SESSION_ID,
                TEST_ROOT_CERT_ALIAS,
                RecoveryCertPath.createRecoveryCertPath(TestData.CERT_PATH_1),
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(
                        new KeyChainProtectionParams(
                                TYPE_LOCKSCREEN,
                                UI_FORMAT_PASSWORD,
                                KeyDerivationParams.createSha256Params(TEST_SALT),
                                TEST_SECRET)));

        assertEquals(1, mRecoverySessionStorage.size());
        RecoverySessionStorage.Entry entry =
                mRecoverySessionStorage.get(Binder.getCallingUid(), TEST_SESSION_ID);
        assertArrayEquals(TEST_SECRET, entry.getLskfHash());
        assertEquals(KEY_CLAIMANT_LENGTH_BYTES, entry.getKeyClaimant().length);
    }

    @Test
    public void startRecoverySessionWithCertPath_checksPermissionFirst() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySessionWithCertPath(
                TEST_SESSION_ID,
                TEST_ROOT_CERT_ALIAS,
                RecoveryCertPath.createRecoveryCertPath(TestData.CERT_PATH_1),
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(
                        new KeyChainProtectionParams(
                                TYPE_LOCKSCREEN,
                                UI_FORMAT_PASSWORD,
                                KeyDerivationParams.createSha256Params(TEST_SALT),
                                TEST_SECRET)));

        verify(mMockContext, times(2))
                .enforceCallingOrSelfPermission(
                        eq(Manifest.permission.RECOVER_KEYSTORE), any());
    }

    @Test
    public void startRecoverySession_storesTheSessionInfo() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySession(
                TEST_SESSION_ID,
                TEST_PUBLIC_KEY,
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(
                        new KeyChainProtectionParams(
                                TYPE_LOCKSCREEN,
                                UI_FORMAT_PASSWORD,
                                KeyDerivationParams.createSha256Params(TEST_SALT),
                                TEST_SECRET)));

        assertEquals(1, mRecoverySessionStorage.size());
        RecoverySessionStorage.Entry entry =
                mRecoverySessionStorage.get(Binder.getCallingUid(), TEST_SESSION_ID);
        assertArrayEquals(TEST_SECRET, entry.getLskfHash());
        assertEquals(KEY_CLAIMANT_LENGTH_BYTES, entry.getKeyClaimant().length);
    }

    @Test
    public void closeSession_closesASession() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySession(
                TEST_SESSION_ID,
                TEST_PUBLIC_KEY,
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(
                        new KeyChainProtectionParams(
                                TYPE_LOCKSCREEN,
                                UI_FORMAT_PASSWORD,
                                KeyDerivationParams.createSha256Params(TEST_SALT),
                                TEST_SECRET)));

        mRecoverableKeyStoreManager.closeSession(TEST_SESSION_ID);

        assertEquals(0, mRecoverySessionStorage.size());
    }

    @Test
    public void closeSession_doesNotCloseUnrelatedSessions() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySession(
                TEST_SESSION_ID,
                TEST_PUBLIC_KEY,
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(
                        new KeyChainProtectionParams(
                                TYPE_LOCKSCREEN,
                                UI_FORMAT_PASSWORD,
                                KeyDerivationParams.createSha256Params(TEST_SALT),
                                TEST_SECRET)));

        mRecoverableKeyStoreManager.closeSession("some random session");

        assertEquals(1, mRecoverySessionStorage.size());
    }

    @Test
    public void closeSession_throwsIfNullSession() throws Exception {
        try {
            mRecoverableKeyStoreManager.closeSession(/*sessionId=*/ null);
            fail("should have thrown");
        } catch (NullPointerException e) {
            assertThat(e.getMessage()).contains("invalid");
        }
    }

    @Test
    public void startRecoverySession_throwsIfBadNumberOfSecrets() throws Exception {
        try {
            mRecoverableKeyStoreManager.startRecoverySession(
                    TEST_SESSION_ID,
                    TEST_PUBLIC_KEY,
                    TEST_VAULT_PARAMS,
                    TEST_VAULT_CHALLENGE,
                    ImmutableList.of());
            fail("should have thrown");
        } catch (UnsupportedOperationException e) {
            assertThat(e.getMessage()).startsWith(
                    "Only a single KeyChainProtectionParams is supported");
        }
    }

    @Test
    public void startRecoverySession_throwsIfPublicKeysMismatch() throws Exception {
        byte[] vaultParams = TEST_VAULT_PARAMS.clone();
        vaultParams[1] ^= (byte) 1;  // Flip 1 bit
        try {
            mRecoverableKeyStoreManager.startRecoverySession(
                    TEST_SESSION_ID,
                    TEST_PUBLIC_KEY,
                    vaultParams,
                    TEST_VAULT_CHALLENGE,
                    ImmutableList.of(
                            new KeyChainProtectionParams(
                                    TYPE_LOCKSCREEN,
                                    UI_FORMAT_PASSWORD,
                                    KeyDerivationParams.createSha256Params(TEST_SALT),
                                    TEST_SECRET)));
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            assertThat(e.getMessage()).contains("do not match");
        }
    }

    @Test
    public void startRecoverySessionWithCertPath_throwsIfBadNumberOfSecrets() throws Exception {
        try {
            mRecoverableKeyStoreManager.startRecoverySessionWithCertPath(
                    TEST_SESSION_ID,
                    TEST_ROOT_CERT_ALIAS,
                    RecoveryCertPath.createRecoveryCertPath(TestData.CERT_PATH_1),
                    TEST_VAULT_PARAMS,
                    TEST_VAULT_CHALLENGE,
                    ImmutableList.of());
            fail("should have thrown");
        } catch (UnsupportedOperationException e) {
            assertThat(e.getMessage()).startsWith(
                    "Only a single KeyChainProtectionParams is supported");
        }
    }

    @Test
    public void startRecoverySessionWithCertPath_throwsIfPublicKeysMismatch() throws Exception {
        byte[] vaultParams = TEST_VAULT_PARAMS.clone();
        vaultParams[1] ^= (byte) 1;  // Flip 1 bit
        try {
            mRecoverableKeyStoreManager.startRecoverySessionWithCertPath(
                    TEST_SESSION_ID,
                    TEST_ROOT_CERT_ALIAS,
                    RecoveryCertPath.createRecoveryCertPath(TestData.CERT_PATH_1),
                    vaultParams,
                    TEST_VAULT_CHALLENGE,
                    ImmutableList.of(
                            new KeyChainProtectionParams(
                                    TYPE_LOCKSCREEN,
                                    UI_FORMAT_PASSWORD,
                                    KeyDerivationParams.createSha256Params(TEST_SALT),
                                    TEST_SECRET)));
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            assertThat(e.getMessage()).contains("do not match");
        }
    }

    @Test
    public void startRecoverySessionWithCertPath_throwsIfEmptyCertPath() throws Exception {
        CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
        CertPath emptyCertPath = certFactory.generateCertPath(new ArrayList<X509Certificate>());
        try {
            mRecoverableKeyStoreManager.startRecoverySessionWithCertPath(
                    TEST_SESSION_ID,
                    TEST_ROOT_CERT_ALIAS,
                    RecoveryCertPath.createRecoveryCertPath(emptyCertPath),
                    TEST_VAULT_PARAMS,
                    TEST_VAULT_CHALLENGE,
                    ImmutableList.of(
                            new KeyChainProtectionParams(
                                    TYPE_LOCKSCREEN,
                                    UI_FORMAT_PASSWORD,
                                    KeyDerivationParams.createSha256Params(TEST_SALT),
                                    TEST_SECRET)));
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            assertThat(e.getMessage()).contains("empty");
        }
    }

    @Test
    public void startRecoverySessionWithCertPath_throwsIfInvalidCertPath() throws Exception {
        CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
        CertPath shortCertPath = certFactory.generateCertPath(
                TestData.CERT_PATH_1.getCertificates()
                        .subList(0, TestData.CERT_PATH_1.getCertificates().size() - 1));
        try {
            mRecoverableKeyStoreManager.startRecoverySessionWithCertPath(
                    TEST_SESSION_ID,
                    TEST_ROOT_CERT_ALIAS,
                    RecoveryCertPath.createRecoveryCertPath(shortCertPath),
                    TEST_VAULT_PARAMS,
                    TEST_VAULT_CHALLENGE,
                    ImmutableList.of(
                            new KeyChainProtectionParams(
                                    TYPE_LOCKSCREEN,
                                    UI_FORMAT_PASSWORD,
                                    KeyDerivationParams.createSha256Params(TEST_SALT),
                                    TEST_SECRET)));
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            // expected
        }
    }

    @Test
    public void recoverKeyChainSnapshot_throwsIfNoSessionIsPresent() throws Exception {
        try {
            WrappedApplicationKey applicationKey = new WrappedApplicationKey.Builder()
                .setAlias(TEST_ALIAS)
                .setEncryptedKeyMaterial(randomBytes(32))
                .build();
            mRecoverableKeyStoreManager.recoverKeyChainSnapshot(
                    TEST_SESSION_ID,
                    /*recoveryKeyBlob=*/ randomBytes(32),
                    /*applicationKeys=*/ ImmutableList.of(applicationKey));
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            // expected
        }
    }

    @Test
    public void recoverKeyChainSnapshot_throwsIfRecoveryClaimCannotBeDecrypted() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySession(
                TEST_SESSION_ID,
                TEST_PUBLIC_KEY,
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(new KeyChainProtectionParams(
                        TYPE_LOCKSCREEN,
                        UI_FORMAT_PASSWORD,
                        KeyDerivationParams.createSha256Params(TEST_SALT),
                        TEST_SECRET)));

        try {
            mRecoverableKeyStoreManager.recoverKeyChainSnapshot(
                    TEST_SESSION_ID,
                    /*encryptedRecoveryKey=*/ randomBytes(60),
                    /*applicationKeys=*/ ImmutableList.of());
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            assertThat(e.getMessage()).startsWith("Failed to decrypt recovery key");
        }
    }

    @Test
    public void recoverKeyChainSnapshot_throwsIfFailedToDecryptAllApplicationKeys() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySession(
                TEST_SESSION_ID,
                TEST_PUBLIC_KEY,
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(new KeyChainProtectionParams(
                        TYPE_LOCKSCREEN,
                        UI_FORMAT_PASSWORD,
                        KeyDerivationParams.createSha256Params(TEST_SALT),
                        TEST_SECRET)));
        byte[] keyClaimant = mRecoverySessionStorage.get(Binder.getCallingUid(), TEST_SESSION_ID)
                .getKeyClaimant();
        SecretKey recoveryKey = randomRecoveryKey();
        byte[] encryptedClaimResponse = encryptClaimResponse(
                keyClaimant, TEST_SECRET, TEST_VAULT_PARAMS, recoveryKey);
        WrappedApplicationKey badApplicationKey = new WrappedApplicationKey.Builder()
                .setAlias(TEST_ALIAS)
                .setEncryptedKeyMaterial(
                            encryptedApplicationKey(randomRecoveryKey(), randomBytes(32)))
                .build();
        try {
            mRecoverableKeyStoreManager.recoverKeyChainSnapshot(
                    TEST_SESSION_ID,
                    /*encryptedRecoveryKey=*/ encryptedClaimResponse,
                    /*applicationKeys=*/ ImmutableList.of(badApplicationKey));
            fail("should have thrown");
        } catch (ServiceSpecificException e) {
            assertThat(e.getMessage()).startsWith("Failed to recover any of the application keys");
        }
    }

    @Test
    public void recoverKeyChainSnapshot_doesNotThrowIfNoApplicationKeysToBeDecrypted()
            throws Exception {
        mRecoverableKeyStoreManager.startRecoverySession(
                TEST_SESSION_ID,
                TEST_PUBLIC_KEY,
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(new KeyChainProtectionParams(
                        TYPE_LOCKSCREEN,
                        UI_FORMAT_PASSWORD,
                        KeyDerivationParams.createSha256Params(TEST_SALT),
                        TEST_SECRET)));
        byte[] keyClaimant = mRecoverySessionStorage.get(Binder.getCallingUid(), TEST_SESSION_ID)
                .getKeyClaimant();
        SecretKey recoveryKey = randomRecoveryKey();
        byte[] encryptedClaimResponse = encryptClaimResponse(
                keyClaimant, TEST_SECRET, TEST_VAULT_PARAMS, recoveryKey);

        mRecoverableKeyStoreManager.recoverKeyChainSnapshot(
                TEST_SESSION_ID,
                /*encryptedRecoveryKey=*/ encryptedClaimResponse,
                /*applicationKeys=*/ ImmutableList.of());
    }

    @Test
    public void recoverKeyChainSnapshot_returnsDecryptedKeys() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySession(
                TEST_SESSION_ID,
                TEST_PUBLIC_KEY,
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(new KeyChainProtectionParams(
                        TYPE_LOCKSCREEN,
                        UI_FORMAT_PASSWORD,
                        KeyDerivationParams.createSha256Params(TEST_SALT),
                        TEST_SECRET)));
        byte[] keyClaimant = mRecoverySessionStorage.get(Binder.getCallingUid(), TEST_SESSION_ID)
                .getKeyClaimant();
        SecretKey recoveryKey = randomRecoveryKey();
        byte[] encryptedClaimResponse = encryptClaimResponse(
                keyClaimant, TEST_SECRET, TEST_VAULT_PARAMS, recoveryKey);
        byte[] applicationKeyBytes = randomBytes(32);
        WrappedApplicationKey applicationKey = new WrappedApplicationKey.Builder()
                    .setAlias(TEST_ALIAS)
                    .setEncryptedKeyMaterial(
                            encryptedApplicationKey(recoveryKey, applicationKeyBytes))
                    .build();

        Map<String, String> recoveredKeys = mRecoverableKeyStoreManager.recoverKeyChainSnapshot(
                TEST_SESSION_ID,
                encryptedClaimResponse,
                ImmutableList.of(applicationKey));

        assertThat(recoveredKeys).hasSize(1);
        assertThat(recoveredKeys).containsKey(TEST_ALIAS);
        // TODO(76083050) Test the grant mechanism for the keys.
    }

    @Test
    public void recoverKeyChainSnapshot_worksOnOtherApplicationKeysIfOneDecryptionFails() throws Exception {
        mRecoverableKeyStoreManager.startRecoverySession(
                TEST_SESSION_ID,
                TEST_PUBLIC_KEY,
                TEST_VAULT_PARAMS,
                TEST_VAULT_CHALLENGE,
                ImmutableList.of(new KeyChainProtectionParams(
                        TYPE_LOCKSCREEN,
                        UI_FORMAT_PASSWORD,
                        KeyDerivationParams.createSha256Params(TEST_SALT),
                        TEST_SECRET)));
        byte[] keyClaimant = mRecoverySessionStorage.get(Binder.getCallingUid(), TEST_SESSION_ID)
                .getKeyClaimant();
        SecretKey recoveryKey = randomRecoveryKey();
        byte[] encryptedClaimResponse = encryptClaimResponse(
                keyClaimant, TEST_SECRET, TEST_VAULT_PARAMS, recoveryKey);

        byte[] applicationKeyBytes1 = randomBytes(32);
        byte[] applicationKeyBytes2 = randomBytes(32);
        WrappedApplicationKey applicationKey1 = new WrappedApplicationKey.Builder()
                    .setAlias(TEST_ALIAS)
                     // Use a different recovery key here, so the decryption will fail
                    .setEncryptedKeyMaterial(
                            encryptedApplicationKey(randomRecoveryKey(), applicationKeyBytes1))
                    .build();
        WrappedApplicationKey applicationKey2 = new WrappedApplicationKey.Builder()
                    .setAlias(TEST_ALIAS2)
                    .setEncryptedKeyMaterial(
                            encryptedApplicationKey(recoveryKey, applicationKeyBytes2))
                    .build();

        Map<String, String> recoveredKeys = mRecoverableKeyStoreManager.recoverKeyChainSnapshot(
                TEST_SESSION_ID,
                encryptedClaimResponse,
                ImmutableList.of(applicationKey1, applicationKey2));

        assertThat(recoveredKeys).hasSize(1);
        assertThat(recoveredKeys).containsKey(TEST_ALIAS2);
        // TODO(76083050) Test the grant mechanism for the keys.
    }

    @Test
    public void setSnapshotCreatedPendingIntent() throws Exception {
        int uid = Binder.getCallingUid();
        PendingIntent intent = PendingIntent.getBroadcast(
                InstrumentationRegistry.getTargetContext(), /*requestCode=*/1,
                new Intent(), /*flags=*/ 0);
        mRecoverableKeyStoreManager.setSnapshotCreatedPendingIntent(intent);
        verify(mMockListenersStorage).setSnapshotListener(eq(uid), any(PendingIntent.class));
    }

    @Test
    public void setServerParams_updatesServerParams() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        byte[] serverParams = new byte[] { 1 };

        mRecoverableKeyStoreManager.setServerParams(serverParams);

        assertThat(mRecoverableKeyStoreDb.getServerParams(userId, uid)).isEqualTo(serverParams);
    }

    @Test
    public void setServerParams_doesNotSetSnapshotPendingIfInitializing() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        byte[] serverParams = new byte[] { 1 };

        mRecoverableKeyStoreManager.setServerParams(serverParams);

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isFalse();
    }

    @Test
    public void setServerParams_doesNotSetSnapshotPendingIfSettingSameValue() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        byte[] serverParams = new byte[] { 1 };

        mRecoverableKeyStoreManager.setServerParams(serverParams);
        mRecoverableKeyStoreManager.setServerParams(serverParams);

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isFalse();
    }

    @Test
    public void setServerParams_setsSnapshotPendingIfUpdatingValue() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();

        mRecoverableKeyStoreManager.setServerParams(new byte[] { 1 });
        mRecoverableKeyStoreManager.setServerParams(new byte[] { 2 });

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isTrue();
    }

    @Test
    public void setRecoverySecretTypes() throws Exception {
        int[] types1 = new int[]{11, 2000};
        int[] types2 = new int[]{1, 2, 3};
        int[] types3 = new int[]{};

        mRecoverableKeyStoreManager.setRecoverySecretTypes(types1);
        assertThat(mRecoverableKeyStoreManager.getRecoverySecretTypes()).isEqualTo(
                types1);

        mRecoverableKeyStoreManager.setRecoverySecretTypes(types2);
        assertThat(mRecoverableKeyStoreManager.getRecoverySecretTypes()).isEqualTo(
                types2);

        mRecoverableKeyStoreManager.setRecoverySecretTypes(types3);
        assertThat(mRecoverableKeyStoreManager.getRecoverySecretTypes()).isEqualTo(
                types3);
    }

    @Test
    public void setRecoverySecretTypes_throwsIfNullTypes() throws Exception {
        try {
            mRecoverableKeyStoreManager.setRecoverySecretTypes(/*types=*/ null);
            fail("should have thrown");
        } catch (NullPointerException e) {
            assertThat(e.getMessage()).contains("is null");
        }
    }

    @Test
    public void setRecoverySecretTypes_updatesShouldCreateSnapshot() throws Exception {
        int uid = Binder.getCallingUid();
        int userId = UserHandle.getCallingUserId();
        int[] types = new int[]{1, 2, 3};

        mRecoverableKeyStoreManager.generateAndStoreKey(TEST_ALIAS);
        // Pretend that key was synced
        mRecoverableKeyStoreDb.setShouldCreateSnapshot(userId, uid, false);
        mRecoverableKeyStoreManager.setRecoverySecretTypes(types);

        assertThat(mRecoverableKeyStoreDb.getShouldCreateSnapshot(userId, uid)).isTrue();
    }

    @Test
    public void setRecoveryStatus() throws Exception {
        int userId = UserHandle.getCallingUserId();
        int uid = Binder.getCallingUid();
        int status = 100;
        int status2 = 200;
        String alias = "key1";
        WrappedKey wrappedKey = new WrappedKey(NONCE, KEY_MATERIAL, GENERATION_ID, status);
        mRecoverableKeyStoreDb.insertKey(userId, uid, alias, wrappedKey);
        Map<String, Integer> statuses =
                mRecoverableKeyStoreManager.getRecoveryStatus();
        assertThat(statuses).hasSize(1);
        assertThat(statuses).containsEntry(alias, status);

        mRecoverableKeyStoreManager.setRecoveryStatus(alias, status2);
        statuses = mRecoverableKeyStoreManager.getRecoveryStatus();
        assertThat(statuses).hasSize(1);
        assertThat(statuses).containsEntry(alias, status2); // updated
    }

    @Test
    public void setRecoveryStatus_throwsIfNullAlias() throws Exception {
        try {
            mRecoverableKeyStoreManager.setRecoveryStatus(/*alias=*/ null, /*status=*/ 100);
            fail("should have thrown");
        } catch (NullPointerException e) {
            assertThat(e.getMessage()).contains("is null");
        }
    }

    private static byte[] encryptedApplicationKey(
            SecretKey recoveryKey, byte[] applicationKey) throws Exception {
        return KeySyncUtils.encryptKeysWithRecoveryKey(recoveryKey, ImmutableMap.of(
                TEST_ALIAS, new SecretKeySpec(applicationKey, "AES")
        )).get(TEST_ALIAS);
    }

    private static byte[] encryptClaimResponse(
            byte[] keyClaimant,
            byte[] lskfHash,
            byte[] vaultParams,
            SecretKey recoveryKey) throws Exception {
        byte[] locallyEncryptedRecoveryKey = KeySyncUtils.locallyEncryptRecoveryKey(
                lskfHash, recoveryKey);
        return SecureBox.encrypt(
                /*theirPublicKey=*/ null,
                /*sharedSecret=*/ keyClaimant,
                /*header=*/ KeySyncUtils.concat(RECOVERY_RESPONSE_HEADER, vaultParams),
                /*payload=*/ locallyEncryptedRecoveryKey);
    }

    private static SecretKey randomRecoveryKey() {
        return new SecretKeySpec(randomBytes(32), "AES");
    }

    private static byte[] getUtf8Bytes(String s) {
        return s.getBytes(StandardCharsets.UTF_8);
    }

    private static byte[] randomBytes(int n) {
        byte[] bytes = new byte[n];
        new Random().nextBytes(bytes);
        return bytes;
    }

    private AndroidKeyStoreSecretKey generateAndroidKeyStoreKey() throws Exception {
        KeyGenerator keyGenerator = KeyGenerator.getInstance(
                KEY_ALGORITHM,
                ANDROID_KEY_STORE_PROVIDER);
        keyGenerator.init(new KeyGenParameterSpec.Builder(
                WRAPPING_KEY_ALIAS, KeyProperties.PURPOSE_ENCRYPT | KeyProperties.PURPOSE_DECRYPT)
                .setBlockModes(KeyProperties.BLOCK_MODE_GCM)
                .setEncryptionPaddings(KeyProperties.ENCRYPTION_PADDING_NONE)
                .build());
        return (AndroidKeyStoreSecretKey) keyGenerator.generateKey();
    }
}