Import ClearCryptoStateTask

Bug: 111386661
Test: make RunBackupEncryptionRoboTests
Change-Id: Ie8a6ed4a0fc7cf015e39170f24c6924430d69619

packages/BackupEncryption/src/com/android/server/backup/encryption/tasks/ClearCryptoStateTask.java

@@ -0,0 +1,71 @@
+/*
+ * Copyright (C) 2019 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.backup.encryption.tasks;
+
+import android.content.Context;
+import android.util.Slog;
+
+import com.android.server.backup.encryption.CryptoSettings;
+import com.android.server.backup.encryption.chunking.ProtoStore;
+import com.android.server.backup.encryption.storage.BackupEncryptionDb;
+import com.android.server.backup.encryption.storage.EncryptionDbException;
+
+import java.io.IOException;
+
+/**
+ * Task to clear local crypto state.
+ *
+ * <p>Needs to run whenever the user changes their backup account.
+ */
+public class ClearCryptoStateTask {
+    private static final String TAG = "ClearCryptoStateTask";
+
+    private final Context mContext;
+    private final CryptoSettings mCryptoSettings;
+
+    /**
+     * A new instance.
+     *
+     * @param context for finding local storage.
+     * @param cryptoSettings to clear
+     */
+    public ClearCryptoStateTask(Context context, CryptoSettings cryptoSettings) {
+        mContext = context;
+        mCryptoSettings = cryptoSettings;
+    }
+
+    /** Deletes all local state for backup (not restore). */
+    public void run() {
+        Slog.d(TAG, "Clearing local crypto state.");
+        try {
+            BackupEncryptionDb.newInstance(mContext).clear();
+        } catch (EncryptionDbException e) {
+            Slog.e(TAG, "Error clearing encryption database", e);
+        }
+        mCryptoSettings.clearAllSettingsForBackup();
+        try {
+            ProtoStore.createChunkListingStore(mContext).deleteAllProtos();
+        } catch (IOException e) {
+            Slog.e(TAG, "Error clearing chunk listing store", e);
+        }
+        try {
+            ProtoStore.createKeyValueListingStore(mContext).deleteAllProtos();
+        } catch (IOException e) {
+            Slog.e(TAG, "Error clearing key-value store", e);
+        }
+    }
+}

packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/tasks/ClearCryptoStateTaskTest.java

@@ -0,0 +1,109 @@
+/*
+ * Copyright (C) 2019 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.backup.encryption.tasks;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import static org.mockito.Mockito.spy;
+
+import android.content.Context;
+import android.platform.test.annotations.Presubmit;
+
+import androidx.test.core.app.ApplicationProvider;
+
+import com.android.server.backup.encryption.CryptoSettings;
+import com.android.server.backup.encryption.chunking.ProtoStore;
+import com.android.server.backup.encryption.protos.nano.ChunksMetadataProto.ChunkListing;
+import com.android.server.backup.encryption.protos.nano.KeyValueListingProto.KeyValueListing;
+import com.android.server.backup.encryption.storage.BackupEncryptionDb;
+import com.android.server.backup.encryption.storage.TertiaryKey;
+import com.android.server.backup.encryption.storage.TertiaryKeysTable;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+
+@RunWith(RobolectricTestRunner.class)
+@Presubmit
+public class ClearCryptoStateTaskTest {
+    private static final String TEST_PACKAGE_NAME = "com.android.example";
+
+    private ClearCryptoStateTask mClearCryptoStateTask;
+    private CryptoSettings mCryptoSettings;
+    private Context mApplication;
+
+    @Before
+    public void setUp() {
+        mApplication = ApplicationProvider.getApplicationContext();
+        mCryptoSettings = spy(CryptoSettings.getInstanceForTesting(mApplication));
+        mClearCryptoStateTask = new ClearCryptoStateTask(mApplication, mCryptoSettings);
+    }
+
+    @Test
+    public void run_clearsChunkListingProtoState() throws Exception {
+        String packageName = TEST_PACKAGE_NAME;
+        ChunkListing chunkListing = new ChunkListing();
+        ProtoStore.createChunkListingStore(mApplication).saveProto(packageName, chunkListing);
+
+        mClearCryptoStateTask.run();
+
+        assertThat(
+                        ProtoStore.createChunkListingStore(mApplication)
+                                .loadProto(packageName)
+                                .isPresent())
+                .isFalse();
+    }
+
+    @Test
+    public void run_clearsKeyValueProtoState() throws Exception {
+        String packageName = TEST_PACKAGE_NAME;
+        KeyValueListing keyValueListing = new KeyValueListing();
+        ProtoStore.createKeyValueListingStore(mApplication).saveProto(packageName, keyValueListing);
+
+        mClearCryptoStateTask.run();
+
+        assertThat(
+                        ProtoStore.createKeyValueListingStore(mApplication)
+                                .loadProto(packageName)
+                                .isPresent())
+                .isFalse();
+    }
+
+    @Test
+    public void run_clearsTertiaryKeysTable() throws Exception {
+        String secondaryKeyAlias = "bob";
+        TertiaryKeysTable tertiaryKeysTable =
+                BackupEncryptionDb.newInstance(mApplication).getTertiaryKeysTable();
+        tertiaryKeysTable.addKey(
+                new TertiaryKey(
+                        secondaryKeyAlias, "packageName", /*wrappedKeyBytes=*/ new byte[0]));
+
+        mClearCryptoStateTask.run();
+
+        assertThat(tertiaryKeysTable.getAllKeys(secondaryKeyAlias)).isEmpty();
+    }
+
+    @Test
+    public void run_clearsSettings() {
+        mCryptoSettings.setSecondaryLastRotated(100001);
+
+        mClearCryptoStateTask.run();
+
+        assertThat(mCryptoSettings.getSecondaryLastRotated().isPresent()).isFalse();
+    }
+}