Add backup data round trip test

Bug: 111386661
Test: make RunBackupEncryptionRoboIntegTests
Change-Id: Idbfec4ff7bcb0d0b44931884d1c11af7a937bd30

packages/BackupEncryption/test/robolectric-integration/Android.bp

@@ -0,0 +1,33 @@
+// 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.
+
+android_robolectric_test {
+    name: "BackupEncryptionRoboIntegTests",
+    srcs: [
+        "src/**/*.java",
+    ],
+    java_resource_dirs: ["config"],
+    libs: [
+        "backup-encryption-protos",
+        "platform-test-annotations",
+        "testng",
+        "truth-prebuilt",
+    ],
+    static_libs: [
+        "androidx.test.core",
+        "androidx.test.runner",
+        "androidx.test.rules",
+    ],
+    instrumentation_for: "BackupEncryption",
+}

packages/BackupEncryption/test/robolectric-integration/AndroidManifest.xml

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<!--
+  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.
+  -->
+
+<manifest xmlns:android="http://schemas.android.com/apk/res/android"
+          coreApp="true"
+          package="com.android.server.backup.encryption.robointeg">
+
+    <application/>
+
+</manifest>

packages/BackupEncryption/test/robolectric-integration/config/robolectric.properties

@@ -0,0 +1,17 @@
+#
+# 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.
+#
+
+sdk=NEWEST_SDK

packages/BackupEncryption/test/robolectric-integration/src/com/android/server/backup/encryption/RoundTripTest.java

@@ -0,0 +1,217 @@
+/*
+ * 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;
+
+import static com.google.common.truth.Truth.assertThat;
+
+import android.content.Context;
+
+import androidx.test.core.app.ApplicationProvider;
+
+import com.android.server.backup.encryption.client.CryptoBackupServer;
+import com.android.server.backup.encryption.keys.RecoverableKeyStoreSecondaryKey;
+import com.android.server.backup.encryption.keys.TertiaryKeyManager;
+import com.android.server.backup.encryption.keys.TertiaryKeyRotationScheduler;
+import com.android.server.backup.encryption.protos.nano.WrappedKeyProto;
+import com.android.server.backup.encryption.tasks.EncryptedFullBackupTask;
+import com.android.server.backup.encryption.tasks.EncryptedFullRestoreTask;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.security.InvalidAlgorithmParameterException;
+import java.security.InvalidKeyException;
+import java.security.NoSuchAlgorithmException;
+import java.security.SecureRandom;
+import java.util.Map;
+
+import javax.crypto.IllegalBlockSizeException;
+import javax.crypto.KeyGenerator;
+import javax.crypto.NoSuchPaddingException;
+import javax.crypto.SecretKey;
+
+@RunWith(RobolectricTestRunner.class)
+public class RoundTripTest {
+    /** Amount of data we want to round trip in this test */
+    private static final int TEST_DATA_SIZE = 1024 * 1024; // 1MB
+
+    /** Buffer size used when reading data from the restore task */
+    private static final int READ_BUFFER_SIZE = 1024; // 1024 byte buffer.
+
+    /** Key parameters used for the secondary encryption key */
+    private static final String KEY_ALGORITHM = "AES";
+    private static final int KEY_SIZE_BITS = 256;
+
+    /** Package name for our test package */
+    private static final String TEST_PACKAGE_NAME = "com.android.backup.test";
+
+    /** The name we use to refer to our secondary key */
+    private static final String TEST_KEY_ALIAS = "test/backup/KEY_ALIAS";
+
+    /** Original data used for comparison after round trip */
+    private final byte[] mOriginalData = new byte[TEST_DATA_SIZE];
+
+    /** App context, used to store the key data and chunk listings */
+    private Context mContext;
+
+    /** The secondary key we're using for the test */
+    private RecoverableKeyStoreSecondaryKey mSecondaryKey;
+
+    /** Source of random material which is considered non-predictable in its' generation */
+    private SecureRandom mSecureRandom = new SecureRandom();
+
+    @Before
+    public void setUp() throws NoSuchAlgorithmException {
+        mContext = ApplicationProvider.getApplicationContext();
+        mSecondaryKey = new RecoverableKeyStoreSecondaryKey(TEST_KEY_ALIAS, generateAesKey());
+        fillBuffer(mOriginalData);
+    }
+
+    @Test
+    public void testRoundTrip() throws Exception {
+        byte[] backupData = performBackup(mOriginalData);
+        assertThat(backupData).isNotEqualTo(mOriginalData);
+        byte[] restoredData = performRestore(backupData);
+        assertThat(restoredData).isEqualTo(mOriginalData);
+    }
+
+    /** Perform a backup and return the backed-up representation of the data */
+    private byte[] performBackup(byte[] backupData) throws Exception {
+        DummyServer dummyServer = new DummyServer();
+        EncryptedFullBackupTask backupTask =
+                EncryptedFullBackupTask.newInstance(
+                        mContext,
+                        dummyServer,
+                        mSecureRandom,
+                        mSecondaryKey,
+                        TEST_PACKAGE_NAME,
+                        new ByteArrayInputStream(backupData));
+        backupTask.call();
+        return dummyServer.mStoredData;
+    }
+
+    /** Perform a restore and resturn the bytes obtained from the restore process */
+    private byte[] performRestore(byte[] backupData)
+            throws IOException, NoSuchAlgorithmException, NoSuchPaddingException,
+                    InvalidAlgorithmParameterException, InvalidKeyException,
+                    IllegalBlockSizeException {
+        ByteArrayOutputStream decryptedOutput = new ByteArrayOutputStream();
+
+        EncryptedFullRestoreTask restoreTask =
+                EncryptedFullRestoreTask.newInstance(
+                        mContext, new FakeFullRestoreDownloader(backupData), getTertiaryKey());
+
+        byte[] buffer = new byte[READ_BUFFER_SIZE];
+        int bytesRead = restoreTask.readNextChunk(buffer);
+        while (bytesRead != -1) {
+            decryptedOutput.write(buffer, 0, bytesRead);
+            bytesRead = restoreTask.readNextChunk(buffer);
+        }
+
+        return decryptedOutput.toByteArray();
+    }
+
+    /** Get the tertiary key for our test package from the key manager */
+    private SecretKey getTertiaryKey()
+            throws IllegalBlockSizeException, InvalidAlgorithmParameterException,
+                    NoSuchAlgorithmException, IOException, NoSuchPaddingException,
+                    InvalidKeyException {
+        TertiaryKeyManager tertiaryKeyManager =
+                new TertiaryKeyManager(
+                        mContext,
+                        mSecureRandom,
+                        TertiaryKeyRotationScheduler.getInstance(mContext),
+                        mSecondaryKey,
+                        TEST_PACKAGE_NAME);
+        return tertiaryKeyManager.getKey();
+    }
+
+    /** Fill a buffer with data in a predictable way */
+    private void fillBuffer(byte[] buffer) {
+        byte loopingCounter = 0;
+        for (int i = 0; i < buffer.length; i++) {
+            buffer[i] = loopingCounter;
+            loopingCounter++;
+        }
+    }
+
+    /** Generate a new, random, AES key */
+    public static SecretKey generateAesKey() throws NoSuchAlgorithmException {
+        KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_ALGORITHM);
+        keyGenerator.init(KEY_SIZE_BITS);
+        return keyGenerator.generateKey();
+    }
+
+    /**
+     * Dummy backup data endpoint. This stores the data so we can use it
+     * in subsequent test steps.
+     */
+    private static class DummyServer implements CryptoBackupServer {
+        private static final String DUMMY_DOC_ID = "DummyDoc";
+
+        byte[] mStoredData = null;
+
+        @Override
+        public String uploadIncrementalBackup(
+                String packageName,
+                String oldDocId,
+                byte[] diffScript,
+                WrappedKeyProto.WrappedKey tertiaryKey) {
+            throw new RuntimeException("Not Implemented");
+        }
+
+        @Override
+        public String uploadNonIncrementalBackup(
+                String packageName, byte[] data, WrappedKeyProto.WrappedKey tertiaryKey) {
+            assertThat(packageName).isEqualTo(TEST_PACKAGE_NAME);
+            mStoredData = data;
+            return DUMMY_DOC_ID;
+        }
+
+        @Override
+        public void setActiveSecondaryKeyAlias(
+                String keyAlias, Map<String, WrappedKeyProto.WrappedKey> tertiaryKeys) {
+            throw new RuntimeException("Not Implemented");
+        }
+    }
+
+    /** Fake package wrapper which returns data from a byte array. */
+    private static class FakeFullRestoreDownloader extends FullRestoreDownloader {
+        private final ByteArrayInputStream mData;
+
+        FakeFullRestoreDownloader(byte[] data) {
+            // We override all methods of the superclass, so it does not require any collaborators.
+            super();
+            mData = new ByteArrayInputStream(data);
+        }
+
+        @Override
+        public int readNextChunk(byte[] buffer) throws IOException {
+            return mData.read(buffer);
+        }
+
+        @Override
+        public void finish(FinishType finishType) {
+            // Do nothing.
+        }
+    }
+}