Merge "Import FullRestoreToFileTask"

/*

 * 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 java.io.IOException;

/** Interface for classes which will provide backup data */

public abstract class FullRestoreDownloader {

    /** Enum to provide information on why a download finished */

    public enum FinishType {

        UNKNOWN_FINISH(0),

        // Finish the downloading and successfully write data to Android OS.

        FINISHED(1),

        // Download failed with any kind of exception.

        TRANSFER_FAILURE(2),

        // Download failed due to auth failure on the device.

        AUTH_FAILURE(3),

        // Aborted by Android Framework.

        FRAMEWORK_ABORTED(4);

        private int mValue;

        FinishType(int value) {

            mValue = value;

        }

    }

    /** Get the next data chunk from the backing store */

    public abstract int readNextChunk(byte[] buffer) throws IOException;

    /** Called when we've finished restoring the data */

    public abstract void finish(FinishType finishType);

}

/*

 * 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.android.internal.util.Preconditions.checkArgument;

import com.android.internal.annotations.VisibleForTesting;

import com.android.server.backup.encryption.FullRestoreDownloader;

import com.android.server.backup.encryption.FullRestoreDownloader.FinishType;

import java.io.BufferedOutputStream;

import java.io.File;

import java.io.FileOutputStream;

import java.io.IOException;

/**

 * Reads a stream from a {@link FullRestoreDownloader} and writes it to a file for consumption by

 * {@link BackupFileDecryptorTask}.

 */

public class FullRestoreToFileTask {

    /**

     * Maximum number of bytes which the framework can request from the full restore data stream in

     * one call to {@link BackupTransport#getNextFullRestoreDataChunk}.

     */

    public static final int MAX_BYTES_FULL_RESTORE_CHUNK = 1024 * 32;

    /** Returned when the end of a backup stream has been reached. */

    private static final int END_OF_STREAM = -1;

    private final FullRestoreDownloader mFullRestoreDownloader;

    private final int mBufferSize;

    /**

     * Constructs a new instance which reads from the given package wrapper, using a buffer of size

     * {@link #MAX_BYTES_FULL_RESTORE_CHUNK}.

     */

    public FullRestoreToFileTask(FullRestoreDownloader fullRestoreDownloader) {

        this(fullRestoreDownloader, MAX_BYTES_FULL_RESTORE_CHUNK);

    }

    @VisibleForTesting

    FullRestoreToFileTask(FullRestoreDownloader fullRestoreDownloader, int bufferSize) {

        checkArgument(bufferSize > 0, "Buffer must have positive size");

        this.mFullRestoreDownloader = fullRestoreDownloader;

        this.mBufferSize = bufferSize;

    }

    /**

     * Downloads the backup file from the server and writes it to the given file.

     *

     * <p>At the end of the download (success or failure), closes the connection and sends a

     * Clearcut log.

     */

    public void restoreToFile(File targetFile) throws IOException {

        try (BufferedOutputStream outputStream =

                new BufferedOutputStream(new FileOutputStream(targetFile))) {

            byte[] buffer = new byte[mBufferSize];

            int bytesRead = mFullRestoreDownloader.readNextChunk(buffer);

            while (bytesRead != END_OF_STREAM) {

                outputStream.write(buffer, /* off=*/ 0, bytesRead);

                bytesRead = mFullRestoreDownloader.readNextChunk(buffer);

            }

            outputStream.flush();

            mFullRestoreDownloader.finish(FinishType.FINISHED);

        } catch (IOException e) {

            mFullRestoreDownloader.finish(FinishType.TRANSFER_FAILURE);

            throw e;

        }

    }

}

/*

 * 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.ArgumentMatchers.any;

import static org.mockito.Mockito.verify;

import static org.mockito.Mockito.when;

import static org.testng.Assert.assertThrows;

import android.platform.test.annotations.Presubmit;

import com.android.server.backup.encryption.FullRestoreDownloader;

import com.android.server.backup.encryption.FullRestoreDownloader.FinishType;

import com.google.common.io.Files;

import org.junit.Before;

import org.junit.Rule;

import org.junit.Test;

import org.junit.rules.TemporaryFolder;

import org.junit.runner.RunWith;

import org.mockito.Mock;

import org.mockito.MockitoAnnotations;

import org.robolectric.RobolectricTestRunner;

import java.io.ByteArrayInputStream;

import java.io.File;

import java.io.IOException;

import java.util.Random;

@RunWith(RobolectricTestRunner.class)

@Presubmit

public class FullRestoreToFileTaskTest {

    private static final int TEST_RANDOM_SEED = 34;

    private static final int TEST_MAX_CHUNK_SIZE_BYTES = 5;

    private static final int TEST_DATA_LENGTH_BYTES = TEST_MAX_CHUNK_SIZE_BYTES * 20;

    @Rule public TemporaryFolder mTemporaryFolder = new TemporaryFolder();

    private byte[] mTestData;

    private File mTargetFile;

    private FakeFullRestoreDownloader mFakeFullRestoreDownloader;

    @Mock private FullRestoreDownloader mMockFullRestoreDownloader;

    @Before

    public void setUp() throws Exception {

        MockitoAnnotations.initMocks(this);

        mTargetFile = mTemporaryFolder.newFile();

        mTestData = new byte[TEST_DATA_LENGTH_BYTES];

        new Random(TEST_RANDOM_SEED).nextBytes(mTestData);

        mFakeFullRestoreDownloader = new FakeFullRestoreDownloader(mTestData);

    }

    private FullRestoreToFileTask createTaskWithFakeDownloader() {

        return new FullRestoreToFileTask(mFakeFullRestoreDownloader, TEST_MAX_CHUNK_SIZE_BYTES);

    }

    private FullRestoreToFileTask createTaskWithMockDownloader() {

        return new FullRestoreToFileTask(mMockFullRestoreDownloader, TEST_MAX_CHUNK_SIZE_BYTES);

    }

    @Test

    public void restoreToFile_readsDataAndWritesToFile() throws Exception {

        FullRestoreToFileTask task = createTaskWithFakeDownloader();

        task.restoreToFile(mTargetFile);

        assertThat(Files.toByteArray(mTargetFile)).isEqualTo(mTestData);

    }

    @Test

    public void restoreToFile_noErrors_closesDownloaderWithFinished() throws Exception {

        FullRestoreToFileTask task = createTaskWithMockDownloader();

        when(mMockFullRestoreDownloader.readNextChunk(any())).thenReturn(-1);

        task.restoreToFile(mTargetFile);

        verify(mMockFullRestoreDownloader).finish(FinishType.FINISHED);

    }

    @Test

    public void restoreToFile_ioException_closesDownloaderWithTransferFailure() throws Exception {

        FullRestoreToFileTask task = createTaskWithMockDownloader();

        when(mMockFullRestoreDownloader.readNextChunk(any())).thenThrow(IOException.class);

        assertThrows(IOException.class, () -> task.restoreToFile(mTargetFile));

        verify(mMockFullRestoreDownloader).finish(FinishType.TRANSFER_FAILURE);

    }

    /** 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();

            this.mData = new ByteArrayInputStream(data);

        }

        @Override

        public int readNextChunk(byte[] buffer) throws IOException {

            return mData.read(buffer);

        }

        @Override

        public void finish(FinishType finishType) {

            // Do nothing.

        }

    }

}

/*

 * 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.

 */

import com.google.common.io.ByteStreams;

import java.io.File;

import java.io.FileInputStream;

import java.io.IOException;

/** Utility methods for use in tests */

public class TestFileUtils {

    /** Read the contents of a file into a byte array */

    public static byte[] toByteArray(File file) throws IOException {

        try (FileInputStream fis = new FileInputStream(file)) {

            return ByteStreams.toByteArray(fis);

        }

    }

}