Move chunk proto definitions into the BackupEncrypter APK

Bug: 111386661
Test: make RunBackupEncryptionRoboTests
Change-Id: I3032210e6eec52b0c925baab770a4578ac7ecbf7

10 files changed, 143 insertions, 505 deletions

diff --git a/packages/BackupEncryption/proto/backup_chunks_metadata.proto b/packages/BackupEncryption/proto/backup_chunks_metadata.proto
new file mode 100644
index 000000000000..2fdedbf70975
--- /dev/null
+++ b/packages/BackupEncryption/proto/backup_chunks_metadata.proto
@@ -0,0 +1,136 @@
+/*
+ * Copyright (C) 2018 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
+ */
+
+syntax = "proto2";
+
+package android_backup_crypto;
+
+option java_package = "com.android.server.backup.encryption.protos";
+option java_outer_classname = "ChunksMetadataProto";
+
+// Cipher type with which the chunks are encrypted. For now we only support AES/GCM/NoPadding, but
+// this is for backwards-compatibility in case we need to change the default Cipher in the future.
+enum CipherType {
+    UNKNOWN_CIPHER_TYPE = 0;
+    // Chunk is prefixed with a 12-byte nonce. The tag length is 16 bytes.
+    AES_256_GCM = 1;
+}
+
+// Checksum type with which the plaintext is verified.
+enum ChecksumType {
+    UNKNOWN_CHECKSUM_TYPE = 0;
+    SHA_256 = 1;
+}
+
+enum ChunkOrderingType {
+    CHUNK_ORDERING_TYPE_UNSPECIFIED = 0;
+    // The chunk ordering contains a list of the start position of each chunk in the encrypted file,
+    // ordered as in the plaintext file. This allows us to recreate the original plaintext file
+    // during decryption. We use this mode for full backups where the order of the data in the file
+    // is important.
+    EXPLICIT_STARTS = 1;
+    // The chunk ordering does not contain any start positions, and instead each encrypted chunk in
+    // the backup file is prefixed with its length. This allows us to decrypt each chunk but does
+    // not give any information about the order. However, we use this mode for key value backups
+    // where the order does not matter.
+    INLINE_LENGTHS = 2;
+}
+
+// Chunk entry (for local state)
+message Chunk {
+    // SHA-256 MAC of the plaintext of the chunk
+    optional bytes hash = 1;
+    // Number of bytes in encrypted chunk
+    optional int32 length = 2;
+}
+
+// List of the chunks in the blob, along with the length of each chunk. From this is it possible to
+// extract individual chunks. (i.e., start position is equal to the sum of the lengths of all
+// preceding chunks.)
+//
+// This is local state stored on the device. It is never sent to the backup server. See
+// ChunkOrdering for how the device restores the chunks in the correct order.
+// Next tag : 6
+message ChunkListing {
+    repeated Chunk chunks = 1;
+
+    // Cipher algorithm with which the chunks are encrypted.
+    optional CipherType cipher_type = 2;
+
+    // Defines the type of chunk order used to encode the backup file on the server, so that we can
+    // consistently use the same type between backups. If unspecified this backup file was created
+    // before INLINE_LENGTHS was supported, thus assume it is EXPLICIT_STARTS.
+    optional ChunkOrderingType chunk_ordering_type = 5;
+
+    // The document ID returned from Scotty server after uploading the blob associated with this
+    // listing. This needs to be sent when uploading new diff scripts.
+    optional string document_id = 3;
+
+    // Fingerprint mixer salt used for content defined chunking. This is randomly generated for each
+    // package during the initial non-incremental backup and reused for incremental backups.
+    optional bytes fingerprint_mixer_salt = 4;
+}
+
+// Ordering information about plaintext and checksum. This is used on restore to reconstruct the
+// blob in its correct order. (The chunk order is randomized so as to give the server less
+// information about which parts of the backup are changing over time.) This proto is encrypted
+// before being uploaded to the server, with a key unknown to the server.
+message ChunkOrdering {
+    // For backups where ChunksMetadata#chunk_ordering_type = EXPLICIT STARTS:
+    // Ordered start positions of chunks. i.e., the file is the chunk starting at this position,
+    // followed by the chunk starting at this position, followed by ... etc. You can compute the
+    // lengths of the chunks by sorting this list then looking at the start position of the next
+    // chunk after the chunk you care about. This is guaranteed to work as all chunks are
+    // represented in this list.
+    //
+    // For backups where ChunksMetadata#chunk_ordering_type = INLINE_LENGTHS:
+    // This field is unused. See ChunkOrderingType#INLINE_LENGTHS.
+    repeated int32 starts = 1 [packed = true];
+
+    // Checksum of plaintext content. (i.e., in correct order.)
+    //
+    // Each chunk also has a MAC, as generated by GCM, so this is NOT Mac-then-Encrypt, which has
+    // security implications. This is an additional checksum to verify that once the chunks have
+    // been reordered, that the file matches the expected plaintext. This prevents the device
+    // restoring garbage data in case of a mismatch between the ChunkOrdering and the backup blob.
+    optional bytes checksum = 2;
+}
+
+// Additional metadata about a backup blob that needs to be synced to the server. This is used on
+// restore to reconstruct the blob in its correct order. (The chunk order is randomized so as to
+// give the server less information about which parts of the backup are changing over time.) This
+// data structure is only ever uploaded to the server encrypted with a key unknown to the server.
+// Next tag : 6
+message ChunksMetadata {
+    // Cipher algorithm with which the chunk listing and chunks are encrypted.
+    optional CipherType cipher_type = 1;
+
+    // Defines the type of chunk order this metadata contains. If unspecified this backup file was
+    // created before INLINE_LENGTHS was supported, thus assume it is EXPLICIT_STARTS.
+    optional ChunkOrderingType chunk_ordering_type = 5
+    [default = CHUNK_ORDERING_TYPE_UNSPECIFIED];
+
+    // Encrypted bytes of ChunkOrdering
+    optional bytes chunk_ordering = 2;
+
+    // The type of algorithm used for the checksum of the plaintext. (See ChunkOrdering.) This is
+    // for forwards compatibility in case we change the algorithm in the future. For now, always
+    // SHA-256.
+    optional ChecksumType checksum_type = 3;
+
+    // This used to be the plaintext tertiary key. No longer used.
+    reserved 4;
+}
\ No newline at end of file
diff --git a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/Chunk.java b/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/Chunk.java
deleted file mode 100644
index ba328609a77e..000000000000
--- a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/Chunk.java
+++ /dev/null
@@ -1,70 +0,0 @@
-/*
- * Copyright (C) 2018 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.chunk;
-
-import android.util.proto.ProtoInputStream;
-
-import java.io.IOException;
-
-/**
- * Information about a chunk entry in a protobuf. Only used for reading from a {@link
- * ProtoInputStream}.
- */
-public class Chunk {
-    /**
-     * Reads a Chunk from a {@link ProtoInputStream}. Expects the message to be of format {@link
-     * ChunksMetadataProto.Chunk}.
-     *
-     * @param inputStream currently at a {@link ChunksMetadataProto.Chunk} message.
-     * @throws IOException when the message is not structured as expected or a field can not be
-     *     read.
-     */
-    static Chunk readFromProto(ProtoInputStream inputStream) throws IOException {
-        Chunk result = new Chunk();
-
-        while (inputStream.nextField() != ProtoInputStream.NO_MORE_FIELDS) {
-            switch (inputStream.getFieldNumber()) {
-                case (int) ChunksMetadataProto.Chunk.HASH:
-                    result.mHash = inputStream.readBytes(ChunksMetadataProto.Chunk.HASH);
-                    break;
-                case (int) ChunksMetadataProto.Chunk.LENGTH:
-                    result.mLength = inputStream.readInt(ChunksMetadataProto.Chunk.LENGTH);
-                    break;
-            }
-        }
-
-        return result;
-    }
-
-    private int mLength;
-    private byte[] mHash;
-
-    /** Private constructor. This class should only be instantiated by calling readFromProto. */
-    private Chunk() {
-        // Set default values for fields in case they are not available in the proto.
-        mHash = new byte[]{};
-        mLength = 0;
-    }
-
-    public int getLength() {
-        return mLength;
-    }
-
-    public byte[] getHash() {
-        return mHash;
-    }
-}
diff --git a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/ChunkListingMap.java b/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/ChunkListingMap.java
deleted file mode 100644
index a44890118717..000000000000
--- a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/ChunkListingMap.java
+++ /dev/null
@@ -1,109 +0,0 @@
-/*
- * 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.chunk;
-
-import android.annotation.Nullable;
-import android.util.proto.ProtoInputStream;
-
-import java.io.IOException;
-import java.util.Collections;
-import java.util.HashMap;
-import java.util.Map;
-
-/**
- * Chunk listing in a format optimized for quick look-up of chunks via their hash keys. This is
- * useful when building an incremental backup. After a chunk has been produced, the algorithm can
- * quickly look up whether the chunk existed in the previous backup by checking this chunk listing.
- * It can then tell the server to use that chunk, through telling it the position and length of the
- * chunk in the previous backup's blob.
- */
-public class ChunkListingMap {
-    /**
-     * Reads a ChunkListingMap from a {@link ProtoInputStream}. Expects the message to be of format
-     * {@link ChunksMetadataProto.ChunkListing}.
-     *
-     * @param inputStream Currently at a {@link ChunksMetadataProto.ChunkListing} message.
-     * @throws IOException when the message is not structured as expected or a field can not be
-     *     read.
-     */
-    public static ChunkListingMap readFromProto(ProtoInputStream inputStream) throws IOException {
-        Map<ChunkHash, Entry> entries = new HashMap();
-
-        long start = 0;
-
-        while (inputStream.nextField() != ProtoInputStream.NO_MORE_FIELDS) {
-            if (inputStream.getFieldNumber() == (int) ChunksMetadataProto.ChunkListing.CHUNKS) {
-                long chunkToken = inputStream.start(ChunksMetadataProto.ChunkListing.CHUNKS);
-                Chunk chunk = Chunk.readFromProto(inputStream);
-                entries.put(new ChunkHash(chunk.getHash()), new Entry(start, chunk.getLength()));
-                start += chunk.getLength();
-                inputStream.end(chunkToken);
-            }
-        }
-
-        return new ChunkListingMap(entries);
-    }
-
-    private final Map<ChunkHash, Entry> mChunksByHash;
-
-    private ChunkListingMap(Map<ChunkHash, Entry> chunksByHash) {
-        mChunksByHash = Collections.unmodifiableMap(new HashMap<>(chunksByHash));
-    }
-
-    /** Returns {@code true} if there is a chunk with the given SHA-256 MAC key in the listing. */
-    public boolean hasChunk(ChunkHash hash) {
-        return mChunksByHash.containsKey(hash);
-    }
-
-    /**
-     * Returns the entry for the chunk with the given hash.
-     *
-     * @param hash The SHA-256 MAC of the plaintext of the chunk.
-     * @return The entry, containing position and length of the chunk in the backup blob, or null if
-     *     it does not exist.
-     */
-    @Nullable
-    public Entry getChunkEntry(ChunkHash hash) {
-        return mChunksByHash.get(hash);
-    }
-
-    /** Returns the number of chunks in this listing. */
-    public int getChunkCount() {
-        return mChunksByHash.size();
-    }
-
-    /** Information about a chunk entry in a backup blob - i.e., its position and length. */
-    public static final class Entry {
-        private final int mLength;
-        private final long mStart;
-
-        private Entry(long start, int length) {
-            mStart = start;
-            mLength = length;
-        }
-
-        /** Returns the length of the chunk in bytes. */
-        public int getLength() {
-            return mLength;
-        }
-
-        /** Returns the start position of the chunk in the backup blob, in bytes. */
-        public long getStart() {
-            return mStart;
-        }
-    }
-}
diff --git a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/ChunkOrderingType.java b/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/ChunkOrderingType.java
index 8cb028e46e9d..9cda3395f79a 100644
--- a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/ChunkOrderingType.java
+++ b/packages/BackupEncryption/src/com/android/server/backup/encryption/chunk/ChunkOrderingType.java
@@ -16,9 +16,9 @@
 
 package com.android.server.backup.encryption.chunk;
 
-import static com.android.server.backup.encryption.chunk.ChunksMetadataProto.CHUNK_ORDERING_TYPE_UNSPECIFIED;
-import static com.android.server.backup.encryption.chunk.ChunksMetadataProto.EXPLICIT_STARTS;
-import static com.android.server.backup.encryption.chunk.ChunksMetadataProto.INLINE_LENGTHS;
+import static com.android.server.backup.encryption.protos.nano.ChunksMetadataProto.CHUNK_ORDERING_TYPE_UNSPECIFIED;
+import static com.android.server.backup.encryption.protos.nano.ChunksMetadataProto.EXPLICIT_STARTS;
+import static com.android.server.backup.encryption.protos.nano.ChunksMetadataProto.INLINE_LENGTHS;
 
 import android.annotation.IntDef;
 
diff --git a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunking/InlineLengthsEncryptedChunkEncoder.java b/packages/BackupEncryption/src/com/android/server/backup/encryption/chunking/InlineLengthsEncryptedChunkEncoder.java
index 7b38dd4a1dc3..6b9be9fd91d3 100644
--- a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunking/InlineLengthsEncryptedChunkEncoder.java
+++ b/packages/BackupEncryption/src/com/android/server/backup/encryption/chunking/InlineLengthsEncryptedChunkEncoder.java
@@ -17,7 +17,7 @@
 package com.android.server.backup.encryption.chunking;
 
 import com.android.server.backup.encryption.chunk.ChunkOrderingType;
-import com.android.server.backup.encryption.chunk.ChunksMetadataProto;
+import com.android.server.backup.encryption.protos.nano.ChunksMetadataProto;
 
 import java.io.IOException;
 
diff --git a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunking/LengthlessEncryptedChunkEncoder.java b/packages/BackupEncryption/src/com/android/server/backup/encryption/chunking/LengthlessEncryptedChunkEncoder.java
index 567f75d59513..e707350505fb 100644
--- a/packages/BackupEncryption/src/com/android/server/backup/encryption/chunking/LengthlessEncryptedChunkEncoder.java
+++ b/packages/BackupEncryption/src/com/android/server/backup/encryption/chunking/LengthlessEncryptedChunkEncoder.java
@@ -17,7 +17,7 @@
 package com.android.server.backup.encryption.chunking;
 
 import com.android.server.backup.encryption.chunk.ChunkOrderingType;
-import com.android.server.backup.encryption.chunk.ChunksMetadataProto;
+import com.android.server.backup.encryption.protos.nano.ChunksMetadataProto;
 
 import java.io.IOException;
 
diff --git a/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunk/ChunkListingMapTest.java b/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunk/ChunkListingMapTest.java
deleted file mode 100644
index 24e5573b891d..000000000000
--- a/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunk/ChunkListingMapTest.java
+++ /dev/null
@@ -1,197 +0,0 @@
-/*
- * 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.chunk;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import android.platform.test.annotations.Presubmit;
-import android.util.proto.ProtoInputStream;
-import android.util.proto.ProtoOutputStream;
-
-import com.android.internal.util.Preconditions;
-
-import com.google.common.base.Charsets;
-
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.robolectric.RobolectricTestRunner;
-
-import java.io.ByteArrayInputStream;
-import java.util.Arrays;
-
-@RunWith(RobolectricTestRunner.class)
-@Presubmit
-public class ChunkListingMapTest {
-    private static final String CHUNK_A = "CHUNK_A";
-    private static final String CHUNK_B = "CHUNK_B";
-    private static final String CHUNK_C = "CHUNK_C";
-
-    private static final int CHUNK_A_LENGTH = 256;
-    private static final int CHUNK_B_LENGTH = 1024;
-    private static final int CHUNK_C_LENGTH = 4055;
-
-    private ChunkHash mChunkHashA;
-    private ChunkHash mChunkHashB;
-    private ChunkHash mChunkHashC;
-
-    @Before
-    public void setUp() throws Exception {
-        mChunkHashA = getHash(CHUNK_A);
-        mChunkHashB = getHash(CHUNK_B);
-        mChunkHashC = getHash(CHUNK_C);
-    }
-
-    @Test
-    public void testHasChunk_whenChunkInListing_returnsTrue() throws Exception {
-        byte[] chunkListingProto =
-                createChunkListingProto(
-                        new ChunkHash[] {mChunkHashA, mChunkHashB, mChunkHashC},
-                        new int[] {CHUNK_A_LENGTH, CHUNK_B_LENGTH, CHUNK_C_LENGTH});
-        ChunkListingMap chunkListingMap =
-                ChunkListingMap.readFromProto(
-                        new ProtoInputStream(new ByteArrayInputStream(chunkListingProto)));
-
-        boolean chunkAInList = chunkListingMap.hasChunk(mChunkHashA);
-        boolean chunkBInList = chunkListingMap.hasChunk(mChunkHashB);
-        boolean chunkCInList = chunkListingMap.hasChunk(mChunkHashC);
-
-        assertThat(chunkAInList).isTrue();
-        assertThat(chunkBInList).isTrue();
-        assertThat(chunkCInList).isTrue();
-    }
-
-    @Test
-    public void testHasChunk_whenChunkNotInListing_returnsFalse() throws Exception {
-        byte[] chunkListingProto =
-                createChunkListingProto(
-                        new ChunkHash[] {mChunkHashA, mChunkHashB},
-                        new int[] {CHUNK_A_LENGTH, CHUNK_B_LENGTH});
-        ChunkListingMap chunkListingMap =
-                ChunkListingMap.readFromProto(
-                        new ProtoInputStream(new ByteArrayInputStream(chunkListingProto)));
-        ChunkHash chunkHashEmpty = getHash("");
-
-        boolean chunkCInList = chunkListingMap.hasChunk(mChunkHashC);
-        boolean emptyChunkInList = chunkListingMap.hasChunk(chunkHashEmpty);
-
-        assertThat(chunkCInList).isFalse();
-        assertThat(emptyChunkInList).isFalse();
-    }
-
-    @Test
-    public void testGetChunkEntry_returnsEntryWithCorrectLength() throws Exception {
-        byte[] chunkListingProto =
-                createChunkListingProto(
-                        new ChunkHash[] {mChunkHashA, mChunkHashB, mChunkHashC},
-                        new int[] {CHUNK_A_LENGTH, CHUNK_B_LENGTH, CHUNK_C_LENGTH});
-        ChunkListingMap chunkListingMap =
-                ChunkListingMap.readFromProto(
-                        new ProtoInputStream(new ByteArrayInputStream(chunkListingProto)));
-
-        ChunkListingMap.Entry entryA = chunkListingMap.getChunkEntry(mChunkHashA);
-        ChunkListingMap.Entry entryB = chunkListingMap.getChunkEntry(mChunkHashB);
-        ChunkListingMap.Entry entryC = chunkListingMap.getChunkEntry(mChunkHashC);
-
-        assertThat(entryA.getLength()).isEqualTo(CHUNK_A_LENGTH);
-        assertThat(entryB.getLength()).isEqualTo(CHUNK_B_LENGTH);
-        assertThat(entryC.getLength()).isEqualTo(CHUNK_C_LENGTH);
-    }
-
-    @Test
-    public void testGetChunkEntry_returnsEntryWithCorrectStart() throws Exception {
-        byte[] chunkListingProto =
-                createChunkListingProto(
-                        new ChunkHash[] {mChunkHashA, mChunkHashB, mChunkHashC},
-                        new int[] {CHUNK_A_LENGTH, CHUNK_B_LENGTH, CHUNK_C_LENGTH});
-        ChunkListingMap chunkListingMap =
-                ChunkListingMap.readFromProto(
-                        new ProtoInputStream(new ByteArrayInputStream(chunkListingProto)));
-
-        ChunkListingMap.Entry entryA = chunkListingMap.getChunkEntry(mChunkHashA);
-        ChunkListingMap.Entry entryB = chunkListingMap.getChunkEntry(mChunkHashB);
-        ChunkListingMap.Entry entryC = chunkListingMap.getChunkEntry(mChunkHashC);
-
-        assertThat(entryA.getStart()).isEqualTo(0);
-        assertThat(entryB.getStart()).isEqualTo(CHUNK_A_LENGTH);
-        assertThat(entryC.getStart()).isEqualTo(CHUNK_A_LENGTH + CHUNK_B_LENGTH);
-    }
-
-    @Test
-    public void testGetChunkEntry_returnsNullForNonExistentChunk() throws Exception {
-        byte[] chunkListingProto =
-                createChunkListingProto(
-                        new ChunkHash[] {mChunkHashA, mChunkHashB},
-                        new int[] {CHUNK_A_LENGTH, CHUNK_B_LENGTH});
-        ChunkListingMap chunkListingMap =
-                ChunkListingMap.readFromProto(
-                        new ProtoInputStream(new ByteArrayInputStream(chunkListingProto)));
-
-        ChunkListingMap.Entry chunkEntryNonexistentChunk =
-                chunkListingMap.getChunkEntry(mChunkHashC);
-
-        assertThat(chunkEntryNonexistentChunk).isNull();
-    }
-
-    @Test
-    public void testReadFromProto_whenEmptyProto_returnsChunkListingMapWith0Chunks()
-            throws Exception {
-        ProtoInputStream emptyProto = new ProtoInputStream(new ByteArrayInputStream(new byte[] {}));
-
-        ChunkListingMap chunkListingMap = ChunkListingMap.readFromProto(emptyProto);
-
-        assertThat(chunkListingMap.getChunkCount()).isEqualTo(0);
-    }
-
-    @Test
-    public void testReadFromProto_returnsChunkListingWithCorrectSize() throws Exception {
-        byte[] chunkListingProto =
-                createChunkListingProto(
-                        new ChunkHash[] {mChunkHashA, mChunkHashB, mChunkHashC},
-                        new int[] {CHUNK_A_LENGTH, CHUNK_B_LENGTH, CHUNK_C_LENGTH});
-
-        ChunkListingMap chunkListingMap =
-                ChunkListingMap.readFromProto(
-                        new ProtoInputStream(new ByteArrayInputStream(chunkListingProto)));
-
-        assertThat(chunkListingMap.getChunkCount()).isEqualTo(3);
-    }
-
-    private byte[] createChunkListingProto(ChunkHash[] hashes, int[] lengths) {
-        Preconditions.checkArgument(hashes.length == lengths.length);
-        ProtoOutputStream outputStream = new ProtoOutputStream();
-
-        for (int i = 0; i < hashes.length; ++i) {
-            writeToProtoOutputStream(outputStream, hashes[i], lengths[i]);
-        }
-        outputStream.flush();
-
-        return outputStream.getBytes();
-    }
-
-    private void writeToProtoOutputStream(ProtoOutputStream out, ChunkHash chunkHash, int length) {
-        long token = out.start(ChunksMetadataProto.ChunkListing.CHUNKS);
-        out.write(ChunksMetadataProto.Chunk.HASH, chunkHash.getHash());
-        out.write(ChunksMetadataProto.Chunk.LENGTH, length);
-        out.end(token);
-    }
-
-    private ChunkHash getHash(String name) {
-        return new ChunkHash(
-                Arrays.copyOf(name.getBytes(Charsets.UTF_8), ChunkHash.HASH_LENGTH_BYTES));
-    }
-}
diff --git a/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunk/ChunkTest.java b/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunk/ChunkTest.java
deleted file mode 100644
index 1796f56ce17a..000000000000
--- a/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunk/ChunkTest.java
+++ /dev/null
@@ -1,122 +0,0 @@
-/*
- * Copyright (C) 2018 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.chunk;
-
-import static com.google.common.truth.Truth.assertThat;
-
-import android.platform.test.annotations.Presubmit;
-import android.util.proto.ProtoInputStream;
-import android.util.proto.ProtoOutputStream;
-
-import com.google.common.base.Charsets;
-
-import org.junit.Before;
-import org.junit.Test;
-import org.junit.runner.RunWith;
-import org.robolectric.RobolectricTestRunner;
-
-import java.io.ByteArrayInputStream;
-import java.util.Arrays;
-
-@RunWith(RobolectricTestRunner.class)
-@Presubmit
-public class ChunkTest {
-    private static final String CHUNK_A = "CHUNK_A";
-    private static final int CHUNK_A_LENGTH = 256;
-
-    private ChunkHash mChunkHashA;
-
-    @Before
-    public void setUp() throws Exception {
-        mChunkHashA = getHash(CHUNK_A);
-    }
-
-    @Test
-    public void testReadFromProto_readsCorrectly() throws Exception {
-        ProtoOutputStream out = new ProtoOutputStream();
-        out.write(ChunksMetadataProto.Chunk.HASH, mChunkHashA.getHash());
-        out.write(ChunksMetadataProto.Chunk.LENGTH, CHUNK_A_LENGTH);
-        out.flush();
-        byte[] protoBytes = out.getBytes();
-
-        Chunk chunk =
-                Chunk.readFromProto(new ProtoInputStream(new ByteArrayInputStream(protoBytes)));
-
-        assertThat(chunk.getHash()).isEqualTo(mChunkHashA.getHash());
-        assertThat(chunk.getLength()).isEqualTo(CHUNK_A_LENGTH);
-    }
-
-    @Test
-    public void testReadFromProto_whenFieldsWrittenInReversedOrder_readsCorrectly()
-            throws Exception {
-        ProtoOutputStream out = new ProtoOutputStream();
-        // Write fields of Chunk proto in reverse order.
-        out.write(ChunksMetadataProto.Chunk.LENGTH, CHUNK_A_LENGTH);
-        out.write(ChunksMetadataProto.Chunk.HASH, mChunkHashA.getHash());
-        out.flush();
-        byte[] protoBytes = out.getBytes();
-
-        Chunk chunk =
-                Chunk.readFromProto(new ProtoInputStream(new ByteArrayInputStream(protoBytes)));
-
-        assertThat(chunk.getHash()).isEqualTo(mChunkHashA.getHash());
-        assertThat(chunk.getLength()).isEqualTo(CHUNK_A_LENGTH);
-    }
-
-    @Test
-    public void testReadFromProto_whenEmptyProto_returnsEmptyHash() throws Exception {
-        ProtoInputStream emptyProto = new ProtoInputStream(new ByteArrayInputStream(new byte[] {}));
-
-        Chunk chunk = Chunk.readFromProto(emptyProto);
-
-        assertThat(chunk.getHash()).asList().hasSize(0);
-        assertThat(chunk.getLength()).isEqualTo(0);
-    }
-
-    @Test
-    public void testReadFromProto_whenOnlyHashSet_returnsChunkWithOnlyHash() throws Exception {
-        ProtoOutputStream out = new ProtoOutputStream();
-        out.write(ChunksMetadataProto.Chunk.HASH, mChunkHashA.getHash());
-        out.flush();
-        byte[] protoBytes = out.getBytes();
-
-        Chunk chunk =
-                Chunk.readFromProto(new ProtoInputStream(new ByteArrayInputStream(protoBytes)));
-
-        assertThat(chunk.getHash()).isEqualTo(mChunkHashA.getHash());
-        assertThat(chunk.getLength()).isEqualTo(0);
-    }
-
-    @Test
-    public void testReadFromProto_whenOnlyLengthSet_returnsChunkWithOnlyLength() throws Exception {
-        ProtoOutputStream out = new ProtoOutputStream();
-        out.write(ChunksMetadataProto.Chunk.LENGTH, CHUNK_A_LENGTH);
-        out.flush();
-        byte[] protoBytes = out.getBytes();
-
-        Chunk chunk =
-                Chunk.readFromProto(new ProtoInputStream(new ByteArrayInputStream(protoBytes)));
-
-        assertThat(chunk.getHash()).isEqualTo(new byte[] {});
-        assertThat(chunk.getLength()).isEqualTo(CHUNK_A_LENGTH);
-    }
-
-    private ChunkHash getHash(String name) {
-        return new ChunkHash(
-                Arrays.copyOf(name.getBytes(Charsets.UTF_8), ChunkHash.HASH_LENGTH_BYTES));
-    }
-}
diff --git a/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunking/InlineLengthsEncryptedChunkEncoderTest.java b/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunking/InlineLengthsEncryptedChunkEncoderTest.java
index 634acdc42eaf..7e1fdedcac80 100644
--- a/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunking/InlineLengthsEncryptedChunkEncoderTest.java
+++ b/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunking/InlineLengthsEncryptedChunkEncoderTest.java
@@ -24,7 +24,7 @@ import static org.mockito.Mockito.mock;
 import android.platform.test.annotations.Presubmit;
 
 import com.android.server.backup.encryption.chunk.ChunkHash;
-import com.android.server.backup.encryption.chunk.ChunksMetadataProto;
+import com.android.server.backup.encryption.protos.nano.ChunksMetadataProto;
 
 import org.junit.Before;
 import org.junit.Test;
diff --git a/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunking/LengthlessEncryptedChunkEncoderTest.java b/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunking/LengthlessEncryptedChunkEncoderTest.java
index d231603e18b1..6f58ee148b83 100644
--- a/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunking/LengthlessEncryptedChunkEncoderTest.java
+++ b/packages/BackupEncryption/test/robolectric/src/com/android/server/backup/encryption/chunking/LengthlessEncryptedChunkEncoderTest.java
@@ -24,7 +24,7 @@ import static org.mockito.Mockito.mock;
 import android.platform.test.annotations.Presubmit;
 
 import com.android.server.backup.encryption.chunk.ChunkHash;
-import com.android.server.backup.encryption.chunk.ChunksMetadataProto;
+import com.android.server.backup.encryption.protos.nano.ChunksMetadataProto;
 
 import org.junit.Before;
 import org.junit.Test;