content: /*
   * 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.chunking;
  
  import static com.google.common.truth.Truth.assertThat;
  
  import static org.testng.Assert.assertThrows;
  
  import android.platform.test.annotations.Presubmit;
  
  import com.android.server.backup.encryption.chunk.ChunkHash;
  
  import com.google.common.primitives.Bytes;
  
  import org.junit.Test;
  import org.junit.runner.RunWith;
  import org.robolectric.RobolectricTestRunner;
  
  import java.util.Arrays;
  
  @RunWith(RobolectricTestRunner.class)
  @Presubmit
  public class EncryptedChunkTest {
      private static final byte[] CHUNK_HASH_1_BYTES =
              Arrays.copyOf(new byte[] {1}, ChunkHash.HASH_LENGTH_BYTES);
      private static final byte[] NONCE_1 =
              Arrays.copyOf(new byte[] {2}, EncryptedChunk.NONCE_LENGTH_BYTES);
      private static final byte[] ENCRYPTED_BYTES_1 =
              Arrays.copyOf(new byte[] {3}, EncryptedChunk.KEY_LENGTH_BYTES);
  
      private static final byte[] CHUNK_HASH_2_BYTES =
              Arrays.copyOf(new byte[] {4}, ChunkHash.HASH_LENGTH_BYTES);
      private static final byte[] NONCE_2 =
              Arrays.copyOf(new byte[] {5}, EncryptedChunk.NONCE_LENGTH_BYTES);
      private static final byte[] ENCRYPTED_BYTES_2 =
              Arrays.copyOf(new byte[] {6}, EncryptedChunk.KEY_LENGTH_BYTES);
  
      @Test
      public void testCreate_withIncorrectLength_throwsException() {
          ChunkHash chunkHash = new ChunkHash(CHUNK_HASH_1_BYTES);
          byte[] shortNonce = Arrays.copyOf(new byte[] {2}, EncryptedChunk.NONCE_LENGTH_BYTES - 1);
  
          assertThrows(
                  IllegalArgumentException.class,
                  () -> EncryptedChunk.create(chunkHash, shortNonce, ENCRYPTED_BYTES_1));
      }
  
      @Test
      public void testEncryptedBytes_forNewlyCreatedObject_returnsCorrectValue() {
          ChunkHash chunkHash = new ChunkHash(CHUNK_HASH_1_BYTES);
          EncryptedChunk encryptedChunk =
                  EncryptedChunk.create(chunkHash, NONCE_1, ENCRYPTED_BYTES_1);
  
          byte[] returnedBytes = encryptedChunk.encryptedBytes();
  
          assertThat(returnedBytes)
                  .asList()
                  .containsExactlyElementsIn(Bytes.asList(ENCRYPTED_BYTES_1))
                  .inOrder();
      }
  
      @Test
      public void testKey_forNewlyCreatedObject_returnsCorrectValue() {
          ChunkHash chunkHash = new ChunkHash(CHUNK_HASH_1_BYTES);
          EncryptedChunk encryptedChunk =
                  EncryptedChunk.create(chunkHash, NONCE_1, ENCRYPTED_BYTES_1);
  
          ChunkHash returnedKey = encryptedChunk.key();
  
          assertThat(returnedKey).isEqualTo(chunkHash);
      }
  
      @Test
      public void testNonce_forNewlycreatedObject_returnCorrectValue() {
          ChunkHash chunkHash = new ChunkHash(CHUNK_HASH_1_BYTES);
          EncryptedChunk encryptedChunk =
                  EncryptedChunk.create(chunkHash, NONCE_1, ENCRYPTED_BYTES_1);
  
          byte[] returnedNonce = encryptedChunk.nonce();
  
          assertThat(returnedNonce).asList().containsExactlyElementsIn(Bytes.asList(NONCE_1));
      }
  
      @Test
      public void testEquals() {
          ChunkHash chunkHash1 = new ChunkHash(CHUNK_HASH_1_BYTES);
          ChunkHash equalChunkHash1 = new ChunkHash(CHUNK_HASH_1_BYTES);
          ChunkHash chunkHash2 = new ChunkHash(CHUNK_HASH_2_BYTES);
          EncryptedChunk encryptedChunk1 =
                  EncryptedChunk.create(chunkHash1, NONCE_1, ENCRYPTED_BYTES_1);
          EncryptedChunk equalEncryptedChunk1 =
                  EncryptedChunk.create(equalChunkHash1, NONCE_1, ENCRYPTED_BYTES_1);
          EncryptedChunk encryptedChunk2 =
                  EncryptedChunk.create(chunkHash2, NONCE_2, ENCRYPTED_BYTES_2);
  
          assertThat(encryptedChunk1).isEqualTo(equalEncryptedChunk1);
          assertThat(encryptedChunk1).isNotEqualTo(encryptedChunk2);
      }
  
      @Test
      public void testHashCode() {
          ChunkHash chunkHash1 = new ChunkHash(CHUNK_HASH_1_BYTES);
          ChunkHash equalChunkHash1 = new ChunkHash(CHUNK_HASH_1_BYTES);
          ChunkHash chunkHash2 = new ChunkHash(CHUNK_HASH_2_BYTES);
          EncryptedChunk encryptedChunk1 =
                  EncryptedChunk.create(chunkHash1, NONCE_1, ENCRYPTED_BYTES_1);
          EncryptedChunk equalEncryptedChunk1 =
                  EncryptedChunk.create(equalChunkHash1, NONCE_1, ENCRYPTED_BYTES_1);
          EncryptedChunk encryptedChunk2 =
                  EncryptedChunk.create(chunkHash2, NONCE_2, ENCRYPTED_BYTES_2);
  
          int hash1 = encryptedChunk1.hashCode();
          int equalHash1 = equalEncryptedChunk1.hashCode();
          int hash2 = encryptedChunk2.hashCode();
  
          assertThat(hash1).isEqualTo(equalHash1);
          assertThat(hash1).isNotEqualTo(hash2);
      }
  }
  