private void checkEncryptedKeyChain(SimpleHDKeyChain encChain, DeterministicKey key1) {
   // Check we can look keys up and extend the chain without the AES key being provided.
   DeterministicKey encKey1 = encChain.findKeyFromPubKey(key1.getPubKey());
   DeterministicKey encKey2 = encChain.getKey(KeyChain.KeyPurpose.RECEIVE_FUNDS);
   assertFalse(key1.isEncrypted());
   assertTrue(encKey1.isEncrypted());
   assertEquals(encKey1.getPubKeyPoint(), key1.getPubKeyPoint());
   final KeyParameter aesKey = checkNotNull(encChain.getKeyCrypter()).deriveKey("open secret");
   encKey1.sign(Sha256Hash.ZERO_HASH, aesKey);
   encKey2.sign(Sha256Hash.ZERO_HASH, aesKey);
   assertTrue(encChain.checkAESKey(aesKey));
   assertFalse(encChain.checkPassword("access denied"));
   assertTrue(encChain.checkPassword("open secret"));
 }
  public void serializeUnencrypted(SimpleHDKeyChain keyChain, String expectedSerialization)
      throws UnreadableWalletException {
    keyChain.setLookaheadSize(10);

    keyChain.maybeLookAhead();
    DeterministicKey key1 = keyChain.getKey(KeyChain.KeyPurpose.RECEIVE_FUNDS);
    DeterministicKey key2 = keyChain.getKey(KeyChain.KeyPurpose.RECEIVE_FUNDS);
    DeterministicKey key3 = keyChain.getKey(KeyChain.KeyPurpose.CHANGE);
    List<Protos.Key> keys = keyChain.toProtobuf();
    // 1 master key, 1 account key, 2 internal keys, 3 derived, 20 lookahead and 5 lookahead
    // threshold.
    int numItems =
        1 // master key/account key
            + 2 // ext/int parent keys
            + (keyChain.getLookaheadSize() + keyChain.getLookaheadThreshold())
                * 2 // lookahead zone on each chain
        ;
    assertEquals(numItems, keys.size());

    // Get another key that will be lost during round-tripping, to ensure we can derive it again.
    DeterministicKey key4 = keyChain.getKey(KeyChain.KeyPurpose.CHANGE);

    String sb = protoToString(keys);
    assertEquals(expectedSerialization, sb);

    // Round trip the data back and forth to check it is preserved.
    int oldLookaheadSize = keyChain.getLookaheadSize();
    keyChain = SimpleHDKeyChain.fromProtobuf(keys, null);
    assertEquals(expectedSerialization, protoToString(keyChain.toProtobuf()));
    assertEquals(key1, keyChain.findKeyFromPubHash(key1.getPubKeyHash()));
    assertEquals(key2, keyChain.findKeyFromPubHash(key2.getPubKeyHash()));
    assertEquals(key3, keyChain.findKeyFromPubHash(key3.getPubKeyHash()));
    assertEquals(key4, keyChain.getKey(KeyChain.KeyPurpose.CHANGE));
    key1.sign(Sha256Hash.ZERO_HASH);
    key2.sign(Sha256Hash.ZERO_HASH);
    key3.sign(Sha256Hash.ZERO_HASH);
    key4.sign(Sha256Hash.ZERO_HASH);
    assertEquals(oldLookaheadSize, keyChain.getLookaheadSize());
  }