/**
   * Called when the client provides the multi-sig contract. Checks that the previously-provided
   * refund transaction spends this transaction (because we will use it as a base to create payment
   * transactions) as well as output value and form (ie it is a 2-of-2 multisig to the correct
   * keys).
   *
   * @param multisigContract The provided multisig contract. Do not mutate this object after this
   *     call.
   * @return A future which completes when the provided multisig contract successfully broadcasts,
   *     or throws if the broadcast fails for some reason Note that if the network simply rejects
   *     the transaction, this future will never complete, a timeout should be used.
   * @throws VerificationException If the provided multisig contract is not well-formed or does not
   *     meet previously-specified parameters
   */
  public synchronized ListenableFuture<PaymentChannelServerState> provideMultiSigContract(
      final Transaction multisigContract) throws VerificationException {
    checkNotNull(multisigContract);
    checkState(state == State.WAITING_FOR_MULTISIG_CONTRACT);
    try {
      multisigContract.verify();
      this.multisigContract = multisigContract;
      this.multisigScript = multisigContract.getOutput(0).getScriptPubKey();

      // Check that multisigContract's first output is a 2-of-2 multisig to the correct pubkeys in
      // the correct order
      final Script expectedScript =
          ScriptBuilder.createMultiSigOutputScript(2, Lists.newArrayList(clientKey, serverKey));
      if (!Arrays.equals(multisigScript.getProgram(), expectedScript.getProgram()))
        throw new VerificationException(
            "Multisig contract's first output was not a standard 2-of-2 multisig to client and server in that order.");

      this.totalValue = multisigContract.getOutput(0).getValue();
      if (this.totalValue.signum() <= 0)
        throw new VerificationException(
            "Not accepting an attempt to open a contract with zero value.");
    } catch (VerificationException e) {
      // We couldn't parse the multisig transaction or its output.
      log.error("Provided multisig contract did not verify: {}", multisigContract.toString());
      throw e;
    }
    log.info("Broadcasting multisig contract: {}", multisigContract);
    state = State.WAITING_FOR_MULTISIG_ACCEPTANCE;
    final SettableFuture<PaymentChannelServerState> future = SettableFuture.create();
    Futures.addCallback(
        broadcaster.broadcastTransaction(multisigContract).future(),
        new FutureCallback<Transaction>() {
          @Override
          public void onSuccess(Transaction transaction) {
            log.info(
                "Successfully broadcast multisig contract {}. Channel now open.",
                transaction.getHashAsString());
            try {
              // Manually add the multisigContract to the wallet, overriding the isRelevant checks
              // so we can track
              // it and check for double-spends later
              wallet.receivePending(multisigContract, null, true);
            } catch (VerificationException e) {
              throw new RuntimeException(
                  e); // Cannot happen, we already called multisigContract.verify()
            }
            state = State.READY;
            future.set(PaymentChannelServerState.this);
          }

          @Override
          public void onFailure(Throwable throwable) {
            // Couldn't broadcast the transaction for some reason.
            log.error("Broadcast multisig contract failed", throwable);
            state = State.ERROR;
            future.setException(throwable);
          }
        });
    return future;
  }
  public static boolean isInternal(@Nonnull final Transaction tx) {
    if (tx.isCoinBase()) return false;

    final List<TransactionOutput> outputs = tx.getOutputs();
    if (outputs.size() != 1) return false;

    try {
      final TransactionOutput output = outputs.get(0);
      final Script scriptPubKey = output.getScriptPubKey();
      if (!scriptPubKey.isSentToRawPubKey()) return false;

      return true;
    } catch (final ScriptException x) {
      return false;
    }
  }
Esempio n. 3
0
 private static Block createGenesis(NetworkParameters n) {
   Block genesisBlock = new Block(n);
   Transaction t = new Transaction(n);
   try {
     // A script containing the difficulty bits and the following message:
     //
     //   "The Times 03/Jan/2009 Chancellor on brink of second bailout for banks"
     byte[] bytes =
         Utils.HEX.decode(
             "04ffff001d0104455468652054696d65732030332f4a616e2f32303039204368616e63656c6c6f72206f6e206272696e6b206f66207365636f6e64206261696c6f757420666f722062616e6b73");
     t.addInput(new TransactionInput(n, t, bytes));
     ByteArrayOutputStream scriptPubKeyBytes = new ByteArrayOutputStream();
     Script.writeBytes(
         scriptPubKeyBytes,
         Utils.HEX.decode(
             "04678afdb0fe5548271967f1a67130b7105cd6a828e03909a67962e0ea1f61deb649f6bc3f4cef38c4f35504e51ec112de5c384df7ba0b8d578a4c702b6bf11d5f"));
     scriptPubKeyBytes.write(ScriptOpCodes.OP_CHECKSIG);
     t.addOutput(new TransactionOutput(n, t, FIFTY_COINS, scriptPubKeyBytes.toByteArray()));
   } catch (Exception e) {
     // Cannot happen.
     throw new RuntimeException(e);
   }
   genesisBlock.addTransaction(t);
   return genesisBlock;
 }
 /**
  * Get the address from the {@link Script} if it exists otherwise return empty string "".
  *
  * @param script The script.
  * @return The address.
  */
 private String getScriptAddress(@Nullable Script script) {
   String address = "";
   try {
     if (script != null) {
       address = script.getToAddress(params, true).toString();
     }
   } catch (Exception e) {
   }
   return address;
 }
 PaymentChannelServerState(
     StoredServerChannel storedServerChannel, Wallet wallet, TransactionBroadcaster broadcaster)
     throws VerificationException {
   synchronized (storedServerChannel) {
     this.wallet = checkNotNull(wallet);
     this.broadcaster = checkNotNull(broadcaster);
     this.multisigContract = checkNotNull(storedServerChannel.contract);
     this.multisigScript = multisigContract.getOutput(0).getScriptPubKey();
     this.clientKey = ECKey.fromPublicOnly(multisigScript.getChunks().get(1).data);
     this.clientOutput = checkNotNull(storedServerChannel.clientOutput);
     this.refundTransactionUnlockTimeSecs = storedServerChannel.refundTransactionUnlockTimeSecs;
     this.serverKey = checkNotNull(storedServerChannel.myKey);
     this.totalValue = multisigContract.getOutput(0).getValue();
     this.bestValueToMe = checkNotNull(storedServerChannel.bestValueToMe);
     this.bestValueSignature = storedServerChannel.bestValueSignature;
     checkArgument(bestValueToMe.equals(Coin.ZERO) || bestValueSignature != null);
     this.storedServerChannel = storedServerChannel;
     storedServerChannel.state = this;
     this.state = State.READY;
   }
 }
  /**
   * This is required for signatures which use a sigHashType which cannot be represented using
   * SigHash and anyoneCanPay See transaction
   * c99c49da4c38af669dea436d3e73780dfdb6c1ecf9958baa52960e8baee30e73, which has sigHashType 0
   */
  public static synchronized byte[] serializeForSignature(
      Transaction spendingTx, int inputIndex, byte[] connectedScript, byte sigHashType) {
    NetworkParameters params = TestNet3Params.get();
    // The SIGHASH flags are used in the design of contracts, please see this page for a further
    // understanding of
    // the purposes of the code in this method:
    //
    //   https://en.bitcoin.it/wiki/Contracts

    try {

      Transaction tx = new Transaction(params, spendingTx.bitcoinSerialize());
      // Store all the input scripts and clear them in preparation for signing. If we're signing a
      // fresh
      // transaction that step isn't very helpful, but it doesn't add much cost relative to the
      // actual
      // EC math so we'll do it anyway.
      //
      // Also store the input sequence numbers in case we are clearing them with SigHash.NONE/SINGLE

      byte[][] inputScripts = new byte[tx.getInputs().size()][];
      long[] inputSequenceNumbers = new long[tx.getInputs().size()];
      for (int i = 0; i < tx.getInputs().size(); i++) {
        inputScripts[i] = tx.getInputs().get(i).getScriptBytes();
        inputSequenceNumbers[i] = tx.getInputs().get(i).getSequenceNumber();
        tx.getInput(i).setScriptSig(new Script(new byte[0]));
      }

      // This step has no purpose beyond being synchronized with the reference clients bugs.
      // OP_CODESEPARATOR
      // is a legacy holdover from a previous, broken design of executing scripts that shipped in
      // Bitcoin 0.1.
      // It was seriously flawed and would have let anyone take anyone elses money. Later versions
      // switched to
      // the design we use today where scripts are executed independently but share a stack. This
      // left the
      // OP_CODESEPARATOR instruction having no purpose as it was only meant to be used internally,
      // not actually
      // ever put into scripts. Deleting OP_CODESEPARATOR is a step that should never be required
      // but if we don't
      // do it, we could split off the main chain.

      connectedScript =
          Script.removeAllInstancesOfOp(connectedScript, ScriptOpCodes.OP_CODESEPARATOR);
      // Set the input to the script of its output. Satoshi does this but the step has no obvious
      // purpose as
      // the signature covers the hash of the prevout transaction which obviously includes the
      // output script
      // already. Perhaps it felt safer to him in some way, or is another leftover from how the code
      // was written.
      TransactionInput input = tx.getInputs().get(inputIndex);
      input.setScriptSig(new Script(connectedScript));
      List<TransactionOutput> outputs = tx.getOutputs();

      if ((sigHashType & 0x1f) == (Transaction.SigHash.NONE.ordinal() + 1)) {
        // SIGHASH_NONE means no outputs are signed at all - the signature is effectively for a
        // "blank cheque".
        // this.outputs = new ArrayList<TransactionOutput>(0);
        tx.clearOutputs();
        // The signature isn't broken by new versions of the transaction issued by other parties.
        for (int i = 0; i < tx.getInputs().size(); i++)
          if (i != inputIndex) tx.getInputs().get(i).setSequenceNumber(0);
      } else if ((sigHashType & 0x1f) == (Transaction.SigHash.SINGLE.ordinal() + 1)) {
        // SIGHASH_SINGLE means only sign the output at the same index as the input (ie, my output).
        if (inputIndex >= tx.getOutputs().size()) {
          // The input index is beyond the number of outputs, it's a buggy signature made by a
          // broken
          // Bitcoin implementation. The reference client also contains a bug in handling this case:
          // any transaction output that is signed in this case will result in both the signed
          // output
          // and any future outputs to this public key being steal-able by anyone who has
          // the resulting signature and the public key (both of which are part of the signed tx
          // input).
          // Put the transaction back to how we found it.
          //
          // TODO: Only allow this to happen if we are checking a signature, not signing a
          // transactions
          for (int i = 0; i < tx.getInputs().size(); i++) {
            // tx.getInputs().get(i).setScriptSig(inputScripts[i]);
            /*                        tx.getInputs().get(i).setScriptSig(ScriptBuilder.createMultiSigInputScriptBytes(
            Arrays.asList(inputScripts[i])));*/
            tx.getInput(i).setScriptSig(new Script(inputScripts[i]));
            tx.getInputs().get(i).setSequenceNumber(inputSequenceNumbers[i]);
          }
          // this.outputs = outputs;

          // Satoshis bug is that SignatureHash was supposed to return a hash and on this codepath
          // it
          // actually returns the constant "1" to indicate an error, which is never checked for.
          // Oops.
          return Utils.HEX.decode(
              "0100000000000000000000000000000000000000000000000000000000000000");
        }

        // In SIGHASH_SINGLE the outputs after the matching input index are deleted, and the outputs
        // before
        // that position are "nulled out". Unintuitively, the value in a "null" transaction is set
        // to -1.
        /*                this.outputs = new ArrayList<TransactionOutput>(this.outputs.subList(0, inputIndex + 1));
        for (int i = 0; i < inputIndex; i++)
            this.outputs.set(i, new TransactionOutput(params, this, Coin.NEGATIVE_SATOSHI, new byte[] {}));
        // The signature isn't broken by new versions of the transaction issued by other parties.
        for (int i = 0; i < inputs.size(); i++)
            if (i != inputIndex)
                inputs.get(i).setSequenceNumber(0);*/
        // In SIGHASH_SINGLE the outputs after the matching input index are deleted, and the outputs
        // before
        // that position are "nulled out". Unintuitively, the value in a "null" transaction is set
        // to -1.
        // tx.outputs = new ArrayList<TransactionOutput>(tx.getOutputs().subList(0, inputIndex +
        // 1));
        tx.clearOutputs();
        for (int i = 0; i <= inputIndex; i++)
          if (i == inputIndex) {
            // need to make sure the output at inputIndex stays the same
            tx.addOutput(spendingTx.getOutput(inputIndex));
          } else {
            // this.outputs.set(i, new TransactionOutput(params, this, Coin.NEGATIVE_SATOSHI, new
            // byte[] {}));
            tx.addOutput(new TransactionOutput(params, tx, Coin.NEGATIVE_SATOSHI, new byte[] {}));
          }

        // The signature isn't broken by new versions of the transaction issued by other parties.
        for (int i = 0; i < tx.getInputs().size(); i++)
          if (i != inputIndex) tx.getInputs().get(i).setSequenceNumber(0);
      }

      List<TransactionInput> inputs = tx.getInputs();
      if ((sigHashType & (byte) 0x80) == 0x80) {
        // SIGHASH_ANYONECANPAY means the signature in the input is not broken by
        // changes/additions/removals
        // of other inputs. For example, this is useful for building assurance contracts.
        tx.clearInputs();
        tx.getInputs().add(input);
      }

      ByteArrayOutputStream bos = new UnsafeByteArrayOutputStream(256);
      tx.bitcoinSerialize(bos);
      // We also have to write a hash type (sigHashType is actually an unsigned char)
      uint32ToByteStreamLE(0x000000ff & sigHashType, bos);
      // Note that this is NOT reversed to ensure it will be signed correctly. If it were to be
      // printed out
      // however then we would expect that it is IS reversed.
      byte[] txSignatureBytes = bos.toByteArray();
      bos.close();

      // Put the transaction back to how we found it.
      // tx.inputs = inputs;
      tx.clearInputs();
      for (int i = 0; i < inputs.size(); i++) {
        tx.addInput(inputs.get(i));
      }
      for (int i = 0; i < inputs.size(); i++) {
        inputs.get(i).setScriptSig(new Script(inputScripts[i]));
        inputs.get(i).setSequenceNumber(inputSequenceNumbers[i]);
      }
      // this.outputs = outputs;
      tx.clearOutputs();
      for (int i = 0; i < outputs.size(); i++) {
        tx.addOutput(outputs.get(i));
      }
      return txSignatureBytes;
    } catch (IOException e) {
      throw new RuntimeException(e); // Cannot happen.
    }
  }
  /**
   * Converts the given wallet to the object representation of the protocol buffers. This can be
   * modified, or additional data fields set, before serialization takes place.
   */
  public Protos.Wallet walletToProto(Wallet wallet) {
    Protos.Wallet.Builder walletBuilder = Protos.Wallet.newBuilder();
    walletBuilder.setNetworkIdentifier(wallet.getNetworkParameters().getId());
    if (wallet.getDescription() != null) {
      walletBuilder.setDescription(wallet.getDescription());
    }

    for (WalletTransaction wtx : wallet.getWalletTransactions()) {
      Protos.Transaction txProto = makeTxProto(wtx);
      walletBuilder.addTransaction(txProto);
    }

    walletBuilder.addAllKey(wallet.serializeKeychainToProtobuf());

    for (Script script : wallet.getWatchedScripts()) {
      Protos.Script protoScript =
          Protos.Script.newBuilder()
              .setProgram(ByteString.copyFrom(script.getProgram()))
              .setCreationTimestamp(script.getCreationTimeSeconds() * 1000)
              .build();

      walletBuilder.addWatchedScript(protoScript);
    }

    // Populate the lastSeenBlockHash field.
    Sha256Hash lastSeenBlockHash = wallet.getLastBlockSeenHash();
    if (lastSeenBlockHash != null) {
      walletBuilder.setLastSeenBlockHash(hashToByteString(lastSeenBlockHash));
      walletBuilder.setLastSeenBlockHeight(wallet.getLastBlockSeenHeight());
    }
    if (wallet.getLastBlockSeenTimeSecs() > 0)
      walletBuilder.setLastSeenBlockTimeSecs(wallet.getLastBlockSeenTimeSecs());

    // Populate the scrypt parameters.
    KeyCrypter keyCrypter = wallet.getKeyCrypter();
    if (keyCrypter == null) {
      // The wallet is unencrypted.
      walletBuilder.setEncryptionType(EncryptionType.UNENCRYPTED);
    } else {
      // The wallet is encrypted.
      walletBuilder.setEncryptionType(keyCrypter.getUnderstoodEncryptionType());
      if (keyCrypter instanceof KeyCrypterScrypt) {
        KeyCrypterScrypt keyCrypterScrypt = (KeyCrypterScrypt) keyCrypter;
        walletBuilder.setEncryptionParameters(keyCrypterScrypt.getScryptParameters());
      } else {
        // Some other form of encryption has been specified that we do not know how to persist.
        throw new RuntimeException(
            "The wallet has encryption of type '"
                + keyCrypter.getUnderstoodEncryptionType()
                + "' but this WalletProtobufSerializer does not know how to persist this.");
      }
    }

    if (wallet.getKeyRotationTime() != null) {
      long timeSecs = wallet.getKeyRotationTime().getTime() / 1000;
      walletBuilder.setKeyRotationTime(timeSecs);
    }

    populateExtensions(wallet, walletBuilder);

    for (Map.Entry<String, ByteString> entry : wallet.getTags().entrySet()) {
      Protos.Tag.Builder tag =
          Protos.Tag.newBuilder().setTag(entry.getKey()).setData(entry.getValue());
      walletBuilder.addTags(tag);
    }

    for (TransactionSigner signer : wallet.getTransactionSigners()) {
      // do not serialize LocalTransactionSigner as it's being added implicitly
      if (signer instanceof LocalTransactionSigner) continue;
      Protos.TransactionSigner.Builder protoSigner = Protos.TransactionSigner.newBuilder();
      protoSigner.setClassName(signer.getClass().getName());
      protoSigner.setData(ByteString.copyFrom(signer.serialize()));
      walletBuilder.addTransactionSigners(protoSigner);
    }

    walletBuilder.setSigsRequiredToSpend(wallet.getSigsRequiredToSpend());

    // Populate the wallet version.
    walletBuilder.setVersion(wallet.getVersion());

    return walletBuilder.build();
  }
Esempio n. 8
0
 /**
  * Set the given program as the scriptSig that is supposed to satisfy the connected output script.
  */
 public void setScriptSig(Script scriptSig) {
   this.scriptSig = new WeakReference<Script>(checkNotNull(scriptSig));
   // TODO: This should all be cleaned up so we have a consistent internal representation.
   setScriptBytes(scriptSig.getProgram());
 }
  @Override
  /** Used during reorgs to connect a block previously on a fork */
  protected synchronized TransactionOutputChanges connectTransactions(StoredBlock newBlock)
      throws VerificationException, BlockStoreException, PrunedException {
    checkState(lock.isHeldByCurrentThread());
    if (!params.passesCheckpoint(newBlock.getHeight(), newBlock.getHeader().getHash()))
      throw new VerificationException("Block failed checkpoint lockin at " + newBlock.getHeight());

    blockStore.beginDatabaseBatchWrite();
    StoredUndoableBlock block = blockStore.getUndoBlock(newBlock.getHeader().getHash());
    if (block == null) {
      // We're trying to re-org too deep and the data needed has been deleted.
      blockStore.abortDatabaseBatchWrite();
      throw new PrunedException(newBlock.getHeader().getHash());
    }
    TransactionOutputChanges txOutChanges;
    try {
      List<Transaction> transactions = block.getTransactions();
      if (transactions != null) {
        LinkedList<UTXO> txOutsSpent = new LinkedList<UTXO>();
        LinkedList<UTXO> txOutsCreated = new LinkedList<UTXO>();
        long sigOps = 0;
        final Set<VerifyFlag> verifyFlags = EnumSet.noneOf(VerifyFlag.class);
        if (newBlock.getHeader().getTimeSeconds() >= NetworkParameters.BIP16_ENFORCE_TIME)
          verifyFlags.add(VerifyFlag.P2SH);
        if (!params.isCheckpoint(newBlock.getHeight())) {
          for (Transaction tx : transactions) {
            Sha256Hash hash = tx.getHash();
            if (blockStore.hasUnspentOutputs(hash, tx.getOutputs().size()))
              throw new VerificationException("Block failed BIP30 test!");
          }
        }
        Coin totalFees = Coin.ZERO;
        Coin coinbaseValue = null;

        if (scriptVerificationExecutor.isShutdown())
          scriptVerificationExecutor =
              Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());
        List<Future<VerificationException>> listScriptVerificationResults =
            new ArrayList<Future<VerificationException>>(transactions.size());
        for (final Transaction tx : transactions) {
          boolean isCoinBase = tx.isCoinBase();
          Coin valueIn = Coin.ZERO;
          Coin valueOut = Coin.ZERO;
          final List<Script> prevOutScripts = new LinkedList<Script>();
          if (!isCoinBase) {
            for (int index = 0; index < tx.getInputs().size(); index++) {
              final TransactionInput in = tx.getInputs().get(index);
              final UTXO prevOut =
                  blockStore.getTransactionOutput(
                      in.getOutpoint().getHash(), in.getOutpoint().getIndex());
              if (prevOut == null)
                throw new VerificationException(
                    "Attempted spend of a non-existent or already spent output!");
              if (prevOut.isCoinbase()
                  && newBlock.getHeight() - prevOut.getHeight()
                      < params.getSpendableCoinbaseDepth())
                throw new VerificationException(
                    "Tried to spend coinbase at depth "
                        + (newBlock.getHeight() - prevOut.getHeight()));
              valueIn = valueIn.add(prevOut.getValue());
              if (verifyFlags.contains(VerifyFlag.P2SH)) {
                if (prevOut.getScript().isPayToScriptHash())
                  sigOps += Script.getP2SHSigOpCount(in.getScriptBytes());
                if (sigOps > Block.MAX_BLOCK_SIGOPS)
                  throw new VerificationException("Too many P2SH SigOps in block");
              }

              prevOutScripts.add(prevOut.getScript());

              blockStore.removeUnspentTransactionOutput(prevOut);
              txOutsSpent.add(prevOut);
            }
          }
          Sha256Hash hash = tx.getHash();
          for (TransactionOutput out : tx.getOutputs()) {
            valueOut = valueOut.add(out.getValue());
            Script script = getScript(out.getScriptBytes());
            UTXO newOut =
                new UTXO(
                    hash,
                    out.getIndex(),
                    out.getValue(),
                    newBlock.getHeight(),
                    isCoinBase,
                    script,
                    getScriptAddress(script));
            blockStore.addUnspentTransactionOutput(newOut);
            txOutsCreated.add(newOut);
          }
          // All values were already checked for being non-negative (as it is verified in
          // Transaction.verify())
          // but we check again here just for defence in depth. Transactions with zero output value
          // are OK.
          if (valueOut.signum() < 0 || valueOut.compareTo(params.getMaxMoney()) > 0)
            throw new VerificationException("Transaction output value out of range");
          if (isCoinBase) {
            coinbaseValue = valueOut;
          } else {
            if (valueIn.compareTo(valueOut) < 0 || valueIn.compareTo(params.getMaxMoney()) > 0)
              throw new VerificationException("Transaction input value out of range");
            totalFees = totalFees.add(valueIn.subtract(valueOut));
          }

          if (!isCoinBase) {
            // Because correctlySpends modifies transactions, this must come after we are done with
            // tx
            FutureTask<VerificationException> future =
                new FutureTask<VerificationException>(
                    new Verifier(tx, prevOutScripts, verifyFlags));
            scriptVerificationExecutor.execute(future);
            listScriptVerificationResults.add(future);
          }
        }
        if (totalFees.compareTo(params.getMaxMoney()) > 0
            || newBlock
                    .getHeader()
                    .getBlockInflation(newBlock.getHeight())
                    .add(totalFees)
                    .compareTo(coinbaseValue)
                < 0) throw new VerificationException("Transaction fees out of range");
        txOutChanges = new TransactionOutputChanges(txOutsCreated, txOutsSpent);
        for (Future<VerificationException> future : listScriptVerificationResults) {
          VerificationException e;
          try {
            e = future.get();
          } catch (InterruptedException thrownE) {
            throw new RuntimeException(thrownE); // Shouldn't happen
          } catch (ExecutionException thrownE) {
            log.error("Script.correctlySpends threw a non-normal exception: " + thrownE.getCause());
            throw new VerificationException(
                "Bug in Script.correctlySpends, likely script malformed in some new and interesting way.",
                thrownE);
          }
          if (e != null) throw e;
        }
      } else {
        txOutChanges = block.getTxOutChanges();
        if (!params.isCheckpoint(newBlock.getHeight()))
          for (UTXO out : txOutChanges.txOutsCreated) {
            Sha256Hash hash = out.getHash();
            if (blockStore.getTransactionOutput(hash, out.getIndex()) != null)
              throw new VerificationException("Block failed BIP30 test!");
          }
        for (UTXO out : txOutChanges.txOutsCreated) blockStore.addUnspentTransactionOutput(out);
        for (UTXO out : txOutChanges.txOutsSpent) blockStore.removeUnspentTransactionOutput(out);
      }
    } catch (VerificationException e) {
      scriptVerificationExecutor.shutdownNow();
      blockStore.abortDatabaseBatchWrite();
      throw e;
    } catch (BlockStoreException e) {
      scriptVerificationExecutor.shutdownNow();
      blockStore.abortDatabaseBatchWrite();
      throw e;
    }
    return txOutChanges;
  }
  @Override
  protected TransactionOutputChanges connectTransactions(int height, Block block)
      throws VerificationException, BlockStoreException {
    checkState(lock.isHeldByCurrentThread());
    if (block.transactions == null)
      throw new RuntimeException(
          "connectTransactions called with Block that didn't have transactions!");
    if (!params.passesCheckpoint(height, block.getHash()))
      throw new VerificationException("Block failed checkpoint lockin at " + height);

    blockStore.beginDatabaseBatchWrite();

    LinkedList<UTXO> txOutsSpent = new LinkedList<UTXO>();
    LinkedList<UTXO> txOutsCreated = new LinkedList<UTXO>();
    long sigOps = 0;
    final Set<VerifyFlag> verifyFlags = EnumSet.noneOf(VerifyFlag.class);
    if (block.getTimeSeconds() >= NetworkParameters.BIP16_ENFORCE_TIME)
      verifyFlags.add(VerifyFlag.P2SH);

    if (scriptVerificationExecutor.isShutdown())
      scriptVerificationExecutor =
          Executors.newFixedThreadPool(Runtime.getRuntime().availableProcessors());

    List<Future<VerificationException>> listScriptVerificationResults =
        new ArrayList<Future<VerificationException>>(block.transactions.size());
    try {
      if (!params.isCheckpoint(height)) {
        // BIP30 violator blocks are ones that contain a duplicated transaction. They are all in the
        // checkpoints list and we therefore only check non-checkpoints for duplicated transactions
        // here. See the
        // BIP30 document for more details on this:
        // https://github.com/bitcoin/bips/blob/master/bip-0030.mediawiki
        for (Transaction tx : block.transactions) {
          Sha256Hash hash = tx.getHash();
          // If we already have unspent outputs for this hash, we saw the tx already. Either the
          // block is
          // being added twice (bug) or the block is a BIP30 violator.
          if (blockStore.hasUnspentOutputs(hash, tx.getOutputs().size()))
            throw new VerificationException("Block failed BIP30 test!");
          if (verifyFlags.contains(
              VerifyFlag
                  .P2SH)) // We already check non-BIP16 sigops in Block.verifyTransactions(true)
          sigOps += tx.getSigOpCount();
        }
      }
      Coin totalFees = Coin.ZERO;
      Coin coinbaseValue = null;
      for (final Transaction tx : block.transactions) {
        boolean isCoinBase = tx.isCoinBase();
        Coin valueIn = Coin.ZERO;
        Coin valueOut = Coin.ZERO;
        final List<Script> prevOutScripts = new LinkedList<Script>();
        if (!isCoinBase) {
          // For each input of the transaction remove the corresponding output from the set of
          // unspent
          // outputs.
          for (int index = 0; index < tx.getInputs().size(); index++) {
            TransactionInput in = tx.getInputs().get(index);
            UTXO prevOut =
                blockStore.getTransactionOutput(
                    in.getOutpoint().getHash(), in.getOutpoint().getIndex());
            if (prevOut == null)
              throw new VerificationException(
                  "Attempted to spend a non-existent or already spent output!");
            // Coinbases can't be spent until they mature, to avoid re-orgs destroying entire
            // transaction
            // chains. The assumption is there will ~never be re-orgs deeper than the spendable
            // coinbase
            // chain depth.
            if (prevOut.isCoinbase()) {
              if (height - prevOut.getHeight() < params.getSpendableCoinbaseDepth()) {
                throw new VerificationException(
                    "Tried to spend coinbase at depth " + (height - prevOut.getHeight()));
              }
            }
            // TODO: Check we're not spending the genesis transaction here. Satoshis code won't
            // allow it.
            valueIn = valueIn.add(prevOut.getValue());
            if (verifyFlags.contains(VerifyFlag.P2SH)) {
              if (prevOut.getScript().isPayToScriptHash())
                sigOps += Script.getP2SHSigOpCount(in.getScriptBytes());
              if (sigOps > Block.MAX_BLOCK_SIGOPS)
                throw new VerificationException("Too many P2SH SigOps in block");
            }

            prevOutScripts.add(prevOut.getScript());
            blockStore.removeUnspentTransactionOutput(prevOut);
            txOutsSpent.add(prevOut);
          }
        }
        Sha256Hash hash = tx.getHash();
        for (TransactionOutput out : tx.getOutputs()) {
          valueOut = valueOut.add(out.getValue());
          // For each output, add it to the set of unspent outputs so it can be consumed in future.
          Script script = getScript(out.getScriptBytes());
          UTXO newOut =
              new UTXO(
                  hash,
                  out.getIndex(),
                  out.getValue(),
                  height,
                  isCoinBase,
                  script,
                  getScriptAddress(script));
          blockStore.addUnspentTransactionOutput(newOut);
          txOutsCreated.add(newOut);
        }
        // All values were already checked for being non-negative (as it is verified in
        // Transaction.verify())
        // but we check again here just for defence in depth. Transactions with zero output value
        // are OK.
        if (valueOut.signum() < 0 || valueOut.compareTo(params.getMaxMoney()) > 0)
          throw new VerificationException("Transaction output value out of range");
        if (isCoinBase) {
          coinbaseValue = valueOut;
        } else {
          if (valueIn.compareTo(valueOut) < 0 || valueIn.compareTo(params.getMaxMoney()) > 0)
            throw new VerificationException("Transaction input value out of range");
          totalFees = totalFees.add(valueIn.subtract(valueOut));
        }

        if (!isCoinBase && runScripts) {
          // Because correctlySpends modifies transactions, this must come after we are done with tx
          FutureTask<VerificationException> future =
              new FutureTask<VerificationException>(new Verifier(tx, prevOutScripts, verifyFlags));
          scriptVerificationExecutor.execute(future);
          listScriptVerificationResults.add(future);
        }
      }
      if (totalFees.compareTo(params.getMaxMoney()) > 0
          || block.getBlockInflation(height).add(totalFees).compareTo(coinbaseValue) < 0)
        throw new VerificationException("Transaction fees out of range");
      for (Future<VerificationException> future : listScriptVerificationResults) {
        VerificationException e;
        try {
          e = future.get();
        } catch (InterruptedException thrownE) {
          throw new RuntimeException(thrownE); // Shouldn't happen
        } catch (ExecutionException thrownE) {
          log.error("Script.correctlySpends threw a non-normal exception: " + thrownE.getCause());
          throw new VerificationException(
              "Bug in Script.correctlySpends, likely script malformed in some new and interesting way.",
              thrownE);
        }
        if (e != null) throw e;
      }
    } catch (VerificationException e) {
      scriptVerificationExecutor.shutdownNow();
      blockStore.abortDatabaseBatchWrite();
      throw e;
    } catch (BlockStoreException e) {
      scriptVerificationExecutor.shutdownNow();
      blockStore.abortDatabaseBatchWrite();
      throw e;
    }
    return new TransactionOutputChanges(txOutsCreated, txOutsSpent);
  }