/**
* When the servers signature for the refund transaction is received, call this to verify it and
* sign the complete refund ourselves.
*
* <p>If this does not throw an exception, we are secure against the loss of funds and can safely
* provide the server with the multi-sig contract to lock in the agreement. In this case, both the
* multisig contract and the refund transaction are automatically committed to wallet so that it
* can handle broadcasting the refund transaction at the appropriate time if necessary.
*/
public synchronized void provideRefundSignature(byte[] theirSignature)
throws VerificationException {
checkNotNull(theirSignature);
checkState(state == State.WAITING_FOR_SIGNED_REFUND);
TransactionSignature theirSig = TransactionSignature.decodeFromBitcoin(theirSignature, true);
if (theirSig.sigHashMode() != Transaction.SigHash.NONE || !theirSig.anyoneCanPay())
throw new VerificationException("Refund signature was not SIGHASH_NONE|SIGHASH_ANYONECANPAY");
// Sign the refund transaction ourselves.
final TransactionOutput multisigContractOutput = multisigContract.getOutput(0);
try {
multisigScript = multisigContractOutput.getScriptPubKey();
} catch (ScriptException e) {
throw new RuntimeException(e); // Cannot happen: we built this ourselves.
}
TransactionSignature ourSignature =
refundTx.calculateSignature(0, myKey, multisigScript, Transaction.SigHash.ALL, false);
// Insert the signatures.
Script scriptSig = ScriptBuilder.createMultiSigInputScript(ourSignature, theirSig);
log.info("Refund scriptSig: {}", scriptSig);
log.info("Multi-sig contract scriptPubKey: {}", multisigScript);
TransactionInput refundInput = refundTx.getInput(0);
refundInput.setScriptSig(scriptSig);
refundInput.verify(multisigContractOutput);
state = State.SAVE_STATE_IN_WALLET;
}
@Test
public void testCreateMultiSigInputScript() throws AddressFormatException {
// Setup transaction and signatures
ECKey key1 =
new DumpedPrivateKey(params, "cVLwRLTvz3BxDAWkvS3yzT9pUcTCup7kQnfT2smRjvmmm1wAP6QT")
.getKey();
ECKey key2 =
new DumpedPrivateKey(params, "cTine92s8GLpVqvebi8rYce3FrUYq78ZGQffBYCS1HmDPJdSTxUo")
.getKey();
ECKey key3 =
new DumpedPrivateKey(params, "cVHwXSPRZmL9adctwBwmn4oTZdZMbaCsR5XF6VznqMgcvt1FDDxg")
.getKey();
Script multisigScript =
ScriptBuilder.createMultiSigOutputScript(2, Arrays.asList(key1, key2, key3));
byte[] bytes =
Hex.decode(
"01000000013df681ff83b43b6585fa32dd0e12b0b502e6481e04ee52ff0fdaf55a16a4ef61000000006b483045022100a84acca7906c13c5895a1314c165d33621cdcf8696145080895cbf301119b7cf0220730ff511106aa0e0a8570ff00ee57d7a6f24e30f592a10cae1deffac9e13b990012102b8d567bcd6328fd48a429f9cf4b315b859a58fd28c5088ef3cb1d98125fc4e8dffffffff02364f1c00000000001976a91439a02793b418de8ec748dd75382656453dc99bcb88ac40420f000000000017a9145780b80be32e117f675d6e0ada13ba799bf248e98700000000");
Transaction transaction = new Transaction(params, bytes);
TransactionOutput output = transaction.getOutput(1);
Transaction spendTx = new Transaction(params);
Address address = new Address(params, "n3CFiCmBXVt5d3HXKQ15EFZyhPz4yj5F3H");
Script outputScript = ScriptBuilder.createOutputScript(address);
spendTx.addOutput(output.getValue(), outputScript);
spendTx.addInput(output);
Sha256Hash sighash = spendTx.hashForSignature(0, multisigScript, SigHash.ALL, false);
ECKey.ECDSASignature party1Signature = key1.sign(sighash);
ECKey.ECDSASignature party2Signature = key2.sign(sighash);
TransactionSignature party1TransactionSignature =
new TransactionSignature(party1Signature, SigHash.ALL, false);
TransactionSignature party2TransactionSignature =
new TransactionSignature(party2Signature, SigHash.ALL, false);
// Create p2sh multisig input script
Script inputScript =
ScriptBuilder.createP2SHMultiSigInputScript(
ImmutableList.of(party1TransactionSignature, party2TransactionSignature),
multisigScript.getProgram());
// Assert that the input script contains 4 chunks
assertTrue(inputScript.getChunks().size() == 4);
// Assert that the input script created contains the original multisig
// script as the last chunk
ScriptChunk scriptChunk = inputScript.getChunks().get(inputScript.getChunks().size() - 1);
Assert.assertArrayEquals(scriptChunk.data, multisigScript.getProgram());
// Create regular multisig input script
inputScript =
ScriptBuilder.createMultiSigInputScript(
ImmutableList.of(party1TransactionSignature, party2TransactionSignature));
// Assert that the input script only contains 3 chunks
assertTrue(inputScript.getChunks().size() == 3);
// Assert that the input script created does not end with the original
// multisig script
scriptChunk = inputScript.getChunks().get(inputScript.getChunks().size() - 1);
Assert.assertThat(scriptChunk.data, IsNot.not(IsEqual.equalTo(multisigScript.getProgram())));
}
/**
* Creates the initial multisig contract and incomplete refund transaction which can be requested
* at the appropriate time using {@link PaymentChannelClientState#getIncompleteRefundTransaction}
* and {@link PaymentChannelClientState#getMultisigContract()}. The way the contract is crafted
* can be adjusted by overriding {@link
* PaymentChannelClientState#editContractSendRequest(com.google.bitcoin.core.Wallet.SendRequest)}.
* By default unconfirmed coins are allowed to be used, as for micropayments the risk should be
* relatively low.
*
* @throws ValueOutOfRangeException if the value being used is too small to be accepted by the
* network
* @throws InsufficientMoneyException if the wallet doesn't contain enough balance to initiate
*/
public synchronized void initiate() throws ValueOutOfRangeException, InsufficientMoneyException {
final NetworkParameters params = wallet.getParams();
Transaction template = new Transaction(params);
// We always place the client key before the server key because, if either side wants some
// privacy, they can
// use a fresh key for the the multisig contract and nowhere else
List<ECKey> keys = Lists.newArrayList(myKey, serverMultisigKey);
// There is also probably a change output, but we don't bother shuffling them as it's obvious
// from the
// format which one is the change. If we start obfuscating the change output better in future
// this may
// be worth revisiting.
TransactionOutput multisigOutput =
template.addOutput(totalValue, ScriptBuilder.createMultiSigOutputScript(2, keys));
if (multisigOutput.getMinNonDustValue().compareTo(totalValue) > 0)
throw new ValueOutOfRangeException("totalValue too small to use");
Wallet.SendRequest req = Wallet.SendRequest.forTx(template);
req.coinSelector = AllowUnconfirmedCoinSelector.get();
editContractSendRequest(req);
req.shuffleOutputs = false; // TODO: Fix things so shuffling is usable.
wallet.completeTx(req);
Coin multisigFee = req.tx.getFee();
multisigContract = req.tx;
// Build a refund transaction that protects us in the case of a bad server that's just trying to
// cause havoc
// by locking up peoples money (perhaps as a precursor to a ransom attempt). We time lock it so
// the server
// has an assurance that we cannot take back our money by claiming a refund before the channel
// closes - this
// relies on the fact that since Bitcoin 0.8 time locked transactions are non-final. This will
// need to change
// in future as it breaks the intended design of timelocking/tx replacement, but for now it
// simplifies this
// specific protocol somewhat.
refundTx = new Transaction(params);
refundTx
.addInput(multisigOutput)
.setSequenceNumber(0); // Allow replacement when it's eventually reactivated.
refundTx.setLockTime(expiryTime);
if (totalValue.compareTo(Coin.CENT) < 0) {
// Must pay min fee.
final Coin valueAfterFee = totalValue.subtract(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
if (Transaction.MIN_NONDUST_OUTPUT.compareTo(valueAfterFee) > 0)
throw new ValueOutOfRangeException("totalValue too small to use");
refundTx.addOutput(valueAfterFee, myKey.toAddress(params));
refundFees = multisigFee.add(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
} else {
refundTx.addOutput(totalValue, myKey.toAddress(params));
refundFees = multisigFee;
}
refundTx.getConfidence().setSource(TransactionConfidence.Source.SELF);
log.info(
"initiated channel with multi-sig contract {}, refund {}",
multisigContract.getHashAsString(),
refundTx.getHashAsString());
state = State.INITIATED;
// Client should now call getIncompleteRefundTransaction() and send it to the server.
}
public Address getAddressForOutput(TransactionOutput out) {
try {
Script script = out.getScriptPubKey();
if (script.isSentToRawPubKey()) {
byte[] key = out.getScriptPubKey().getPubKey();
byte[] address_bytes = com.google.bitcoin.core.Utils.sha256hash160(key);
Address a = new Address(params, address_bytes);
return a;
} else {
Address a = script.getToAddress(params);
return a;
}
} catch (ScriptException e) {
// System.out.println(out.getParentTransaction().getHash() + " - " + out);
// e.printStackTrace();
// jelly.getEventLog().log("Unable process tx output: " +
// out.getParentTransaction().getHash());
}
return null;
}
@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<StoredTransactionOutput> txOutsSpent = new LinkedList<StoredTransactionOutput>();
LinkedList<StoredTransactionOutput> txOutsCreated =
new LinkedList<StoredTransactionOutput>();
long sigOps = 0;
final boolean enforcePayToScriptHash =
newBlock.getHeader().getTimeSeconds() >= NetworkParameters.BIP16_ENFORCE_TIME;
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 StoredTransactionOutput 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 (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 (enforcePayToScriptHash) {
Script script = new Script(prevOut.getScriptBytes());
if (script.isPayToScriptHash())
sigOps += Script.getP2SHSigOpCount(in.getScriptBytes());
if (sigOps > Block.MAX_BLOCK_SIGOPS)
throw new VerificationException("Too many P2SH SigOps in block");
}
prevOutScripts.add(new Script(prevOut.getScriptBytes()));
blockStore.removeUnspentTransactionOutput(prevOut);
txOutsSpent.add(prevOut);
}
}
Sha256Hash hash = tx.getHash();
for (TransactionOutput out : tx.getOutputs()) {
valueOut = valueOut.add(out.getValue());
StoredTransactionOutput newOut =
new StoredTransactionOutput(
hash,
out.getIndex(),
out.getValue(),
newBlock.getHeight(),
isCoinBase,
out.getScriptBytes());
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(NetworkParameters.MAX_MONEY) > 0)
throw new VerificationException("Transaction output value out of range");
if (isCoinBase) {
coinbaseValue = valueOut;
} else {
if (valueIn.compareTo(valueOut) < 0
|| valueIn.compareTo(NetworkParameters.MAX_MONEY) > 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, enforcePayToScriptHash));
scriptVerificationExecutor.execute(future);
listScriptVerificationResults.add(future);
}
}
if (totalFees.compareTo(NetworkParameters.MAX_MONEY) > 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 (StoredTransactionOutput out : txOutChanges.txOutsCreated) {
Sha256Hash hash = out.getHash();
if (blockStore.getTransactionOutput(hash, out.getIndex()) != null)
throw new VerificationException("Block failed BIP30 test!");
}
for (StoredTransactionOutput out : txOutChanges.txOutsCreated)
blockStore.addUnspentTransactionOutput(out);
for (StoredTransactionOutput 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<StoredTransactionOutput> txOutsSpent = new LinkedList<StoredTransactionOutput>();
LinkedList<StoredTransactionOutput> txOutsCreated = new LinkedList<StoredTransactionOutput>();
long sigOps = 0;
final boolean enforcePayToScriptHash =
block.getTimeSeconds() >= NetworkParameters.BIP16_ENFORCE_TIME;
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 (enforcePayToScriptHash) // 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);
StoredTransactionOutput 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 (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 (enforcePayToScriptHash) {
if (new Script(prevOut.getScriptBytes()).isPayToScriptHash())
sigOps += Script.getP2SHSigOpCount(in.getScriptBytes());
if (sigOps > Block.MAX_BLOCK_SIGOPS)
throw new VerificationException("Too many P2SH SigOps in block");
}
prevOutScripts.add(new Script(prevOut.getScriptBytes()));
// in.getScriptSig().correctlySpends(tx, index, new Script(params,
// prevOut.getScriptBytes(), 0, prevOut.getScriptBytes().length));
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.
StoredTransactionOutput newOut =
new StoredTransactionOutput(
hash, out.getIndex(), out.getValue(), height, isCoinBase, out.getScriptBytes());
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(NetworkParameters.MAX_MONEY) > 0)
throw new VerificationException("Transaction output value out of range");
if (isCoinBase) {
coinbaseValue = valueOut;
} else {
if (valueIn.compareTo(valueOut) < 0 || valueIn.compareTo(NetworkParameters.MAX_MONEY) > 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, enforcePayToScriptHash));
scriptVerificationExecutor.execute(future);
listScriptVerificationResults.add(future);
}
}
if (totalFees.compareTo(NetworkParameters.MAX_MONEY) > 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);
}
private static Protos.Transaction makeTxProto(WalletTransaction wtx) {
Transaction tx = wtx.getTransaction();
Protos.Transaction.Builder txBuilder = Protos.Transaction.newBuilder();
txBuilder
.setPool(Protos.Transaction.Pool.valueOf(wtx.getPool().getValue()))
.setHash(hashToByteString(tx.getHash()))
.setVersion((int) tx.getVersion());
if (tx.getUpdateTime() != null) {
txBuilder.setUpdatedAt(tx.getUpdateTime().getTime());
}
if (tx.getLockTime() > 0) {
txBuilder.setLockTime((int) tx.getLockTime());
}
// Handle inputs.
for (TransactionInput input : tx.getInputs()) {
Protos.TransactionInput.Builder inputBuilder =
Protos.TransactionInput.newBuilder()
.setScriptBytes(ByteString.copyFrom(input.getScriptBytes()))
.setTransactionOutPointHash(hashToByteString(input.getOutpoint().getHash()))
.setTransactionOutPointIndex((int) input.getOutpoint().getIndex());
if (input.hasSequence()) {
inputBuilder.setSequence((int) input.getSequenceNumber());
}
txBuilder.addTransactionInput(inputBuilder);
}
// Handle outputs.
for (TransactionOutput output : tx.getOutputs()) {
Protos.TransactionOutput.Builder outputBuilder =
Protos.TransactionOutput.newBuilder()
.setScriptBytes(ByteString.copyFrom(output.getScriptBytes()))
.setValue(output.getValue().longValue());
final TransactionInput spentBy = output.getSpentBy();
if (spentBy != null) {
Sha256Hash spendingHash = spentBy.getParentTransaction().getHash();
int spentByTransactionIndex = spentBy.getParentTransaction().getInputs().indexOf(spentBy);
outputBuilder
.setSpentByTransactionHash(hashToByteString(spendingHash))
.setSpentByTransactionIndex(spentByTransactionIndex);
}
txBuilder.addTransactionOutput(outputBuilder);
}
// Handle which blocks tx was seen in.
if (tx.getAppearsInHashes() != null) {
for (Sha256Hash hash : tx.getAppearsInHashes()) {
txBuilder.addBlockHash(hashToByteString(hash));
}
}
if (tx.hasConfidence()) {
TransactionConfidence confidence = tx.getConfidence();
Protos.TransactionConfidence.Builder confidenceBuilder =
Protos.TransactionConfidence.newBuilder();
writeConfidence(txBuilder, confidence, confidenceBuilder);
}
return txBuilder.build();
}
