/**
* 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;
}
