org.bitcoinj.protocols.channels.IPaymentChannelClient.ClientChannelProperties Java Examples

/**
 * Attempts to open a new connection to and open a payment channel with the given host and port, blocking until the
 * connection is open.  The server is requested to keep the channel open for {@code timeoutSeconds}
 * seconds. If the server proposes a longer time the channel will be closed.
 *
 * @param server                  The host/port pair where the server is listening.
 * @param timeoutSeconds          The connection timeout and read timeout during initialization. This should be large enough
 *                                to accommodate ECDSA signature operations and network latency.
 * @param wallet                  The wallet which will be paid from, and where completed transactions will be committed.
 *                                Can be encrypted if user key is supplied when needed. Must already have a
 *                                {@link StoredPaymentChannelClientStates} object in its extensions set.
 * @param myKey                   A freshly generated keypair used for the multisig contract and refund output.
 * @param maxValue                The maximum value this channel is allowed to request
 * @param serverId                A unique ID which is used to attempt reopening of an existing channel.
 *                                This must be unique to the server, and, if your application is exposing payment channels to some
 *                                API, this should also probably encompass some caller UID to avoid applications opening channels
 *                                which were created by others.
 * @param userKeySetup            Key derived from a user password, used to decrypt myKey, if it is encrypted, during setup.
 * @param clientChannelProperties Modifier to change the channel's configuration.
 * @throws IOException              if there's an issue using the network.
 * @throws ValueOutOfRangeException if the balance of wallet is lower than maxValue.
 */
public PaymentChannelClientConnection(InetSocketAddress server, int timeoutSeconds, Wallet wallet, ECKey myKey,
                                      Coin maxValue, String serverId,
                                      @Nullable KeyParameter userKeySetup, final ClientChannelProperties clientChannelProperties)
        throws IOException, ValueOutOfRangeException {
    // Glue the object which vends/ingests protobuf messages in order to manage state to the network object which
    // reads/writes them to the wire in length prefixed form.
    channelClient = new PaymentChannelClient(wallet, myKey, maxValue, Sha256Hash.of(serverId.getBytes()),
            userKeySetup, clientChannelProperties, new PaymentChannelClient.ClientConnection() {
        @Override
        public void sendToServer(Protos.TwoWayChannelMessage msg) {
            wireParser.write(msg);
        }

        @Override
        public void destroyConnection(PaymentChannelCloseException.CloseReason reason) {
            channelOpenFuture.setException(new PaymentChannelCloseException("Payment channel client requested that the connection be closed: " + reason, reason));
            wireParser.closeConnection();
        }

        @Override
        public boolean acceptExpireTime(long expireTime) {
            return expireTime <= (clientChannelProperties.timeWindow() + Utils.currentTimeSeconds() + 60);  // One extra minute to compensate for time skew and latency
        }

        @Override
        public void channelOpen(boolean wasInitiated) {
            wireParser.setSocketTimeout(0);
            // Inform the API user that we're done and ready to roll.
            channelOpenFuture.set(PaymentChannelClientConnection.this);
        }
    });

    // And glue back in the opposite direction - network to the channelClient.
    wireParser = new ProtobufConnection<Protos.TwoWayChannelMessage>(new ProtobufConnection.Listener<Protos.TwoWayChannelMessage>() {
        @Override
        public void messageReceived(ProtobufConnection<Protos.TwoWayChannelMessage> handler, Protos.TwoWayChannelMessage msg) {
            try {
                channelClient.receiveMessage(msg);
            } catch (InsufficientMoneyException e) {
                // We should only get this exception during INITIATE, so channelOpen wasn't called yet.
                channelOpenFuture.setException(e);
            }
        }

        @Override
        public void connectionOpen(ProtobufConnection<Protos.TwoWayChannelMessage> handler) {
            channelClient.connectionOpen();
        }

        @Override
        public void connectionClosed(ProtobufConnection<Protos.TwoWayChannelMessage> handler) {
            channelClient.connectionClosed();
            channelOpenFuture.setException(new PaymentChannelCloseException("The TCP socket died",
                    PaymentChannelCloseException.CloseReason.CONNECTION_CLOSED));
        }
    }, Protos.TwoWayChannelMessage.getDefaultInstance(), Short.MAX_VALUE, timeoutSeconds * 1000);

    // Initiate the outbound network connection. We don't need to keep this around. The wireParser object will handle
    // things from here on out.
    new NioClient(server, wireParser, timeoutSeconds * 1000);
}
 

@Override
public synchronized void initiate(@Nullable KeyParameter userKey, ClientChannelProperties clientChannelProperties) throws ValueOutOfRangeException, InsufficientMoneyException {
    final NetworkParameters params = wallet.getParams();
    Transaction template = new Transaction(params);
    // 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.
    Script redeemScript =
            ScriptBuilder.createCLTVPaymentChannelOutput(BigInteger.valueOf(expiryTime), myKey, serverKey);
    TransactionOutput transactionOutput = template.addOutput(totalValue,
            ScriptBuilder.createP2SHOutputScript(redeemScript));
    if (transactionOutput.isDust())
        throw new ValueOutOfRangeException("totalValue too small to use");
    SendRequest req = SendRequest.forTx(template);
    req.coinSelector = AllowUnconfirmedCoinSelector.get();
    req.shuffleOutputs = false;   // TODO: Fix things so shuffling is usable.
    req = clientChannelProperties.modifyContractSendRequest(req);
    if (userKey != null)
        req.aesKey = userKey;
    wallet.completeTx(req);
    Coin multisigFee = req.tx.getFee();
    contract = 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 because the
    // CheckLockTimeVerify opcode requires a lock time to be specified and the input to have a non-final sequence
    // number (so that the lock time is not disabled).
    refundTx = new Transaction(params);
    // by using this sequence value, we avoid extra full replace-by-fee and relative lock time processing.
    refundTx.addInput(contract.getOutput(0)).setSequenceNumber(TransactionInput.NO_SEQUENCE - 1L);
    refundTx.setLockTime(expiryTime);
    if (Context.get().isEnsureMinRequiredFee()) {
        // 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, LegacyAddress.fromKey(params, myKey));
        refundFees = multisigFee.add(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
    } else {
        refundTx.addOutput(totalValue, LegacyAddress.fromKey(params, myKey));
        refundFees = multisigFee;
    }

    TransactionSignature refundSignature =
            refundTx.calculateSignature(0, myKey.maybeDecrypt(userKey),
                    getSignedScript(), Transaction.SigHash.ALL, false);
    refundTx.getInput(0).setScriptSig(ScriptBuilder.createCLTVPaymentChannelP2SHRefund(refundSignature, redeemScript));

    refundTx.getConfidence().setSource(TransactionConfidence.Source.SELF);
    log.info("initiated channel with contract {}", contract.getHashAsString());
    stateMachine.transition(State.SAVE_STATE_IN_WALLET);
    // Client should now call getIncompleteRefundTransaction() and send it to the server.
}
 

/**
 * Creates the initial multisig contract and incomplete refund transaction which can be requested at the appropriate
 * time using {@link PaymentChannelV1ClientState#getIncompleteRefundTransaction} and
 * {@link PaymentChannelV1ClientState#getContract()}.
 * By default unconfirmed coins are allowed to be used, as for micropayments the risk should be relatively low.
 *
 * @param userKey                 Key derived from a user password, needed for any signing when the wallet is encrypted.
 *                                The wallet KeyCrypter is assumed.
 * @param clientChannelProperties Modify the channel's configuration.
 * @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
 */
@Override
public synchronized void initiate(@Nullable KeyParameter userKey, ClientChannelProperties clientChannelProperties) 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, serverKey);
    // 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.isDust())
        throw new ValueOutOfRangeException("totalValue too small to use");
    SendRequest req = SendRequest.forTx(template);
    req.coinSelector = AllowUnconfirmedCoinSelector.get();
    req.shuffleOutputs = false;   // TODO: Fix things so shuffling is usable.
    req = clientChannelProperties.modifyContractSendRequest(req);
    if (userKey != null)
        req.aesKey = userKey;
    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);
    // don't disable lock time. the sequence will be included in the server's signature and thus won't be changeable.
    // by using this sequence value, we avoid extra full replace-by-fee and relative lock time processing.
    refundTx.addInput(multisigOutput).setSequenceNumber(TransactionInput.NO_SEQUENCE - 1L);
    refundTx.setLockTime(expiryTime);
    if (Context.get().isEnsureMinRequiredFee()) {
        // 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, LegacyAddress.fromKey(params, myKey));
        refundFees = multisigFee.add(Transaction.REFERENCE_DEFAULT_MIN_TX_FEE);
    } else {
        refundTx.addOutput(totalValue, LegacyAddress.fromKey(params, myKey));
        refundFees = multisigFee;
    }
    refundTx.getConfidence().setSource(TransactionConfidence.Source.SELF);
    log.info("initiated channel with multi-sig contract {}, refund {}", multisigContract.getHashAsString(),
            refundTx.getHashAsString());
    stateMachine.transition(State.INITIATED);
    // Client should now call getIncompleteRefundTransaction() and send it to the server.
}
 

/**
 * Attempts to open a new connection to and open a payment channel with the given host and port, blocking until the
 * connection is open.  The server is requested to keep the channel open for {@param timeWindow}
 * seconds. If the server proposes a longer time the channel will be closed.
 *
 * @param server The host/port pair where the server is listening.
 * @param timeoutSeconds The connection timeout and read timeout during initialization. This should be large enough
 *                       to accommodate ECDSA signature operations and network latency.
 * @param wallet The wallet which will be paid from, and where completed transactions will be committed.
 *               Can be encrypted if user key is supplied when needed. Must already have a
 *               {@link StoredPaymentChannelClientStates} object in its extensions set.
 * @param myKey A freshly generated keypair used for the multisig contract and refund output.
 * @param maxValue The maximum value this channel is allowed to request
 * @param serverId A unique ID which is used to attempt reopening of an existing channel.
 *                 This must be unique to the server, and, if your application is exposing payment channels to some
 *                 API, this should also probably encompass some caller UID to avoid applications opening channels
 *                 which were created by others.
 * @param userKeySetup Key derived from a user password, used to decrypt myKey, if it is encrypted, during setup.
 * @param clientChannelProperties Modifier to change the channel's configuration.
 *
 * @throws IOException if there's an issue using the network.
 * @throws ValueOutOfRangeException if the balance of wallet is lower than maxValue.
 */
public PaymentChannelClientConnection(InetSocketAddress server, int timeoutSeconds, Wallet wallet, ECKey myKey,
                                      Coin maxValue, String serverId,
                                      @Nullable KeyParameter userKeySetup, final ClientChannelProperties clientChannelProperties)
        throws IOException, ValueOutOfRangeException {
    // Glue the object which vends/ingests protobuf messages in order to manage state to the network object which
    // reads/writes them to the wire in length prefixed form.
    channelClient = new PaymentChannelClient(wallet, myKey, maxValue, Sha256Hash.of(serverId.getBytes()),
            userKeySetup, clientChannelProperties, new PaymentChannelClient.ClientConnection() {
        @Override
        public void sendToServer(Protos.TwoWayChannelMessage msg) {
            wireParser.write(msg);
        }

        @Override
        public void destroyConnection(PaymentChannelCloseException.CloseReason reason) {
            channelOpenFuture.setException(new PaymentChannelCloseException("Payment channel client requested that the connection be closed: " + reason, reason));
            wireParser.closeConnection();
        }

        @Override
        public boolean acceptExpireTime(long expireTime) {
            return expireTime <= (clientChannelProperties.timeWindow() + Utils.currentTimeSeconds() + 60);  // One extra minute to compensate for time skew and latency
        }

        @Override
        public void channelOpen(boolean wasInitiated) {
            wireParser.setSocketTimeout(0);
            // Inform the API user that we're done and ready to roll.
            channelOpenFuture.set(PaymentChannelClientConnection.this);
        }
    });

    // And glue back in the opposite direction - network to the channelClient.
    wireParser = new ProtobufConnection<Protos.TwoWayChannelMessage>(new ProtobufConnection.Listener<Protos.TwoWayChannelMessage>() {
        @Override
        public void messageReceived(ProtobufConnection<Protos.TwoWayChannelMessage> handler, Protos.TwoWayChannelMessage msg) {
            try {
                channelClient.receiveMessage(msg);
            } catch (InsufficientMoneyException e) {
                // We should only get this exception during INITIATE, so channelOpen wasn't called yet.
                channelOpenFuture.setException(e);
            }
        }

        @Override
        public void connectionOpen(ProtobufConnection<Protos.TwoWayChannelMessage> handler) {
            channelClient.connectionOpen();
        }

        @Override
        public void connectionClosed(ProtobufConnection<Protos.TwoWayChannelMessage> handler) {
            channelClient.connectionClosed();
            channelOpenFuture.setException(new PaymentChannelCloseException("The TCP socket died",
                    PaymentChannelCloseException.CloseReason.CONNECTION_CLOSED));
        }
    }, Protos.TwoWayChannelMessage.getDefaultInstance(), Short.MAX_VALUE, timeoutSeconds*1000);

    // Initiate the outbound network connection. We don't need to keep this around. The wireParser object will handle
    // things from here on out.
    new NioClient(server, wireParser, timeoutSeconds * 1000);
}
 

@Override
public synchronized void initiate(@Nullable KeyParameter userKey, ClientChannelProperties clientChannelProperties) throws ValueOutOfRangeException, InsufficientMoneyException {
    final NetworkParameters params = wallet.getParams();
    Transaction template = new Transaction(params);
    // 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.
    Script redeemScript =
            ScriptBuilder.createCLTVPaymentChannelOutput(BigInteger.valueOf(expiryTime), myKey, serverKey);
    TransactionOutput transactionOutput = template.addOutput(totalValue,
            ScriptBuilder.createP2SHOutputScript(redeemScript));
    if (transactionOutput.isDust())
        throw new ValueOutOfRangeException("totalValue too small to use");
    SendRequest req = SendRequest.forTx(template);
    req.coinSelector = AllowUnconfirmedCoinSelector.get();
    req.shuffleOutputs = false;   // TODO: Fix things so shuffling is usable.
    req = clientChannelProperties.modifyContractSendRequest(req);
    if (userKey != null) req.aesKey = userKey;
    wallet.completeTx(req);
    Coin multisigFee = req.tx.getFee();
    contract = 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 because the
    // CheckLockTimeVerify opcode requires a lock time to be specified and the input to have a non-final sequence
    // number (so that the lock time is not disabled).
    refundTx = new Transaction(params);
    // by using this sequence value, we avoid extra full replace-by-fee and relative lock time processing.
    refundTx.addInput(contract.getOutput(0)).setSequenceNumber(TransactionInput.NO_SEQUENCE - 1L);
    refundTx.setLockTime(expiryTime);
    if (Context.get().isEnsureMinRequiredFee()) {
        // 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;
    }

    TransactionSignature refundSignature =
            refundTx.calculateSignature(0, myKey.maybeDecrypt(userKey),
                    getSignedScript(), Transaction.SigHash.ALL, false);
    refundTx.getInput(0).setScriptSig(ScriptBuilder.createCLTVPaymentChannelP2SHRefund(refundSignature, redeemScript));

    refundTx.getConfidence().setSource(TransactionConfidence.Source.SELF);
    log.info("initiated channel with contract {}", contract.getHashAsString());
    stateMachine.transition(State.SAVE_STATE_IN_WALLET);
    // Client should now call getIncompleteRefundTransaction() and send it to the server.
}
 

/**
 * Creates the initial multisig contract and incomplete refund transaction which can be requested at the appropriate
 * time using {@link PaymentChannelV1ClientState#getIncompleteRefundTransaction} and
 * {@link PaymentChannelV1ClientState#getContract()}.
 * By default unconfirmed coins are allowed to be used, as for micropayments the risk should be relatively low.
 * @param userKey Key derived from a user password, needed for any signing when the wallet is encrypted.
 *                The wallet KeyCrypter is assumed.
 * @param clientChannelProperties Modify the channel's configuration.
 *
 * @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
 */
@Override
public synchronized void initiate(@Nullable KeyParameter userKey, ClientChannelProperties clientChannelProperties) 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, serverKey);
    // 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.isDust())
        throw new ValueOutOfRangeException("totalValue too small to use");
    SendRequest req = SendRequest.forTx(template);
    req.coinSelector = AllowUnconfirmedCoinSelector.get();
    req.shuffleOutputs = false;   // TODO: Fix things so shuffling is usable.
    req = clientChannelProperties.modifyContractSendRequest(req);
    if (userKey != null) req.aesKey = userKey;
    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);
    // don't disable lock time. the sequence will be included in the server's signature and thus won't be changeable.
    // by using this sequence value, we avoid extra full replace-by-fee and relative lock time processing.
    refundTx.addInput(multisigOutput).setSequenceNumber(TransactionInput.NO_SEQUENCE - 1L);
    refundTx.setLockTime(expiryTime);
    if (Context.get().isEnsureMinRequiredFee()) {
        // 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());
    stateMachine.transition(State.INITIATED);
    // Client should now call getIncompleteRefundTransaction() and send it to the server.
}
 

/**
 * Attempts to open a new connection to and open a payment channel with the given host and port, blocking until the
 * connection is open.  The server is requested to keep the channel open for {@param timeWindow}
 * seconds. If the server proposes a longer time the channel will be closed.
 *
 * @param server The host/port pair where the server is listening.
 * @param timeoutSeconds The connection timeout and read timeout during initialization. This should be large enough
 *                       to accommodate ECDSA signature operations and network latency.
 * @param wallet The wallet which will be paid from, and where completed transactions will be committed.
 *               Can be encrypted if user key is supplied when needed. Must already have a
 *               {@link StoredPaymentChannelClientStates} object in its extensions set.
 * @param myKey A freshly generated keypair used for the multisig contract and refund output.
 * @param maxValue The maximum value this channel is allowed to request
 * @param serverId A unique ID which is used to attempt reopening of an existing channel.
 *                 This must be unique to the server, and, if your application is exposing payment channels to some
 *                 API, this should also probably encompass some caller UID to avoid applications opening channels
 *                 which were created by others.
 * @param userKeySetup Key derived from a user password, used to decrypt myKey, if it is encrypted, during setup.
 * @param clientChannelProperties Modifier to change the channel's configuration.
 *
 * @throws IOException if there's an issue using the network.
 * @throws ValueOutOfRangeException if the balance of wallet is lower than maxValue.
 */
public PaymentChannelClientConnection(InetSocketAddress server, int timeoutSeconds, Wallet wallet, ECKey myKey,
                                      Coin maxValue, String serverId,
                                      @Nullable KeyParameter userKeySetup, final ClientChannelProperties clientChannelProperties)
        throws IOException, ValueOutOfRangeException {
    // Glue the object which vends/ingests protobuf messages in order to manage state to the network object which
    // reads/writes them to the wire in length prefixed form.
    channelClient = new PaymentChannelClient(wallet, myKey, maxValue, Sha256Hash.of(serverId.getBytes()),
            userKeySetup, clientChannelProperties, new PaymentChannelClient.ClientConnection() {
        @Override
        public void sendToServer(Protos.TwoWayChannelMessage msg) {
            wireParser.write(msg);
        }

        @Override
        public void destroyConnection(PaymentChannelCloseException.CloseReason reason) {
            channelOpenFuture.setException(new PaymentChannelCloseException("Payment channel client requested that the connection be closed: " + reason, reason));
            wireParser.closeConnection();
        }

        @Override
        public boolean acceptExpireTime(long expireTime) {
            return expireTime <= (clientChannelProperties.timeWindow() + Utils.currentTimeSeconds() + 60);  // One extra minute to compensate for time skew and latency
        }

        @Override
        public void channelOpen(boolean wasInitiated) {
            wireParser.setSocketTimeout(0);
            // Inform the API user that we're done and ready to roll.
            channelOpenFuture.set(PaymentChannelClientConnection.this);
        }
    });

    // And glue back in the opposite direction - network to the channelClient.
    wireParser = new ProtobufConnection<Protos.TwoWayChannelMessage>(new ProtobufConnection.Listener<Protos.TwoWayChannelMessage>() {
        @Override
        public void messageReceived(ProtobufConnection<Protos.TwoWayChannelMessage> handler, Protos.TwoWayChannelMessage msg) {
            try {
                channelClient.receiveMessage(msg);
            } catch (InsufficientMoneyException e) {
                // We should only get this exception during INITIATE, so channelOpen wasn't called yet.
                channelOpenFuture.setException(e);
            }
        }

        @Override
        public void connectionOpen(ProtobufConnection<Protos.TwoWayChannelMessage> handler) {
            channelClient.connectionOpen();
        }

        @Override
        public void connectionClosed(ProtobufConnection<Protos.TwoWayChannelMessage> handler) {
            channelClient.connectionClosed();
            channelOpenFuture.setException(new PaymentChannelCloseException("The TCP socket died",
                    PaymentChannelCloseException.CloseReason.CONNECTION_CLOSED));
        }
    }, Protos.TwoWayChannelMessage.getDefaultInstance(), Short.MAX_VALUE, timeoutSeconds*1000);

    // Initiate the outbound network connection. We don't need to keep this around. The wireParser object will handle
    // things from here on out.
    new NioClient(server, wireParser, timeoutSeconds * 1000);
}
 

@Override
public synchronized void initiate(@Nullable KeyParameter userKey, ClientChannelProperties clientChannelProperties) throws ValueOutOfRangeException, InsufficientMoneyException {
    final NetworkParameters params = wallet.getParams();
    Transaction template = new Transaction(params);
    // 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.
    Script redeemScript =
            ScriptBuilder.createCLTVPaymentChannelOutput(BigInteger.valueOf(expiryTime), myKey, serverKey);
    TransactionOutput transactionOutput = template.addOutput(totalValue,
            ScriptBuilder.createP2SHOutputScript(redeemScript));
    if (transactionOutput.isDust())
        throw new ValueOutOfRangeException("totalValue too small to use");
    SendRequest req = SendRequest.forTx(template);
    req.coinSelector = AllowUnconfirmedCoinSelector.get();
    req.shuffleOutputs = false;   // TODO: Fix things so shuffling is usable.
    req = clientChannelProperties.modifyContractSendRequest(req);
    if (userKey != null) req.aesKey = userKey;
    wallet.completeTx(req);
    Coin multisigFee = req.tx.getFee();
    contract = 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 because the
    // CheckLockTimeVerify opcode requires a lock time to be specified and the input to have a non-final sequence
    // number (so that the lock time is not disabled).
    refundTx = new Transaction(params);
    // by using this sequence value, we avoid extra full replace-by-fee and relative lock time processing.
    refundTx.addInput(contract.getOutput(0)).setSequenceNumber(TransactionInput.NO_SEQUENCE - 1L);
    refundTx.setLockTime(expiryTime);
    if (Context.get().isEnsureMinRequiredFee()) {
        // 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;
    }

    TransactionSignature refundSignature =
            refundTx.calculateSignature(0, myKey.maybeDecrypt(userKey),
                    getSignedScript(), Transaction.SigHash.ALL, false);
    refundTx.getInput(0).setScriptSig(ScriptBuilder.createCLTVPaymentChannelP2SHRefund(refundSignature, redeemScript));

    refundTx.getConfidence().setSource(TransactionConfidence.Source.SELF);
    log.info("initiated channel with contract {}", contract.getHashAsString());
    stateMachine.transition(State.SAVE_STATE_IN_WALLET);
    // Client should now call getIncompleteRefundTransaction() and send it to the server.
}
 

/**
 * Creates the initial multisig contract and incomplete refund transaction which can be requested at the appropriate
 * time using {@link PaymentChannelV1ClientState#getIncompleteRefundTransaction} and
 * {@link PaymentChannelV1ClientState#getContract()}.
 * By default unconfirmed coins are allowed to be used, as for micropayments the risk should be relatively low.
 * @param userKey Key derived from a user password, needed for any signing when the wallet is encrypted.
 *                The wallet KeyCrypter is assumed.
 * @param clientChannelProperties Modify the channel's configuration.
 *
 * @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
 */
@Override
public synchronized void initiate(@Nullable KeyParameter userKey, ClientChannelProperties clientChannelProperties) 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, serverKey);
    // 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.isDust())
        throw new ValueOutOfRangeException("totalValue too small to use");
    SendRequest req = SendRequest.forTx(template);
    req.coinSelector = AllowUnconfirmedCoinSelector.get();
    req.shuffleOutputs = false;   // TODO: Fix things so shuffling is usable.
    req = clientChannelProperties.modifyContractSendRequest(req);
    if (userKey != null) req.aesKey = userKey;
    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);
    // don't disable lock time. the sequence will be included in the server's signature and thus won't be changeable.
    // by using this sequence value, we avoid extra full replace-by-fee and relative lock time processing.
    refundTx.addInput(multisigOutput).setSequenceNumber(TransactionInput.NO_SEQUENCE - 1L);
    refundTx.setLockTime(expiryTime);
    if (Context.get().isEnsureMinRequiredFee()) {
        // 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());
    stateMachine.transition(State.INITIATED);
    // Client should now call getIncompleteRefundTransaction() and send it to the server.
}
 

/**
 * Creates the initial multisig contract and incomplete refund transaction which can be requested at the appropriate
 * time using {@link PaymentChannelV1ClientState#getIncompleteRefundTransaction} and
 * {@link PaymentChannelClientState#getContract()}.
 * By default unconfirmed coins are allowed to be used, as for micropayments the risk should be relatively low.
 *
 * @param userKey                 Key derived from a user password, needed for any signing when the wallet is encrypted.
 *                                The wallet KeyCrypter is assumed.
 * @param clientChannelProperties Modify the channel's configuration.
 * @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 abstract void initiate(@Nullable KeyParameter userKey, ClientChannelProperties clientChannelProperties) throws ValueOutOfRangeException, InsufficientMoneyException;
 

/**
 * Creates the initial multisig contract and incomplete refund transaction which can be requested at the appropriate
 * time using {@link PaymentChannelV1ClientState#getIncompleteRefundTransaction} and
 * {@link PaymentChannelClientState#getContract()}.
 * By default unconfirmed coins are allowed to be used, as for micropayments the risk should be relatively low.
 * @param userKey Key derived from a user password, needed for any signing when the wallet is encrypted.
 *                The wallet KeyCrypter is assumed.
 * @param clientChannelProperties Modify the channel's configuration.
 *
 * @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 abstract void initiate(@Nullable KeyParameter userKey, ClientChannelProperties clientChannelProperties) throws ValueOutOfRangeException, InsufficientMoneyException;
 

/**
 * Creates the initial multisig contract and incomplete refund transaction which can be requested at the appropriate
 * time using {@link PaymentChannelV1ClientState#getIncompleteRefundTransaction} and
 * {@link PaymentChannelClientState#getContract()}.
 * By default unconfirmed coins are allowed to be used, as for micropayments the risk should be relatively low.
 * @param userKey Key derived from a user password, needed for any signing when the wallet is encrypted.
 *                The wallet KeyCrypter is assumed.
 * @param clientChannelProperties Modify the channel's configuration.
 *
 * @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 abstract void initiate(@Nullable KeyParameter userKey, ClientChannelProperties clientChannelProperties) throws ValueOutOfRangeException, InsufficientMoneyException;