Java Code Examples for org.bitcoinj.crypto.TransactionSignature#anyoneCanPay()

/**
 * <p>When the servers signature for the refund transaction is received, call this to verify it and sign the
 * complete refund ourselves.</p>
 * <p>
 * <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.</p>
 */
public synchronized void provideRefundSignature(byte[] theirSignature, @Nullable KeyParameter userKey)
        throws VerificationException {
    checkNotNull(theirSignature);
    stateMachine.checkState(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.maybeDecrypt(userKey),
                    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);
    stateMachine.transition(State.SAVE_STATE_IN_WALLET);
}
 

/**
 * <p>When the servers signature for the refund transaction is received, call this to verify it and sign the
 * complete refund ourselves.</p>
 *
 * <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.</p>
 */
public synchronized void provideRefundSignature(byte[] theirSignature, @Nullable KeyParameter userKey)
        throws VerificationException {
    checkNotNull(theirSignature);
    stateMachine.checkState(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.maybeDecrypt(userKey),
                    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);
    stateMachine.transition(State.SAVE_STATE_IN_WALLET);
}
 

/**
 * <p>When the servers signature for the refund transaction is received, call this to verify it and sign the
 * complete refund ourselves.</p>
 *
 * <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.</p>
 */
public synchronized void provideRefundSignature(byte[] theirSignature, @Nullable KeyParameter userKey)
        throws VerificationException {
    checkNotNull(theirSignature);
    stateMachine.checkState(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.maybeDecrypt(userKey),
                    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);
    stateMachine.transition(State.SAVE_STATE_IN_WALLET);
}
 

/**
 * Called when the client provides us with a new signature and wishes to increment total payment by size.		+
 * Verifies the provided signature and only updates values if everything checks out.
 * If the new refundSize is not the lowest we have seen, it is simply ignored.
 *
 * @param refundSize     How many satoshis of the original contract are refunded to the client (the rest are ours)
 * @param signatureBytes The new signature spending the multi-sig contract to a new payment transaction
 * @return true if there is more value left on the channel, false if it is now fully used up.
 * @throws VerificationException If the signature does not verify or size is out of range (incl being rejected by the network as dust).
 */
public synchronized boolean incrementPayment(Coin refundSize, byte[] signatureBytes) throws VerificationException, ValueOutOfRangeException, InsufficientMoneyException {
    stateMachine.checkState(State.READY);
    checkNotNull(refundSize);
    checkNotNull(signatureBytes);
    TransactionSignature signature = TransactionSignature.decodeFromBitcoin(signatureBytes, true);
    // We allow snapping to zero for the payment amount because it's treated specially later, but not less than
    // the dust level because that would prevent the transaction from being relayed/mined.
    final boolean fullyUsedUp = refundSize.equals(Coin.ZERO);
    Coin newValueToMe = getTotalValue().subtract(refundSize);
    if (newValueToMe.signum() < 0)
        throw new ValueOutOfRangeException("Attempt to refund more than the contract allows.");
    if (newValueToMe.compareTo(bestValueToMe) < 0)
        throw new ValueOutOfRangeException("Attempt to roll back payment on the channel.");

    SendRequest req = makeUnsignedChannelContract(newValueToMe);

    if (!fullyUsedUp && refundSize.isLessThan(req.tx.getOutput(0).getMinNonDustValue()))
        throw new ValueOutOfRangeException("Attempt to refund negative value or value too small to be accepted by the network");

    // Get the wallet's copy of the contract (ie with confidence information), if this is null, the wallet
    // was not connected to the peergroup when the contract was broadcast (which may cause issues down the road, and
    // disables our double-spend check next)
    Transaction walletContract = wallet.getTransaction(contract.getHash());
    checkNotNull(walletContract, "Wallet did not contain multisig contract {} after state was marked READY", contract.getHash());

    // Note that we check for DEAD state here, but this test is essentially useless in production because we will
    // miss most double-spends due to bloom filtering right now anyway. This will eventually fixed by network-wide
    // double-spend notifications, so we just wait instead of attempting to add all dependant outpoints to our bloom
    // filters (and probably missing lots of edge-cases).
    if (walletContract.getConfidence().getConfidenceType() == TransactionConfidence.ConfidenceType.DEAD) {
        close();
        throw new VerificationException("Multisig contract was double-spent");
    }

    Transaction.SigHash mode;
    // If the client doesn't want anything back, they shouldn't sign any outputs at all.
    if (fullyUsedUp)
        mode = Transaction.SigHash.NONE;
    else
        mode = Transaction.SigHash.SINGLE;

    if (signature.sigHashMode() != mode || !signature.anyoneCanPay())
        throw new VerificationException("New payment signature was not signed with the right SIGHASH flags.");

    // Now check the signature is correct.
    // Note that the client must sign with SIGHASH_{SINGLE/NONE} | SIGHASH_ANYONECANPAY to allow us to add additional
    // inputs (in case we need to add significant fee, or something...) and any outputs we want to pay to.
    Sha256Hash sighash = req.tx.hashForSignature(0, getSignedScript(), mode, true);

    if (!getClientKey().verify(sighash, signature))
        throw new VerificationException("Signature does not verify on tx\n" + req.tx);
    bestValueToMe = newValueToMe;
    bestValueSignature = signatureBytes;
    updateChannelInWallet();
    return !fullyUsedUp;
}
 

/**
 * Called when the client provides us with a new signature and wishes to increment total payment by size.		+
 * Verifies the provided signature and only updates values if everything checks out.
 * If the new refundSize is not the lowest we have seen, it is simply ignored.
 *
 * @param refundSize How many satoshis of the original contract are refunded to the client (the rest are ours)
 * @param signatureBytes The new signature spending the multi-sig contract to a new payment transaction
 * @throws VerificationException If the signature does not verify or size is out of range (incl being rejected by the network as dust).
 * @return true if there is more value left on the channel, false if it is now fully used up.
 */
public synchronized boolean incrementPayment(Coin refundSize, byte[] signatureBytes) throws VerificationException, ValueOutOfRangeException, InsufficientMoneyException {
    stateMachine.checkState(State.READY);
    checkNotNull(refundSize);
    checkNotNull(signatureBytes);
    TransactionSignature signature = TransactionSignature.decodeFromBitcoin(signatureBytes, true);
    // We allow snapping to zero for the payment amount because it's treated specially later, but not less than
    // the dust level because that would prevent the transaction from being relayed/mined.
    final boolean fullyUsedUp = refundSize.equals(Coin.ZERO);
    Coin newValueToMe = getTotalValue().subtract(refundSize);
    if (newValueToMe.signum() < 0)
        throw new ValueOutOfRangeException("Attempt to refund more than the contract allows.");
    if (newValueToMe.compareTo(bestValueToMe) < 0)
        throw new ValueOutOfRangeException("Attempt to roll back payment on the channel.");

    SendRequest req = makeUnsignedChannelContract(newValueToMe);

    if (!fullyUsedUp && refundSize.isLessThan(req.tx.getOutput(0).getMinNonDustValue()))
        throw new ValueOutOfRangeException("Attempt to refund negative value or value too small to be accepted by the network");

    // Get the wallet's copy of the contract (ie with confidence information), if this is null, the wallet
    // was not connected to the peergroup when the contract was broadcast (which may cause issues down the road, and
    // disables our double-spend check next)
    Transaction walletContract = wallet.getTransaction(contract.getHash());
    checkNotNull(walletContract, "Wallet did not contain multisig contract {} after state was marked READY", contract.getHash());

    // Note that we check for DEAD state here, but this test is essentially useless in production because we will
    // miss most double-spends due to bloom filtering right now anyway. This will eventually fixed by network-wide
    // double-spend notifications, so we just wait instead of attempting to add all dependant outpoints to our bloom
    // filters (and probably missing lots of edge-cases).
    if (walletContract.getConfidence().getConfidenceType() == TransactionConfidence.ConfidenceType.DEAD) {
        close();
        throw new VerificationException("Multisig contract was double-spent");
    }

    Transaction.SigHash mode;
    // If the client doesn't want anything back, they shouldn't sign any outputs at all.
    if (fullyUsedUp)
        mode = Transaction.SigHash.NONE;
    else
        mode = Transaction.SigHash.SINGLE;

    if (signature.sigHashMode() != mode || !signature.anyoneCanPay())
        throw new VerificationException("New payment signature was not signed with the right SIGHASH flags.");

    // Now check the signature is correct.
    // Note that the client must sign with SIGHASH_{SINGLE/NONE} | SIGHASH_ANYONECANPAY to allow us to add additional
    // inputs (in case we need to add significant fee, or something...) and any outputs we want to pay to.
    Sha256Hash sighash = req.tx.hashForSignature(0, getSignedScript(), mode, true);

    if (!getClientKey().verify(sighash, signature))
        throw new VerificationException("Signature does not verify on tx\n" + req.tx);
    bestValueToMe = newValueToMe;
    bestValueSignature = signatureBytes;
    updateChannelInWallet();
    return !fullyUsedUp;
}
 

/**
 * Called when the client provides us with a new signature and wishes to increment total payment by size.		+
 * Verifies the provided signature and only updates values if everything checks out.
 * If the new refundSize is not the lowest we have seen, it is simply ignored.
 *
 * @param refundSize How many satoshis of the original contract are refunded to the client (the rest are ours)
 * @param signatureBytes The new signature spending the multi-sig contract to a new payment transaction
 * @throws VerificationException If the signature does not verify or size is out of range (incl being rejected by the network as dust).
 * @return true if there is more value left on the channel, false if it is now fully used up.
 */
public synchronized boolean incrementPayment(Coin refundSize, byte[] signatureBytes) throws VerificationException, ValueOutOfRangeException, InsufficientMoneyException {
    stateMachine.checkState(State.READY);
    checkNotNull(refundSize);
    checkNotNull(signatureBytes);
    TransactionSignature signature = TransactionSignature.decodeFromBitcoin(signatureBytes, true);
    // We allow snapping to zero for the payment amount because it's treated specially later, but not less than
    // the dust level because that would prevent the transaction from being relayed/mined.
    final boolean fullyUsedUp = refundSize.equals(Coin.ZERO);
    Coin newValueToMe = getTotalValue().subtract(refundSize);
    if (newValueToMe.signum() < 0)
        throw new ValueOutOfRangeException("Attempt to refund more than the contract allows.");
    if (newValueToMe.compareTo(bestValueToMe) < 0)
        throw new ValueOutOfRangeException("Attempt to roll back payment on the channel.");

    SendRequest req = makeUnsignedChannelContract(newValueToMe);

    if (!fullyUsedUp && refundSize.isLessThan(req.tx.getOutput(0).getMinNonDustValue()))
        throw new ValueOutOfRangeException("Attempt to refund negative value or value too small to be accepted by the network");

    // Get the wallet's copy of the contract (ie with confidence information), if this is null, the wallet
    // was not connected to the peergroup when the contract was broadcast (which may cause issues down the road, and
    // disables our double-spend check next)
    Transaction walletContract = wallet.getTransaction(contract.getHash());
    checkNotNull(walletContract, "Wallet did not contain multisig contract {} after state was marked READY", contract.getHash());

    // Note that we check for DEAD state here, but this test is essentially useless in production because we will
    // miss most double-spends due to bloom filtering right now anyway. This will eventually fixed by network-wide
    // double-spend notifications, so we just wait instead of attempting to add all dependant outpoints to our bloom
    // filters (and probably missing lots of edge-cases).
    if (walletContract.getConfidence().getConfidenceType() == TransactionConfidence.ConfidenceType.DEAD) {
        close();
        throw new VerificationException("Multisig contract was double-spent");
    }

    Transaction.SigHash mode;
    // If the client doesn't want anything back, they shouldn't sign any outputs at all.
    if (fullyUsedUp)
        mode = Transaction.SigHash.NONE;
    else
        mode = Transaction.SigHash.SINGLE;

    if (signature.sigHashMode() != mode || !signature.anyoneCanPay())
        throw new VerificationException("New payment signature was not signed with the right SIGHASH flags.");

    // Now check the signature is correct.
    // Note that the client must sign with SIGHASH_{SINGLE/NONE} | SIGHASH_ANYONECANPAY to allow us to add additional
    // inputs (in case we need to add significant fee, or something...) and any outputs we want to pay to.
    Sha256Hash sighash = req.tx.hashForSignature(0, getSignedScript(), mode, true);

    if (!getClientKey().verify(sighash, signature))
        throw new VerificationException("Signature does not verify on tx\n" + req.tx);
    bestValueToMe = newValueToMe;
    bestValueSignature = signatureBytes;
    updateChannelInWallet();
    return !fullyUsedUp;
}