// SignThis isn't used anymore...
func (t *TxStore) SignThis(tx *wire.MsgTx) error {
fmt.Printf("-= SignThis =-\n")
// sort tx before signing.
txsort.InPlaceSort(tx)
sigs := make([][]byte, len(tx.TxIn))
// first iterate over each input
for j, in := range tx.TxIn {
for k := uint32(0); k < uint32(len(t.Adrs)); k++ {
child, err := t.rootPrivKey.Child(k + hdkeychain.HardenedKeyStart)
if err != nil {
return err
}
myadr, err := child.Address(t.Param)
if err != nil {
return err
}
adrScript, err := txscript.PayToAddrScript(myadr)
if err != nil {
return err
}
if bytes.Equal(adrScript, in.SignatureScript) {
fmt.Printf("Hit; key %d matches input %d. Signing.\n", k, j)
priv, err := child.ECPrivKey()
if err != nil {
return err
}
sigs[j], err = txscript.SignatureScript(
tx, j, in.SignatureScript, txscript.SigHashAll, priv, true)
if err != nil {
return err
}
break
}
}
}
for i, s := range sigs {
if s != nil {
tx.TxIn[i].SignatureScript = s
}
}
return nil
}
func testSingleFunderReservationWorkflowResponder(miner *rpctest.Harness,
wallet *lnwallet.LightningWallet, t *testing.T) {
t.Log("Running single funder workflow responder test")
// For this scenario, bob will initiate the channel, while we simply act as
// the responder.
capacity := btcutil.Amount(4 * 1e8)
// Create the bob-test wallet which will be initiator of a single
// funder channel shortly.
bobNode, err := newBobNode(miner, capacity)
if err != nil {
t.Fatalf("unable to create bob node: %v", err)
}
// Bob sends over a single funding request, so we allocate our
// contribution and the necessary resources.
fundingAmt := btcutil.Amount(0)
chanReservation, err := wallet.InitChannelReservation(capacity,
fundingAmt, bobNode.id, bobAddr, numReqConfs, 4)
if err != nil {
t.Fatalf("unable to init channel reservation: %v", err)
}
// Verify all contribution fields have been set properly. Since we are
// the recipient of a single-funder channel, we shouldn't have selected
// any coins or generated any change outputs.
ourContribution := chanReservation.OurContribution()
if len(ourContribution.Inputs) != 0 {
t.Fatalf("outputs for funding tx not properly selected, have %v "+
"outputs should have 0", len(ourContribution.Inputs))
}
if len(ourContribution.ChangeOutputs) != 0 {
t.Fatalf("coin selection failed, should have no change outputs, "+
"instead have: %v", ourContribution.ChangeOutputs[0].Value)
}
if ourContribution.MultiSigKey == nil {
t.Fatalf("alice's key for multi-sig not found")
}
if ourContribution.CommitKey == nil {
t.Fatalf("alice's key for commit not found")
}
if ourContribution.DeliveryAddress == nil {
t.Fatalf("alice's final delivery address not found")
}
if ourContribution.CsvDelay == 0 {
t.Fatalf("csv delay not set")
}
// Next we process Bob's single funder contribution which doesn't
// include any inputs or change addresses, as only Bob will construct
// the funding transaction.
bobContribution := bobNode.Contribution(ourContribution.CommitKey)
if err := chanReservation.ProcessSingleContribution(bobContribution); err != nil {
t.Fatalf("unable to process bob's contribution: %v", err)
}
if chanReservation.FinalFundingTx() != nil {
t.Fatalf("funding transaction populated!")
}
if len(bobContribution.Inputs) != 1 {
t.Fatalf("bob shouldn't have one inputs, instead has %v",
len(bobContribution.Inputs))
}
if ourContribution.RevocationKey == nil {
t.Fatalf("alice's revocation key not found")
}
if len(bobContribution.ChangeOutputs) != 1 {
t.Fatalf("bob shouldn't have one change output, instead "+
"has %v", len(bobContribution.ChangeOutputs))
}
if bobContribution.MultiSigKey == nil {
t.Fatalf("bob's key for multi-sig not found")
}
if bobContribution.CommitKey == nil {
t.Fatalf("bob's key for commit tx not found")
}
if bobContribution.DeliveryAddress == nil {
t.Fatalf("bob's final delivery address not found")
}
if bobContribution.RevocationKey == nil {
t.Fatalf("bob's revocaiton key not found")
}
fundingRedeemScript, multiOut, err := lnwallet.GenFundingPkScript(
ourContribution.MultiSigKey.SerializeCompressed(),
bobContribution.MultiSigKey.SerializeCompressed(),
// TODO(roasbeef): account for hard-coded fee, remove bob node
int64(capacity)+5000)
if err != nil {
t.Fatalf("unable to generate multi-sig output: %v", err)
}
// At this point, we send Bob our contribution, allowing him to
// construct the funding transaction, and sign our version of the
// commitment transaction.
fundingTx := wire.NewMsgTx()
fundingTx.AddTxIn(bobNode.availableOutputs[0])
fundingTx.AddTxOut(bobNode.changeOutputs[0])
fundingTx.AddTxOut(multiOut)
txsort.InPlaceSort(fundingTx)
if _, err := bobNode.signFundingTx(fundingTx); err != nil {
t.Fatalf("unable to generate bob's funding sigs: %v", err)
}
// Locate the output index of the 2-of-2 in order to send back to the
// wallet so it can finalize the transaction by signing bob's commitment
// transaction.
fundingTxID := fundingTx.TxSha()
_, multiSigIndex := lnwallet.FindScriptOutputIndex(fundingTx, multiOut.PkScript)
fundingOutpoint := wire.NewOutPoint(&fundingTxID, multiSigIndex)
fundingTxIn := wire.NewTxIn(fundingOutpoint, nil, nil)
aliceCommitTx, err := lnwallet.CreateCommitTx(fundingTxIn, ourContribution.CommitKey,
bobContribution.CommitKey, ourContribution.RevocationKey,
ourContribution.CsvDelay, 0, capacity)
if err != nil {
t.Fatalf("unable to create alice's commit tx: %v", err)
}
txsort.InPlaceSort(aliceCommitTx)
bobCommitSig, err := bobNode.signCommitTx(aliceCommitTx,
// TODO(roasbeef): account for hard-coded fee, remove bob node
fundingRedeemScript, int64(capacity)+5000)
if err != nil {
t.Fatalf("unable to sign alice's commit tx: %v", err)
}
// With this stage complete, Alice can now complete the reservation.
bobRevokeKey := bobContribution.RevocationKey
if err := chanReservation.CompleteReservationSingle(bobRevokeKey,
fundingOutpoint, bobCommitSig); err != nil {
t.Fatalf("unable to complete reservation: %v", err)
}
// Alice should have saved the funding output.
if chanReservation.FundingOutpoint() != fundingOutpoint {
t.Fatalf("funding outputs don't match: %#v vs %#v",
chanReservation.FundingOutpoint(), fundingOutpoint)
}
// Some period of time later, Bob presents us with an SPV proof
// attesting to an open channel. At this point Alice recognizes the
// channel, saves the state to disk, and creates the channel itself.
if _, err := chanReservation.FinalizeReservation(); err != nil {
t.Fatalf("unable to finalize reservation: %v", err)
}
// TODO(roasbeef): bob verify alice's sig
}
// handleContributionMsg processes the second workflow step for the lifetime of
// a channel reservation. Upon completion, the reservation will carry a
// completed funding transaction (minus the counterparty's input signatures),
// both versions of the commitment transaction, and our signature for their
// version of the commitment transaction.
func (l *LightningWallet) handleContributionMsg(req *addContributionMsg) {
l.limboMtx.Lock()
pendingReservation, ok := l.fundingLimbo[req.pendingFundingID]
l.limboMtx.Unlock()
if !ok {
req.err <- fmt.Errorf("attempted to update non-existant funding state")
return
}
// Grab the mutex on the ChannelReservation to ensure thead-safety
pendingReservation.Lock()
defer pendingReservation.Unlock()
// Create a blank, fresh transaction. Soon to be a complete funding
// transaction which will allow opening a lightning channel.
pendingReservation.fundingTx = wire.NewMsgTx()
fundingTx := pendingReservation.fundingTx
// Some temporary variables to cut down on the resolution verbosity.
pendingReservation.theirContribution = req.contribution
theirContribution := req.contribution
ourContribution := pendingReservation.ourContribution
// Add all multi-party inputs and outputs to the transaction.
for _, ourInput := range ourContribution.Inputs {
fundingTx.AddTxIn(ourInput)
}
for _, theirInput := range theirContribution.Inputs {
fundingTx.AddTxIn(theirInput)
}
for _, ourChangeOutput := range ourContribution.ChangeOutputs {
fundingTx.AddTxOut(ourChangeOutput)
}
for _, theirChangeOutput := range theirContribution.ChangeOutputs {
fundingTx.AddTxOut(theirChangeOutput)
}
ourKey := pendingReservation.partialState.OurMultiSigKey
theirKey := theirContribution.MultiSigKey
// Finally, add the 2-of-2 multi-sig output which will set up the lightning
// channel.
channelCapacity := int64(pendingReservation.partialState.Capacity)
witnessScript, multiSigOut, err := GenFundingPkScript(ourKey.SerializeCompressed(),
theirKey.SerializeCompressed(), channelCapacity)
if err != nil {
req.err <- err
return
}
pendingReservation.partialState.FundingWitnessScript = witnessScript
// Sort the transaction. Since both side agree to a canonical
// ordering, by sorting we no longer need to send the entire
// transaction. Only signatures will be exchanged.
fundingTx.AddTxOut(multiSigOut)
txsort.InPlaceSort(pendingReservation.fundingTx)
// Next, sign all inputs that are ours, collecting the signatures in
// order of the inputs.
pendingReservation.ourFundingInputScripts = make([]*InputScript, 0, len(ourContribution.Inputs))
signDesc := SignDescriptor{
HashType: txscript.SigHashAll,
SigHashes: txscript.NewTxSigHashes(fundingTx),
}
for i, txIn := range fundingTx.TxIn {
info, err := l.FetchInputInfo(&txIn.PreviousOutPoint)
if err == ErrNotMine {
continue
} else if err != nil {
req.err <- err
return
}
signDesc.Output = info
signDesc.InputIndex = i
inputScript, err := l.Signer.ComputeInputScript(fundingTx, &signDesc)
if err != nil {
req.err <- err
return
}
txIn.SignatureScript = inputScript.ScriptSig
txIn.Witness = inputScript.Witness
pendingReservation.ourFundingInputScripts = append(
pendingReservation.ourFundingInputScripts,
inputScript,
)
}
// Locate the index of the multi-sig outpoint in order to record it
// since the outputs are canonically sorted. If this is a single funder
// workflow, then we'll also need to send this to the remote node.
fundingTxID := fundingTx.TxSha()
_, multiSigIndex := FindScriptOutputIndex(fundingTx, multiSigOut.PkScript)
fundingOutpoint := wire.NewOutPoint(&fundingTxID, multiSigIndex)
pendingReservation.partialState.FundingOutpoint = fundingOutpoint
// Initialize an empty sha-chain for them, tracking the current pending
// revocation hash (we don't yet know the pre-image so we can't add it
// to the chain).
e := &elkrem.ElkremReceiver{}
pendingReservation.partialState.RemoteElkrem = e
pendingReservation.partialState.TheirCurrentRevocation = theirContribution.RevocationKey
masterElkremRoot, err := l.deriveMasterElkremRoot()
if err != nil {
req.err <- err
return
}
// Now that we have their commitment key, we can create the revocation
// key for the first version of our commitment transaction. To do so,
// we'll first create our elkrem root, then grab the first pre-iamge
// from it.
elkremRoot := deriveElkremRoot(masterElkremRoot, ourKey, theirKey)
elkremSender := elkrem.NewElkremSender(elkremRoot)
pendingReservation.partialState.LocalElkrem = elkremSender
firstPreimage, err := elkremSender.AtIndex(0)
if err != nil {
req.err <- err
return
}
theirCommitKey := theirContribution.CommitKey
ourRevokeKey := DeriveRevocationPubkey(theirCommitKey, firstPreimage[:])
// Create the txIn to our commitment transaction; required to construct
// the commitment transactions.
fundingTxIn := wire.NewTxIn(wire.NewOutPoint(&fundingTxID, multiSigIndex), nil, nil)
// With the funding tx complete, create both commitment transactions.
// TODO(roasbeef): much cleanup + de-duplication
pendingReservation.fundingLockTime = theirContribution.CsvDelay
ourBalance := ourContribution.FundingAmount
theirBalance := theirContribution.FundingAmount
ourCommitKey := ourContribution.CommitKey
ourCommitTx, err := CreateCommitTx(fundingTxIn, ourCommitKey, theirCommitKey,
ourRevokeKey, ourContribution.CsvDelay,
ourBalance, theirBalance)
if err != nil {
req.err <- err
return
}
theirCommitTx, err := CreateCommitTx(fundingTxIn, theirCommitKey, ourCommitKey,
theirContribution.RevocationKey, theirContribution.CsvDelay,
theirBalance, ourBalance)
if err != nil {
req.err <- err
return
}
// Sort both transactions according to the agreed upon cannonical
// ordering. This lets us skip sending the entire transaction over,
// instead we'll just send signatures.
txsort.InPlaceSort(ourCommitTx)
txsort.InPlaceSort(theirCommitTx)
deliveryScript, err := txscript.PayToAddrScript(theirContribution.DeliveryAddress)
if err != nil {
req.err <- err
return
}
// Record newly available information witin the open channel state.
pendingReservation.partialState.RemoteCsvDelay = theirContribution.CsvDelay
pendingReservation.partialState.TheirDeliveryScript = deliveryScript
pendingReservation.partialState.ChanID = fundingOutpoint
pendingReservation.partialState.TheirCommitKey = theirCommitKey
pendingReservation.partialState.TheirMultiSigKey = theirContribution.MultiSigKey
pendingReservation.partialState.OurCommitTx = ourCommitTx
pendingReservation.ourContribution.RevocationKey = ourRevokeKey
// Generate a signature for their version of the initial commitment
// transaction.
signDesc = SignDescriptor{
WitnessScript: witnessScript,
PubKey: ourKey,
Output: multiSigOut,
HashType: txscript.SigHashAll,
SigHashes: txscript.NewTxSigHashes(theirCommitTx),
InputIndex: 0,
}
sigTheirCommit, err := l.Signer.SignOutputRaw(theirCommitTx, &signDesc)
if err != nil {
req.err <- err
return
}
pendingReservation.ourCommitmentSig = sigTheirCommit
req.err <- nil
}
// handleSingleFunderSigs is called once the remote peer who initiated the
// single funder workflow has assembled the funding transaction, and generated
// a signature for our version of the commitment transaction. This method
// progresses the workflow by generating a signature for the remote peer's
// version of the commitment transaction.
func (l *LightningWallet) handleSingleFunderSigs(req *addSingleFunderSigsMsg) {
l.limboMtx.RLock()
pendingReservation, ok := l.fundingLimbo[req.pendingFundingID]
l.limboMtx.RUnlock()
if !ok {
req.err <- fmt.Errorf("attempted to update non-existant funding state")
return
}
// Grab the mutex on the ChannelReservation to ensure thead-safety
pendingReservation.Lock()
defer pendingReservation.Unlock()
pendingReservation.partialState.FundingOutpoint = req.fundingOutpoint
pendingReservation.partialState.TheirCurrentRevocation = req.revokeKey
pendingReservation.partialState.ChanID = req.fundingOutpoint
fundingTxIn := wire.NewTxIn(req.fundingOutpoint, nil, nil)
// Now that we have the funding outpoint, we can generate both versions
// of the commitment transaction, and generate a signature for the
// remote node's commitment transactions.
ourCommitKey := pendingReservation.ourContribution.CommitKey
theirCommitKey := pendingReservation.theirContribution.CommitKey
ourBalance := pendingReservation.ourContribution.FundingAmount
theirBalance := pendingReservation.theirContribution.FundingAmount
ourCommitTx, err := CreateCommitTx(fundingTxIn, ourCommitKey, theirCommitKey,
pendingReservation.ourContribution.RevocationKey,
pendingReservation.ourContribution.CsvDelay, ourBalance, theirBalance)
if err != nil {
req.err <- err
return
}
theirCommitTx, err := CreateCommitTx(fundingTxIn, theirCommitKey, ourCommitKey,
req.revokeKey, pendingReservation.theirContribution.CsvDelay,
theirBalance, ourBalance)
if err != nil {
req.err <- err
return
}
// Sort both transactions according to the agreed upon cannonical
// ordering. This ensures that both parties sign the same sighash
// without further synchronization.
txsort.InPlaceSort(ourCommitTx)
pendingReservation.partialState.OurCommitTx = ourCommitTx
txsort.InPlaceSort(theirCommitTx)
witnessScript := pendingReservation.partialState.FundingWitnessScript
channelValue := int64(pendingReservation.partialState.Capacity)
hashCache := txscript.NewTxSigHashes(ourCommitTx)
theirKey := pendingReservation.theirContribution.MultiSigKey
ourKey := pendingReservation.partialState.OurMultiSigKey
sigHash, err := txscript.CalcWitnessSigHash(witnessScript, hashCache,
txscript.SigHashAll, ourCommitTx, 0, channelValue)
if err != nil {
req.err <- err
return
}
// Verify that we've received a valid signature from the remote party
// for our version of the commitment transaction.
sig, err := btcec.ParseSignature(req.theirCommitmentSig, btcec.S256())
if err != nil {
req.err <- err
return
} else if !sig.Verify(sigHash, theirKey) {
req.err <- fmt.Errorf("counterparty's commitment signature is invalid")
return
}
pendingReservation.partialState.OurCommitSig = req.theirCommitmentSig
// With their signature for our version of the commitment transactions
// verified, we can now generate a signature for their version,
// allowing the funding transaction to be safely broadcast.
p2wsh, err := witnessScriptHash(witnessScript)
if err != nil {
req.err <- err
return
}
signDesc := SignDescriptor{
WitnessScript: witnessScript,
PubKey: ourKey,
Output: &wire.TxOut{
PkScript: p2wsh,
Value: channelValue,
},
HashType: txscript.SigHashAll,
SigHashes: txscript.NewTxSigHashes(theirCommitTx),
InputIndex: 0,
}
sigTheirCommit, err := l.Signer.SignOutputRaw(theirCommitTx, &signDesc)
if err != nil {
req.err <- err
return
}
pendingReservation.ourCommitmentSig = sigTheirCommit
req.err <- nil
}
// SendCoins does send coins, but it's very rudimentary
// wit makes it into p2wpkh. Which is not yet spendable.
func (s *SPVCon) SendCoins(adrs []btcutil.Address, sendAmts []int64) error {
if len(adrs) != len(sendAmts) {
return fmt.Errorf("%d addresses and %d amounts", len(adrs), len(sendAmts))
}
var err error
var score, totalSend, fee int64
dustCutoff := int64(20000) // below this amount, just give to miners
satPerByte := int64(80) // satoshis per byte fee; have as arg later
rawUtxos, err := s.TS.GetAllUtxos()
if err != nil {
return err
}
var allUtxos SortableUtxoSlice
// start with utxos sorted by value.
for _, utxo := range rawUtxos {
score += utxo.Value
allUtxos = append(allUtxos, *utxo)
}
// smallest and unconfirmed last (because it's reversed)
sort.Sort(sort.Reverse(allUtxos))
// sort.Reverse(allUtxos)
for _, amt := range sendAmts {
totalSend += amt
}
// important rule in bitcoin, output total > input total is invalid.
if totalSend > score {
return fmt.Errorf("trying to send %d but %d available.",
totalSend, score)
}
tx := wire.NewMsgTx() // make new tx
// add non-change (arg) outputs
for i, adr := range adrs {
// make address script 76a914...88ac or 0014...
outAdrScript, err := txscript.PayToAddrScript(adr)
if err != nil {
return err
}
// make user specified txout and add to tx
txout := wire.NewTxOut(sendAmts[i], outAdrScript)
tx.AddTxOut(txout)
}
// generate a utxo slice for your inputs
var ins utxoSlice
// add utxos until we've had enough
nokori := totalSend // nokori is how much is needed on input side
for _, utxo := range allUtxos {
// skip unconfirmed. Or de-prioritize?
// if utxo.AtHeight == 0 {
// continue
// }
// yeah, lets add this utxo!
ins = append(ins, utxo)
// as we add utxos, fill in sigscripts
// generate previous pkscripts (subscritpt?) for all utxos
// then make txins with the utxo and prevpk, and insert them into the tx
// these are all zeroed out during signing but it's an easy way to keep track
var prevPKs []byte
if utxo.IsWit {
//tx.Flags = 0x01
wa, err := btcutil.NewAddressWitnessPubKeyHash(
s.TS.Adrs[utxo.KeyIdx].PkhAdr.ScriptAddress(), s.TS.Param)
prevPKs, err = txscript.PayToAddrScript(wa)
if err != nil {
return err
}
} else { // otherwise generate directly
prevPKs, err = txscript.PayToAddrScript(
s.TS.Adrs[utxo.KeyIdx].PkhAdr)
if err != nil {
return err
}
}
tx.AddTxIn(wire.NewTxIn(&utxo.Op, prevPKs, nil))
nokori -= utxo.Value
// if nokori is positive, don't bother checking fee yet.
if nokori < 0 {
fee = EstFee(tx, satPerByte)
if nokori < -fee { // done adding utxos: nokori below negative est. fee
break
}
}
}
// see if there's enough left to also add a change output
changeOld, err := s.TS.NewAdr() // change is witnessy
if err != nil {
return err
}
changeAdr, err := btcutil.NewAddressWitnessPubKeyHash(
changeOld.ScriptAddress(), s.TS.Param)
if err != nil {
return err
}
changeScript, err := txscript.PayToAddrScript(changeAdr)
if err != nil {
return err
}
changeOut := wire.NewTxOut(0, changeScript)
tx.AddTxOut(changeOut)
fee = EstFee(tx, satPerByte)
changeOut.Value = -(nokori + fee)
if changeOut.Value < dustCutoff {
// remove last output (change) : not worth it
tx.TxOut = tx.TxOut[:len(tx.TxOut)-1]
}
// sort utxos on the input side. use this instead of txsort
// because we want to remember which keys are associated with which inputs
sort.Sort(ins)
// sort tx -- this only will change txouts since inputs are already sorted
txsort.InPlaceSort(tx)
// tx is ready for signing,
sigStash := make([][]byte, len(ins))
witStash := make([][][]byte, len(ins))
// generate tx-wide hashCache for segwit stuff
// middle index number doesn't matter for sighashAll.
hCache := txscript.NewTxSigHashes(tx)
for i, txin := range tx.TxIn {
// pick key
child, err := s.TS.rootPrivKey.Child(
ins[i].KeyIdx + hdkeychain.HardenedKeyStart)
if err != nil {
return err
}
priv, err := child.ECPrivKey()
if err != nil {
return err
}
// This is where witness based sighash types need to happen
// sign into stash
if ins[i].IsWit {
witStash[i], err = txscript.WitnessScript(
tx, hCache, i, ins[i].Value, txin.SignatureScript,
txscript.SigHashAll, priv, true)
if err != nil {
return err
}
} else {
sigStash[i], err = txscript.SignatureScript(
tx, i, txin.SignatureScript,
txscript.SigHashAll, priv, true)
if err != nil {
return err
}
}
}
// swap sigs into sigScripts in txins
for i, txin := range tx.TxIn {
if sigStash[i] != nil {
txin.SignatureScript = sigStash[i]
}
if witStash[i] != nil {
txin.Witness = witStash[i]
txin.SignatureScript = nil
}
}
// fmt.Printf("tx: %s", TxToString(tx))
// buf := bytes.NewBuffer(make([]byte, 0, tx.SerializeSize()))
// send it out on the wire. hope it gets there.
// we should deal with rejects. Don't yet.
err = s.NewOutgoingTx(tx)
if err != nil {
return err
}
return nil
}
