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lnwallet: expand TestForceClose to ensure outgoing HTLC's can be swept

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This commit expands the existing TestForceClose test case to add an
HTLC (outgoing) to Alice’s commitment transaction before force closing.
We then ensure that both the pre-signed timeout transaction _and_ the
sign descriptor to sweep the second-level output are fully valid.
This commit is contained in:
Olaoluwa Osuntokun 2017-09-29 14:38:35 -07:00
parent dc764c992c
commit d79c0ff95b
No known key found for this signature in database
GPG Key ID: 964EA263DD637C21
1 changed files with 108 additions and 10 deletions
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118
lnwallet/channel_test.go
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@ -831,20 +831,42 @@ func TestForceClose(t *testing.T) {
}
defer cleanUp()
htlcAmount := lnwire.NewMSatFromSatoshis(500)
aliceAmount := aliceChannel.channelState.LocalBalance
bobAmount := bobChannel.channelState.LocalBalance
// First, we'll add an outgoing HTLC from Alice to Bob, such that it
// will still be present within the broadcast commitment transaction.
// We'll ensure that the HTLC amount is above Alice's dust limit.
htlcAmount := lnwire.NewMSatFromSatoshis(20000)
htlc, _ := createHTLC(0, htlcAmount)
if _, err := aliceChannel.AddHTLC(htlc); err != nil {
t.Fatalf("alice unable to add htlc: %v", err)
}
if _, err := bobChannel.ReceiveHTLC(htlc); err != nil {
t.Fatalf("bob unable to recv add htlc: %v", err)
}
if err := forceStateTransition(aliceChannel, bobChannel); err != nil {
t.Fatalf("Can't update the channel state: %v", err)
}
// Now with the HTLC in tact, we'll perform a force close on Alice's
// part.
closeSummary, err := aliceChannel.ForceClose()
if err != nil {
t.Fatalf("unable to force close channel: %v", err)
}
// The SelfOutputSignDesc should be non-nil since the outout to-self is
// Alice's force close summary should have a single HTLC resolution.
if len(closeSummary.HtlcResolutions) != 1 {
t.Fatalf("alice htlc resolutions not populated: expected %v "+
"htlcs, got %v htlcs",
1, len(closeSummary.HtlcResolutions))
}
// The SelfOutputSignDesc should be non-nil since the output to-self is
// non-dust.
if closeSummary.SelfOutputSignDesc == nil {
t.Fatalf("alice fails to include to-self output in ForceCloseSummary")
t.Fatalf("alice fails to include to-self output in " +
"ForceCloseSummary")
}
// The rest of the close summary should have been populated properly.
@ -852,22 +874,97 @@ func TestForceClose(t *testing.T) {
if !closeSummary.SelfOutputSignDesc.PubKey.IsEqual(aliceDelayPoint) {
t.Fatalf("alice incorrect pubkey in SelfOutputSignDesc")
}
if closeSummary.SelfOutputSignDesc.Output.Value !=
int64(aliceAmount.ToSatoshis()) {
// Factoring in the fee rate, Alice's amount should properly reflect
// that we've added an additional HTLC to the commitment transaction.
totalCommitWeight := commitWeight + htlcWeight
feePerKw := aliceChannel.channelState.FeePerKw
commitFee := btcutil.Amount((int64(feePerKw) * totalCommitWeight) / 1000)
expectedAmount := (aliceChannel.Capacity / 2) - htlcAmount.ToSatoshis() - commitFee
if closeSummary.SelfOutputSignDesc.Output.Value != int64(expectedAmount) {
t.Fatalf("alice incorrect output value in SelfOutputSignDesc, "+
"expected %v, got %v",
aliceChannel.channelState.LocalBalance.ToSatoshis(),
"expected %v, got %v", int64(expectedAmount),
closeSummary.SelfOutputSignDesc.Output.Value)
}
// Alice's listed CSV delay should also match the delay that was
// pre-committed to at channel opening.
if closeSummary.SelfOutputMaturity !=
uint32(aliceChannel.localChanCfg.CsvDelay) {
t.Fatalf("alice: incorrect local CSV delay in ForceCloseSummary, "+
"expected %v, got %v",
aliceChannel.channelState.LocalChanCfg.CsvDelay,
closeSummary.SelfOutputMaturity)
}
// Next, we'll ensure that the second level HTLC transaction it itself
// spendable, and also that the delivery output (with delay) itself has
// a valid sign descriptor.
var senderHtlcPkScript []byte
for _, txOut := range closeSummary.CloseTx.TxOut {
if txOut.Value == int64(htlcAmount.ToSatoshis()) {
senderHtlcPkScript = txOut.PkScript
break
}
}
if senderHtlcPkScript == nil {
t.Fatalf("unable to find htlc script")
}
// First, verify that the second level transaction can properly spend
// the multi-sig clause within the
htlcResolution := closeSummary.HtlcResolutions[0]
timeoutTx := htlcResolution.SignedTimeoutTx
vm, err := txscript.NewEngine(senderHtlcPkScript,
timeoutTx, 0, txscript.StandardVerifyFlags, nil,
nil, int64(htlcAmount.ToSatoshis()))
if err != nil {
t.Fatalf("unable to create engine: %v", err)
}
if err := vm.Execute(); err != nil {
t.Fatalf("htlc timeout spend is invalid: %v", err)
}
// Next, we'll ensure that we can spend the output of the second level
// transaction given a properly crafted sweep transaction.
sweepTx := wire.NewMsgTx(2)
sweepTx.AddTxIn(&wire.TxIn{
PreviousOutPoint: wire.OutPoint{
Hash: htlcResolution.SignedTimeoutTx.TxHash(),
Index: 0,
},
})
sweepTx.AddTxOut(&wire.TxOut{
PkScript: senderHtlcPkScript,
Value: htlcResolution.SweepSignDesc.Output.Value,
})
htlcResolution.SweepSignDesc.InputIndex = 0
sweepTx.TxIn[0].Witness, err = htlcSpendSuccess(aliceChannel.signer,
&htlcResolution.SweepSignDesc, sweepTx,
uint32(aliceChannel.channelState.LocalChanCfg.CsvDelay))
if err != nil {
t.Fatalf("unable to gen witness for timeout output: %v", err)
}
// With the witness fully populated for the success spend from the
// second-level transaction, we ensure that the scripts properly
// validate given the information within the htlc resolution struct.
vm, err = txscript.NewEngine(
htlcResolution.SweepSignDesc.Output.PkScript,
sweepTx, 0, txscript.StandardVerifyFlags, nil,
nil, htlcResolution.SweepSignDesc.Output.Value,
)
if err != nil {
t.Fatalf("unable to create engine: %v", err)
}
if err := vm.Execute(); err != nil {
t.Fatalf("htlc timeout spend is invalid: %v", err)
}
// Finally, the txid of the commitment transaction and the one returned
// as the closing transaction should also match.
closeTxHash := closeSummary.CloseTx.TxHash()
commitTxHash := aliceChannel.channelState.CommitTx.TxHash()
if !bytes.Equal(closeTxHash[:], commitTxHash[:]) {
@ -886,7 +983,8 @@ func TestForceClose(t *testing.T) {
if !closeSummary.SelfOutputSignDesc.PubKey.IsEqual(bobDelayPoint) {
t.Fatalf("bob incorrect pubkey in SelfOutputSignDesc")
}
if closeSummary.SelfOutputSignDesc.Output.Value != int64(bobAmount.ToSatoshis()) {
if closeSummary.SelfOutputSignDesc.Output.Value !=
int64(bobAmount.ToSatoshis()) {
t.Fatalf("bob incorrect output value in SelfOutputSignDesc, "+
"expected %v, got %v",