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mirror of https://github.com/lightninglabs/loop synced 2024-11-16 00:12:52 +00:00
loop/swap/htlc_test.go
Harsha Goli 173c213a66
swap: HTLCV3 added
In this commit we add the version 3 htlc, which is implemented with
taproot script spending the two payment paths: the claim path case, and
the timeout case.
2022-04-20 10:52:42 -04:00

623 lines
15 KiB
Go

package swap
import (
"bytes"
"crypto/sha256"
"encoding/hex"
"fmt"
"testing"
"github.com/btcsuite/btcd/btcec/v2"
"github.com/btcsuite/btcd/btcec/v2/schnorr"
"github.com/btcsuite/btcd/btcutil"
"github.com/btcsuite/btcd/chaincfg"
"github.com/btcsuite/btcd/chaincfg/chainhash"
"github.com/btcsuite/btcd/txscript"
"github.com/btcsuite/btcd/wire"
secp "github.com/decred/dcrd/dcrec/secp256k1/v4"
"github.com/lightninglabs/loop/test"
"github.com/lightningnetwork/lnd/input"
"github.com/lightningnetwork/lnd/keychain"
"github.com/lightningnetwork/lnd/lntypes"
"github.com/stretchr/testify/require"
)
// assertEngineExecution executes the VM returned by the newEngine closure,
// asserting the result matches the validity expectation. In the case where it
// doesn't match the expectation, it executes the script step-by-step and
// prints debug information to stdout.
// This code is adopted from: lnd/input/script_utils_test.go
func assertEngineExecution(t *testing.T, valid bool,
newEngine func() (*txscript.Engine, error)) {
t.Helper()
// Get a new VM to execute.
vm, err := newEngine()
require.NoError(t, err, "unable to create engine")
// Execute the VM, only go on to the step-by-step execution if it
// doesn't validate as expected.
vmErr := vm.Execute()
executionValid := vmErr == nil
if valid == executionValid {
return
}
// Now that the execution didn't match what we expected, fetch a new VM
// to step through.
vm, err = newEngine()
require.NoError(t, err, "unable to create engine")
// This buffer will trace execution of the Script, dumping out to
// stdout.
var debugBuf bytes.Buffer
done := false
for !done {
dis, err := vm.DisasmPC()
if err != nil {
t.Fatalf("stepping (%v)\n", err)
}
debugBuf.WriteString(fmt.Sprintf("stepping %v\n", dis))
done, err = vm.Step()
if err != nil && valid {
fmt.Println(debugBuf.String())
t.Fatalf("spend test case failed, spend "+
"should be valid: %v", err)
} else if err == nil && !valid && done {
fmt.Println(debugBuf.String())
t.Fatalf("spend test case succeed, spend "+
"should be invalid: %v", err)
}
debugBuf.WriteString(
fmt.Sprintf("Stack: %v", vm.GetStack()),
)
debugBuf.WriteString(
fmt.Sprintf("AltStack: %v", vm.GetAltStack()),
)
}
// If we get to this point the unexpected case was not reached
// during step execution, which happens for some checks, like
// the clean-stack rule.
validity := "invalid"
if valid {
validity = "valid"
}
fmt.Println(debugBuf.String())
t.Fatalf(
"%v spend test case execution ended with: %v", validity, vmErr,
)
}
// TestHtlcV2 tests the HTLC V2 script success and timeout spend cases.
func TestHtlcV2(t *testing.T) {
const (
htlcValue = btcutil.Amount(1 * 10e8)
testCltvExpiry = 24
)
var (
testPreimage = lntypes.Preimage([32]byte{1, 2, 3})
err error
receiverKey [33]byte
senderKey [33]byte
)
// We generate a fake output, and the corresponding txin. This output
// doesn't need to exist, as we'll only be validating spending from the
// transaction that references this.
fundingOut := &wire.OutPoint{
Hash: chainhash.Hash(sha256.Sum256([]byte{1, 2, 3})),
Index: 50,
}
fakeFundingTxIn := wire.NewTxIn(fundingOut, nil, nil)
sweepTx := wire.NewMsgTx(2)
sweepTx.AddTxIn(fakeFundingTxIn)
sweepTx.AddTxOut(
&wire.TxOut{
PkScript: []byte("doesn't matter"),
Value: int64(htlcValue),
},
)
// Create sender and receiver keys.
senderPrivKey, senderPubKey := test.CreateKey(1)
receiverPrivKey, receiverPubKey := test.CreateKey(2)
copy(receiverKey[:], receiverPubKey.SerializeCompressed())
copy(senderKey[:], senderPubKey.SerializeCompressed())
hash := sha256.Sum256(testPreimage[:])
// Create the htlc.
htlc, err := NewHtlc(
HtlcV2, testCltvExpiry, senderKey, receiverKey, nil, hash,
HtlcP2WSH, &chaincfg.MainNetParams,
)
require.NoError(t, err)
// Create the htlc output we'll try to spend.
htlcOutput := &wire.TxOut{
Value: int64(htlcValue),
PkScript: htlc.PkScript,
}
// Create signers for sender and receiver.
senderSigner := &input.MockSigner{
Privkeys: []*btcec.PrivateKey{senderPrivKey},
}
receiverSigner := &input.MockSigner{
Privkeys: []*btcec.PrivateKey{receiverPrivKey},
}
prevOutFetcher := txscript.NewCannedPrevOutputFetcher(
htlc.PkScript, 800_000,
)
signTx := func(tx *wire.MsgTx, pubkey *btcec.PublicKey,
signer *input.MockSigner) (input.Signature, error) {
signDesc := &input.SignDescriptor{
KeyDesc: keychain.KeyDescriptor{
PubKey: pubkey,
},
WitnessScript: htlc.Script(),
Output: htlcOutput,
HashType: txscript.SigHashAll,
SigHashes: txscript.NewTxSigHashes(
tx, prevOutFetcher,
),
InputIndex: 0,
}
return signer.SignOutputRaw(tx, signDesc)
}
testCases := []struct {
name string
witness func(*testing.T) wire.TxWitness
valid bool
}{
{
// Receiver can spend with valid preimage.
"success case spend with valid preimage",
func(t *testing.T) wire.TxWitness {
sweepTx.TxIn[0].Sequence = htlc.SuccessSequence()
sweepSig, err := signTx(
sweepTx, receiverPubKey, receiverSigner,
)
require.NoError(t, err)
witness, err := htlc.GenSuccessWitness(
sweepSig.Serialize(), testPreimage,
)
require.NoError(t, err)
return witness
}, true,
},
{
// Receiver can't spend with the valid preimage and with
// zero sequence.
"success case no spend with valid preimage and zero sequence",
func(t *testing.T) wire.TxWitness {
sweepTx.TxIn[0].Sequence = 0
sweepSig, err := signTx(
sweepTx, receiverPubKey, receiverSigner,
)
require.NoError(t, err)
witness, err := htlc.GenSuccessWitness(
sweepSig.Serialize(), testPreimage,
)
require.NoError(t, err)
return witness
}, false,
},
{
// Sender can't spend when haven't yet timed out.
"timeout case no spend before timeout",
func(t *testing.T) wire.TxWitness {
sweepTx.LockTime = testCltvExpiry - 1
sweepSig, err := signTx(
sweepTx, senderPubKey, senderSigner,
)
require.NoError(t, err)
witness, err := htlc.GenTimeoutWitness(
sweepSig.Serialize(),
)
require.NoError(t, err)
return witness
}, false,
},
{
// Sender can spend after timeout.
"timeout case spend after timeout",
func(t *testing.T) wire.TxWitness {
sweepTx.LockTime = testCltvExpiry
sweepSig, err := signTx(
sweepTx, senderPubKey, senderSigner,
)
require.NoError(t, err)
witness, err := htlc.GenTimeoutWitness(
sweepSig.Serialize(),
)
require.NoError(t, err)
return witness
}, true,
},
{
// Receiver can't spend after timeout.
"timeout case receiver cannot spend",
func(t *testing.T) wire.TxWitness {
sweepTx.LockTime = testCltvExpiry
sweepSig, err := signTx(
sweepTx, receiverPubKey, receiverSigner,
)
require.NoError(t, err)
witness, err := htlc.GenTimeoutWitness(
sweepSig.Serialize(),
)
require.NoError(t, err)
return witness
}, false,
},
{
// Sender can't spend after timeout with wrong sender
// key.
"timeout case cannot spend with wrong key",
func(t *testing.T) wire.TxWitness {
bogusKey := [33]byte{0xb, 0xa, 0xd}
// Create the htlc with the bogus key.
htlc, err = NewHtlc(
HtlcV2, testCltvExpiry,
bogusKey, receiverKey, nil, hash,
HtlcP2WSH, &chaincfg.MainNetParams,
)
require.NoError(t, err)
// Create the htlc output we'll try to spend.
htlcOutput = &wire.TxOut{
Value: int64(htlcValue),
PkScript: htlc.PkScript,
}
sweepTx.LockTime = testCltvExpiry
sweepSig, err := signTx(
sweepTx, senderPubKey, senderSigner,
)
require.NoError(t, err)
witness, err := htlc.GenTimeoutWitness(
sweepSig.Serialize(),
)
require.NoError(t, err)
return witness
}, false,
},
}
for _, testCase := range testCases {
testCase := testCase
t.Run(testCase.name, func(t *testing.T) {
sweepTx.TxIn[0].Witness = testCase.witness(t)
newEngine := func() (*txscript.Engine, error) {
return txscript.NewEngine(
htlc.PkScript, sweepTx, 0,
txscript.StandardVerifyFlags, nil,
nil, int64(htlcValue), prevOutFetcher,
)
}
assertEngineExecution(t, testCase.valid, newEngine)
})
}
}
// TestHtlcV3 tests the HTLC V3 script success and timeout spend cases.
func TestHtlcV3(t *testing.T) {
var (
receiverKey [33]byte
senderKey [33]byte
)
preimage := [32]byte{1, 2, 3}
p := lntypes.Preimage(preimage)
hashedPreimage := sha256.Sum256(p[:])
value := int64(800_000)
cltvExpiry := int32(10)
senderPrivKey, senderPubKey := test.CreateKey(1)
receiverPrivKey, receiverPubKey := test.CreateKey(2)
copy(receiverKey[:], receiverPubKey.SerializeCompressed())
copy(senderKey[:], senderPubKey.SerializeCompressed())
randomSharedKey, err := hex.DecodeString(
"03fcb7d1b502bd59f4dbc6cf503e5c280189e0e6dd2d10c4c14d97ed8611" +
"a99178",
)
require.NoError(t, err)
randomSharedPubKey, err := btcec.ParsePubKey(randomSharedKey)
require.NoError(t, err)
htlc, err := NewHtlc(
HtlcV3, cltvExpiry, senderKey, receiverKey, randomSharedPubKey,
hashedPreimage, HtlcP2TR, &chaincfg.MainNetParams,
)
require.NoError(t, err)
trAddress, ok := htlc.Address.(*btcutil.AddressTaproot)
require.True(t, ok)
p2trPkScript, err := txscript.PayToAddrScript(trAddress)
require.NoError(t, err)
tx := wire.NewMsgTx(2)
tx.TxIn = []*wire.TxIn{{
PreviousOutPoint: wire.OutPoint{
Hash: chainhash.Hash(sha256.Sum256([]byte{1, 2, 3})),
Index: 50,
},
}}
tx.TxOut = []*wire.TxOut{{
PkScript: []byte{
0, 20, 2, 141, 221, 230, 144,
171, 89, 230, 219, 198, 90, 157,
110, 89, 89, 67, 128, 16, 150, 186,
},
Value: value,
}}
prevOutFetcher := txscript.NewCannedPrevOutputFetcher(
p2trPkScript, value,
)
hashCache := txscript.NewTxSigHashes(
tx, prevOutFetcher,
)
signTx := func(tx *wire.MsgTx, privateKey *secp.PrivateKey,
leaf txscript.TapLeaf) []byte {
sig, err := txscript.RawTxInTapscriptSignature(
tx, hashCache, 0, value, p2trPkScript, leaf,
txscript.SigHashDefault, privateKey,
)
require.NoError(t, err)
return sig
}
testCases := []struct {
name string
witness func(*testing.T) wire.TxWitness
valid bool
}{
{
// Receiver can spend with valid preimage.
"success case spend with valid preimage",
func(t *testing.T) wire.TxWitness {
tx.TxIn[0].Sequence = htlc.SuccessSequence()
tx.LockTime = uint32(cltvExpiry)
var trHtlc *HtlcScriptV3
trHtlc, ok := htlc.HtlcScript.(*HtlcScriptV3)
require.True(t, ok)
sig := signTx(
tx, receiverPrivKey,
txscript.NewBaseTapLeaf(
trHtlc.SuccessScript,
),
)
witness, err := htlc.genSuccessWitness(
sig, preimage,
)
require.NoError(t, err)
return witness
}, true,
},
{
// Receiver can't spend with the valid preimage and with
// zero sequence.
"success case no spend with valid preimage and zero sequence",
func(t *testing.T) wire.TxWitness {
tx.TxIn[0].Sequence = 0
var trHtlc *HtlcScriptV3
trHtlc, ok := htlc.HtlcScript.(*HtlcScriptV3)
require.True(t, ok)
sig := signTx(
tx, receiverPrivKey,
txscript.NewBaseTapLeaf(
trHtlc.SuccessScript,
),
)
witness, err := htlc.genSuccessWitness(
sig, preimage,
)
require.NoError(t, err)
return witness
}, false,
},
{
// Sender can't spend when haven't yet timed out.
"timeout case no spend before timeout",
func(t *testing.T) wire.TxWitness {
tx.TxIn[0].Sequence = htlc.SuccessSequence()
tx.LockTime = uint32(cltvExpiry) - 1
var trHtlc *HtlcScriptV3
trHtlc, ok := htlc.HtlcScript.(*HtlcScriptV3)
require.True(t, ok)
sig := signTx(
tx, senderPrivKey,
txscript.NewBaseTapLeaf(
trHtlc.TimeoutScript,
),
)
witness, err := htlc.GenTimeoutWitness(sig)
require.NoError(t, err)
return witness
}, false,
},
{
// Sender can spend after timeout.
"timeout case spend after timeout",
func(t *testing.T) wire.TxWitness {
tx.TxIn[0].Sequence = htlc.SuccessSequence()
tx.LockTime = uint32(cltvExpiry)
var trHtlc *HtlcScriptV3
trHtlc, ok := htlc.HtlcScript.(*HtlcScriptV3)
require.True(t, ok)
sig := signTx(
tx, senderPrivKey,
txscript.NewBaseTapLeaf(
trHtlc.TimeoutScript,
),
)
witness, err := htlc.GenTimeoutWitness(sig)
require.NoError(t, err)
return witness
}, true,
},
{
// Receiver can't spend after timeout.
"timeout case receiver cannot spend",
func(t *testing.T) wire.TxWitness {
tx.TxIn[0].Sequence = htlc.SuccessSequence()
tx.LockTime = uint32(cltvExpiry)
var trHtlc *HtlcScriptV3
trHtlc, ok := htlc.HtlcScript.(*HtlcScriptV3)
require.True(t, ok)
sig := signTx(
tx, receiverPrivKey,
txscript.NewBaseTapLeaf(
trHtlc.TimeoutScript,
),
)
witness, err := htlc.GenTimeoutWitness(sig)
require.NoError(t, err)
return witness
}, false,
},
{
// Sender can't spend after timeout with wrong sender
// key.
"timeout case cannot spend with wrong key",
func(t *testing.T) wire.TxWitness {
var bogusKeyBytes [33]byte
_, bogusKey := test.CreateKey(5)
copy(
bogusKeyBytes[:],
bogusKey.SerializeCompressed(),
)
var shnorrSenderKey [32]byte
copy(
shnorrSenderKey[:],
schnorr.SerializePubKey(
senderPubKey,
),
)
htlc, err := NewHtlc(
HtlcV3, cltvExpiry, bogusKeyBytes,
receiverKey, randomSharedPubKey,
hashedPreimage, HtlcP2TR,
&chaincfg.MainNetParams,
)
require.NoError(t, err)
var trAddress *btcutil.AddressTaproot
trAddress, ok := htlc.Address.(*btcutil.AddressTaproot)
require.True(t, ok)
p2trPkScript, err := txscript.PayToAddrScript(
trAddress,
)
require.NoError(t, err)
prevOutFetcher := txscript.NewCannedPrevOutputFetcher(
p2trPkScript, 800_000,
)
hashCache = txscript.NewTxSigHashes(
tx, prevOutFetcher,
)
timeoutScript, err := GenTimeoutPathScript(
shnorrSenderKey, int64(cltvExpiry),
)
require.NoError(t, err)
sig := signTx(
tx, senderPrivKey,
txscript.NewBaseTapLeaf(
timeoutScript,
),
)
witness, err := htlc.genSuccessWitness(
sig, preimage,
)
require.NoError(t, err)
return witness
}, false,
},
}
for _, testCase := range testCases {
testCase := testCase
t.Run(testCase.name, func(t *testing.T) {
tx.TxIn[0].Witness = testCase.witness(t)
newEngine := func() (*txscript.Engine, error) {
return txscript.NewEngine(
p2trPkScript, tx, 0,
txscript.StandardVerifyFlags, nil,
hashCache, value, prevOutFetcher)
}
assertEngineExecution(t, testCase.valid, newEngine)
})
}
}