Support every type of tapscript closure

internal/application/finalization.go

@@ -151,7 +151,7 @@ func getSignedInputs(ptx psbt.Packet, signerPublicKey *btcec.PublicKey) (map[wir
 			continue // not signed: skip
 		}
 
-		script, err := arkade.ReadArkadeScript(&ptx, inputIndex, signerPublicKey, entry)
+		script, err := arkade.ReadArkadeScript(&ptx, signerPublicKey, entry)
 		if err != nil {
 			return nil, fmt.Errorf("failed to read arkade script: %w", err)
 		}

internal/application/intent.go

@@ -47,7 +47,7 @@ func (s *service) SubmitIntent(ctx context.Context, intent Intent) (*psbt.Packet
 			continue
 		}
 
-		script, err := arkade.ReadArkadeScript(ptx, inputIndex, signerPublicKey, entry)
+		script, err := arkade.ReadArkadeScript(ptx, signerPublicKey, entry)
 		if err != nil {
 			// skip if the input is not a valid arkade script
 			continue

internal/application/tx.go

@@ -46,7 +46,7 @@ func (s *service) SubmitTx(ctx context.Context, tx OffchainTx) (*OffchainTx, err
 	var nSigned = 0
 	for _, entry := range packet {
 		inputIndex := int(entry.Vin)
-		script, err := arkade.ReadArkadeScript(arkPtx, inputIndex, signerPublicKey, entry)
+		script, err := arkade.ReadArkadeScript(arkPtx, signerPublicKey, entry)
 		if err != nil {
 			// there may be input/entry pairs attributed to a different signer
 			if errors.Is(err, arkade.ErrTweakedArkadePubKeyNotFound) && len(arkPtx.Inputs) > 1 {

pkg/arkade/script.go

@@ -34,7 +34,8 @@ func WithDebugCallback(callback func(*StepInfo, *Engine) error) ExecuteOption {
 	}
 }
 
-func ReadArkadeScript(ptx *psbt.Packet, inputIndex int, signerPublicKey *btcec.PublicKey, entry IntrospectorEntry) (*ArkadeScript, error) {
+func ReadArkadeScript(ptx *psbt.Packet, signerPublicKey *btcec.PublicKey, entry IntrospectorEntry) (*ArkadeScript, error) {
+	inputIndex := int(entry.Vin)
 	if len(ptx.Inputs) <= inputIndex {
 		return nil, fmt.Errorf("input index out of range")
 	}
@@ -53,18 +54,29 @@ func ReadArkadeScript(ptx *psbt.Packet, inputIndex int, signerPublicKey *btcec.P
 	expectedPublicKey := ComputeArkadeScriptPublicKey(signerPublicKey, scriptHash)
 	expectedPublicKeyXonly := schnorr.SerializePubKey(expectedPublicKey)
 
-	// TODO: allow any type of closure (condition, cltv ...)
-	var tapscript scriptlib.MultisigClosure
-	valid, err := tapscript.Decode(spendingTapscript.Script)
+	closure, err := scriptlib.DecodeClosure(spendingTapscript.Script)
 	if err != nil {
-		return nil, fmt.Errorf("unexpected error while decoding tapscript: %w", err)
+		return nil, fmt.Errorf("failed to decode tapscript: %w", err)
 	}
-	if !valid {
-		return nil, fmt.Errorf("spendingtapscript is not a MultisigClosure")
+
+	var pubkeys []*btcec.PublicKey
+	switch c := closure.(type) {
+	case *scriptlib.MultisigClosure:
+		pubkeys = c.PubKeys
+	case *scriptlib.CSVMultisigClosure:
+		pubkeys = c.PubKeys
+	case *scriptlib.CLTVMultisigClosure:
+		pubkeys = c.PubKeys
+	case *scriptlib.ConditionMultisigClosure:
+		pubkeys = c.PubKeys
+	case *scriptlib.ConditionCSVMultisigClosure:
+		pubkeys = c.PubKeys
+	default:
+		return nil, fmt.Errorf("unsupported closure type: %T", closure)
 	}
 
 	found := false
-	for _, pubkey := range tapscript.PubKeys {
+	for _, pubkey := range pubkeys {
 		xonly := schnorr.SerializePubKey(pubkey)
 		if bytes.Equal(xonly, expectedPublicKeyXonly) {
 			found = true

pkg/arkade/script_test.go

@@ -0,0 +1,133 @@
+package arkade
+
+import (
+	"encoding/hex"
+	"encoding/json"
+	"os"
+	"strings"
+	"testing"
+
+	"github.com/btcsuite/btcd/btcec/v2"
+	"github.com/btcsuite/btcd/btcec/v2/schnorr"
+	"github.com/btcsuite/btcd/btcutil/psbt"
+	"github.com/btcsuite/btcd/txscript"
+	"github.com/btcsuite/btcd/wire"
+	"github.com/stretchr/testify/require"
+)
+
+
+func TestReadArkadeScript(t *testing.T) {
+	fix := readScriptFixtures(t)
+
+	t.Run("valid", func(t *testing.T) {
+		for _, f := range fix.Valid {
+			t.Run(f.Name, func(t *testing.T) {
+				ptx := decodePSBT(t, f.Psbt)
+				signerPubKey := decodeXOnlyPubKey(t, f.SignerPublicKey)
+				entry := decodeEntry(t, f.Entry)
+
+				result, err := ReadArkadeScript(ptx, signerPubKey, entry)
+				require.NoError(t, err)
+				require.NotNil(t, result)
+
+				require.Equal(t, entry.Script, result.script)
+				require.Equal(t, ArkadeScriptHash(entry.Script), result.hash)
+				require.Equal(t, len(entry.Witness), len(result.witness))
+				for i := range entry.Witness {
+					require.Equal(t, entry.Witness[i], result.witness[i])
+				}
+
+				expectedPubKey := ComputeArkadeScriptPublicKey(signerPubKey, result.hash)
+				require.True(t, expectedPubKey.IsEqual(result.pubkey))
+
+				tapscript := ptx.Inputs[entry.Vin].TaprootLeafScript[0].Script
+				require.Equal(t, txscript.NewBaseTapLeaf(tapscript), result.tapLeaf)
+			})
+		}
+	})
+
+	t.Run("invalid", func(t *testing.T) {
+		for _, f := range fix.Invalid {
+			t.Run(f.Name, func(t *testing.T) {
+				ptx := decodePSBT(t, f.Psbt)
+				signerPubKey := decodeXOnlyPubKey(t, f.SignerPublicKey)
+				entry := decodeEntry(t, f.Entry)
+
+				_, err := ReadArkadeScript(ptx, signerPubKey, entry)
+				require.Error(t, err)
+				require.Contains(t, err.Error(), f.ErrorContains)
+			})
+		}
+	})
+}
+
+type scriptFixtureEntry struct {
+	Vin     int      `json:"vin"`
+	Script  string   `json:"script"`
+	Witness []string `json:"witness"`
+}
+
+type validScriptFixture struct {
+	Name            string             `json:"name"`
+	SignerPublicKey string             `json:"signerPublicKey"`
+	Psbt            string             `json:"psbt"`
+	Entry           scriptFixtureEntry `json:"entry"`
+}
+
+type invalidScriptFixture struct {
+	Name            string             `json:"name"`
+	SignerPublicKey string             `json:"signerPublicKey"`
+	Psbt            string             `json:"psbt"`
+	Entry           scriptFixtureEntry `json:"entry"`
+	ErrorContains   string             `json:"errorContains"`
+}
+
+type scriptFixtures struct {
+	Valid   []validScriptFixture   `json:"valid"`
+	Invalid []invalidScriptFixture `json:"invalid"`
+}
+
+
+func readScriptFixtures(t *testing.T) scriptFixtures {
+	t.Helper()
+	data, err := os.ReadFile("testdata/read_arkade_script.json")
+	require.NoError(t, err)
+
+	var fix scriptFixtures
+	require.NoError(t, json.Unmarshal(data, &fix))
+	return fix
+}
+
+func decodePSBT(t *testing.T, b64 string) *psbt.Packet {
+	t.Helper()
+	ptx, err := psbt.NewFromRawBytes(strings.NewReader(b64), true)
+	require.NoError(t, err)
+	return ptx
+}
+
+func decodeXOnlyPubKey(t *testing.T, hexStr string) *btcec.PublicKey {
+	t.Helper()
+	data, err := hex.DecodeString(hexStr)
+	require.NoError(t, err)
+	pubKey, err := schnorr.ParsePubKey(data)
+	require.NoError(t, err)
+	return pubKey
+}
+
+func decodeEntry(t *testing.T, raw scriptFixtureEntry) IntrospectorEntry {
+	t.Helper()
+	script, err := hex.DecodeString(raw.Script)
+	require.NoError(t, err)
+
+	witness := make(wire.TxWitness, len(raw.Witness))
+	for i, w := range raw.Witness {
+		witness[i], err = hex.DecodeString(w)
+		require.NoError(t, err)
+	}
+
+	return IntrospectorEntry{
+		Vin:     uint16(raw.Vin),
+		Script:  script,
+		Witness: witness,
+	}
+}

pkg/arkade/testdata/read_arkade_script.json

@@ -0,0 +1,134 @@
+{
+  "valid": [
+    {
+      "name": "multisig closure (checksig)",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrARSBNS2zRNhAyypvSrrnZAKpNRdnq2ArJQjN0xFGnJU0HZq0g0jHBebSFpXbjA9Dk50Bdv1PRbqKWwJAw9xEERODAz2uswAAA",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      }
+    },
+    {
+      "name": "multisig closure (checksigadd)",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrARyBNS2zRNhAyypvSrrnZAKpNRdnq2ArJQjN0xFGnJU0HZqwg0jHBebSFpXbjA9Dk50Bdv1PRbqKWwJAw9xEERODAz2u6UpzAAAA=",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      }
+    },
+    {
+      "name": "csv multisig closure",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrASFqydSBNS2zRNhAyypvSrrnZAKpNRdnq2ArJQjN0xFGnJU0HZq0g0jHBebSFpXbjA9Dk50Bdv1PRbqKWwJAw9xEERODAz2uswAAA",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      }
+    },
+    {
+      "name": "cltv multisig closure",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrASQFksXUgTUts0TYQMsqb0q652QCqTUXZ6tgKyUIzdMRRpyVNB2atINIxwXm0haV24wPQ5OdAXb9T0W6ilsCQMPcRBETgwM9rrMAAAA==",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      }
+    },
+    {
+      "name": "condition multisig closure",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrAR1FpIE1LbNE2EDLKm9KuudkAqk1F2erYCslCM3TEUaclTQdmrSDSMcF5tIWlduMD0OTnQF2/U9FuopbAkDD3EQRE4MDPa6zAAAA=",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      }
+    },
+    {
+      "name": "condition csv multisig closure",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrASlFpWrJ1IE1LbNE2EDLKm9KuudkAqk1F2erYCslCM3TEUaclTQdmrSDSMcF5tIWlduMD0OTnQF2/U9FuopbAkDD3EQRE4MDPa6zAAAA=",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      }
+    },
+    {
+      "name": "with witness data",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrARSDSMcF5tIWlduMD0OTnQF2/U9FuopbAkDD3EQRE4MDPa60gTUts0TYQMsqb0q652QCqTUXZ6tgKyUIzdMRRpyVNB2aswAAA",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": [
+          "deadbeef",
+          "cafebabe"
+        ]
+      }
+    }
+  ],
+  "invalid": [
+    {
+      "name": "input index out of range",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrARSBNS2zRNhAyypvSrrnZAKpNRdnq2ArJQjN0xFGnJU0HZq0g0jHBebSFpXbjA9Dk50Bdv1PRbqKWwJAw9xEERODAz2uswAAA",
+      "entry": {
+        "vin": 2,
+        "script": "51",
+        "witness": []
+      },
+      "errorContains": "input index out of range"
+    },
+    {
+      "name": "no taproot leaf script",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      },
+      "errorContains": "TaprootLeafScript"
+    },
+    {
+      "name": "invalid tapscript",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrABd6tvu/AAAA=",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      },
+      "errorContains": "failed to decode tapscript"
+    },
+    {
+      "name": "tweaked pubkey not found (wrong signer)",
+      "signerPublicKey": "462779ad4aad39514614751a71085f2f10e1c7a593e4e030efb5b8721ce55b0b",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrARSBNS2zRNhAyypvSrrnZAKpNRdnq2ArJQjN0xFGnJU0HZq0g0jHBebSFpXbjA9Dk50Bdv1PRbqKWwJAw9xEERODAz2uswAAA",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      },
+      "errorContains": "tweaked arkade script public key not found"
+    },
+    {
+      "name": "tweaked pubkey not found (wrong arkade script)",
+      "signerPublicKey": "1b84c5567b126440995d3ed5aaba0565d71e1834604819ff9c17f5e9d5dd078f",
+      "psbt": "cHNidP8BAFICAAAAAQAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAD/////AegDAAAAAAAAFgAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAACIVwFCSm3TBoElUt4tLYDXpel4HiloPKOyW1Ue/7prOgDrARSBNS2zRNhAyypvSrrnZAKpNRdnq2ArJQjN0xFGnJU0HZq0gUx/mBoE0UD0nIxMyJ8hnrI+myDxTfppEw8W9vcsf4zeswAAA",
+      "entry": {
+        "vin": 0,
+        "script": "51",
+        "witness": []
+      },
+      "errorContains": "tweaked arkade script public key not found"
+    }
+  ]
+}

test/tx_test.go

@@ -934,24 +934,9 @@ func TestIntrospectorRejectsInvalidArkadeScript(t *testing.T) {
 				ptx.Inputs[0].TaprootLeafScript = nil
 			},
 		},
-		{
-			name:     "non-multisig tapscript",
-			contains: "spendingtapscript is not a MultisigClosure",
-			entry: arkade.IntrospectorEntry{
-				Vin:    0,
-				Script: arkadeScript,
-			},
-			mutateTx: func(t *testing.T, ptx *psbt.Packet) {
-				t.Helper()
-				require.NotEmpty(t, ptx.Inputs)
-				require.NotEmpty(t, ptx.Inputs[0].TaprootLeafScript)
-				require.NotNil(t, ptx.Inputs[0].TaprootLeafScript[0])
-				ptx.Inputs[0].TaprootLeafScript[0].Script = []byte{txscript.OP_TRUE}
-			},
-		},
 		{
 			name:     "malformed tapscript decode",
-			contains: "unexpected error while decoding tapscript",
+			contains: "failed to decode tapscript",
 			entry: arkade.IntrospectorEntry{
 				Vin:    0,
 				Script: arkadeScript,
@@ -1013,7 +998,7 @@ func TestIntrospectorRejectsInvalidArkadeScript(t *testing.T) {
 				require.Len(t, packet, 1)
 
 				entry := packet[0]
-				_, err = arkade.ReadArkadeScript(invalidTx, int(entry.Vin), introspectorPublicKey, entry)
+				_, err = arkade.ReadArkadeScript(invalidTx, introspectorPublicKey, entry)
 				require.Error(t, err)
 				require.Contains(t, err.Error(), tc.contains)
 			}

test/utils_test.go

@@ -728,7 +728,7 @@ func debugExecuteArkadeScripts(t *testing.T, ptx *psbt.Packet, signerPublicKey *
 
 	for _, entry := range packet {
 		inputIndex := int(entry.Vin)
-		script, err := arkade.ReadArkadeScript(ptx, inputIndex, signerPublicKey, entry)
+		script, err := arkade.ReadArkadeScript(ptx, signerPublicKey, entry)
 		if err != nil {
 			return fmt.Errorf("failed to read arkade script at input %d: %w", inputIndex, err)
 		}