SubmitTx: Reject invalid arkade scripts instead of skipping them (#27)

* fix: typo unknwonPacket -> unknownPacket

* test: verify introspector client rejects invalid arkade scripts with an error

* test: verify SubmitTx handles entries for mixed introspectors

* fix: #26 return an error from SubmitTx for invalid arkade scripts

Author: chris-ricketts

internal/application/tx.go

@@ -2,6 +2,7 @@ package application
 
 import (
 	"context"
+	"errors"
 	"fmt"
 
 	"github.com/ArkLabsHQ/introspector/pkg/arkade"
@@ -42,17 +43,21 @@ func (s *service) SubmitTx(ctx context.Context, tx OffchainTx) (*OffchainTx, err
 
 	signerPublicKey := s.signer.secretKey.PubKey()
 
+	var nSigned = 0
 	for _, entry := range packet {
 		inputIndex := int(entry.Vin)
 		script, err := arkade.ReadArkadeScript(arkPtx, inputIndex, signerPublicKey, entry)
 		if err != nil {
-			// skip if the input is not a valid arkade script
-			continue
+			// there may be input/entry pairs attributed to a different signer
+			if errors.Is(err, arkade.ErrTweakedArkadePubKeyNotFound) && len(arkPtx.Inputs) > 1 {
+				continue
+			}
+			return nil, fmt.Errorf("failed to read arkade script: %w vin=%d", err, inputIndex)
 		}
 
 		log.Debugf("executing arkade script: %x", script.Script())
 		if err := script.Execute(arkPtx.UnsignedTx, prevoutFetcher, inputIndex); err != nil {
-			return nil, fmt.Errorf("failed to execute arkade script: %w", err)
+			return nil, fmt.Errorf("failed to execute arkade script: %w vin=%d", err, inputIndex)
 		}
 		log.Debugf("execution of %x succeeded", script.Script())
 
@@ -75,6 +80,12 @@ func (s *service) SubmitTx(ctx context.Context, tx OffchainTx) (*OffchainTx, err
 		if err := s.signer.signInput(checkpointPtx, 0, script.Hash(), checkpointPrevoutFetcher); err != nil {
 			return nil, fmt.Errorf("failed to sign checkpoint input %d: %w", inputIndex, err)
 		}
+
+		nSigned++
+	}
+
+	if nSigned == 0 {
+		return nil, fmt.Errorf("failed to find any valid input/entry pairs")
 	}
 
 	signedCheckpointTxs := make([]*psbt.Packet, 0, len(orderedCheckpointTxids))

pkg/arkade/introspector_packet.go

@@ -166,13 +166,12 @@ func FindIntrospectorPacket(tx *wire.MsgTx) (IntrospectorPacket, error) {
 		if pkt.Type() != PacketType {
 			continue
 		}
-		unknwonPacket, ok := pkt.(extension.UnknownPacket)
+		unknownPacket, ok := pkt.(extension.UnknownPacket)
 		if !ok {
 			continue
 		}
-		
-		return DeserializeIntrospectorPacket(unknwonPacket.Data)
+
+		return DeserializeIntrospectorPacket(unknownPacket.Data)
 	}
 	return nil, nil
 }
-

pkg/arkade/script.go

@@ -2,6 +2,7 @@ package arkade
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 
 	"github.com/arkade-os/arkd/pkg/ark-lib/extension"
@@ -13,6 +14,8 @@ import (
 	"github.com/btcsuite/btcd/wire"
 )
 
+var ErrTweakedArkadePubKeyNotFound = errors.New("tweaked arkade script public key not found in tapscript")
+
 type ArkadeScript struct {
 	script  []byte
 	hash    []byte
@@ -70,7 +73,7 @@ func ReadArkadeScript(ptx *psbt.Packet, inputIndex int, signerPublicKey *btcec.P
 	}
 
 	if !found {
-		return nil, fmt.Errorf("tweaked arkade script public key not found in tapscript")
+		return nil, ErrTweakedArkadePubKeyNotFound
 	}
 
 	return &ArkadeScript{