feat(BUX-290): updated calculation and verification of merkle roots

bump.go

@@ -2,6 +2,7 @@ package paymail
 
 import (
 	"errors"
+
 	"github.com/libsv/go-bc"
 	"github.com/libsv/go-bt/v2"
 )
@@ -30,17 +31,27 @@ const (
 	txIDFlag
 )
 
-func (b BUMP) calculateMerkleRoots() ([]string, error) {
-	merkleRoots := make([]string, 0)
+func (b BUMP) calculateMerkleRoot() (string, error) {
+	merkleRoot := ""
 
 	for _, bumpPathElement := range b.path[0] {
-		merkleRoot, err := calculateMerkleRoot(bumpPathElement, b)
-		if err != nil {
-			return nil, err
+		if bumpPathElement.txId {
+			calcMerkleRoot, err := calculateMerkleRoot(bumpPathElement, b)
+			if err != nil {
+				return "", err
+			}
+
+			if merkleRoot == "" {
+				merkleRoot = calcMerkleRoot
+				continue
+			}
+
+			if calcMerkleRoot != merkleRoot {
+				return "", errors.New("different merkle roots for the same block")
+			}
 		}
-		merkleRoots = append(merkleRoots, merkleRoot)
 	}
-	return merkleRoots, nil
+	return merkleRoot, nil
 }
 
 func findLeafByOffset(offset uint64, bumpLeaves []BUMPLeaf) *BUMPLeaf {
@@ -52,7 +63,7 @@ func findLeafByOffset(offset uint64, bumpLeaves []BUMPLeaf) *BUMPLeaf {
 	return nil
 }
 
-// calculateMerkleRoots will calculate one merkle root for tx in the BUMPPath
+// calculateMerkleRoots will calculate one merkle root for tx in the BUMPLeaf
 func calculateMerkleRoot(baseLeaf BUMPLeaf, bump BUMP) (string, error) {
 	calculatedHash := baseLeaf.hash
 	offset := baseLeaf.offset

definitions.go

@@ -79,3 +79,10 @@ type AddressInformation struct {
 	PrivateKey  string `json:"-"`            // PrivateKey hex encoded
 	PubKey      string `json:"pubkey"`       // PublicKey hex encoded
 }
+
+// MerkleRootConfirmationRequestItem is a request type for verification
+// of Merkle Roots inclusion in the longest chain.
+type MerkleRootConfirmationRequestItem struct {
+	MerkleRoot  string `json:"merkleRoot"`
+	BlockHeight int32  `json:"blockHeight"`
+}

examples/server/run_server/demo_interface.go

@@ -14,39 +14,38 @@ type demoServiceProvider struct {
 
 // GetPaymailByAlias is a demo implementation of this interface
 func (d *demoServiceProvider) GetPaymailByAlias(_ context.Context, alias, domain string,
-	_ *server.RequestMetadata) (*paymail.AddressInformation, error) {
-
+	_ *server.RequestMetadata,
+) (*paymail.AddressInformation, error) {
 	// Get the data from the demo database
 	return DemoGetPaymailByAlias(alias, domain)
 }
 
 // CreateAddressResolutionResponse is a demo implementation of this interface
 func (d *demoServiceProvider) CreateAddressResolutionResponse(ctx context.Context, alias, domain string,
-	senderValidation bool, _ *server.RequestMetadata) (*paymail.ResolutionPayload, error) {
-
+	senderValidation bool, _ *server.RequestMetadata,
+) (*paymail.ResolutionPayload, error) {
 	// Generate a new destination / output for the basic address resolution
 	return DemoCreateAddressResolutionResponse(ctx, alias, domain, senderValidation)
 }
 
 // CreateP2PDestinationResponse is a demo implementation of this interface
 func (d *demoServiceProvider) CreateP2PDestinationResponse(ctx context.Context, alias, domain string,
-	satoshis uint64, _ *server.RequestMetadata) (*paymail.PaymentDestinationPayload, error) {
-
+	satoshis uint64, _ *server.RequestMetadata,
+) (*paymail.PaymentDestinationPayload, error) {
 	// Generate a new destination for the p2p request
 	return DemoCreateP2PDestinationResponse(ctx, alias, domain, satoshis)
 }
 
 // RecordTransaction is a demo implementation of this interface
 func (d *demoServiceProvider) RecordTransaction(ctx context.Context,
-	p2pTx *paymail.P2PTransaction, _ *server.RequestMetadata) (*paymail.P2PTransactionPayload, error) {
-
+	p2pTx *paymail.P2PTransaction, _ *server.RequestMetadata,
+) (*paymail.P2PTransactionPayload, error) {
 	// Record the tx into your datastore layer
 	return DemoRecordTransaction(ctx, p2pTx)
 }
 
 // VerifyMerkleRoots is a demo implementation of this interface
-func (d *demoServiceProvider) VerifyMerkleRoots(ctx context.Context, merkleProofs []string) error {
-
+func (d *demoServiceProvider) VerifyMerkleRoots(ctx context.Context, merkleProofs []paymail.MerkleRootConfirmationRequestItem) error {
 	// Verify the Merkle roots
 	return nil
 }

p2p_beef_tx.go

@@ -4,6 +4,7 @@ import (
 	"encoding/hex"
 	"errors"
 	"fmt"
+
 	"github.com/libsv/go-bt/v2"
 )
 
@@ -35,16 +36,23 @@ type DecodedBEEF struct {
 }
 
 // GetMerkleRoots will calculate the merkle roots for the BUMPs in the BEEF transaction
-func (dBeef *DecodedBEEF) GetMerkleRoots() ([]string, error) {
-	var merkleRoots []string
+func (dBeef *DecodedBEEF) GetMerkleRootsRequest() ([]MerkleRootConfirmationRequestItem, error) {
+	var merkleRootsRequest []MerkleRootConfirmationRequestItem
+
 	for _, bump := range dBeef.BUMPs {
-		partialMerkleRoots, err := bump.calculateMerkleRoots()
+		merkleRoot, err := bump.calculateMerkleRoot()
 		if err != nil {
 			return nil, err
 		}
-		merkleRoots = append(merkleRoots, partialMerkleRoots...)
+
+		request := MerkleRootConfirmationRequestItem{
+			BlockHeight: int32(bump.blockHeight),
+			MerkleRoot:  merkleRoot,
+		}
+		merkleRootsRequest = append(merkleRootsRequest, request)
 	}
-	return merkleRoots, nil
+
+	return merkleRootsRequest, nil
 }
 
 func DecodeBEEF(beefHex string) (*DecodedBEEF, error) {

p2p_beef_tx_test.go

@@ -3,10 +3,10 @@ package paymail
 import (
 	"context"
 	"errors"
-	"github.com/libsv/go-bt/v2/bscript"
 	"testing"
 
 	"github.com/libsv/go-bt/v2"
+	"github.com/libsv/go-bt/v2/bscript"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -15,7 +15,7 @@ import (
 type mockServiceProvider struct{}
 
 // VerifyMerkleRoots is a mock implementation of this interface
-func (m *mockServiceProvider) VerifyMerkleRoots(_ context.Context, _ []string) error {
+func (m *mockServiceProvider) VerifyMerkleRoots(_ context.Context, _ []MerkleRootConfirmationRequestItem) error {
 	// Verify the merkle roots
 	return nil
 }
@@ -79,7 +79,8 @@ func TestDecodeBEEF_DecodeBEEF_HappyPaths(t *testing.T) {
 									Satoshis:      26174,
 									LockingScript: bscript.NewFromBytes([]byte("76a9146bfd5c7fbe21529d45803dbcf0c87dd3c71efbc288ac")),
 								},
-							}},
+							},
+						},
 						PathIndex: func(v bt.VarInt) *bt.VarInt { return &v }(0x0),
 					},
 				},
@@ -100,7 +101,8 @@ func TestDecodeBEEF_DecodeBEEF_HappyPaths(t *testing.T) {
 								Satoshis:      26172,
 								LockingScript: bscript.NewFromBytes([]byte("76a9146bfd5c7fbe21529d45803dbcf0c87dd3c71efbc288ac")),
 							},
-						}},
+						},
+					},
 					PathIndex: nil,
 				},
 			},

p2p_spv.go

@@ -4,14 +4,15 @@ import (
 	"context"
 	"errors"
 	"fmt"
+
 	"github.com/libsv/go-bt/v2"
 	"github.com/libsv/go-bt/v2/bscript/interpreter"
 )
 
 type MerkleRootVerifier interface {
 	VerifyMerkleRoots(
 		ctx context.Context,
-		merkleRoots []string,
+		merkleRoots []MerkleRootConfirmationRequestItem,
 	) error
 }
 
@@ -41,7 +42,7 @@ func ExecuteSimplifiedPaymentVerification(dBeef *DecodedBEEF, provider MerkleRoo
 }
 
 func verifyMerkleRoots(dBeef *DecodedBEEF, provider MerkleRootVerifier) error {
-	merkleRoots, err := dBeef.GetMerkleRoots()
+	merkleRoots, err := dBeef.GetMerkleRootsRequest()
 	if err != nil {
 		return err
 	}

server/interface.go

@@ -36,6 +36,6 @@ type PaymailServiceProvider interface {
 
 	VerifyMerkleRoots(
 		ctx context.Context,
-		merkleProofs []string,
+		merkleProofs []paymail.MerkleRootConfirmationRequestItem,
 	) error
 }

server/mock_test.go

@@ -41,7 +41,7 @@ func (m *mockServiceProvider) RecordTransaction(_ context.Context,
 }
 
 // VerifyMerkleRoots is a mock implementation of this interface
-func (m *mockServiceProvider) VerifyMerkleRoots(_ context.Context, _ []string) error {
+func (m *mockServiceProvider) VerifyMerkleRoots(_ context.Context, _ []paymail.MerkleRootConfirmationRequestItem) error {
 
 	// Verify the merkle roots
 	return nil