multi: add blinded path TLVs to onion payload / hops

This commit adds the encrypted_data, blinding_point and total_amt_msat
tlvs to the known set of even tlvs for the onion payload. These TLVs
are added in two places (the onion payload and hop struct) because
lnd uses the same set of TLV types for both structs (and they
inherently represent the same thing).

Note: in some places, unit tests intentionally mimic the style
of older tests, so as to be more consistently readable.

channeldb/payments_test.go

@@ -21,9 +21,10 @@ import (
 var (
 	priv, _ = btcec.NewPrivateKey()
 	pub     = priv.PubKey()
+	vertex  = route.NewVertex(pub)
 
 	testHop1 = &route.Hop{
-		PubKeyBytes:      route.NewVertex(pub),
+		PubKeyBytes:      vertex,
 		ChannelID:        12345,
 		OutgoingTimeLock: 111,
 		AmtToForward:     555,
@@ -36,7 +37,7 @@ var (
 	}
 
 	testHop2 = &route.Hop{
-		PubKeyBytes:      route.NewVertex(pub),
+		PubKeyBytes:      vertex,
 		ChannelID:        12345,
 		OutgoingTimeLock: 111,
 		AmtToForward:     555,
@@ -46,12 +47,39 @@ var (
 	testRoute = route.Route{
 		TotalTimeLock: 123,
 		TotalAmount:   1234567,
-		SourcePubKey:  route.NewVertex(pub),
+		SourcePubKey:  vertex,
 		Hops: []*route.Hop{
 			testHop2,
 			testHop1,
 		},
 	}
+
+	testBlindedRoute = route.Route{
+		TotalTimeLock: 150,
+		TotalAmount:   1000,
+		SourcePubKey:  vertex,
+		Hops: []*route.Hop{
+			{
+				PubKeyBytes:      vertex,
+				ChannelID:        9876,
+				OutgoingTimeLock: 120,
+				AmtToForward:     900,
+				EncryptedData:    []byte{1, 3, 3},
+				BlindingPoint:    pub,
+			},
+			{
+				PubKeyBytes:   vertex,
+				EncryptedData: []byte{3, 2, 1},
+			},
+			{
+				PubKeyBytes:      vertex,
+				Metadata:         []byte{4, 5, 6},
+				AmtToForward:     500,
+				OutgoingTimeLock: 100,
+				TotalAmtMsat:     500,
+			},
+		},
+	}
 )
 
 func makeFakeInfo() (*PaymentCreationInfo, *HTLCAttemptInfo) {
@@ -140,27 +168,24 @@ func assertRouteEqual(a, b *route.Route) error {
 	return nil
 }
 
+// TestRouteSerialization tests serialization of a regular and blinded route.
 func TestRouteSerialization(t *testing.T) {
 	t.Parallel()
 
+	testSerializeRoute(t, testRoute)
+	testSerializeRoute(t, testBlindedRoute)
+}
+
+func testSerializeRoute(t *testing.T, route route.Route) {
 	var b bytes.Buffer
-	if err := SerializeRoute(&b, testRoute); err != nil {
-		t.Fatal(err)
-	}
+	err := SerializeRoute(&b, route)
+	require.NoError(t, err)
 
 	r := bytes.NewReader(b.Bytes())
 	route2, err := DeserializeRoute(r)
-	if err != nil {
-		t.Fatal(err)
-	}
+	require.NoError(t, err)
 
-	// First we verify all the records match up porperly, as they aren't
-	// able to be properly compared using reflect.DeepEqual.
-	err = assertRouteEqual(&testRoute, &route2)
-	if err != nil {
-		t.Fatalf("routes not equal: \n%v vs \n%v",
-			spew.Sdump(testRoute), spew.Sdump(route2))
-	}
+	reflect.DeepEqual(route, route2)
 }
 
 // deletePayment removes a payment with paymentHash from the payments database.