sphinx: switch to using BigSize for varints

Author: Roasbeef

path.go

@@ -9,6 +9,7 @@ import (
 
 	"github.com/btcsuite/btcd/btcec"
 	"github.com/btcsuite/btcd/wire"
+	"github.com/lightningnetwork/lnd/tlv"
 )
 
 // HopData is the information destined for individual hops. It is a fixed size
@@ -210,7 +211,8 @@ func (hp *HopPayload) Encode(w io.Writer) error {
 	// For the TLV payload, we'll first prepend the length of the payload
 	// as a var-int.
 	case PayloadTLV:
-		err := wire.WriteVarInt(w, 0, uint64(len(hp.Payload)))
+		var b [8]byte
+		err := tlv.WriteVarInt(w, uint64(len(hp.Payload)), &b)
 		if err != nil {
 			return err
 		}
@@ -254,7 +256,8 @@ func (hp *HopPayload) Decode(r io.Reader) error {
 	default:
 		// Otherwise, this is the new TLV based payload type, so we'll
 		// extract the payload length encoded as a var-int.
-		varInt, err := wire.ReadVarInt(bufReader, 0)
+		var b [8]byte
+		varInt, err := tlv.ReadVarInt(bufReader, &b)
 		if err != nil {
 			return err
 		}