Store everything in uint64 to avoid overflow

fmp/fmp_util.go

@@ -1,14 +1,14 @@
 package fmp
 
-func parseVarUint32(payload []byte) uint32 {
-	var length uint32
+func parseVarUint64(payload []byte) uint64 {
+	var length uint64
 	n := len(payload)
-	if n > 4 {
-		n = 4 // clamp to max uint32
+	if n > 8 {
+		n = 8 // clamp to max uint64
 	}
 	for i := range n {
 		length <<= 8
-		length |= uint32(payload[i])
+		length |= uint64(payload[i])
 	}
 	return length
 }