fix: use cryptobyte for internal helper

`helper.Uint8to16()` now calls `(*cryptobyte.String).ReadUint16()`

internal/helper/typeconv.go

@@ -1,35 +1,23 @@
 package helper
 
 import (
-	"bytes"
-	"encoding/binary"
-	"io"
-)
+	"errors"
 
-func ReadUint16(r io.Reader, v *uint16) error {
-	var buf [2]byte
-	if _, err := io.ReadFull(r, buf[:]); err != nil {
-		return err
-	}
-	*v = binary.BigEndian.Uint16(buf[:])
-	return nil
-}
+	"golang.org/x/crypto/cryptobyte"
+)
 
 // Uint8to16 converts a slice of uint8 to a slice of uint16.
 // e.g. []uint8{0x00, 0x01, 0x00, 0x02} -> []uint16{0x0001, 0x0002}
 func Uint8to16(in []uint8) ([]uint16, error) {
-	reader := bytes.NewReader(in)
+	s := cryptobyte.String(in)
 	var out []uint16
-	for {
+	for !s.Empty() {
 		var v uint16
-		err := ReadUint16(reader, &v)
-		if err == io.EOF {
-			break
+		if s.ReadUint16(&v) {
+			out = append(out, v)
+		} else {
+			return nil, errors.New("ReadUint16 failed")
 		}
-		if err != nil {
-			return nil, err
-		}
-		out = append(out, v)
 	}
 	return out, nil
 }