rename to common/packetpadding

common/packetpadding/container.go

@@ -0,0 +1,49 @@
+package packetpadding
+
+import "encoding/binary"
+
+func New() PacketPaddingContainer {
+	return packetPaddingContainer{}
+}
+
+type packetPaddingContainer struct {
+}
+
+func (c packetPaddingContainer) Pack(data_OWNERSHIP_RELINQUISHED []byte, paddingLength int) []byte {
+	data := append(data_OWNERSHIP_RELINQUISHED, make([]byte, paddingLength)...)
+	dataLength := len(data_OWNERSHIP_RELINQUISHED)
+	data = binary.BigEndian.AppendUint16(data, uint16(dataLength))
+	return data
+}
+
+func (c packetPaddingContainer) Pad(paddingLength int) []byte {
+	if assertPaddingLengthIsNotNegative := paddingLength < 0; assertPaddingLengthIsNotNegative {
+		return nil
+	}
+	switch paddingLength {
+	case 0:
+		return []byte{}
+	case 1:
+		return []byte{0}
+	case 2:
+		return []byte{0, 0}
+	default:
+		return append(make([]byte, paddingLength-2), byte(paddingLength>>8), byte(paddingLength))
+	}
+
+}
+
+func (c packetPaddingContainer) Unpack(wrappedData_OWNERSHIP_RELINQUISHED []byte) ([]byte, int) {
+	dataLength := len(wrappedData_OWNERSHIP_RELINQUISHED)
+	if dataLength < 2 {
+		return nil, dataLength
+	}
+
+	dataLen := int(binary.BigEndian.Uint16(wrappedData_OWNERSHIP_RELINQUISHED[dataLength-2:]))
+	paddingLength := dataLength - dataLen - 2
+	if paddingLength < 0 {
+		return nil, paddingLength
+	}
+
+	return wrappedData_OWNERSHIP_RELINQUISHED[:dataLen], paddingLength
+}