use a type alias for the STK

interface.go

@@ -5,7 +5,8 @@ import (
 	"io"
 	"net"
 	"time"
-
+	
+	"github.com/lucas-clemente/quic-go/handshake"
 	"github.com/lucas-clemente/quic-go/internal/protocol"
 )
 
@@ -15,6 +16,9 @@ type StreamID = protocol.StreamID
 // A VersionNumber is a QUIC version number.
 type VersionNumber = protocol.VersionNumber
 
+// An STK can be used to verify the ownership of the client address.
+type STK = handshake.STK
+
 // Stream is the interface implemented by QUIC streams
 type Stream interface {
 	// Read reads data from the stream.
@@ -79,18 +83,6 @@ type NonFWSession interface {
 	WaitUntilHandshakeComplete() error
 }
 
-// An STK is a Source Address token.
-// It is issued by the server and sent to the client. For the client, it is an opaque blob.
-// The client can send the STK in subsequent handshakes to prove ownership of its IP address.
-type STK struct {
-	// The remote address this token was issued for.
-	// If the server is run on a net.UDPConn, this is the string representation of the IP address (net.IP.String())
-	// Otherwise, this is the string representation of the net.Addr (net.Addr.String())
-	remoteAddr string
-	// The time that the STK was issued (resolution 1 second)
-	sentTime time.Time
-}
-
 // Config contains all configuration data needed for a QUIC server or client.
 type Config struct {
 	// The QUIC versions that can be negotiated.