Add client and service

v1_server.go

@@ -0,0 +1,37 @@
+package shadowtls
+
+import (
+	"bytes"
+	"encoding/binary"
+	"io"
+
+	E "github.com/sagernet/sing/common/exceptions"
+)
+
+func copyUntilHandshakeFinished(dst io.Writer, src io.Reader) error {
+	var hasSeenChangeCipherSpec bool
+	var tlsHdr [tlsHeaderSize]byte
+	for {
+		_, err := io.ReadFull(src, tlsHdr[:])
+		if err != nil {
+			return err
+		}
+		length := binary.BigEndian.Uint16(tlsHdr[3:])
+		_, err = io.Copy(dst, io.MultiReader(bytes.NewReader(tlsHdr[:]), io.LimitReader(src, int64(length))))
+		if err != nil {
+			return err
+		}
+		if tlsHdr[0] != handshake {
+			if tlsHdr[0] != changeCipherSpec {
+				return E.New("unexpected tls frame type: ", tlsHdr[0])
+			}
+			if !hasSeenChangeCipherSpec {
+				hasSeenChangeCipherSpec = true
+				continue
+			}
+		}
+		if hasSeenChangeCipherSpec {
+			return nil
+		}
+	}
+}