v1.0.0

transport/internet/headers/tls/dtls.go

@@ -0,0 +1,55 @@
+package tls
+
+import (
+	"context"
+
+	"github.com/xtls/xray-core/v1/common"
+	"github.com/xtls/xray-core/v1/common/dice"
+)
+
+// DTLS writes header as DTLS. See https://tools.ietf.org/html/rfc6347
+type DTLS struct {
+	epoch    uint16
+	length   uint16
+	sequence uint32
+}
+
+// Size implements PacketHeader.
+func (*DTLS) Size() int32 {
+	return 1 + 2 + 2 + 6 + 2
+}
+
+// Serialize implements PacketHeader.
+func (d *DTLS) Serialize(b []byte) {
+	b[0] = 23 // application data
+	b[1] = 254
+	b[2] = 253
+	b[3] = byte(d.epoch >> 8)
+	b[4] = byte(d.epoch)
+	b[5] = 0
+	b[6] = 0
+	b[7] = byte(d.sequence >> 24)
+	b[8] = byte(d.sequence >> 16)
+	b[9] = byte(d.sequence >> 8)
+	b[10] = byte(d.sequence)
+	d.sequence++
+	b[11] = byte(d.length >> 8)
+	b[12] = byte(d.length)
+	d.length += 17
+	if d.length > 100 {
+		d.length -= 50
+	}
+}
+
+// New creates a new UTP header for the given config.
+func New(ctx context.Context, config interface{}) (interface{}, error) {
+	return &DTLS{
+		epoch:    dice.RollUint16(),
+		sequence: 0,
+		length:   17,
+	}, nil
+}
+
+func init() {
+	common.Must(common.RegisterConfig((*PacketConfig)(nil), New))
+}