open the crypto stream during session setup

session.go

@@ -258,21 +258,24 @@ func (s *session) setup(
 	)
 	s.unpacker = &packetUnpacker{aead: s.cryptoSetup, version: s.version}
 
+	// open the crypto stream
+	if s.perspective == protocol.PerspectiveServer {
+		_, _ = s.GetOrOpenStream(1)
+		_, _ = s.AcceptStream() // don't expose the crypto stream
+	} else {
+		_, _ = s.OpenStream()
+	}
+
 	return s, handshakeChan, nil
 }
 
 // run the session main loop
 func (s *session) run() error {
-	// Start the crypto stream handler
-	var cryptoStream Stream
-	if s.perspective == protocol.PerspectiveServer {
-		cryptoStream, _ = s.GetOrOpenStream(1)
-		_, _ = s.AcceptStream() // don't expose the crypto stream
-	} else {
-		cryptoStream, _ = s.OpenStream()
-	}
+	defer s.ctxCancel()
 
+	// Start the crypto stream handler
 	go func() {
+		cryptoStream, _ := s.GetOrOpenStream(1)
 		if err := s.cryptoSetup.HandleCryptoStream(cryptoStream); err != nil {
 			s.Close(err)
 		}
@@ -366,7 +369,6 @@ runLoop:
 		s.handshakeChan <- handshakeEvent{err: closeErr.err}
 	}
 	s.handleCloseError(closeErr)
-	defer s.ctxCancel()
 	return closeErr.err
 }
 

session_test.go

@@ -208,7 +208,7 @@ var _ = Describe("Session", func() {
 		)
 		Expect(err).NotTo(HaveOccurred())
 		sess = pSess.(*session)
-		Expect(sess.streamsMap.openStreams).To(BeEmpty()) // the crypto stream is opened in session.run()
+		Expect(sess.streamsMap.openStreams).To(HaveLen(1)) // 1 stream: the crypto stream
 
 		sess.connParams = &mockParamsNegotiator{}
 	})
@@ -684,15 +684,15 @@ var _ = Describe("Session", func() {
 			}()
 			Consistently(strChan).ShouldNot(Receive())
 			err := sess.handleStreamFrame(&wire.StreamFrame{
-				StreamID: 3,
+				StreamID: 5,
 				Data:     []byte("foobar"),
 			})
 			Expect(err).ToNot(HaveOccurred())
 			var str Stream
 			Eventually(strChan).Should(Receive(&str))
-			Expect(str.StreamID()).To(Equal(protocol.StreamID(1)))
-			Eventually(strChan).Should(Receive(&str))
 			Expect(str.StreamID()).To(Equal(protocol.StreamID(3)))
+			Eventually(strChan).Should(Receive(&str))
+			Expect(str.StreamID()).To(Equal(protocol.StreamID(5)))
 		})
 
 		It("stops accepting when the session is closed", func() {
@@ -1684,7 +1684,7 @@ var _ = Describe("Client Session", func() {
 		)
 		sess = sessP.(*session)
 		Expect(err).ToNot(HaveOccurred())
-		Expect(sess.streamsMap.openStreams).To(BeEmpty()) // the crypto stream is opened in session.run()
+		Expect(sess.streamsMap.openStreams).To(HaveLen(1))
 	})
 
 	AfterEach(func() {