From 96db15c836dd88c254863d172c227f63e93cf1d0 Mon Sep 17 00:00:00 2001
From: Marten Seemann <martenseemann@gmail.com>
Date: Sat, 31 Aug 2019 12:26:37 +0700
Subject: [PATCH] accept smaller stateless resets

---
 packet_handler_map.go      |  2 +-
 packet_handler_map_test.go | 15 +++++++++++++++
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/packet_handler_map.go b/packet_handler_map.go
index 35265b59..12e2e70e 100644
--- a/packet_handler_map.go
+++ b/packet_handler_map.go
@@ -223,7 +223,7 @@ func (h *packetHandlerMap) maybeHandleStatelessReset(data []byte) bool {
 	if data[0]&0x80 != 0 {
 		return false
 	}
-	if len(data) < protocol.MinStatelessResetSize {
+	if len(data) < 17 /* type byte + 16 bytes for the reset token */ {
 		return false
 	}
 
diff --git a/packet_handler_map_test.go b/packet_handler_map_test.go
index e52c1305..a4c15798 100644
--- a/packet_handler_map_test.go
+++ b/packet_handler_map_test.go
@@ -265,6 +265,21 @@ var _ = Describe("Packet Handler Map", func() {
 				// make sure we give it enough time to be called to cause an error here
 				time.Sleep(scaleDuration(25 * time.Millisecond))
 			})
+
+			It("ignores packets too small to contain a stateless reset", func() {
+				handler.connIDLen = 0
+				packetHandler := NewMockPacketHandler(mockCtrl)
+				token := [16]byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16}
+				handler.AddResetToken(token, packetHandler)
+				packet := append([]byte{0x40} /* short header packet */, token[:15]...)
+				done := make(chan struct{})
+				// don't EXPECT any calls here, but register the closing of the done channel
+				packetHandler.EXPECT().destroy(gomock.Any()).Do(func(error) {
+					close(done)
+				}).AnyTimes()
+				conn.dataToRead <- packet
+				Consistently(done).ShouldNot(BeClosed())
+			})
 		})
 
 		Context("generating", func() {