implement ss2022 client timestamp check as per spec

v2fly · Nov 19, 2023 · 12b4065 · 12b4065
1 parent 1c9cace
commit 12b4065
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Showing 2 changed files with 10 additions and 1 deletion.
diff --git a/proxy/shadowsocks2022/client_session.go b/proxy/shadowsocks2022/client_session.go
@@ -73,6 +73,15 @@ func (c *ClientUDPSession) KeepReading() {
 				newError("unable to decode udp response").Base(err).WriteToLog()
 				continue
 			}
+
+			{
+				timeDifference := int64(udpResp.TimeStamp) - time.Now().Unix()
+				if timeDifference < -30 || timeDifference > 30 {
+					newError("udp packet timestamp difference too large, packet discarded").WriteToLog()
+					continue
+				}
+			}
+
 			c.locker.Lock()
 			session, ok := c.sessionMap[string(udpResp.ClientSessionID[:])]
 			if ok {

diff --git a/proxy/shadowsocks2022/encoding.go b/proxy/shadowsocks2022/encoding.go
@@ -211,7 +211,7 @@ func (t *TCPRequest) DecodeTCPResponseHeader(effectivePsk []byte, In io.Reader)
 		return newError("unexpected TCP header type")
 	}
 	timeDifference := int64(fixedLengthHeader.Timestamp) - time.Now().Unix()
-	if timeDifference < -60 || timeDifference > 60 {
+	if timeDifference < -30 || timeDifference > 30 {
 		return newError("timestamp is too far away")
 	}