From 91e2a902d867c46bf8267b3a4a39a7bc3ba4d747 Mon Sep 17 00:00:00 2001
From: Rod Hynes <rod-hynes@users.noreply.github.com>
Date: Mon, 11 Mar 2024 11:45:05 -0400
Subject: [PATCH] Fix "missing port in address" gQUIC dial failure

---
 psiphon/common/quic/gquic.go     | 7 +++++++
 psiphon/common/quic/quic_test.go | 7 ++++++-
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/psiphon/common/quic/gquic.go b/psiphon/common/quic/gquic.go
index 2ca19bfae..1ece60cde 100644
--- a/psiphon/common/quic/gquic.go
+++ b/psiphon/common/quic/gquic.go
@@ -112,6 +112,13 @@ func gQUICDialContext(
 	quicSNIAddress string,
 	versionNumber uint32) (quicConnection, error) {
 
+	// The legacy gquic-go fork expects a port number in the SNI field
+	// (which is then stripped). Add a stub port value if none is present.
+	_, _, err := net.SplitHostPort(quicSNIAddress)
+	if err != nil {
+		quicSNIAddress = net.JoinHostPort(quicSNIAddress, "0")
+	}
+
 	quicConfig := &gquic.Config{
 		HandshakeTimeout: time.Duration(1<<63 - 1),
 		IdleTimeout:      CLIENT_IDLE_TIMEOUT,
diff --git a/psiphon/common/quic/quic_test.go b/psiphon/common/quic/quic_test.go
index ddda029cc..353ab7425 100644
--- a/psiphon/common/quic/quic_test.go
+++ b/psiphon/common/quic/quic_test.go
@@ -188,11 +188,16 @@ func runQUIC(
 				}
 			}
 
+			quicSNIAddress, _, err := net.SplitHostPort(serverAddress)
+			if err != nil {
+				return errors.Trace(err)
+			}
+
 			conn, err := Dial(
 				ctx,
 				packetConn,
 				remoteAddr,
-				serverAddress,
+				quicSNIAddress,
 				quicVersion,
 				clientHelloSeed,
 				clientObfuscationKey,