From 60dc5138135c8512fd095fc88ace4ccb21b2fd84 Mon Sep 17 00:00:00 2001
From: uditaren <uditaren@udico.de>
Date: Sat, 31 Aug 2024 14:01:30 +0200
Subject: [PATCH] Fix: support comma-separated values to the Connection HTTP
 header

---
 header.go   | 40 ++++++++++++++++++++++++++++++++++++++++
 listener.go |  9 +++++----
 2 files changed, 45 insertions(+), 4 deletions(-)
 create mode 100644 header.go

diff --git a/header.go b/header.go
new file mode 100644
index 0000000..524450c
--- /dev/null
+++ b/header.go
@@ -0,0 +1,40 @@
+package zocket
+
+import (
+	"net/http"
+	"strings"
+	"udico.de/util/log"
+)
+
+type zocketHeader struct {
+	http.Header
+}
+
+// Has returns true, if one entry of the given key has the exact value.
+func (f zocketHeader) Has(key, value string) bool {
+	log.TRACE.To(logger).If(func(msg log.Fn) {
+		msg("Has(%v, %v)? Dumping", key, value)
+		for k, v := range f.Values(key) {
+			msg("  [%v]: %v", k, v)
+		}
+	})
+	for _, v := range f.Values(key) {
+		if v == value {
+			return true
+		}
+	}
+	return false
+}
+
+// Contains returns true, if at least one entry of the given key contains the value as part of a comma separated list.
+func (f zocketHeader) Contains(key, value string) bool {
+	for _, v := range f.Values(key) {
+		for _, w := range strings.Split(v, ",") {
+			ws := strings.TrimSpace(w)
+			if ws == value {
+				return true
+			}
+		}
+	}
+	return false
+}
diff --git a/listener.go b/listener.go
index c3cd9c9..225ec03 100644
--- a/listener.go
+++ b/listener.go
@@ -106,19 +106,20 @@ func (l Listener) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 	//	return
 	//}
 
-	if req.Header.Get("Connection") != "Upgrade" {
+	head := &zocketHeader{req.Header}
+	if !head.Contains("Connection", "Upgrade") {
 		log.ERROR.To(logger).Msg("Connection != Upgrade")
 		resp.WriteHeader(http.StatusUpgradeRequired)
 		return
 	}
 
-	if req.Header.Get("Upgrade") != "websocket" {
+	if head.Get("Upgrade") != "websocket" {
 		log.ERROR.To(logger).Msg("Upgrade != websocket")
 		resp.WriteHeader(http.StatusUpgradeRequired)
 		return
 	}
 
-	if req.Header.Get("Sec-WebSocket-Version") != "13" {
+	if head.Get("Sec-WebSocket-Version") != "13" {
 		log.ERROR.To(logger).Msg("Invalid WebSocket Version")
 		resp.WriteHeader(http.StatusUpgradeRequired)
 		return
@@ -130,7 +131,7 @@ func (l Listener) ServeHTTP(resp http.ResponseWriter, req *http.Request) {
 		log.INFO.To(logger).Msg("   %v: %v", k, v[0])
 	}
 
-	wsKey := req.Header.Get("Sec-Websocket-Key")
+	wsKey := head.Get("Sec-Websocket-Key")
 	wsKey += "258EAFA5-E914-47DA-95CA-C5AB0DC85B11"
 	shakey := sha1.Sum([]byte(wsKey))
 	wsKey = base64.StdEncoding.EncodeToString(shakey[:])