From a6c41b2aac0b3495046baa62e63a60186e73643f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thorben=20G=C3=BCnther?= <admin@xenrox.net>
Date: Mon, 10 Oct 2022 19:55:33 +0200
Subject: [PATCH] Use middleware for basic auth

---
 main.go | 39 +++++++++++++++++++++++++--------------
 1 file changed, 25 insertions(+), 14 deletions(-)

diff --git a/main.go b/main.go
index b94524a..2fad806 100644
--- a/main.go
+++ b/main.go
@@ -34,19 +34,6 @@ type alert struct {
 }
 
 func (rcv *receiver) handleWebhooks(w http.ResponseWriter, r *http.Request) {
-	if rcv.cfg.User != "" && rcv.cfg.Password != "" {
-		user, pass, ok := r.BasicAuth()
-		if !ok {
-			rcv.logger.Debug("basic auth failure")
-			return
-		}
-
-		if user != rcv.cfg.User || pass != rcv.cfg.Password {
-			rcv.logger.Debug("basic auth: wrong user or password")
-			return
-		}
-	}
-
 	defer r.Body.Close()
 
 	if r.Method != http.MethodPost {
@@ -121,6 +108,23 @@ func (rcv *receiver) handleWebhooks(w http.ResponseWriter, r *http.Request) {
 	}
 }
 
+func (rcv *receiver) basicAuthMiddleware(handler http.HandlerFunc) http.HandlerFunc {
+	return func(w http.ResponseWriter, r *http.Request) {
+		user, pass, ok := r.BasicAuth()
+		if !ok {
+			rcv.logger.Debug("basic auth failure")
+			return
+		}
+
+		if user != rcv.cfg.User || pass != rcv.cfg.Password {
+			rcv.logger.Debug("basic auth: wrong user or password")
+			return
+		}
+
+		handler(w, r)
+	}
+}
+
 func main() {
 	var configPath string
 	flag.StringVar(&configPath, "config", "/etc/ntfy-alertmanager/config", "config file path")
@@ -139,7 +143,14 @@ func main() {
 
 	receiver := &receiver{cfg: cfg, logger: logger}
 
-	http.HandleFunc("/", receiver.handleWebhooks)
 	logger.Infof("Listening on %s", cfg.HTTPAddress)
+
+	if cfg.User != "" && cfg.Password != "" {
+		logger.Info("Enabling HTTP Basic Authentication")
+		http.HandleFunc("/", receiver.basicAuthMiddleware(receiver.handleWebhooks))
+	} else {
+		http.HandleFunc("/", receiver.handleWebhooks)
+	}
+
 	logger.Fatal(http.ListenAndServe(cfg.HTTPAddress, nil))
 }