From 59eaec4fd8e35e84585645cb1dff48373d8cf572 Mon Sep 17 00:00:00 2001
From: Till Faelligen <2353100+S7evinK@users.noreply.github.com>
Date: Thu, 16 Mar 2023 12:43:40 +0100
Subject: [PATCH] Make Dendrite spec compliant, fix #2903

---
 internal/httputil/routing.go | 41 +++++++++++++++---------------------
 setup/base/base.go           |  3 +++
 2 files changed, 20 insertions(+), 24 deletions(-)

diff --git a/internal/httputil/routing.go b/internal/httputil/routing.go
index 5522514b4..c733c8ce7 100644
--- a/internal/httputil/routing.go
+++ b/internal/httputil/routing.go
@@ -15,7 +15,6 @@
 package httputil
 
 import (
-	"fmt"
 	"net/http"
 	"net/url"
 
@@ -64,31 +63,25 @@ func NewRouters() Routers {
 	return r
 }
 
+var NotAllowedHandler = WrapHandlerInCORS(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusMethodNotAllowed)
+	w.Header().Set("Content-Type", "application/json")
+	_, _ = w.Write([]byte(`{"errcode":"M_UNRECOGNIZED","error":"Unrecognized request"}`)) // nolint:misspell
+}))
+
+var NotFoundCORSHandler = WrapHandlerInCORS(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+	w.WriteHeader(http.StatusNotFound)
+	w.Header().Set("Content-Type", "application/json")
+	_, _ = w.Write([]byte(`{"errcode":"M_UNRECOGNIZED","error":"Unrecognized request"}`)) // nolint:misspell
+}))
+
 func (r *Routers) configureHTTPErrors() {
-	notAllowedHandler := func(w http.ResponseWriter, r *http.Request) {
-		w.WriteHeader(http.StatusMethodNotAllowed)
-		_, _ = w.Write([]byte(fmt.Sprintf("405 %s not allowed on this endpoint", r.Method)))
-	}
-
-	clientNotFoundHandler := func(w http.ResponseWriter, r *http.Request) {
-		w.WriteHeader(http.StatusNotFound)
-		w.Header().Set("Content-Type", "application/json")
-		_, _ = w.Write([]byte(`{"errcode":"M_UNRECOGNIZED","error":"Unrecognized request"}`)) // nolint:misspell
-	}
-
-	notFoundCORSHandler := WrapHandlerInCORS(http.NotFoundHandler())
-	notAllowedCORSHandler := WrapHandlerInCORS(http.HandlerFunc(notAllowedHandler))
-
 	for _, router := range []*mux.Router{
-		r.Media, r.DendriteAdmin,
-		r.SynapseAdmin, r.WellKnown,
-		r.Static,
+		r.Client, r.Federation, r.Keys,
+		r.Media, r.WellKnown, r.Static,
+		r.DendriteAdmin, r.SynapseAdmin,
 	} {
-		router.NotFoundHandler = notFoundCORSHandler
-		router.MethodNotAllowedHandler = notAllowedCORSHandler
+		router.NotFoundHandler = NotFoundCORSHandler
+		router.MethodNotAllowedHandler = NotAllowedHandler
 	}
-
-	// Special case so that we don't upset clients on the CS API.
-	r.Client.NotFoundHandler = http.HandlerFunc(clientNotFoundHandler)
-	r.Client.MethodNotAllowedHandler = http.HandlerFunc(clientNotFoundHandler)
 }
diff --git a/setup/base/base.go b/setup/base/base.go
index 021e7168c..ed3445019 100644
--- a/setup/base/base.go
+++ b/setup/base/base.go
@@ -353,6 +353,9 @@ func (b *BaseDendrite) SetupAndServeHTTP(
 
 	b.startupLock.Unlock()
 
+	externalRouter.NotFoundHandler = httputil.NotFoundCORSHandler
+	externalRouter.MethodNotAllowedHandler = httputil.NotAllowedHandler
+
 	if externalHTTPAddr.Enabled() {
 		go func() {
 			var externalShutdown atomic.Bool // RegisterOnShutdown can be called more than once