From 06a8df3bb8e1881a93f0ae65bfb7cc5246b988ce Mon Sep 17 00:00:00 2001
From: Peter Stuifzand <peter@stuifzand.eu>
Date: Wed, 25 Jul 2018 13:51:00 +0200
Subject: [PATCH] Check if grant_type is used in token_endpoint

---
 cmd/eksterd/http.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/cmd/eksterd/http.go b/cmd/eksterd/http.go
index 05d015d..093be21 100644
--- a/cmd/eksterd/http.go
+++ b/cmd/eksterd/http.go
@@ -559,7 +559,12 @@ func (h *mainHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 			http.Redirect(w, r, redirectURI.String(), 302)
 			return
 		} else if r.URL.Path == "/auth/token" {
-			//grantType := r.FormValue("grant_type")
+			grantType := r.FormValue("grant_type")
+			if grantType != "authorization_code" {
+				w.WriteHeader(400)
+				fmt.Fprintf(w, "ERROR: grant_type is not set to %q", "authorization_code")
+				return
+			}
 			code := r.FormValue("code")
 			//clientID := r.FormValue("client_id")
 			//redirectURI := r.FormValue("redirect_uri")