From 90c816d82bb9fa83154ec97411ace0942f09d63b Mon Sep 17 00:00:00 2001
From: Artyom Pervukhin <artyom@evasive.ru>
Date: Tue, 1 Dec 2015 23:52:40 +0300
Subject: [PATCH] Add X-Forwarded-Proto header

Guess protocol from redirect-url scheme if present, or from
cookie-secure flag value.

closes #171
---
 oauthproxy.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/oauthproxy.go b/oauthproxy.go
index 94f0983ef..3e9b9b83b 100644
--- a/oauthproxy.go
+++ b/oauthproxy.go
@@ -707,6 +707,14 @@ func (p *OAuthProxy) Authenticate(rw http.ResponseWriter, req *http.Request) int
 	} else {
 		rw.Header().Set("GAP-Auth", session.Email)
 	}
+	switch {
+	case p.redirectURL.Scheme != "":
+		req.Header.Set("X-Forwarded-Proto", p.redirectURL.Scheme)
+	case p.CookieSecure:
+		req.Header.Set("X-Forwarded-Proto", "https")
+	default:
+		req.Header.Set("X-Forwarded-Proto", "http")
+	}
 	return http.StatusAccepted
 }