From 790cc439495ac1803f958f736499f95978bf8869 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Torjus=20H=C3=A5kestad?= <torjus@usit.uio.no>
Date: Thu, 20 Jan 2022 01:11:40 +0100
Subject: [PATCH] Add authlevel to middleware

---
 auth.go       |  8 ++++++++
 middleware.go | 14 ++++++++++++++
 2 files changed, 22 insertions(+)

diff --git a/auth.go b/auth.go
index e655bfd..6e7da52 100644
--- a/auth.go
+++ b/auth.go
@@ -8,6 +8,14 @@ import (
 	"github.com/google/uuid"
 )
 
+type AuthLevel int
+
+const (
+	AuthLevelUnset AuthLevel = iota
+	AuthLevelUser
+	AuthLevelAdmin
+)
+
 type AuthService struct {
 	users      UserStore
 	hmacSecret []byte
diff --git a/middleware.go b/middleware.go
index f658e12..31b5ff0 100644
--- a/middleware.go
+++ b/middleware.go
@@ -14,6 +14,7 @@ type authCtxKey int
 
 const (
 	authCtxUsername authCtxKey = iota
+	authCtxAuthLevel
 )
 
 func (s *HTTPServer) MiddlewareAccessLogger(next http.Handler) http.Handler {
@@ -64,6 +65,7 @@ func (s *HTTPServer) MiddlewareAuthentication(next http.Handler) http.Handler {
 		}
 
 		ctx := context.WithValue(r.Context(), authCtxUsername, claims.Subject)
+		ctx = context.WithValue(ctx, authCtxAuthLevel, AuthLevelUser)
 		withCtx := r.WithContext(ctx)
 		s.Logger.Debugw("Request is authenticated.", "req_id", reqID, "username", claims.Subject)
 
@@ -85,3 +87,15 @@ func UsernameFromRequest(r *http.Request) (string, error) {
 	}
 	return username, nil
 }
+
+func AuthLevelFromRequest(r *http.Request) (AuthLevel, error) {
+	rawLevel := r.Context().Value(authCtxAuthLevel)
+	if rawLevel == nil {
+		return AuthLevelUnset, fmt.Errorf("no username")
+	}
+	level, ok := rawLevel.(AuthLevel)
+	if !ok {
+		return AuthLevelUnset, fmt.Errorf("no username")
+	}
+	return level, nil
+}