From 323fd919d17d5bc5250c625da9e14873b4dd5a15 Mon Sep 17 00:00:00 2001
From: Hayden <64056131+hay-kot@users.noreply.github.com>
Date: Sat, 3 Dec 2022 10:36:55 -0900
Subject: [PATCH] add role based middleware

---
 backend/app/api/middleware.go | 77 +++++++++++++++++++++++++++++++++--
 1 file changed, 74 insertions(+), 3 deletions(-)

diff --git a/backend/app/api/middleware.go b/backend/app/api/middleware.go
index 505ba40..8baddfb 100644
--- a/backend/app/api/middleware.go
+++ b/backend/app/api/middleware.go
@@ -1,6 +1,7 @@
 package main
 
 import (
+	"context"
 	"errors"
 	"net/http"
 	"strings"
@@ -10,17 +11,87 @@ import (
 	"github.com/hay-kot/homebox/backend/pkgs/server"
 )
 
+type tokenHasKey struct {
+	key string
+}
+
+var (
+	hashedToken = tokenHasKey{key: "hashedToken"}
+)
+
+type RoleMode int
+
+const (
+	RoleModeOr  RoleMode = 0
+	RoleModeAnd RoleMode = 1
+)
+
+// mwRoles is a middleware that will validate the required roles are met. All roles
+// are required to be met for the request to be allowed. If the user does not have
+// the required roles, a 403 Forbidden will be returned.
+//
+// WARNING: This middleware _MUST_ be called after mwAuthToken or else it will panic
+func (a *app) mwRoles(rm RoleMode, required ...string) server.Middleware {
+	return func(next server.Handler) server.Handler {
+		return server.HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
+			ctx := r.Context()
+
+			maybeToken := ctx.Value(hashedToken)
+			if maybeToken == nil {
+				panic("mwRoles: token not found in context, you must call mwAuthToken before mwRoles")
+			}
+
+			token := maybeToken.(string)
+
+			roles, err := a.repos.AuthTokens.GetRoles(r.Context(), token)
+			if err != nil {
+				return err
+			}
+
+		outer:
+			switch rm {
+			case RoleModeOr:
+				for _, role := range required {
+					if roles.Contains(role) {
+						break outer
+					}
+				}
+				return validate.NewRequestError(errors.New("Forbidden"), http.StatusForbidden)
+			case RoleModeAnd:
+				for _, req := range required {
+					if !roles.Contains(req) {
+						return validate.NewRequestError(errors.New("Unauthorized"), http.StatusForbidden)
+					}
+				}
+			}
+
+			return next.ServeHTTP(w, r)
+		})
+	}
+}
+
 // mwAuthToken is a middleware that will check the database for a stateful token
-// and attach it to the request context with the user, or return a 401 if it doesn't exist.
+// and attach it's user to the request context, or return an appropriate error.
+// Authorization support is by token via Headers or Query Parameter
+//
+// Example:
+//   - header = "Bearer 1234567890"
+//   - query = "?access_token=1234567890"
 func (a *app) mwAuthToken(next server.Handler) server.Handler {
 	return server.HandlerFunc(func(w http.ResponseWriter, r *http.Request) error {
 		requestToken := r.Header.Get("Authorization")
-
 		if requestToken == "" {
-			return validate.NewRequestError(errors.New("Authorization header is required"), http.StatusUnauthorized)
+			// check for query param
+			requestToken = r.URL.Query().Get("access_token")
+			if requestToken == "" {
+				return validate.NewRequestError(errors.New("Authorization header or query is required"), http.StatusUnauthorized)
+			}
 		}
 
 		requestToken = strings.TrimPrefix(requestToken, "Bearer ")
+
+		r = r.WithContext(context.WithValue(r.Context(), hashedToken, requestToken))
+
 		usr, err := a.services.User.GetSelf(r.Context(), requestToken)
 
 		// Check the database for the token