From dd3e78eb28dcf5906bf640b24e36f3f9dc3374b2 Mon Sep 17 00:00:00 2001
From: Mike Shoup <mike@shoup.io>
Date: Sat, 13 Oct 2018 09:32:13 -0600
Subject: [PATCH] Succesfully redirect if 401

---
 auth.go               | 76 +++++++++++++++++++++++++++++++++++++++++++
 html/js/thermostat.js |  4 +--
 web.go                |  5 +--
 3 files changed, 81 insertions(+), 4 deletions(-)
 create mode 100644 auth.go

diff --git a/auth.go b/auth.go
new file mode 100644
index 0000000..dcdd167
--- /dev/null
+++ b/auth.go
@@ -0,0 +1,76 @@
+// Copyright 2014 Manu Martinez-Almeida.  All rights reserved.
+// Use of this source code is governed by a MIT style
+// license that can be found in the LICENSE file.
+
+// Modified to remove the WWW-Authenticate header for uses in TempGopher
+
+package main
+
+import (
+	"encoding/base64"
+	"log"
+	"net/http"
+
+	"github.com/gin-gonic/gin"
+)
+
+type authPair struct {
+	value string
+	user  string
+}
+
+type authPairs []authPair
+
+func (a authPairs) searchCredential(authValue string) (string, bool) {
+	if authValue == "" {
+		return "", false
+	}
+	for _, pair := range a {
+		if pair.value == authValue {
+			return pair.user, true
+		}
+	}
+	return "", false
+}
+
+// BasicAuth returns a Basic HTTP Authorization middleware. It takes as arguments a map[string]string where
+// the key is the user name and the value is the password. This does not set a www-authenticate header.
+func BasicAuth(accounts gin.Accounts) gin.HandlerFunc {
+	pairs := processAccounts(accounts)
+	return func(c *gin.Context) {
+		// Search user in the slice of allowed credentials
+		user, found := pairs.searchCredential(c.GetHeader("Authorization"))
+		if !found {
+			// Credentials doesn't match, we return 401 and abort handlers chain.
+			c.AbortWithStatus(http.StatusUnauthorized)
+			return
+		}
+
+		// The user credentials was found, set user's id to key AuthUserKey in this context, the user's id can be read later using
+		// c.MustGet(gin.AuthUserKey).
+		c.Set(gin.AuthUserKey, user)
+	}
+}
+
+func processAccounts(accounts gin.Accounts) authPairs {
+	if len(accounts) == 0 {
+		log.Panic("Empty list of authorized credentials")
+	}
+	pairs := make(authPairs, 0, len(accounts))
+	for user, password := range accounts {
+		if user == "" {
+			log.Panic("User can not be empty")
+		}
+		value := authorizationHeader(user, password)
+		pairs = append(pairs, authPair{
+			value: value,
+			user:  user,
+		})
+	}
+	return pairs
+}
+
+func authorizationHeader(user, password string) string {
+	base := user + ":" + password
+	return "Basic " + base64.StdEncoding.EncodeToString([]byte(base))
+}
diff --git a/html/js/thermostat.js b/html/js/thermostat.js
index e2138e1..2be281d 100644
--- a/html/js/thermostat.js
+++ b/html/js/thermostat.js
@@ -12,10 +12,10 @@ function redirectIfNotAuthorized() {
         beforeSend: authHeaders,
         statusCode: {
             401: function() {
-                window.location.replace(baseurl + "/app/login.html");
+                window.location.replace(jsconfig.baseurl + "/app/login.html");
             },
             403: function() {
-                window.location.replace(baseurl + "/app/login.html");
+                window.location.replace(jsconfig.baseurl + "/app/login.html");
             }
         }
     });
diff --git a/web.go b/web.go
index da3c8ae..2d33d1e 100644
--- a/web.go
+++ b/web.go
@@ -130,7 +130,8 @@ func SetupRouter(config *Config, states *map[string]State) *gin.Engine {
 	if len(config.Users) == 0 {
 		api = r.Group("/api")
 	} else {
-		api = r.Group("/api", gin.BasicAuth(GetGinAccounts(config)))
+		api = r.Group("/api")
+		api.Use(BasicAuth(GetGinAccounts(config)))
 	}
 
 	api.GET("/status", StatusHandler(states))
@@ -166,7 +167,7 @@ func reloadWebConfig(c *Config, p string) error {
 
 // GetGinAccounts returns a gin.Accounts struct with values pulled from a Config struct
 func GetGinAccounts(config *Config) gin.Accounts {
-	var a gin.Accounts
+	a := make(gin.Accounts)
 	for _, user := range config.Users {
 		a[user.Name] = user.Password
 	}