From 6b080f3821d8a503aeba175b44fa483ba7514846 Mon Sep 17 00:00:00 2001
From: Pierre Zemb <contact@pierrezemb.fr>
Date: Tue, 14 Nov 2017 00:19:45 +0100
Subject: [PATCH] Fixes #6: add http basic auth

---
 README.md | 23 ++++++++++++++++++++++
 auth.go   | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 main.go   | 27 +++++++++++++++++++++++---
 3 files changed, 105 insertions(+), 3 deletions(-)
 create mode 100644 auth.go

diff --git a/README.md b/README.md
index 185476e..f4eb154 100644
--- a/README.md
+++ b/README.md
@@ -37,6 +37,29 @@ Many links should provide you with additionnal info to see my point of view:
 docker run -d -p 80:8043 -v path/to/website:/srv/http --name goStatic pierrezemb/gostatic
 ```
 
+### Usage 
+
+```
+./goStatic --help
+Usage of ./goStatic:
+  -append-header HeaderName:Value
+        HTTP response header, specified as HeaderName:Value that should be added to all responses.
+  -default-user-basic-auth string
+        Define the user (default "gopher")
+  -enable-basic-auth
+        Enable basic auth. By default, password are randomly generated. Use --set-basic-auth to set it.
+  -password-length int
+        Size of the randomized password (default 16)
+  -path string
+        The path for the static files (default "/srv/http")
+  -port int
+        The listening port (default 8043)
+  -set-basic-auth string
+        Define the basic auth. Form must be user:password
+```
+
+
+
 ### Wow, such container! What are you using?
 
 I'm using the centurylink/ca-certs image instead of the scratch image to avoid this error:
diff --git a/auth.go b/auth.go
new file mode 100644
index 0000000..88fd9cb
--- /dev/null
+++ b/auth.go
@@ -0,0 +1,58 @@
+package main
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"fmt"
+	"log"
+	"net/http"
+	"strings"
+)
+
+// authMiddleware checks basic auth
+func authMiddleware(next http.Handler) http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+
+		auth := strings.SplitN(r.Header.Get("Authorization"), " ", 2)
+
+		if len(auth) != 2 || auth[0] != "Basic" {
+			http.Error(w, "authorization failed", http.StatusUnauthorized)
+			return
+		}
+
+		payload, _ := base64.StdEncoding.DecodeString(auth[1])
+		pair := strings.SplitN(string(payload), ":", 2)
+
+		if strings.Compare(pair[0], username) != 0 || strings.Compare(pair[1], password) != 0 {
+			http.Error(w, "authorization failed", http.StatusUnauthorized)
+			return
+		}
+
+		next.ServeHTTP(w, r)
+	})
+}
+
+func parseAuth(auth string) {
+	identity := strings.Split(*setBasicAuth, ":")
+	if len(identity) != 2 {
+		log.Fatalln("basic auth must be like this: user:password")
+	}
+
+	username = identity[0]
+	password = identity[1]
+}
+
+func generateRandomAuth() {
+	username = "gopher"
+	password = generateRandomString()
+	log.Printf("User generated for basic auth. User:'%v', password:'%v'\n", username, password)
+}
+
+func generateRandomString() string {
+
+	b := make([]byte, *sizeRandom)
+	if _, err := rand.Read(b); err != nil {
+		panic(err)
+	}
+	return fmt.Sprintf("%X", b)
+}
diff --git a/main.go b/main.go
index 9d91148..a1017cc 100644
--- a/main.go
+++ b/main.go
@@ -13,9 +13,16 @@ import (
 
 var (
 	// Def of flags
-	portPtr    = flag.Int("p", 8043, "The listening port")
-	path       = flag.String("static", "/srv/http", "The path for the static files")
-	headerFlag = flag.String("appendHeader", "", "HTTP response header, specified as `HeaderName:Value` that should be added to all responses.")
+	portPtr                  = flag.Int("port", 8043, "The listening port")
+	path                     = flag.String("path", "/srv/http", "The path for the static files")
+	headerFlag               = flag.String("append-header", "", "HTTP response header, specified as `HeaderName:Value` that should be added to all responses.")
+	basicAuth                = flag.Bool("enable-basic-auth", false, "Enable basic auth. By default, password are randomly generated. Use --set-basic-auth to set it.")
+	setBasicAuth             = flag.String("set-basic-auth", "", "Define the basic auth. Form must be user:password")
+	defaultUsernameBasicAuth = flag.String("default-user-basic-auth", "gopher", "Define the user")
+	sizeRandom               = flag.Int("password-length", 16, "Size of the randomized password")
+
+	username string
+	password string
 )
 
 func parseHeaderFlag(headerFlag string) (string, string) {
@@ -33,10 +40,24 @@ func main() {
 
 	flag.Parse()
 
+	// sanity check
+	if len(*setBasicAuth) != 0 && !*basicAuth {
+		*basicAuth = true
+	}
+
 	port := ":" + strconv.FormatInt(int64(*portPtr), 10)
 
 	handler := http.FileServer(http.Dir(*path))
 
+	if *basicAuth {
+		if len(*setBasicAuth) != 0 {
+			parseAuth(*setBasicAuth)
+		} else {
+			generateRandomAuth()
+		}
+		handler = authMiddleware(handler)
+	}
+
 	// Extra headers.
 	if len(*headerFlag) > 0 {
 		header, headerValue := parseHeaderFlag(*headerFlag)