Add TLS support (fixes #4), clean up error handling.

Makefile

@@ -1,4 +1,4 @@
-VERSION = 1.5.3
+VERSION = 1.6.0
 
 APP      := http-file-server
 PACKAGES := $(shell go list -f {{.Dir}} ./...)

README.md

@@ -13,6 +13,7 @@
   - [Serving multiple paths, setting the HTTP port via CLI arguments](#serving-multiple-paths-setting-the-http-port-via-cli-arguments)
   - [Setting the HTTP port via environment variables](#setting-the-http-port-via-environment-variables)
   - [Uploading files using cURL](#uploading-files-using-curl)
+  - [HTTPS (SSL/TLS)](#https-ssltls)
 - [Get it](#get-it)
   - [Using `go get`](#using-go-get)
   - [Pre-built binary](#pre-built-binary)
@@ -71,6 +72,15 @@ $ ./http-file-server -uploads /=/path/to/serve
 curl -LF "[email protected]" localhost:8080/path/to/upload/to
 ```
 
+### HTTPS (SSL/TLS)
+
+To terminate SSL at the file server, set `-ssl-cert` (`SSL_CERTIFICATE`) and `-ssl-key` (`SSL_KEY`) to the respective files' paths:
+
+```sh
+$ ./http-file-server -port 8443 -ssl-cert server.crt -ssl-key server.key
+2020/03/10 22:00:54 http-file-server (HTTPS) listening on ":8443"
+```
+
 ## Get it
 
 ### Using `go get`
@@ -85,14 +95,14 @@ Or [download a binary](https://github.com/sgreben/http-file-server/releases/late
 
 ```sh
 # Linux
-curl -L https://github.com/sgreben/http-file-server/releases/download/1.5.3/http-file-server_1.5.3_linux_x86_64.tar.gz | tar xz
+curl -L https://github.com/sgreben/http-file-server/releases/download/1.6.0/http-file-server_1.6.0_linux_x86_64.tar.gz | tar xz
 
 # OS X
-curl -L https://github.com/sgreben/http-file-server/releases/download/1.5.3/http-file-server_1.5.3_osx_x86_64.tar.gz | tar xz
+curl -L https://github.com/sgreben/http-file-server/releases/download/1.6.0/http-file-server_1.6.0_osx_x86_64.tar.gz | tar xz
 
 # Windows
-curl -LO https://github.com/sgreben/http-file-server/releases/download/1.5.3/http-file-server_1.5.3_windows_x86_64.zip
-unzip http-file-server_1.5.3_windows_x86_64.zip
+curl -LO https://github.com/sgreben/http-file-server/releases/download/1.6.0/http-file-server_1.6.0_windows_x86_64.zip
+unzip http-file-server_1.6.0_windows_x86_64.zip
 ```
 
 ## Use it
@@ -118,6 +128,10 @@ Usage of http-file-server:
     	(alias for -route)
   -route value
     	a route definition ROUTE=PATH (ROUTE defaults to basename of PATH if omitted)
+  -ssl-cert string
+    	path to SSL server certificate (environment variable "SSL_CERTIFICATE")
+  -ssl-key string
+    	path to SSL private key (environment variable "SSL_KEY")
   -u	(alias for -uploads)
   -uploads
     	allow uploads (environment variable "UPLOADS")

README.template.md

@@ -13,6 +13,7 @@
   - [Serving multiple paths, setting the HTTP port via CLI arguments](#serving-multiple-paths-setting-the-http-port-via-cli-arguments)
   - [Setting the HTTP port via environment variables](#setting-the-http-port-via-environment-variables)
   - [Uploading files using cURL](#uploading-files-using-curl)
+  - [HTTPS (SSL/TLS)](#https-ssltls)
 - [Get it](#get-it)
   - [Using `go get`](#using-go-get)
   - [Pre-built binary](#pre-built-binary)
@@ -71,6 +72,15 @@ $ ./http-file-server -uploads /=/path/to/serve
 curl -LF "[email protected]" localhost:8080/path/to/upload/to
 ```
 
+### HTTPS (SSL/TLS)
+
+To terminate SSL at the file server, set `-ssl-cert` (`SSL_CERTIFICATE`) and `-ssl-key` (`SSL_KEY`) to the respective files' paths:
+
+```sh
+$ ./http-file-server -port 8443 -ssl-cert server.crt -ssl-key server.key
+2020/03/10 22:00:54 http-file-server (HTTPS) listening on ":8443"
+```
+
 ## Get it
 
 ### Using `go get`

main.go

@@ -13,21 +13,25 @@ import (
 )
 
 const (
-	defaultAddr            = ":8080"
-	addrEnvVarName         = "ADDR"
-	portEnvVarName         = "PORT"
-	quietEnvVarName        = "QUIET"
-	allowUploadsEnvVarName = "UPLOADS"
-	rootRoute              = "/"
+	addrEnvVarName           = "ADDR"
+	allowUploadsEnvVarName   = "UPLOADS"
+	defaultAddr              = ":8080"
+	portEnvVarName           = "PORT"
+	quietEnvVarName          = "QUIET"
+	rootRoute                = "/"
+	sslCertificateEnvVarName = "SSL_CERTIFICATE"
+	sslKeyEnvVarName         = "SSL_KEY"
 )
 
 var (
 	addrFlag         = os.Getenv(addrEnvVarName)
+	allowUploadsFlag = os.Getenv(allowUploadsEnvVarName) == "true"
 	portFlag64, _    = strconv.ParseInt(os.Getenv(portEnvVarName), 10, 64)
 	portFlag         = int(portFlag64)
 	quietFlag        = os.Getenv(quietEnvVarName) == "true"
-	allowUploadsFlag = os.Getenv(allowUploadsEnvVarName) == "true"
 	routesFlag       routes
+	sslCertificate   = os.Getenv(sslCertificateEnvVarName)
+	sslKey           = os.Getenv(sslKeyEnvVarName)
 )
 
 func init() {
@@ -46,6 +50,8 @@ func init() {
 	flag.BoolVar(&allowUploadsFlag, "u", allowUploadsFlag, "(alias for -uploads)")
 	flag.Var(&routesFlag, "route", routesFlag.help())
 	flag.Var(&routesFlag, "r", "(alias for -route)")
+	flag.StringVar(&sslCertificate, "ssl-cert", sslCertificate, fmt.Sprintf("path to SSL server certificate (environment variable %q)", sslCertificateEnvVarName))
+	flag.StringVar(&sslKey, "ssl-key", sslKey, fmt.Sprintf("path to SSL private key (environment variable %q)", sslKeyEnvVarName))
 	flag.Parse()
 	if quietFlag {
 		log.SetOutput(ioutil.Discard)
@@ -76,7 +82,7 @@ func server(addr string, routes routes) error {
 	paths := make(map[string]string)
 
 	if len(routes.Values) == 0 {
-		routes.Set(".")
+		_ = routes.Set(".")
 	}
 
 	for _, route := range routes.Values {
@@ -104,6 +110,10 @@ func server(addr string, routes routes) error {
 	if binaryPath == "" {
 		binaryPath = "server"
 	}
+	if sslCertificate != "" && sslKey != "" {
+		log.Printf("%s (HTTPS) listening on %q", filepath.Base(binaryPath), addr)
+		return http.ListenAndServeTLS(addr, sslCertificate, sslKey, mux)
+	}
 	log.Printf("%s listening on %q", filepath.Base(binaryPath), addr)
 	return http.ListenAndServe(addr, mux)
 }

server.go

@@ -116,39 +116,41 @@ var (
 	directoryListingTemplate = template.Must(template.New("").Parse(directoryListingTemplateText))
 )
 
-func (f *fileHandler) serveStatus(w http.ResponseWriter, r *http.Request, status int) {
+func (f *fileHandler) serveStatus(w http.ResponseWriter, r *http.Request, status int) error {
 	w.WriteHeader(status)
-	w.Write([]byte(http.StatusText(status)))
+	_, err := w.Write([]byte(http.StatusText(status)))
+	if err != nil {
+		return err
+	}
+	return nil
 }
 
-func (f *fileHandler) serveTarGz(w http.ResponseWriter, r *http.Request, path string) {
+func (f *fileHandler) serveTarGz(w http.ResponseWriter, r *http.Request, path string) error {
 	w.Header().Set("Content-Type", tarGzContentType)
 	name := filepath.Base(path) + ".tar.gz"
 	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename=%q`, name))
-	tarGz(w, path)
+	return tarGz(w, path)
 }
 
-func (f *fileHandler) serveZip(w http.ResponseWriter, r *http.Request, osPath string) {
+func (f *fileHandler) serveZip(w http.ResponseWriter, r *http.Request, osPath string) error {
 	w.Header().Set("Content-Type", zipContentType)
 	name := filepath.Base(osPath) + ".zip"
 	w.Header().Set("Content-Disposition", fmt.Sprintf(`attachment; filename=%q`, name))
-	zip(w, osPath)
+	return zip(w, osPath)
 }
 
-func (f *fileHandler) serveDir(w http.ResponseWriter, r *http.Request, osPath string) {
+func (f *fileHandler) serveDir(w http.ResponseWriter, r *http.Request, osPath string) error {
 	d, err := os.Open(osPath)
 	if err != nil {
-		f.serveStatus(w, r, http.StatusInternalServerError)
-		return
+		return err
 	}
 	files, err := d.Readdir(-1)
 	if err != nil {
-		f.serveStatus(w, r, http.StatusInternalServerError)
-		return
+		return err
 	}
 	sort.Slice(files, func(i, j int) bool { return files[i].Name() < files[j].Name() })
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
-	directoryListingTemplate.Execute(w, directoryListingData{
+	return directoryListingTemplate.Execute(w, directoryListingData{
 		AllowUpload: f.allowUpload,
 		Title: func() string {
 			relPath, _ := filepath.Rel(f.path, osPath)
@@ -194,33 +196,31 @@ func (f *fileHandler) serveDir(w http.ResponseWriter, r *http.Request, osPath st
 	})
 }
 
-func (f *fileHandler) serveUploadTo(w http.ResponseWriter, r *http.Request, osPath string) {
+func (f *fileHandler) serveUploadTo(w http.ResponseWriter, r *http.Request, osPath string) error {
 	if err := r.ParseForm(); err != nil {
-		f.serveStatus(w, r, http.StatusInternalServerError)
-		return
+		return err
 	}
 	in, h, err := r.FormFile("file")
 	if err == http.ErrMissingFile {
 		w.Header().Set("Location", r.URL.String())
 		w.WriteHeader(303)
 	}
 	if err != nil {
-		f.serveStatus(w, r, http.StatusInternalServerError)
-		return
+		return err
 	}
 	outPath := filepath.Join(osPath, filepath.Base(h.Filename))
 	out, err := os.OpenFile(outPath, os.O_CREATE|os.O_WRONLY, 0600)
-	defer out.Close()
 	if err != nil {
-		f.serveStatus(w, r, http.StatusInternalServerError)
-		return
+		return err
 	}
+	defer out.Close()
+
 	if _, err := io.Copy(out, in); err != nil {
-		f.serveStatus(w, r, http.StatusInternalServerError)
-		return
+		return err
 	}
 	w.Header().Set("Location", r.URL.String())
 	w.WriteHeader(303)
+	return nil
 }
 
 // ServeHTTP is http.Handler.ServeHTTP
@@ -239,19 +239,31 @@ func (f *fileHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 	info, err := os.Stat(osPath)
 	switch {
 	case os.IsNotExist(err):
-		f.serveStatus(w, r, http.StatusNotFound)
+		_ = f.serveStatus(w, r, http.StatusNotFound)
 	case os.IsPermission(err):
-		f.serveStatus(w, r, http.StatusForbidden)
+		_ = f.serveStatus(w, r, http.StatusForbidden)
 	case err != nil:
-		f.serveStatus(w, r, http.StatusInternalServerError)
+		_ = f.serveStatus(w, r, http.StatusInternalServerError)
 	case r.URL.Query().Get(zipKey) != "":
-		f.serveZip(w, r, osPath)
+		err := f.serveZip(w, r, osPath)
+		if err != nil {
+			_ = f.serveStatus(w, r, http.StatusInternalServerError)
+		}
 	case r.URL.Query().Get(tarGzKey) != "":
-		f.serveTarGz(w, r, osPath)
+		err := f.serveTarGz(w, r, osPath)
+		if err != nil {
+			_ = f.serveStatus(w, r, http.StatusInternalServerError)
+		}
 	case f.allowUpload && info.IsDir() && r.Method == http.MethodPost:
-		f.serveUploadTo(w, r, osPath)
+		err := f.serveUploadTo(w, r, osPath)
+		if err != nil {
+			_ = f.serveStatus(w, r, http.StatusInternalServerError)
+		}
 	case info.IsDir():
-		f.serveDir(w, r, osPath)
+		err := f.serveDir(w, r, osPath)
+		if err != nil {
+			_ = f.serveStatus(w, r, http.StatusInternalServerError)
+		}
 	default:
 		http.ServeFile(w, r, osPath)
 	}

tar.gz.go

@@ -22,6 +22,9 @@ func tarGz(w io.Writer, path string) error {
 		defer file.Close()
 		header := new(tar.Header)
 		path, err = filepath.Rel(basePath, path)
+		if err != nil {
+			return err
+		}
 		header.Name = path
 		header.Size = stat.Size()
 		header.Mode = int64(stat.Mode())

zip.go

@@ -20,6 +20,9 @@ func zip(w io.Writer, path string) error {
 		}
 		defer file.Close()
 		path, err = filepath.Rel(basePath, path)
+		if err != nil {
+			return err
+		}
 		zw, err := w.Create(path)
 		if err != nil {
 			return err