Move administrator password to data/config.json.

INSTALL

@@ -12,15 +12,6 @@ On Windows, do
     go build -ldflags="-s -w"
 
 
-## Set the server administrator credentials
-
-This step is optional, it is currently only relevant for access to the
-`/stats.html` and `/stats.json` locations.
-
-    mkdir data
-    echo 'god:topsecret' > data/passwd
-
-
 ## Set up a group
 
 Set up a group called *test* by creating a file `groups/test.json`:

README

@@ -37,6 +37,21 @@ available commands; the output depends on whether you are an operator or
 not.
 
 
+# The global configuration file
+
+The server may be configured in the JSON file `data/config.json`.  This
+file may look as follows:
+
+    {
+        "admin":[{"username":"root","password":"secret"}]
+    }
+
+The fields are as follows:
+
+- `admin` defines the users allowed to look at the `/stats.html` file; it
+  has the same syntax as user definitions in groups (see below).
+
+
 # Group definitions
 
 Groups are defined by files in the `./groups` directory (this may be

galene.go

@@ -21,7 +21,7 @@ import (
 )
 
 func main() {
-	var cpuprofile, memprofile, mutexprofile, httpAddr, dataDir string
+	var cpuprofile, memprofile, mutexprofile, httpAddr string
 	var udpRange string
 
 	flag.StringVar(&httpAddr, "http", ":8443", "web server `address`")
@@ -31,7 +31,7 @@ func main() {
 		"redirect to canonical `host`")
 	flag.BoolVar(&webserver.Insecure, "insecure", false,
 		"act as an HTTP server rather than HTTPS")
-	flag.StringVar(&dataDir, "data", "./data/",
+	flag.StringVar(&group.DataDirectory, "data", "./data/",
 		"data `directory`")
 	flag.StringVar(&group.Directory, "groups", "./groups/",
 		"group description `directory`")
@@ -112,7 +112,7 @@ func main() {
 		log.Printf("File descriptor limit is %v, please increase it!", n)
 	}
 
-	ice.ICEFilename = filepath.Join(dataDir, "ice-servers.json")
+	ice.ICEFilename = filepath.Join(group.DataDirectory, "ice-servers.json")
 
 	// make sure the list of public groups is updated early
 	go group.Update()
@@ -123,7 +123,7 @@ func main() {
 
 	serverDone := make(chan struct{})
 	go func() {
-		err := webserver.Serve(httpAddr, dataDir)
+		err := webserver.Serve(httpAddr, group.DataDirectory)
 		if err != nil {
 			log.Printf("Server: %v", err)
 		}

group/group.go

@@ -17,7 +17,7 @@ import (
 	"github.com/pion/webrtc/v3"
 )
 
-var Directory string
+var Directory, DataDirectory string
 var UseMDNS bool
 var UDPMin, UDPMax uint16
 
@@ -802,8 +802,67 @@ func matchClient(group string, creds ClientCredentials, users []ClientPattern) (
 	return false, false
 }
 
-// Type Description represents a group description together with some
-// metadata about the JSON file it was deserialised from.
+// Configuration represents the contents of the data/config.json file.
+type Configuration struct {
+	// The modtime and size of the file.  These are used to detect
+	// when a file has changed on disk.
+	modTime  time.Time `json:"-"`
+	fileSize int64     `json:"-"`
+
+	Admin []ClientPattern `json:"admin"`
+}
+
+var configuration struct {
+	mu            sync.Mutex
+	configuration *Configuration
+}
+
+func GetConfiguration() (*Configuration, error) {
+	configuration.mu.Lock()
+	defer configuration.mu.Unlock()
+
+	if configuration.configuration == nil {
+		configuration.configuration = &Configuration{}
+	}
+
+	filename := filepath.Join(DataDirectory, "config.json")
+	fi, err := os.Stat(filename)
+	if err != nil {
+		if os.IsNotExist(err) {
+			if !configuration.configuration.modTime.Equal(
+				time.Time{},
+			) {
+				configuration.configuration = &Configuration{}
+				return configuration.configuration, nil
+			}
+		}
+		return nil, err
+	}
+
+	if configuration.configuration.modTime.Equal(fi.ModTime()) &&
+		configuration.configuration.fileSize == fi.Size() {
+		return configuration.configuration, nil
+	}
+
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer f.Close()
+
+	d := json.NewDecoder(f)
+	d.DisallowUnknownFields()
+	var conf Configuration
+	err = d.Decode(&conf)
+	if err != nil {
+		return nil, err
+	}
+	configuration.configuration = &conf
+	return configuration.configuration, nil
+}
+
+// Description represents a group description together with some metadata
+// about the JSON file it was deserialised from.
 type Description struct {
 	// The file this was deserialised from.  This is not necessarily
 	// the name of the group, for example in case of a subgroup.

webserver/webserver.go

 package webserver
 
 import (
-	"bufio"
 	"context"
 	"crypto/tls"
 	"encoding/json"
@@ -327,26 +326,20 @@ func publicHandler(w http.ResponseWriter, r *http.Request) {
 	return
 }
 
-func getPassword(dataDir string) (string, string, error) {
-	f, err := os.Open(filepath.Join(dataDir, "passwd"))
+func adminMatch(username, password string) (bool, error) {
+	conf, err := group.GetConfiguration()
 	if err != nil {
-		return "", "", err
+		return false, err
 	}
-	defer f.Close()
-
-	r := bufio.NewReader(f)
 
-	s, err := r.ReadString('\n')
-	if err != nil {
-		return "", "", err
-	}
-
-	l := strings.SplitN(strings.TrimSpace(s), ":", 2)
-	if len(l) != 2 {
-		return "", "", errors.New("couldn't parse passwords")
+	for _, cred := range conf.Admin {
+		if cred.Username == "" || cred.Username == username {
+			if ok, _ := cred.Password.Match(password); ok {
+				return true, nil
+			}
+		}
 	}
-
-	return l[0], l[1], nil
+	return false, nil
 }
 
 func failAuthentication(w http.ResponseWriter, realm string) {
@@ -356,15 +349,16 @@ func failAuthentication(w http.ResponseWriter, realm string) {
 }
 
 func statsHandler(w http.ResponseWriter, r *http.Request, dataDir string) {
-	u, p, err := getPassword(dataDir)
-	if err != nil {
-		log.Printf("Passwd: %v", err)
+	username, password, ok := r.BasicAuth()
+	if !ok {
 		failAuthentication(w, "stats")
 		return
 	}
 
-	username, password, ok := r.BasicAuth()
-	if !ok || username != u || password != p {
+	if ok, err := adminMatch(username, password); !ok {
+		if err != nil {
+			log.Printf("Administrator password: %v", err)
+		}
 		failAuthentication(w, "stats")
 		return
 	}
@@ -377,7 +371,7 @@ func statsHandler(w http.ResponseWriter, r *http.Request, dataDir string) {
 
 	ss := stats.GetGroups()
 	e := json.NewEncoder(w)
-	err = e.Encode(ss)
+	err := e.Encode(ss)
 	if err != nil {
 		log.Printf("stats.json: %v", err)
 	}