Add Webhook Support

Resolves #140 #375

Author: Sean-Der

README.md

@@ -206,6 +206,7 @@ The frontend can be configured by passing these URL Parameters.
 
 The backend can be configured with the following environment variables.
 
+- `WEBHOOK_URL` - URL for Webhook Backend. Provides authentication and logging
 - `DISABLE_STATUS` - Disable the status API
 - `DISABLE_FRONTEND` - Disable the serving of frontend. Only REST APIs + WebRTC is enabled.
 - `HTTP_ADDRESS` - HTTP Server Address
@@ -235,6 +236,16 @@ The backend can be configured with the following environment variables.
 - `DEBUG_PRINT_OFFER` - Print WebRTC Offers from client to Broadcast Box. Debug things like accepted codecs.
 - `DEBUG_PRINT_ANSWER` - Print WebRTC Answers from Broadcast Box to Browser. Debug things like IP/Ports returned to client.
 
+## Authentication and Logging
+
+To prevent random users from streaming to your server, you can set the `WEBHOOK_URL` and validate/process requests in your code.
+
+If the request succeeds (meaning the stream key is accepted), broadcast-box redirects the stream to an url given
+by the external server, otherwise the streaming request is dropped.
+
+See [here](examples/webhook-server.go). For an example Webhook Server that only allows the stream `broadcastBoxRulez`
+
+
 ## Network Test on Start
 
 When running in Docker Broadcast Box runs a network tests on startup. This tests that WebRTC traffic can be established

examples/webhook-server.go

@@ -0,0 +1,47 @@
+package main
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+)
+
+type webhookPayload struct {
+	Action      string            `json:"action"`
+	IP          string            `json:"ip"`
+	BearerToken string            `json:"bearerToken"`
+	QueryParams map[string]string `json:"queryParams"`
+	UserAgent   string            `json:"userAgent"`
+}
+
+type webhookResponse struct {
+	StreamKey string `json:"streamKey"`
+}
+
+func main() {
+	http.HandleFunc("/", func(w http.ResponseWriter, r *http.Request) {
+		if r.Method != "POST" {
+			http.Error(w, "Only POST method is accepted", http.StatusMethodNotAllowed)
+			return
+		}
+
+		var payload webhookPayload
+		if err := json.NewDecoder(r.Body).Decode(&payload); err != nil {
+			http.Error(w, "Invalid JSON", http.StatusBadRequest)
+			return
+		}
+
+		if payload.BearerToken == "broadcastBoxRulez" {
+			w.WriteHeader(http.StatusOK)
+			json.NewEncoder(w).Encode(webhookResponse{StreamKey: payload.BearerToken})
+		} else {
+			w.WriteHeader(http.StatusForbidden)
+			json.NewEncoder(w).Encode(webhookResponse{})
+		}
+	})
+
+	log.Println("Server listening on port 8081")
+	if err := http.ListenAndServe("127.0.0.1:8081", nil); err != nil {
+		log.Fatalf("Could not start server: %s\n", err)
+	}
+}

internal/webhook/webhook.go

@@ -8,6 +8,8 @@ import (
 	"time"
 )
 
+const defaultTimeout = time.Second * 5
+
 type webhookPayload struct {
 	Action      string            `json:"action"`
 	IP          string            `json:"ip"`
@@ -20,7 +22,7 @@ type webhookResponse struct {
 	StreamKey string `json:"streamKey"`
 }
 
-func CallWebhook(url, action, bearerToken string, timeout int, r *http.Request) (string, error) {
+func CallWebhook(url, action, bearerToken string, r *http.Request) (string, error) {
 	start := time.Now()
 
 	queryParams := make(map[string]string)
@@ -41,17 +43,15 @@ func CallWebhook(url, action, bearerToken string, timeout int, r *http.Request)
 		return "", fmt.Errorf("failed to marshal payload: %w", err)
 	}
 
-	client := &http.Client{
-		Timeout: time.Duration(timeout) * time.Millisecond,
-	}
-
 	req, err := http.NewRequest("POST", url, bytes.NewBuffer(jsonPayload))
 	if err != nil {
 		return "", fmt.Errorf("failed to create request: %w", err)
 	}
 	req.Header.Set("Content-Type", "application/json")
 
-	resp, err := client.Do(req)
+	resp, err := (&http.Client{
+		Timeout: defaultTimeout,
+	}).Do(req)
 	if err != nil {
 		return "", fmt.Errorf("webhook request failed after %v: %w", time.Since(start), err)
 	}

main.go

@@ -16,6 +16,7 @@ import (
 	"time"
 
 	"github.com/glimesh/broadcast-box/internal/networktest"
+	"github.com/glimesh/broadcast-box/internal/webhook"
 	"github.com/glimesh/broadcast-box/internal/webrtc"
 	"github.com/joho/godotenv"
 )
@@ -44,7 +45,7 @@ type (
 	}
 )
 
-func getStreamKey(r *http.Request) (string, error) {
+func getStreamKey(action string, r *http.Request) (streamKey string, err error) {
 	authorizationHeader := r.Header.Get("Authorization")
 	if authorizationHeader == "" {
 		return "", errAuthorizationNotSet
@@ -55,13 +56,19 @@ func getStreamKey(r *http.Request) (string, error) {
 		return "", errInvalidStreamKey
 	}
 
-	bearerToken := strings.TrimPrefix(authorizationHeader, bearerPrefix)
-	if !streamKeyRegex.MatchString(bearerToken) {
-		return "", errInvalidStreamKey
+	streamKey = strings.TrimPrefix(authorizationHeader, bearerPrefix)
+	if webhookUrl := os.Getenv("WEBHOOK_URL"); webhookUrl != "" {
+		streamKey, err = webhook.CallWebhook(webhookUrl, action, streamKey, r)
+		if err != nil {
+			return "", err
+		}
 	}
 
-	return bearerToken, nil
+	if !streamKeyRegex.MatchString(streamKey) {
+		return "", errInvalidStreamKey
+	}
 
+	return streamKey, nil
 }
 
 func logHTTPError(w http.ResponseWriter, err string, code int) {
@@ -74,9 +81,10 @@ func whipHandler(res http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	streamKey, err := getStreamKey(r)
+	streamKey, err := getStreamKey("whip-connect", r)
 	if err != nil {
 		logHTTPError(res, err.Error(), http.StatusBadRequest)
+		return
 	}
 
 	offer, err := io.ReadAll(r.Body)
@@ -104,9 +112,10 @@ func whepHandler(res http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	streamKey, err := getStreamKey(req)
+	streamKey, err := getStreamKey("whep-connect", req)
 	if err != nil {
 		logHTTPError(res, err.Error(), http.StatusBadRequest)
+		return
 	}
 
 	offer, err := io.ReadAll(req.Body)
@@ -207,25 +216,25 @@ func corsHandler(next func(w http.ResponseWriter, r *http.Request)) http.Handler
 	}
 }
 
-func main() {
-	loadConfigs := func() error {
-		if os.Getenv("APP_ENV") == "development" {
-			log.Println("Loading `" + envFileDev + "`")
-			return godotenv.Load(envFileDev)
-		} else {
-			log.Println("Loading `" + envFileProd + "`")
-			if err := godotenv.Load(envFileProd); err != nil {
-				return err
-			}
-
-			if _, err := os.Stat("./web/build"); os.IsNotExist(err) && os.Getenv("DISABLE_FRONTEND") == "" {
-				return errNoBuildDirectoryErr
-			}
+func loadConfigs() error {
+	if os.Getenv("APP_ENV") == "development" {
+		log.Println("Loading `" + envFileDev + "`")
+		return godotenv.Load(envFileDev)
+	} else {
+		log.Println("Loading `" + envFileProd + "`")
+		if err := godotenv.Load(envFileProd); err != nil {
+			return err
+		}
 
-			return nil
+		if _, err := os.Stat("./web/build"); os.IsNotExist(err) && os.Getenv("DISABLE_FRONTEND") == "" {
+			return errNoBuildDirectoryErr
 		}
+
+		return nil
 	}
+}
 
+func main() {
 	if err := loadConfigs(); err != nil {
 		log.Println("Failed to find config in CWD, changing CWD to executable path")