webrtc: fix ETag header name according to specification (#2396) (#2401)

internal/core/webrtc_http_server.go

@@ -262,8 +262,8 @@ func (s *webRTCHTTPServer) onRequest(ctx *gin.Context) {
 			}
 
 			ctx.Writer.Header().Set("Content-Type", "application/sdp")
-			ctx.Writer.Header().Set("Access-Control-Expose-Headers", "E-Tag, Accept-Patch, Link")
-			ctx.Writer.Header().Set("E-Tag", res.sx.secret.String())
+			ctx.Writer.Header().Set("Access-Control-Expose-Headers", "ETag, Accept-Patch, Link")
+			ctx.Writer.Header().Set("ETag", res.sx.secret.String())
 			ctx.Writer.Header().Set("ID", res.sx.uuid.String())
 			ctx.Writer.Header().Set("Accept-Patch", "application/trickle-ice-sdpfrag")
 			ctx.Writer.Header()["Link"] = whip.LinkHeaderMarshal(servers)

internal/core/webrtc_publish_index.html

@@ -346,7 +346,7 @@ class Transmitter {
                 if (res.status !== 201) {
                     throw new Error('bad status code');
                 }
-                this.eTag = res.headers.get('E-Tag');
+                this.eTag = res.headers.get('ETag');
                 return res.text();
             })
             .then((sdp) => this.onRemoteAnswer(new RTCSessionDescription({

internal/core/webrtc_read_index.html

@@ -155,7 +155,7 @@ class WHEPClient {
                 if (res.status !== 201) {
                     throw new Error('bad status code');
                 }
-                this.eTag = res.headers.get('E-Tag');
+                this.eTag = res.headers.get('ETag');
                 return res.text();
             })
             .then((sdp) => this.onRemoteAnswer(new RTCSessionDescription({

internal/core/webrtc_source_test.go

@@ -88,7 +88,7 @@ func TestWebRTCSource(t *testing.T) {
 
 				w.Header().Set("Content-Type", "application/sdp")
 				w.Header().Set("Accept-Patch", "application/trickle-ice-sdpfrag")
-				w.Header().Set("E-Tag", "test_etag")
+				w.Header().Set("ETag", "test_etag")
 				w.Header().Set("Location", "/my/resource/sessionid")
 				w.WriteHeader(http.StatusCreated)
 				w.Write([]byte(pc.LocalDescription().SDP))

internal/whip/post_offer.go

@@ -53,9 +53,9 @@ func PostOffer(
 
 	Location := res.Header.Get("Location")
 
-	etag := res.Header.Get("E-Tag")
+	etag := res.Header.Get("ETag")
 	if etag == "" {
-		return nil, fmt.Errorf("E-Tag is missing")
+		return nil, fmt.Errorf("ETag is missing")
 	}
 
 	sdp, err := io.ReadAll(res.Body)