fix(llc): sanitize header string

packages/stream_video/CHANGELOG.md

@@ -1,3 +1,9 @@
+## Unreleased
+
+### 🐞 Fixed
+
+- Fixed a `FormatException` when sending requests if the application name (or other device/app info) contains non-ASCII characters. Values included in the `X-Stream-Client` header are now sanitized to valid header characters.
+
 ## 1.4.2
 
 ### ✅ Added

packages/stream_video/lib/src/coordinator/open_api/coordinator_ws.dart

@@ -34,7 +34,7 @@ String _buildUrl(String baseUrl, String apiKey) {
   return '$baseUrl'
       '?api_key=$apiKey'
       '&stream-auth-type=jwt'
-      '&X-Stream-Client=$xStreamClientHeader';
+      '&X-Stream-Client=${Uri.encodeQueryComponent(xStreamClientHeader)}';
 }
 
 class CoordinatorWebSocket extends StreamWebSocket implements HealthListener {

packages/stream_video/lib/src/sfu/ws/sfu_ws.dart

@@ -48,7 +48,7 @@ class SfuWebSocket extends StreamWebSocket implements HealthListener {
           .toString();
     }
     final finalWsEndpoint =
-        '$sfuWsEndpoint?X-Stream-Client=$xStreamClientHeader&attempt=${++sessionSeq}&cid=$cid&user_id=$userId&api_key=$apiKey&user_session_id=$sessionId';
+        '$sfuWsEndpoint?X-Stream-Client=${Uri.encodeQueryComponent(xStreamClientHeader)}&attempt=${++sessionSeq}&cid=$cid&user_id=$userId&api_key=$apiKey&user_session_id=$sessionId';
     streamLog.i(tag, () => '<factory> wsEndpoint: $wsEndpoint');
     streamLog.i(tag, () => '<factory> sfuWsEndpoint: $sfuWsEndpoint');
     streamLog.i(tag, () => '<factory> finalWsEndpoint: $finalWsEndpoint');

packages/stream_video/lib/src/video_environment.dart

@@ -68,13 +68,39 @@ extension VideoEnvironmentHeader on VideoEnvironment {
   /// Builds the `X-Stream-Client` header value.
   String get xStreamClientHeader => [
     'stream-video-flutter-v$sdkVersion',
-    if (appName case final name?) 'app=$name',
-    if (appVersion case final version?) 'app_version=$version',
-    switch ((osName, osVersion)) {
-      (final name, final version?) => 'os=$name $version',
-      (final name, null) => 'os=$name',
-    },
-    if (deviceModel case final model?) 'device_model=$model',
-    if (browserName case final name?) 'browser=$name',
-  ].join('|');
+    _headerSegment('app', [appName]),
+    _headerSegment('app_version', [appVersion]),
+    _headerSegment('os', [osName, osVersion]),
+    _headerSegment('device_model', [deviceModel]),
+    _headerSegment('browser', [browserName]),
+  ].nonNulls.join('|');
+
+  /// Builds a single `key=value` header segment from [parts], joined by a space.
+  ///
+  /// Returns `null` when every part is null or sanitizes to an empty string, so
+  /// the header never contains a dangling `key=` segment.
+  static String? _headerSegment(String key, Iterable<String?> parts) {
+    final value = parts.nonNulls
+        .map(_sanitizeHeaderValue)
+        .where((part) => part.isNotEmpty)
+        .join(' ');
+
+    if (value.isEmpty) return null;
+    return '$key=$value';
+  }
+
+  /// Removes characters that are not valid in an HTTP header field value.
+  ///
+  /// Keeps printable US-ASCII characters (`0x20`–`0x7E`) and drops the `|`
+  /// separator used to join the header segments so individual values cannot
+  /// break the header structure.
+  static String _sanitizeHeaderValue(String value) {
+    final buffer = StringBuffer();
+    for (final codeUnit in value.codeUnits) {
+      if (codeUnit >= 0x20 && codeUnit <= 0x7E && codeUnit != 0x7C) {
+        buffer.writeCharCode(codeUnit);
+      }
+    }
+    return buffer.toString().trim();
+  }
 }

packages/stream_video/test/src/video_environment_test.dart

@@ -0,0 +1,54 @@
+import 'package:flutter_test/flutter_test.dart';
+import 'package:stream_video/src/video_environment.dart';
+
+void main() {
+  group('VideoEnvironment.xStreamClientHeader', () {
+    test('builds header from all fields', () {
+      const environment = VideoEnvironment(
+        sdkVersion: '1.4.1',
+        osName: 'android',
+        osVersion: '16',
+        appName: 'MyApp',
+        appVersion: '2.5.1',
+        deviceModel: 'Nothing A142',
+      );
+
+      expect(
+        environment.xStreamClientHeader,
+        'stream-video-flutter-v1.4.1|app=MyApp|app_version=2.5.1|'
+        'os=android 16|device_model=Nothing A142',
+      );
+    });
+
+    test('strips non-ASCII characters from the app name', () {
+      const environment = VideoEnvironment(
+        sdkVersion: '1.4.1',
+        osName: 'android',
+        osVersion: '16',
+        appName: 'aąbęcódńfśłżźć',
+        appVersion: '2.5.1',
+        deviceModel: 'Nothing A142',
+      );
+
+      final header = environment.xStreamClientHeader;
+
+      expect(header.contains('app=abcdf'), isTrue);
+      expect(header.contains('ó'), isFalse);
+      // The resulting header value must be valid US-ASCII.
+      expect(header.codeUnits.every((c) => c >= 0x20 && c <= 0x7E), isTrue);
+    });
+
+    test('drops the "|" separator from field values', () {
+      const environment = VideoEnvironment(
+        sdkVersion: '1.4.1',
+        osName: 'android',
+        appName: 'My|App',
+      );
+
+      expect(
+        environment.xStreamClientHeader,
+        'stream-video-flutter-v1.4.1|app=MyApp|os=android',
+      );
+    });
+  });
+}