Initial commit

lib/utils/custom_http_client.dart

@@ -0,0 +1,41 @@
+// SPDX-FileCopyrightText: 2019-Present Christian Kußowski
+// SPDX-FileCopyrightText: 2019-Present Contributors to FluffyChat
+//
+// SPDX-License-Identifier: AGPL-3.0-or-later
+
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:tatchat/config/isrg_x1.dart';
+import 'package:tatchat/config/isrg_x2.dart';
+import 'package:tatchat/utils/platform_infos.dart';
+import 'package:http/http.dart' as http;
+import 'package:http/io_client.dart';
+import 'package:http/retry.dart' as retry;
+
+/// Custom HTTP client that adds the ISRG Root certificates used by Let's
+/// Encrypt. Older Android versions may not include these roots in their
+/// trust store, so we ship them ourselves to ensure TLS connections to
+/// Let's Encrypt–signed servers continue to work.
+class CustomHttpClient {
+  static HttpClient customHttpClient() {
+    final context = SecurityContext.defaultContext;
+
+    try {
+      context.setTrustedCertificatesBytes(utf8.encode(ISRG_X1));
+      context.setTrustedCertificatesBytes(utf8.encode(ISRG_X2));
+    } on TlsException catch (e) {
+      if (e.osError != null &&
+          e.osError!.message.contains('CERT_ALREADY_IN_HASH_TABLE')) {
+      } else {
+        rethrow;
+      }
+    }
+
+    return HttpClient(context: context);
+  }
+
+  static http.Client createHTTPClient() => retry.RetryClient(
+    PlatformInfos.isAndroid ? IOClient(customHttpClient()) : http.Client(),
+  );
+}