flutter_user_certificates_android

A Flutter plugin for getting user installed certificates on Android.

This is useful for working around the limitation that Dart's HttpClient doesn't honor user installed certificates on Android. See:

• dart-lang/sdk#50435
• flutter/flutter#56607

Getting Started

Here is an example that trusts and lists all the user installed certificates on the device.

import 'package:flutter/material.dart';
import 'dart:async';
import 'dart:io';

import 'package:flutter/services.dart';
import 'package:flutter_user_certificates_android/flutter_user_certificates_android.dart';

final _flutterUserCertificatesAndroidPlugin = FlutterUserCertificatesAndroid();

void main() async {
  WidgetsFlutterBinding.ensureInitialized();

  // Extend the default security context to trust Android user certificates.
  // This is a workaround for <https://github.com/dart-lang/sdk/issues/50435>.
  await _flutterUserCertificatesAndroidPlugin.trustAndroidUserCertificates(SecurityContext.defaultContext);

  runApp(const MyApp());
}

class MyApp extends StatefulWidget {
  const MyApp({super.key});

  @override
  State<MyApp> createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  Map<String, Uint8List> _certs = {};
  String? error;

  @override
  void initState() {
    super.initState();
    initPlatformState();
  }

  Future<void> initPlatformState() async {
    Map<String, Uint8List>? certs;
    try {
      certs = await _flutterUserCertificatesAndroidPlugin.getUserCertificates();
    } on PlatformException {
      error = 'Failed to get user certificates from device.';
    }

    if (!mounted) return;

    if (certs == null) return;

    setState(() {
      _certs = certs!;
    });
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: const Text('Plugin example app'),
        ),
        body: error != null
            ? Center(
                child: Text(error!),
              )
            : ListView.builder(
                itemCount: _certs.length,
                itemBuilder: (c, i) => ListTile(
                  title: Text(_certs.keys.elementAt(i)),
                ),
              ),
      ),
    );
  }
}

Note about native Android HTTP

The above example only affects HTTP calls with Dart's http library. If you (or some library you depend on) are using javax.net.ssl.HttpsURLConnection or Cronet, then you will also need a <network-security-config> that adds user certificates as a trust anchor.

android/app/src/main/AndroidManifest.xml:

<manifest xmlns:android="http://schemas.android.com/apk/res/android" ...>
  <application ... android:networkSecurityConfig="@xml/network_security_config">
  ...
</manifest>

android/app/src/main/res/xml/network_security_config.xml:

<?xml version="1.0" encoding="utf-8"?>
<network-security-config>
  <base-config>
    <trust-anchors>
      <certificates src="system"/>
      <certificates src="user"/>
    </trust-anchors>
  </base-config>
</network-security-config>

See https://developer.android.com/privacy-and-security/security-config#network-security-config for more details.