aia_chaser_dio 0.1.0

Dio HTTP client adapter for aia_chaser, enabling scoped AIA intermediate certificate chasing and transparent retry-once.

aia_chaser_dio

A drop-in Dio HttpClientAdapter for aia_chaser that enables scoped Authority Information Access (AIA) certificate chasing and transparent retry-once resilience for Flutter and Dart.

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The Problem

When interacting with backend servers that omit intermediate CA certificates, Dio throws:

DioException [bad certificate]: HandshakeException: CERTIFICATE_VERIFY_FAILED: unable to get local issuer certificate

Standard workarounds like validateCertificate: (cert, host, port) => true expose applications to catastrophic Man-in-the-Middle (MitM) attacks.

aia_chaser_dio transparently connects with the native AIA Chaser engine to fetch missing intermediate certificates, validate the complete cryptographic trust path against the system trust store, and automatically retry failed requests once.

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Installation

Add aia_chaser and aia_chaser_dio to your pubspec.yaml:

dependencies:
  aia_chaser: ^0.1.0
  aia_chaser_dio: ^0.1.0
  dio: ^5.7.0

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Quick Start

1. Initialize AIA Chaser

import 'package:aia_chaser/aia_chaser.dart';

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

  await AiaChaser.initialize(AiaConfig(
    hosts: {
      'api.example.com': const HostPolicy(
        chase: true,
        retryOnce: true, // Transparently retry upon validation
      ),
    },
  ));

  runApp(const MyApp());
}

2. Attach Adapter to Dio

import 'package:aia_chaser_dio/aia_chaser_dio.dart';
import 'package:dio/dio.dart';

final dio = Dio();
dio.httpClientAdapter = AiaDioAdapter();

// All requests now benefit from AIA resolution and auto-retry!
final response = await dio.get('https://api.example.com/v1/profile');

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How It Works

1. Fast-Path Verification: If the target host has already been validated or prewarmed, the TLS connection succeeds immediately with $O(1)$ memory overhead.
2. Failure Interception: When a handshake fails with CERTIFICATE_VERIFY_FAILED, AiaDioAdapter intercepts the exception.
3. AIA Resolution: The native engine fetches missing intermediate certificates via AIA, verifies signatures, and validates trust against the Android Conscrypt trust store.
4. Retry Once: If the chain validates successfully, the request is transparently re-attempted once.