worker library

Flutter-free entry point for DPoP token generation in worker threads/isolates.

This library provides a minimal, Flutter-independent API for generating DPoP tokens from serialized credentials. It's specifically designed for use in Dart isolates and web workers where Flutter dependencies are not available.

Purpose

The main solid_oidc_auth library depends on Flutter for UI components and platform-specific storage. Worker threads and isolates cannot access Flutter APIs, so this library provides a separate entry point that:

Contains zero Flutter dependencies
Exports only what's needed for DPoP token generation
Can be safely imported in isolate entry points
Uses only pure Dart and platform-independent cryptography

Usage Pattern

// Main thread (can use full solid_oidc_auth library)
import 'package:solid_oidc_auth/solid_oidc_auth.dart';

final solidAuth = SolidOidcAuth(...);
await solidAuth.init();
await solidAuth.authenticate('https://alice.pod.com/profile/card#me');

// Export credentials for worker
final credentials = solidAuth.exportDpopCredentials();

// Spawn worker with serialized credentials
await Isolate.spawn(workerEntryPoint, credentials.toJson());

// Worker thread (uses Flutter-free worker library)
import 'package:solid_oidc_auth/worker.dart';

void workerEntryPoint(Map<String, dynamic> credentialsJson) {
  // Deserialize credentials
  final credentials = DpopCredentials.fromJson(credentialsJson);

  // Generate DPoP tokens (no Flutter APIs needed)
  final dpop = credentials.generateDpopToken(
    url: 'https://alice.pod.com/data/',
    method: 'GET',
  );

  // Use dpop.httpHeaders() for authenticated requests
}

What's Exported

DpopCredentials: Serializable credentials container
DPoP: Result object containing DPoP token and access token
KeyPair: Platform-agnostic RSA key pair representation

What's NOT Exported

SolidOidcAuth: Main authentication class (requires Flutter)
OIDC flow management (requires Flutter for browser redirects)
Session persistence (requires Flutter for platform storage)
Any UI or platform-specific components

Architecture

┌─────────────────────────────────────────┐
│         Main Thread (Flutter)           │
│  import 'package:solid_oidc_auth/solid_oidc_auth' │
│                                         │
│  - SolidOidcAuth (authentication)       │
│  - Browser redirects                    │
│  - Session management                   │
│  - exportDpopCredentials()             │
└─────────────────────────────────────────┘
                     │
                     │ Serialize credentials
                     │ (DpopCredentials.toJson())
                     ▼
┌─────────────────────────────────────────┐
│       Worker Thread (Pure Dart)         │
│  import 'package:solid_oidc_auth/worker'     │
│                                         │
│  - DpopCredentials.fromJson()           │
│  - generateDpopToken()                  │
│  - No Flutter dependencies              │
└─────────────────────────────────────────┘

Security Considerations

Credentials contain sensitive cryptographic material:

RSA private key
OAuth2 access token

While safe for intra-process transfer (isolates/workers), never:

Serialize credentials to persistent storage
Send credentials over the network
Log credentials in plaintext

See doc/dpop_worker_threads.md for comprehensive security guidelines.