tagion_dart_api 1.0.7

This plugin serves as a Dart interface to the existing Tagion API, designed to streamline its integration and usage within the Dart/Flutter ecosystem.

example/lib/main.dart

import 'dart:ffi';

import 'package:crypto/crypto.dart';
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:tagion_dart_api/enums/document_error_code.dart';
import 'package:tagion_dart_api/enums/text_format.dart';
import 'package:tagion_dart_api/exception/crypto_exception.dart';
import 'package:tagion_dart_api/module/basic/basic.dart';
import 'package:tagion_dart_api/module/crypto/crypto.dart';
import 'package:tagion_dart_api/module/crypto/crypto_interface.dart';
import 'package:tagion_dart_api/module/crypto/ffi/crypto_ffi.dart';
import 'package:tagion_dart_api/module/document/document.dart';
import 'package:tagion_dart_api/module/hibon/hibon.dart';
import 'package:tagion_dart_api/pointer_manager/pointer_manager.dart';

void main() {
  runApp(const MyApp());
}

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

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

class _MyAppState extends State<MyApp> {
  //
  late final TGNBasic _basic;
  late final ICrypto _crypto;
  //
  final TextEditingController _passPhraseCtrl =
      TextEditingController(text: 'pass phrase example');
  final TextEditingController _pinCodeCtrl =
      TextEditingController(text: '123456');
  final TextEditingController _keyPairCtrl = TextEditingController();
  final TextEditingController _hibonCtrl = TextEditingController();
  final TextEditingController _signatureCtrl = TextEditingController();
  //
  final FocusNode _passPhraseFN = FocusNode();
  final FocusNode _pinCodeFN = FocusNode();
  final FocusNode _keyPairFN = FocusNode();
  final FocusNode _hibonFN = FocusNode();
  final FocusNode _signatureFN = FocusNode();
  //
  late final Pointer<SecureNet> _secureNetPtr;
  //
  Uint8List? _keyPair;
  Uint8List? _hibon;
  String? _hibonStatus;
  String? _signatureStatus;
  //
  final Map<String, bool> _collapsedState = {
    'keyPair': false,
    'hibon': false,
    'signature': false,
  };

  @override
  void initState() {
    super.initState();
    //
    _secureNetPtr = const PointerManager().allocate<SecureNet>();
    //
    _basic = TGNBasic.init();
    _basic.startDRuntime();
    //
    _crypto = TGNCrypto.init();
  }

  void _generateKeypair() {
    _keyPair = _crypto.generateKeypair(
      _passPhraseCtrl.text,
      _pinCodeCtrl.text,
      '',
      _secureNetPtr,
    );
    _keyPairCtrl.text = _toBase64Url(_keyPair);
    _unfocus();
  }

  void _signData() {
    setState(() {
      try {
        if (_hibon == null) {
          _signatureStatus = 'Create hibon first';
          return;
        }
        List<int> dataHash = sha256.convert(_hibon!).bytes;
        _signatureCtrl.text = _toBase64Url(
            _crypto.sign(Uint8List.fromList(dataHash), _secureNetPtr));
        _signatureStatus = 'Signed';
      } on CryptoApiException catch (e) {
        _signatureStatus =
            'Failed: ${e.runtimeType}: ${e.errorCode.toString()} - ${e.message}';
      }
    });
  }

  String _toBase64Url(Uint8List? data) {
    if (data == null) return 'No data';
    return _basic.encodeBase64Url(data);
  }

  // Create a hibon.
  void _createHibon() {
    TGNHibon bill = TGNHibon.init();
    bill.create();
    bill.addString("\$@", "TGN");

    TGNHibon value = TGNHibon.init();
    value.create();
    value.addInt<Uint64>("\$", 1000);

    bill.addHibonByKey("\$V", value);
    bill.addArrayByKey("\$Y", Uint8List.fromList([1, 2, 3, 4, 5]));
    bill.addTime("\$t", DateTime.now().millisecondsSinceEpoch);

    _hibon = bill.getAsDocumentBuffer();
    _representHibon(_hibon, TextFormat.prettyJson);
  }

  void _representHibon(Uint8List? hibon, TextFormat textFormat) {
    if (hibon == null) return;
    TGNDocument doc = TGNDocument.init(hibon);
    _hibonCtrl.text = doc.getAsString(textFormat);
  }

  // Read the hibon with a Document.
  void _validateHibon() {
    if (_hibon == null) {
      setState(() {
        _hibonStatus = 'No hibon';
      });
      return;
    }
    TGNDocument doc = TGNDocument.init(_hibon!);
    DocumentErrorCode code = doc.validate();
    setState(() {
      if (code == DocumentErrorCode.none) {
        _hibonStatus = 'Valid';
      } else {
        _hibonStatus = code.toString();
      }
    });
  }

  void _clearKeyPair() {
    _passPhraseCtrl.clear();
    _pinCodeCtrl.clear();
    _keyPairCtrl.clear();
    _keyPair = null;
    const PointerManager().zeroOutAndFree(_secureNetPtr, 1);
  }

  void _clearHibon() {
    _hibonCtrl.clear();
    _hibon = null;
  }

  void _unfocus() {
    _passPhraseFN.unfocus();
    _pinCodeFN.unfocus();
    _keyPairFN.unfocus();
  }

  Widget _buildCollapsableContainer({
    required String key,
    required String title,
    required Widget child,
  }) {
    return GestureDetector(
        onTap: () {
          setState(() {
            _collapsedState[key] = !_collapsedState[key]!;
          });
        },
        child: Container(
          key: Key(key),
          padding: const EdgeInsets.all(10),
          width: double.infinity,
          margin: const EdgeInsets.only(bottom: 10),
          decoration: BoxDecoration(
            color: Colors.white,
            borderRadius: BorderRadius.circular(10),
          ),
          child: Column(
            children: [
              Row(
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                children: [
                  Text(title, style: const TextStyle(fontSize: 16)),
                  Icon(_collapsedState[key]!
                      ? Icons.arrow_drop_down
                      : Icons.arrow_drop_up),
                ],
              ),
              Visibility(
                visible: _collapsedState[key]!,
                child: child,
              ),
            ],
          ),
        ));
  }

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        backgroundColor: Colors.white70,
        appBar: AppBar(
          title: const Text('Example'),
        ),
        body: Padding(
          padding: const EdgeInsets.all(8.0),
          child: GestureDetector(
            onTap: _unfocus,
            child: SingleChildScrollView(
              child: Center(
                child: Column(
                  children: [
                    _buildCollapsableContainer(
                      key: 'keyPair',
                      title: 'Key pair',
                      child: Column(
                        children: [
                          TextField(
                            decoration:
                                const InputDecoration(labelText: 'Pass phrase'),
                            controller: _passPhraseCtrl,
                            focusNode: _passPhraseFN,
                            minLines: 1,
                            maxLines: 3,
                            onChanged: (value) {
                              _passPhraseCtrl.text = value;
                            },
                          ),
                          TextField(
                            decoration:
                                const InputDecoration(labelText: 'Pin code'),
                            controller: _pinCodeCtrl,
                            focusNode: _pinCodeFN,
                            onChanged: (value) {
                              _pinCodeCtrl.text = value;
                            },
                          ),
                          TextField(
                            decoration:
                                const InputDecoration(labelText: 'Result'),
                            controller: _keyPairCtrl,
                            focusNode: _keyPairFN,
                            readOnly: true,
                            minLines: 1,
                            maxLines: 8,
                          ),
                          const SizedBox(height: 10),
                          Row(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: [
                              OutlinedButton(
                                onPressed: _generateKeypair,
                                child: const Text('Generate'),
                              ),
                              const SizedBox(width: 10),
                              OutlinedButton(
                                onPressed: _clearKeyPair,
                                child: const Text('Clear'),
                              ),
                            ],
                          ),
                        ],
                      ),
                    ),
                    _buildCollapsableContainer(
                      key: 'hibon',
                      title: 'Hibon',
                      child: Column(
                        children: [
                          TextField(
                            decoration:
                                const InputDecoration(labelText: 'Hibon'),
                            controller: _hibonCtrl,
                            focusNode: _hibonFN,
                            minLines: 1,
                            maxLines: 100,
                            onChanged: (value) {
                              _passPhraseCtrl.text = value;
                            },
                          ),
                          const SizedBox(height: 10),
                          Text(_hibonStatus ?? ''),
                          const SizedBox(height: 10),
                          Row(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: [
                              OutlinedButton(
                                onPressed: _createHibon,
                                child: const Text('Generate'),
                              ),
                              const SizedBox(width: 10),
                              OutlinedButton(
                                onPressed: _validateHibon,
                                child: const Text('Validate'),
                              ),
                              const SizedBox(width: 10),
                              OutlinedButton(
                                onPressed: _clearHibon,
                                child: const Text('Clear'),
                              ),
                            ],
                          ),
                        ],
                      ),
                    ),
                    _buildCollapsableContainer(
                      key: 'signature',
                      title: 'Sign a hibon',
                      child: Column(
                        children: [
                          TextField(
                            decoration:
                                const InputDecoration(labelText: 'Result'),
                            controller: _signatureCtrl,
                            focusNode: _signatureFN,
                            readOnly: true,
                            minLines: 1,
                            maxLines: 10,
                          ),
                          const SizedBox(height: 10),
                          Text(_signatureStatus ?? ''),
                          const SizedBox(height: 10),
                          Row(
                            mainAxisAlignment: MainAxisAlignment.center,
                            children: [
                              OutlinedButton(
                                onPressed: _signData,
                                child: const Text('Sign'),
                              ),
                              const SizedBox(width: 10),
                              OutlinedButton(
                                onPressed: _clearHibon,
                                child: const Text('Clear'),
                              ),
                            ],
                          ),
                        ],
                      ),
                    ),
                  ],
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}