tsa_rfc3161 1.0.12

This is a TSA (Time Stamping Authority) client/library RFC3161 for Flutter apps. With it, you can timestamp any files or any text message

example/example.dart

import 'dart:io';
import 'package:file_picker/file_picker.dart';
import 'package:dio/dio.dart';
import 'package:flutter/foundation.dart';
import 'package:flutter/material.dart';
import 'package:tsa_rfc3161/src/tsa_common.dart';

import 'package:tsa_rfc3161/tsa_rfc3161.dart';

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

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

  // This widget is the root of your application.
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        colorScheme: ColorScheme.fromSeed(seedColor: Colors.deepPurple),
        useMaterial3: true,
      ),
      home: const MyHomePage(title: 'TSA Rfc3161'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  const MyHomePage({super.key, required this.title});

  final String title;

  @override
  State<MyHomePage> createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  int? _iStatusCode = 0;
  String? _errorMessage = "";
  String? _dumpTSA = "";
  String? _dumpTST = "";

  void _timestamp() async {
    setState(() {
      _iStatusCode = 0;
      _dumpTSA = "";
      _dumpTST = "";
      _errorMessage = "";
    });

    FilePickerResult? result = await FilePicker.platform.pickFiles();
    int nonceValue =
        DateTime.now().millisecondsSinceEpoch; // Utiliser un entier unique

    if (result == null) {
      return;
    }
    File file = File(result.files.single.path!);

    try {
      TSARequest tsq = TSARequest.fromFile(
          filepath: file.path,
          algorithm: TSAHashAlgo.sha256,
          nonce: nonceValue,
          certReq: true);

      tsq.write("file.digicert.tsq");
      tsq.hexaPrint();
      // tsq.hexaPrint();,

      // tsq.write("test.tsq");

      Response response =
          await tsq.run(hostname: "http://timestamp.digicert.com");

      /*
      
      example with Certigna server
      Response response = await tsq.run(
          hostname: "https://timestamp.dhimyotis.com/api/v1/",
          credentials: "$user:$password");
          
      */

      _iStatusCode = response.statusCode;
      if (_iStatusCode == 200) {
        _errorMessage = "good";
        TSAResponse tsr = TSAResponse.fromHTTPResponse(response: response);
        tsr.write("file.digicert.tsr");

        // ASN1Sequence tsr.asn1sequence contains the parsed response
        _dumpTSA = TSACommon.explore(tsr.asn1sequence, 0);

        // TimeStampToken ?
        if (kDebugMode) {
          print(tsr.asn1SequenceTSTInfo);
        }

        if (tsr.asn1SequenceTSTInfo != null) {
          _dumpTST = TSACommon.explore(tsr.asn1SequenceTSTInfo!, 0);
        }

        setState(() {});
        /* 
        openssl ts -reply -in test.tsr -text provides
        
        Version: 1
        Policy OID: 2.16.840.1.114412.7.1
        Hash Algorithm: sha512
        Message data:
            0000 - 89 bd 94 b7 92 4b 2f 16-d8 c5 c0 0f 11 02 12 b1   .....K/.........
            0010 - bb b1 5a bb 72 7d be 06-33 bf 7d d0 9f 6f d6 07   ..Z.r}..3.}..o..
            0020 - 02 4d a3 df d6 7b cf c7-89 e2 2f 2d d9 fa 9b c3   .M...{..../-....
            0030 - 39 9a d4 34 11 e1 11 d8-c6 7b a7 a0 b4 96 42 2d   9..4.....{....B-
        Serial number: 0x4194EF54150D2496B2C3F1A78D82C41B
        Time stamp: Sep  7 08:37:47 2024 GMT
        Accuracy: unspecified
        Ordering: no
        Nonce: 0x0191CBA1D914
        TSA: unspecified
        Extensions:
        */
      } else {
        _errorMessage = "error";
      }
    } on Exception catch (e) {
      _iStatusCode = 0;
      _errorMessage = "exception : ${e.toString()}";
    }
    setState(() {});
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Theme.of(context).colorScheme.inversePrimary,
        title: Text(widget.title),
      ),
      body: Padding(
        padding: const EdgeInsets.all(8.0),
        child: SingleChildScrollView(
          child: Column(
            mainAxisSize: MainAxisSize.max,
            mainAxisAlignment: MainAxisAlignment.start,
            children: <Widget>[
              const Row(mainAxisSize: MainAxisSize.max, children: [
                Text(
                  "press button, choose a file and wait for digicert timestamp",
                )
              ]),
              if (_iStatusCode != 0)
                Row(mainAxisSize: MainAxisSize.max, children: [
                  Text("status code from tsa server = $_iStatusCode")
                ]),
              if (_errorMessage != "")
                Row(mainAxisSize: MainAxisSize.max, children: [
                  Text(_errorMessage!),
                ]),
              const SizedBox(height: 50),
              if (_dumpTST != "")
                Container(
                    color: Colors.lightGreen, child: SelectableText(_dumpTST!)),
              const SizedBox(height: 50),
              if (_dumpTSA != "") SelectableText(_dumpTSA!)
            ],
          ),
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: _timestamp,
        tooltip: 'Timestamp',
        child: const Icon(Icons.add),
      ),
    );
  }
}