Problem with DB encryption on Release (1.5.4) about sembast.dart HOT 11 CLOSED

import 'dart:convert';
import 'package:meta/meta.dart';
import 'package:sembast/sembast.dart';
import 'package:encrypt/encrypt.dart';

class _EncryptEncoder extends Converter<Map<String, dynamic>, String> {
  final String key;
  final String signature;
  _EncryptEncoder(this.key, this.signature);

  @override
  String convert(Map<String, dynamic> input) {
    String encoded;
    switch (signature) {
      case "Salsa20":
        encoded = Encrypter(Salsa20(Key.fromUtf8(key)))
            .encrypt(json.encode(input), iv: IV.fromLength(8))
            .base64;
        break;
      case "AES":
        encoded = Encrypter(AES(Key.fromUtf8(key)))
            .encrypt(json.encode(input), iv: IV.fromLength(16))
            .base64;
        break;
      default:
        throw FormatException('invalid $signature');
        break;
    }
    return encoded;
  }
}

class _EncryptDecoder extends Converter<String, Map<String, dynamic>> {
  final String key;
  final String signature;
  _EncryptDecoder(this.key, this.signature);

  @override
  Map<String, dynamic> convert(String input) {
    var decoded;
    switch (signature) {
      case "Salsa20":
        decoded = json.decode(Encrypter(Salsa20(Key.fromUtf8(key)))
            .decrypt64(input, iv: IV.fromLength(8)));
        break;
      case "AES":
        decoded = json.decode(Encrypter(AES(Key.fromUtf8(key)))
            .decrypt64(input, iv: IV.fromLength(16)));
        break;
      default:
        break;
    }
    if (decoded is Map) {
      return decoded.cast<String, dynamic>();
    }
    throw FormatException('invalid input $input');
  }
}

class _EncryptCodec extends Codec<Map<String, dynamic>, String> {
  final String signature;
  _EncryptEncoder _encoder;
  _EncryptDecoder _decoder;
  _EncryptCodec(String password, this.signature) {
    _encoder = _EncryptEncoder(password, signature);
    _decoder = _EncryptDecoder(password, signature);
  }

  @override
  Converter<String, Map<String, dynamic>> get decoder => _decoder;

  @override
  Converter<Map<String, dynamic>, String> get encoder => _encoder;
}

// Salsa20 (16 length key required) or AES (32 length key required)
SembastCodec getEncryptSembastCodec(
        {@required String password, String signature = "Salsa20"}) =>
    SembastCodec(
        signature: signature, codec: _EncryptCodec(password, signature));

import 'package:pointycastle/api.dart';
import 'package:pointycastle/stream/salsa20.dart';

class Salsa20Encoder extends Converter<Map<String, dynamic>, String> {
  Uint8List password;
  Salsa20Encoder(this.password) {
    assert(password.length == 32);
  }

  @override
  String convert(Map<String, dynamic> input) {
    Uint8List initialValue = randBytes(8);
    String encoded = base64.encode(initialValue);
    assert(encoded.length == 12);

    final Salsa20Engine salsa20 = Salsa20Engine();
    salsa20.init(true,
        ParametersWithIV<KeyParameter>(KeyParameter(password), initialValue));
    encoded += base64.encode(salsa20.process(utf8.encode(jsonEncode(input))));
    return encoded;
  }
} 

class Salsa20Decoder extends Converter<String, Map<String, dynamic>> {
  Uint8List password;
  Salsa20Decoder(this.password) {
    assert(password.length == 32);
  }

  @override
  Map<String, dynamic> convert(String input) {
    assert(input.length >= 12);
    Uint8List initialValue = base64.decode(input.substring(0, 12));
    input = input.substring(12);

    final Salsa20Engine salsa20 = Salsa20Engine();
    salsa20.init(false,
        ParametersWithIV<KeyParameter>(KeyParameter(password), initialValue));
    var decoded =
        json.decode(utf8.decode(salsa20.process(base64.decode(input))));
    if (decoded is Map) {
      return decoded.cast<String, dynamic>();
    }
    throw FormatException('invalid input $input');
  }
}