| 1 | import 'package:encrypt/encrypt.dart' as encrypt; |
| 2 | |
| 3 | const ivEncodedStringLength = 12; |
| 4 | |
| 5 | String generateKey() { |
| 6 | final key = encrypt.Key.fromSecureRandom(512); |
| 7 | final iv = encrypt.IV.fromSecureRandom(8); |
| 8 | |
| 9 | return key.base64 + iv.base64; |
| 10 | } |
| 11 | |
| 12 | List<String> extractKeys(String key) { |
| 13 | final _key = key.substring(0, key.length - ivEncodedStringLength); |
| 14 | final iv = key.substring(key.length - ivEncodedStringLength); |
| 15 | |
| 16 | return [_key, iv]; |
| 17 | } |
| 18 | |
| 19 | Future<String> encode( |
| 20 | {required encrypt.Key key, required encrypt.IV iv, required String data}) async { |
| 21 | final encrypter = encrypt.Encrypter(encrypt.Salsa20(key)); |
| 22 | final encrypted = encrypter.encrypt(data, iv: iv); |
| 23 | |
| 24 | return encrypted.base64; |
| 25 | } |
| 26 | |
| 27 | Future<String> decode({required String password, required String data}) async { |
| 28 | final keys = extractKeys(password); |
| 29 | final key = encrypt.Key.fromBase64(keys.first); |
| 30 | final iv = encrypt.IV.fromBase64(keys.last); |
| 31 | final encrypter = encrypt.Encrypter(encrypt.Salsa20(key)); |
| 32 | final encrypted = encrypter.decrypt64(data, iv: iv); |
| 33 | |
| 34 | return encrypted; |
| 35 | } |