Вот решение, которое я нашел. Надеюсь, поможет. Не забудьте добавить пакет пакет шифрования в pubspe c .yaml
import 'dart:convert';
import 'dart:io';
import 'package:encrypt/encrypt.dart';
main() {
perfomEncryptionTasks();
}
perfomEncryptionTasks() async {
await encryptFile();
await decryptFile();
}
encryptFile() async {
File inFile = new File("video.mp4");
File outFile = new File("videoenc.aes");
bool outFileExists = await outFile.exists();
if(!outFileExists){
await outFile.create();
}
final videoFileContents = await inFile.readAsStringSync(encoding: latin1);
final key = Key.fromUtf8('my 32 length key................');
final iv = IV.fromLength(16);
final encrypter = Encrypter(AES(key));
final encrypted = encrypter.encrypt(videoFileContents, iv: iv);
await outFile.writeAsBytes(encrypted.bytes);
}
decryptFile() async {
File inFile = new File("videoenc.aes");
File outFile = new File("videodec.mp4");
bool outFileExists = await outFile.exists();
if(!outFileExists){
await outFile.create();
}
final videoFileContents = await inFile.readAsBytesSync();
final key = Key.fromUtf8('my 32 length key................');
final iv = IV.fromLength(16);
final encrypter = Encrypter(AES(key));
final encryptedFile = Encrypted(videoFileContents);
final decrypted = encrypter.decrypt(encryptedFile, iv: iv);
final decryptedBytes = latin1.encode(decrypted);
await outFile.writeAsBytes(decryptedBytes);
}