decryptChaCha20 function
Implementation
Future<Uint8List> decryptChaCha20(
Uint8List key, Uint8List nonce, Uint8List ciphertext) async {
final algorithm = Chacha20(macAlgorithm: MacAlgorithm.empty);
final skey = SecretKey(key);
final secretBox = SecretBox(
ciphertext,
nonce: nonce,
mac: Mac.empty,
);
final plaintext = await algorithm.decrypt(
secretBox,
secretKey: skey,
);
return Uint8List.fromList(plaintext);
}