Dart
encrypt
Learn encryption with the encrypt package.
The encrypt package
encrypt is Dart's symmetric encryption package. It uses the AES algorithm. It is imported with import 'package:encrypt/encrypt.dart';. It works with the Encrypter, Key and IV classes.
Example: final key = Key.fromUtf8('16baytlikkey1234'); final iv = IV.fromUtf8('16baytlikiv01234'); final encrypter = Encrypter(AES(key)); final encrypted = encrypter.encrypt('msg', iv: iv);. Here AES encryption is done with a 16-byte key and an initialization vector (IV). The result is an Encrypted object; .base64 turns it into a base64 string.
The AES encryption flow
AES encryption works with three parts: Key (key), IV (initialization vector) and Encrypter. The key is secret for encryption; the IV is a value that should differ per message.
To decrypt use encrypter.decrypt(encrypted, iv: iv). Data encrypted with a key and IV is decrypted with the same key and IV. This is the foundation of symmetric encryption: the same key is used for both encryption and decryption. In this lesson we define the encryption function.
Exercise Define an encryption function
Add import 'package:encrypt/encrypt.dart';. Define encryptMessage(String msg, Key key, IV iv) with final encrypter = Encrypter(AES(key)); and return encrypter.encrypt(msg, iv: iv).base64; inside. In main add print('encrypt: AES encryption') and print('Output: base64 ciphertext').
Show example solution
import 'package:encrypt/encrypt.dart';
String encryptMessage(String msg, Key key, IV iv) {
final encrypter = Encrypter(AES(key));
return encrypter.encrypt(msg, iv: iv).base64;
}
void main() {
print('encrypt: AES encryption');
print('Output: base64 ciphertext');
}
Test yourself
-
Match the encrypt parts
- encrypt
- Encryption package
- AES
- Algorithm
- Encrypter
- Encrypter
- IV
- Init vector
-
Which algorithm does the encrypt package use?
Show answer
AES — the encrypt package uses the AES algorithm.
-
Creating an Encrypter
final encrypter = ____(AES(key));
Show answer
final encrypter = Encrypter(AES(key));
Next lesson: Secure random
