Merge pull request #1 from leocavalcante/salsa20

Add Salsa20 Stream Cipher

README.md

@@ -2,6 +2,7 @@
 A set of high-level APIs over PointyCastle for two-way cryptography.
 
 - [x] AES
+- [x] Salsa20
 - [ ] RSA
 
 ```dart

lib/encrypt.dart

@@ -1,6 +1,7 @@
 library encrypt;
 
 export 'src/aes.dart';
+export 'src/salsa20.dart';
 
 abstract class Algorithm {
   String encrypt(String plainText);

lib/src/salsa20.dart

@@ -0,0 +1,44 @@
+import '../encrypt.dart';
+
+import 'package:pointycastle/stream/salsa20.dart';
+
+import 'package:pointycastle/api.dart' show ParametersWithIV, KeyParameter;
+
+import 'dart:typed_data';
+
+import 'helpers.dart';
+
+class Salsa20 implements Algorithm {
+  final String key;
+  final String iv;
+  final ParametersWithIV _params;
+
+  final Salsa20Engine _cipher = new Salsa20Engine();
+
+  Salsa20(this.key, this.iv)
+      : _params = new ParametersWithIV(
+            new KeyParameter(new Uint8List.fromList(key.codeUnits)),
+            new Uint8List.fromList(iv.codeUnits));
+
+  String encrypt(String plainText) {
+    _cipher
+      ..reset()
+      ..init(true, _params);
+
+    final input = new Uint8List.fromList(plainText.codeUnits);
+    final output = _cipher.process(input);
+
+    return formatBytesAsHexString(output);
+  }
+
+  String decrypt(String cipherText) {
+    _cipher
+      ..reset()
+      ..init(false, _params);
+
+    final input = createUint8ListFromHexString(cipherText);
+    final output = _cipher.process(input);
+
+    return new String.fromCharCodes(output);
+  }
+}

test/encrypt_test.dart

@@ -2,12 +2,14 @@ import 'package:encrypt/encrypt.dart';
 import 'package:test/test.dart';
 
 void main() {
-  group('AES', () {
-    final key = 'my32lengthsupersecretnooneknows1';
+  final key = 'my32lengthsupersecretnooneknows1';
+  final iv = '8bytesiv';
 
+  group('AES', () {
     final encrypter = new Encrypter(new AES(key));
-    final plainText =
-        'Lorem ipsum dolor sit amet, consectetur adipiscing elit ........';
+
+    final plainText = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit '
+        .padRight(64, '.');
     final cipherText =
         'db066ce180f62f020617eb720b891c1efcc48b217cb83272812a8efe3b30e7eae4373ddcede4ea77bdae77d126d95457b3759b1983bf4cb4a6a5b051a5690bdf';
 
@@ -17,4 +19,18 @@ void main() {
     test('decrypt',
         () => expect(encrypter.decrypt(cipherText), equals(plainText)));
   });
+
+  group('Salsa20', () {
+    final encrypter = new Encrypter(new Salsa20(key, iv));
+
+    final plainText = 'Lorem ipsum dolor sit amet, consectetur adipiscing elit';
+    final cipherText =
+        '5d8dae261d5a2b5960595a9480f18156bfad5f36c07c05ae59a46870d9cb1305d2502a3b35f3fc1d1977c247bee7540068efa779284161';
+
+    test('encrypt',
+        () => expect(encrypter.encrypt(plainText), equals(cipherText)));
+
+    test('decrypt',
+        () => expect(encrypter.decrypt(cipherText), equals(plainText)));
+  });
 }