Fixes various issues in 'cryptography' and 'cryptography_flutter'.

cryptography/lib/src/cryptography/algorithms/aes_gcm.dart

@@ -67,8 +67,8 @@ int _uint32ChangeEndian(int v) {
       (0xFF & (v >> 24));
 }
 
-/// {@nodoc}
-@visibleForTesting
+/// _AES-GCM_ implementation for subclassing.
+/// For documentation, see [aesGcm].
 class AesGcm extends AesCipher {
   static final _r = () {
     final result = Uint32List(4);
@@ -93,8 +93,8 @@ class AesGcm extends AesCipher {
   @override
   Future<Uint8List> decrypt(
     List<int> cipherText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) async {
@@ -131,8 +131,8 @@ class AesGcm extends AesCipher {
   @override
   Future<Uint8List> encrypt(
     List<int> cipherText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) async {
@@ -150,8 +150,8 @@ class AesGcm extends AesCipher {
   @override
   Uint8List encryptSync(
     List<int> plainText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) {

cryptography/lib/src/cryptography/algorithms/chacha20_impl.dart

@@ -267,11 +267,13 @@ class ChaCha extends Cipher {
   Set<int> get secretKeyValidLengths => const <int>{32};
 
   @override
-  Uint8List decryptSync(List<int> cipherText,
-      {SecretKey secretKey,
-      Nonce nonce,
-      List<int> aad,
-      int keyStreamIndex = 0}) {
+  Uint8List decryptSync(
+    List<int> cipherText, {
+    @required SecretKey secretKey,
+    @required Nonce nonce,
+    List<int> aad,
+    int keyStreamIndex = 0,
+  }) {
     return encryptSync(
       cipherText,
       secretKey: secretKey,
@@ -284,8 +286,8 @@ class ChaCha extends Cipher {
   @override
   Uint8List encryptSync(
     List<int> plainText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) {

cryptography/lib/src/cryptography/algorithms/chacha20_poly1305_aead.dart

@@ -79,8 +79,10 @@ const CipherWithAppendedMac xchacha20Poly1305Aead = Chacha20Poly1305Aead(
   cipher: xchacha20,
 );
 
-/// {@nodoc}
-@visibleForTesting
+/// _AEAD_CHACHA20_POLY1305_ implementation for subclassing.
+/// For documentation, see [chacha20Poly1305Aead].
+///
+/// This is used by [chacha20Poly1305Aead] and [xchacha20Poly1305Aead].
 class Chacha20Poly1305Aead extends CipherWithAppendedMac {
   static final _tmpByteData = ByteData(16);
   static final _tmpUint8List = Uint8List.view(_tmpByteData.buffer);
@@ -91,8 +93,9 @@ class Chacha20Poly1305Aead extends CipherWithAppendedMac {
   const Chacha20Poly1305Aead({
     @required this.name,
     @required Cipher cipher,
-    MacAlgorithm macAlgorithm = poly1305,
-  }) : super(cipher, macAlgorithm);
+  })  : assert(name != null),
+        assert(cipher != null),
+        super(cipher, poly1305);
 
   @override
   bool get supportsAad => true;
@@ -198,8 +201,8 @@ class Chacha20Poly1305Aead extends CipherWithAppendedMac {
   @override
   Future<Uint8List> decrypt(
     List<int> cipherText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) async {
@@ -227,8 +230,8 @@ class Chacha20Poly1305Aead extends CipherWithAppendedMac {
   @override
   Uint8List decryptSync(
     List<int> cipherText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) {
@@ -256,8 +259,8 @@ class Chacha20Poly1305Aead extends CipherWithAppendedMac {
   @override
   Future<Uint8List> encrypt(
     List<int> plainText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) async {
@@ -284,8 +287,8 @@ class Chacha20Poly1305Aead extends CipherWithAppendedMac {
   @override
   Uint8List encryptSync(
     List<int> plainText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) {

cryptography/lib/src/cryptography/algorithms/ec_dsa_impl.dart

@@ -12,8 +12,6 @@
 // For specification, see the License for the specific language governing permissions and
 // limitations under the License.
 
-import 'dart:math';
-
 import 'package:cryptography/cryptography.dart';
 import 'package:meta/meta.dart';
 
@@ -218,4 +216,4 @@ abstract class _EcdsaNist extends SignatureAlgorithm {
   bool verifySync(List<int> input, Signature signature) {
     throw UnimplementedError();
   }
-}
+}

cryptography_flutter/README.md

@@ -33,4 +33,17 @@ Then just use:
 import 'package:cryptography_flutter/cryptography.dart';
 ```
 
-For more instructions, read documentation for [cryptography](https://pub.dev/packages/cryptography).
+For more instructions, read documentation for [cryptography](https://pub.dev/packages/cryptography).
+
+# Contributing?
+## Testing
+Run "no plugin available" tests:
+```
+flutter test
+```
+
+Run e2e tests:
+```
+cd example
+flutter driver test/cryptography_flutter_e2e.dart
+```

cryptography_flutter/analysis_options.yaml

@@ -0,0 +1 @@
+include: package:pedantic/analysis_options.yaml

cryptography_flutter/example/test/cryptography_flutter_e2e.dart

@@ -13,7 +13,7 @@ void main() {
     Nonce nonce;
     List<int> cipherText;
 
-    setUpAll(() {
+    setUp(() {
       secretKey = algo.newSecretKeySync();
       nonce = algo.newNonce();
       cipherText = algo.encryptSync(
@@ -48,7 +48,7 @@ void main() {
     Nonce nonce;
     List<int> cipherText;
 
-    setUpAll(() {
+    setUp(() {
       secretKey = algo.newSecretKeySync();
       nonce = algo.newNonce();
       cipherText = algo.encryptSync(

cryptography_flutter/ios/Classes/SwiftCryptographyFlutterPlugin.swift

@@ -10,6 +10,11 @@ public class SwiftCryptographyFlutterPlugin: NSObject, FlutterPlugin {
   }
 
   public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
+    if call.method == "ping" {
+      result("ok")
+      return
+    }
+
     let args = call.arguments as! [String: Any];
     if #available(iOS 13.0, OSX 15.0, tvOS 13.0, watchOS 6.0, *) {
     switch call.method {

cryptography_flutter/lib/cryptography.dart

@@ -15,12 +15,5 @@
 /// An optimized version of [package:cryptography](https://pub.dev/packages/cryptography).
 library cryptography_flutter;
 
-export 'package:cryptography/cryptography.dart'
-    hide
-        aesGcm,
-        AesGcm,
-        chacha20Poly1305Aead,
-        Chacha20Poly1305Aead;
-
-export 'src/all_overrides.dart'
+export 'src/all_exports.dart'
     if (dart.library.js) 'package:cryptography/cryptography.dart';

cryptography_flutter/lib/src/aes_gcm.dart

@@ -17,16 +17,16 @@ import 'dart:typed_data';
 
 import 'package:cryptography/cryptography.dart' hide aesGcm, AesGcm;
 import 'package:cryptography/cryptography.dart' as cryptography;
-import 'package:flutter/foundation.dart';
-import 'package:meta/meta.dart';
 
 import 'plugin.dart';
 
-const Cipher aesGcm = cryptography.aesGcm;
+/// Optimized _AES-GCM_ implementation.
+///
+/// See [cryptography.aesGcm].
+const Cipher aesGcm = AesGcm();
 
-/// {@nodoc}
-@visibleForTesting
-// ignore: invalid_use_of_visible_for_testing_member
+/// Optimized _AES-GCM_ implementation for subclassing.
+/// For documentation, see [aesGcm].
 class AesGcm extends cryptography.AesGcm {
   const AesGcm();
 
@@ -39,7 +39,9 @@ class AesGcm extends cryptography.AesGcm {
     int keyStreamIndex = 0,
   }) async {
     aad ??= const <int>[];
-    if (aad.isEmpty &&
+    final isPluginAvailable = await getIsPluginAvailable();
+    if (isPluginAvailable &&
+        aad.isEmpty &&
         keyStreamIndex == 0 &&
         cipherText.length > 128 &&
         (Platform.isIOS || Platform.isMacOS)) {
@@ -77,8 +79,10 @@ class AesGcm extends cryptography.AesGcm {
     List<int> aad,
     int keyStreamIndex = 0,
   }) async {
+    final isPluginAvailable = await getIsPluginAvailable();
     aad ??= const <int>[];
-    if (aad.isEmpty &&
+    if (isPluginAvailable &&
+        aad.isEmpty &&
         keyStreamIndex == 0 &&
         plainText.length > 128 &&
         (Platform.isIOS || Platform.isMacOS)) {
@@ -105,6 +109,7 @@ class AesGcm extends cryptography.AesGcm {
     }
     return super.encrypt(
       plainText,
+      secretKey: secretKey,
       nonce: nonce,
       aad: aad,
       keyStreamIndex: keyStreamIndex,

cryptography_flutter/lib/src/all_overrides.dart → cryptography_flutter/lib/src/all_exports.dart

@@ -12,5 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+export 'package:cryptography/cryptography.dart'
+    hide aesGcm, AesGcm, chacha20Poly1305Aead, Chacha20Poly1305Aead;
 export 'aes_gcm.dart';
 export 'chacha20.dart';

cryptography_flutter/lib/src/chacha20.dart

@@ -20,28 +20,39 @@ import 'plugin.dart';
 import 'dart:typed_data';
 import 'dart:io';
 
-const Cipher chacha20Poly1305Aead = Chacha20Poly1305Aead();
+/// Optimized _AEAD_CHACHA20_POLY1305_  implementation.
+///
+/// See [cryptography.chacha20Poly1305Aead].
+const Cipher chacha20Poly1305Aead = Chacha20Poly1305Aead(
+  name: 'chacha20Poly1305Aead',
+  cipher: chacha20,
+);
 
-/// {@nodoc}
-@visibleForTesting
-// ignore: invalid_use_of_visible_for_testing_member
+/// Optimized _AEAD_CHACHA20_POLY1305_  implementation for subclassing.
+/// For documentation, see [chacha20Poly1305Aead].
 class Chacha20Poly1305Aead extends cryptography.Chacha20Poly1305Aead {
-  const Chacha20Poly1305Aead()
-      : super(
-          name: 'chacha20Poly1305Aead',
-          cipher: chacha20,
+  const Chacha20Poly1305Aead({
+    @required String name,
+    @required Cipher cipher,
+  })  : assert(name != null),
+        assert(cipher != null),
+        super(
+          name: name,
+          cipher: cipher,
         );
 
   @override
   Future<Uint8List> decrypt(
     List<int> cipherText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) async {
     aad ??= const <int>[];
-    if (aad.isEmpty &&
+    final isPluginAvailable = await getIsPluginAvailable();
+    if (isPluginAvailable &&
+        aad.isEmpty &&
         keyStreamIndex == 0 &&
         cipherText.length > 128 &&
         (Platform.isIOS || Platform.isMacOS)) {
@@ -74,13 +85,15 @@ class Chacha20Poly1305Aead extends cryptography.Chacha20Poly1305Aead {
   @override
   Future<Uint8List> encrypt(
     List<int> plainText, {
-    SecretKey secretKey,
-    Nonce nonce,
+    @required SecretKey secretKey,
+    @required Nonce nonce,
     List<int> aad,
     int keyStreamIndex = 0,
   }) async {
     aad ??= const <int>[];
-    if (aad.isEmpty &&
+    final isPluginAvailable = await getIsPluginAvailable();
+    if (isPluginAvailable &&
+        aad.isEmpty &&
         keyStreamIndex == 0 &&
         plainText.length > 128 &&
         (Platform.isIOS || Platform.isMacOS)) {
@@ -107,6 +120,7 @@ class Chacha20Poly1305Aead extends cryptography.Chacha20Poly1305Aead {
     }
     return super.encrypt(
       plainText,
+      secretKey: secretKey,
       nonce: nonce,
       aad: aad,
       keyStreamIndex: keyStreamIndex,

cryptography_flutter/lib/src/plugin.dart

@@ -14,4 +14,19 @@
 
 import 'package:flutter/services.dart';
 
-const MethodChannel channel = const MethodChannel('cryptography_flutter');
+const MethodChannel channel = MethodChannel('cryptography_flutter');
+
+Future<bool> _isPluginAvailable;
+
+Future<bool> getIsPluginAvailable() {
+  return _isPluginAvailable ??= _getIsPluginAvailable();
+}
+
+Future<bool> _getIsPluginAvailable() async {
+  try {
+    await channel.invokeMethod('ping').timeout(const Duration(seconds: 1));
+    return true;
+  } on MissingPluginException {
+    return false;
+  }
+}

cryptography_flutter/macos/Classes/CryptographyFlutterPlugin.swift

@@ -10,6 +10,10 @@ public class CryptographyFlutterPlugin: NSObject, FlutterPlugin {
   }
 
   public func handle(_ call: FlutterMethodCall, result: @escaping FlutterResult) {
+    if call.method == "ping" {
+      result("ok")
+      return
+    }
     let args = call.arguments as! [String: Any];
     if #available(iOS 13.0, OSX 15.0, tvOS 13.0, watchOS 6.0, *) {
     switch call.method {