feat: Bring over the cryptography API from moxplatform

pigeon/cryptography.dart

@@ -0,0 +1,34 @@
+import 'package:pigeon/pigeon.dart';
+
+@ConfigurePigeon(
+  PigeonOptions(
+    dartOut: 'lib/pigeon/cryptography.g.dart',
+    kotlinOut: 'android/src/main/kotlin/org/moxxy/moxxy_native/cryptography/CryptographyApi.kt',
+    kotlinOptions: KotlinOptions(
+      package: 'org.moxxy.moxxy_native.cryptography',
+    ),
+  ),
+)
+enum CipherAlgorithm {
+  aes128GcmNoPadding,
+  aes256GcmNoPadding,
+  aes256CbcPkcs7;
+}
+
+class CryptographyResult {
+  const CryptographyResult(this.plaintextHash, this.ciphertextHash);
+  final Uint8List plaintextHash;
+  final Uint8List ciphertextHash;
+}
+
+@HostApi()
+abstract class MoxxyCryptographyApi {
+  @async
+  CryptographyResult? encryptFile(String sourcePath, String destPath, Uint8List key, Uint8List iv, CipherAlgorithm algorithm, String hashSpec);
+
+  @async
+  CryptographyResult? decryptFile(String sourcePath, String destPath, Uint8List key, Uint8List iv, CipherAlgorithm algorithm, String hashSpec);
+
+  @async
+  Uint8List? hashFile(String sourcePath, String hashSpec);
+}