feat: Bring over the cryptography API from moxplatform

android/src/main/AndroidManifest.xml

@@ -4,7 +4,7 @@
     <application>
         <provider
             android:name="org.moxxy.moxxy_native.content.MoxxyFileProvider"
-            android:authorities="org.moxxy.moxxyv2.fileprovider"
+            android:authorities="org.moxxy.moxxyv2.fileprovider2"
             android:exported="false"
             android:grantUriPermissions="true">
             <meta-data

android/src/main/kotlin/org/moxxy/moxxy_native/Constants.kt

@@ -2,6 +2,9 @@ package org.moxxy.moxxy_native
 
 const val TAG = "moxxy_native"
 
+// The size of buffers to use for various operations
+const val BUFFER_SIZE = 4096
+
 // The data key for text entered in the notification's reply field
 const val REPLY_TEXT_KEY = "key_reply_text"
 

android/src/main/kotlin/org/moxxy/moxxy_native/MoxxyNativePlugin.kt

@@ -13,6 +13,8 @@ import io.flutter.embedding.engine.plugins.FlutterPlugin
 import io.flutter.embedding.engine.plugins.activity.ActivityAware
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding
 import io.flutter.plugin.common.EventChannel
+import org.moxxy.moxxy_native.cryptography.CryptographyImplementation
+import org.moxxy.moxxy_native.cryptography.MoxxyCryptographyApi
 import org.moxxy.moxxy_native.notifications.MessagingNotification
 import org.moxxy.moxxy_native.notifications.MoxxyNotificationsApi
 import org.moxxy.moxxy_native.notifications.NotificationChannel
@@ -57,11 +59,13 @@ class MoxxyNativePlugin : FlutterPlugin, ActivityAware, MoxxyPickerApi, MoxxyNot
     private var activity: Activity? = null
     private lateinit var activityClass: Class<Any>
     private lateinit var pickerListener: PickerResultListener
+    private val cryptographyImplementation = CryptographyImplementation()
 
     override fun onAttachedToEngine(@NonNull flutterPluginBinding: FlutterPlugin.FlutterPluginBinding) {
         context = flutterPluginBinding.applicationContext
         MoxxyPickerApi.setUp(flutterPluginBinding.binaryMessenger, this)
         MoxxyNotificationsApi.setUp(flutterPluginBinding.binaryMessenger, this)
+        MoxxyCryptographyApi.setUp(flutterPluginBinding.binaryMessenger, cryptographyImplementation)
         pickerListener = PickerResultListener(context!!)
         Log.d(TAG, "Attached to engine")
     }

android/src/main/kotlin/org/moxxy/moxxy_native/cryptography/CryptographyApi.kt

@@ -0,0 +1,192 @@
+// Autogenerated from Pigeon (v11.0.1), do not edit directly.
+// See also: https://pub.dev/packages/pigeon
+
+package org.moxxy.moxxy_native.cryptography
+
+import android.util.Log
+import io.flutter.plugin.common.BasicMessageChannel
+import io.flutter.plugin.common.BinaryMessenger
+import io.flutter.plugin.common.MessageCodec
+import io.flutter.plugin.common.StandardMessageCodec
+import java.io.ByteArrayOutputStream
+import java.nio.ByteBuffer
+
+private fun wrapResult(result: Any?): List<Any?> {
+    return listOf(result)
+}
+
+private fun wrapError(exception: Throwable): List<Any?> {
+    if (exception is FlutterError) {
+        return listOf(
+            exception.code,
+            exception.message,
+            exception.details,
+        )
+    } else {
+        return listOf(
+            exception.javaClass.simpleName,
+            exception.toString(),
+            "Cause: " + exception.cause + ", Stacktrace: " + Log.getStackTraceString(exception),
+        )
+    }
+}
+
+/**
+ * Error class for passing custom error details to Flutter via a thrown PlatformException.
+ * @property code The error code.
+ * @property message The error message.
+ * @property details The error details. Must be a datatype supported by the api codec.
+ */
+class FlutterError(
+    val code: String,
+    override val message: String? = null,
+    val details: Any? = null,
+) : Throwable()
+
+enum class CipherAlgorithm(val raw: Int) {
+    AES128GCMNOPADDING(0),
+    AES256GCMNOPADDING(1),
+    AES256CBCPKCS7(2),
+    ;
+
+    companion object {
+        fun ofRaw(raw: Int): CipherAlgorithm? {
+            return values().firstOrNull { it.raw == raw }
+        }
+    }
+}
+
+/** Generated class from Pigeon that represents data sent in messages. */
+data class CryptographyResult(
+    val plaintextHash: ByteArray,
+    val ciphertextHash: ByteArray,
+
+) {
+    companion object {
+        @Suppress("UNCHECKED_CAST")
+        fun fromList(list: List<Any?>): CryptographyResult {
+            val plaintextHash = list[0] as ByteArray
+            val ciphertextHash = list[1] as ByteArray
+            return CryptographyResult(plaintextHash, ciphertextHash)
+        }
+    }
+    fun toList(): List<Any?> {
+        return listOf<Any?>(
+            plaintextHash,
+            ciphertextHash,
+        )
+    }
+}
+
+@Suppress("UNCHECKED_CAST")
+private object MoxxyCryptographyApiCodec : StandardMessageCodec() {
+    override fun readValueOfType(type: Byte, buffer: ByteBuffer): Any? {
+        return when (type) {
+            128.toByte() -> {
+                return (readValue(buffer) as? List<Any?>)?.let {
+                    CryptographyResult.fromList(it)
+                }
+            }
+            else -> super.readValueOfType(type, buffer)
+        }
+    }
+    override fun writeValue(stream: ByteArrayOutputStream, value: Any?) {
+        when (value) {
+            is CryptographyResult -> {
+                stream.write(128)
+                writeValue(stream, value.toList())
+            }
+            else -> super.writeValue(stream, value)
+        }
+    }
+}
+
+/** Generated interface from Pigeon that represents a handler of messages from Flutter. */
+interface MoxxyCryptographyApi {
+    fun encryptFile(sourcePath: String, destPath: String, key: ByteArray, iv: ByteArray, algorithm: CipherAlgorithm, hashSpec: String, callback: (Result<CryptographyResult?>) -> Unit)
+    fun decryptFile(sourcePath: String, destPath: String, key: ByteArray, iv: ByteArray, algorithm: CipherAlgorithm, hashSpec: String, callback: (Result<CryptographyResult?>) -> Unit)
+    fun hashFile(sourcePath: String, hashSpec: String, callback: (Result<ByteArray?>) -> Unit)
+
+    companion object {
+        /** The codec used by MoxxyCryptographyApi. */
+        val codec: MessageCodec<Any?> by lazy {
+            MoxxyCryptographyApiCodec
+        }
+
+        /** Sets up an instance of `MoxxyCryptographyApi` to handle messages through the `binaryMessenger`. */
+        @Suppress("UNCHECKED_CAST")
+        fun setUp(binaryMessenger: BinaryMessenger, api: MoxxyCryptographyApi?) {
+            run {
+                val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.moxxy_native.MoxxyCryptographyApi.encryptFile", codec)
+                if (api != null) {
+                    channel.setMessageHandler { message, reply ->
+                        val args = message as List<Any?>
+                        val sourcePathArg = args[0] as String
+                        val destPathArg = args[1] as String
+                        val keyArg = args[2] as ByteArray
+                        val ivArg = args[3] as ByteArray
+                        val algorithmArg = CipherAlgorithm.ofRaw(args[4] as Int)!!
+                        val hashSpecArg = args[5] as String
+                        api.encryptFile(sourcePathArg, destPathArg, keyArg, ivArg, algorithmArg, hashSpecArg) { result: Result<CryptographyResult?> ->
+                            val error = result.exceptionOrNull()
+                            if (error != null) {
+                                reply.reply(wrapError(error))
+                            } else {
+                                val data = result.getOrNull()
+                                reply.reply(wrapResult(data))
+                            }
+                        }
+                    }
+                } else {
+                    channel.setMessageHandler(null)
+                }
+            }
+            run {
+                val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.moxxy_native.MoxxyCryptographyApi.decryptFile", codec)
+                if (api != null) {
+                    channel.setMessageHandler { message, reply ->
+                        val args = message as List<Any?>
+                        val sourcePathArg = args[0] as String
+                        val destPathArg = args[1] as String
+                        val keyArg = args[2] as ByteArray
+                        val ivArg = args[3] as ByteArray
+                        val algorithmArg = CipherAlgorithm.ofRaw(args[4] as Int)!!
+                        val hashSpecArg = args[5] as String
+                        api.decryptFile(sourcePathArg, destPathArg, keyArg, ivArg, algorithmArg, hashSpecArg) { result: Result<CryptographyResult?> ->
+                            val error = result.exceptionOrNull()
+                            if (error != null) {
+                                reply.reply(wrapError(error))
+                            } else {
+                                val data = result.getOrNull()
+                                reply.reply(wrapResult(data))
+                            }
+                        }
+                    }
+                } else {
+                    channel.setMessageHandler(null)
+                }
+            }
+            run {
+                val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.moxxy_native.MoxxyCryptographyApi.hashFile", codec)
+                if (api != null) {
+                    channel.setMessageHandler { message, reply ->
+                        val args = message as List<Any?>
+                        val sourcePathArg = args[0] as String
+                        val hashSpecArg = args[1] as String
+                        api.hashFile(sourcePathArg, hashSpecArg) { result: Result<ByteArray?> ->
+                            val error = result.exceptionOrNull()
+                            if (error != null) {
+                                reply.reply(wrapError(error))
+                            } else {
+                                val data = result.getOrNull()
+                                reply.reply(wrapResult(data))
+                            }
+                        }
+                    }
+                } else {
+                    channel.setMessageHandler(null)
+                }
+            }
+        }
+    }
+}

android/src/main/kotlin/org/moxxy/moxxy_native/cryptography/CryptographyImplementation.kt

@@ -0,0 +1,169 @@
+package org.moxxy.moxxy_native.cryptography
+
+import android.util.Log
+import org.moxxy.moxxy_native.BUFFER_SIZE
+import org.moxxy.moxxy_native.TAG
+import java.io.FileInputStream
+import java.security.MessageDigest
+import javax.crypto.Cipher
+import javax.crypto.CipherOutputStream
+import javax.crypto.spec.IvParameterSpec
+import javax.crypto.spec.SecretKeySpec
+import kotlin.concurrent.thread
+
+/*
+ * Convert the algorithm spec @algorithm to the format that Java/Android understands
+ * */
+private fun getCipherSpecFromInteger(algorithm: CipherAlgorithm): String {
+    return when (algorithm) {
+        CipherAlgorithm.AES128GCMNOPADDING -> "AES_128/GCM/NoPadding"
+        CipherAlgorithm.AES256GCMNOPADDING -> "AES_256/GCM/NoPadding"
+        CipherAlgorithm.AES256CBCPKCS7 -> "AES_256/CBC/PKCS7PADDING"
+    }
+}
+
+/*
+ * Implementation of Moxxy's cryptography API
+ * */
+class CryptographyImplementation : MoxxyCryptographyApi {
+    override fun encryptFile(
+        sourcePath: String,
+        destPath: String,
+        key: ByteArray,
+        iv: ByteArray,
+        algorithm: CipherAlgorithm,
+        hashSpec: String,
+        callback: (Result<CryptographyResult?>) -> Unit,
+    ) {
+        thread(start = true) {
+            val cipherSpec = getCipherSpecFromInteger(algorithm)
+            val buffer = ByteArray(BUFFER_SIZE)
+            val secretKey = SecretKeySpec(key, cipherSpec)
+            val inputStream = FileInputStream(sourcePath)
+            try {
+                val digest = MessageDigest.getInstance(hashSpec)
+                val cipher = Cipher.getInstance(cipherSpec).apply {
+                    init(Cipher.ENCRYPT_MODE, secretKey, IvParameterSpec(iv))
+                }
+                val fileOutputStream = HashedFileOutputStream(destPath, hashSpec)
+                val cipherOutputStream = CipherOutputStream(fileOutputStream, cipher)
+                var length: Int
+                while (true) {
+                    length = inputStream.read(buffer)
+                    if (length <= 0) break
+
+                    digest.update(buffer, 0, length)
+                    cipherOutputStream.write(buffer, 0, length)
+                }
+
+                // Clean up
+                cipherOutputStream.apply {
+                    flush()
+                    close()
+                }
+
+                // Success
+                callback(
+                    Result.success(
+                        CryptographyResult(
+                            plaintextHash = digest.digest(),
+                            ciphertextHash = fileOutputStream.digest(),
+                        ),
+                    ),
+                )
+            } catch (ex: Exception) {
+                Log.e(TAG, "Failed to encrypt file $sourcePath: ${ex.message}")
+                callback(Result.success(null))
+            } finally {
+                // Clean up
+                inputStream.close()
+            }
+        }
+    }
+
+    override fun decryptFile(
+        sourcePath: String,
+        destPath: String,
+        key: ByteArray,
+        iv: ByteArray,
+        algorithm: CipherAlgorithm,
+        hashSpec: String,
+        callback: (Result<CryptographyResult?>) -> Unit,
+    ) {
+        thread(start = true) {
+            val cipherSpec = getCipherSpecFromInteger(algorithm)
+            val buffer = ByteArray(BUFFER_SIZE)
+            val secretKey = SecretKeySpec(key, cipherSpec)
+            val inputStream = FileInputStream(sourcePath)
+            try {
+                val digest = MessageDigest.getInstance(hashSpec)
+                val cipher = Cipher.getInstance(cipherSpec).apply {
+                    init(Cipher.DECRYPT_MODE, secretKey, IvParameterSpec(iv))
+                }
+                val fileOutputStream = HashedFileOutputStream(destPath, hashSpec)
+                val cipherOutputStream = CipherOutputStream(fileOutputStream, cipher)
+                var length: Int
+                while (true) {
+                    length = inputStream.read(buffer)
+                    if (length <= 0) break
+
+                    digest.update(buffer, 0, length)
+                    cipherOutputStream.write(buffer, 0, length)
+                }
+
+                // Clean up
+                cipherOutputStream.apply {
+                    flush()
+                    close()
+                }
+
+                // Success
+                callback(
+                    Result.success(
+                        CryptographyResult(
+                            plaintextHash = digest.digest(),
+                            ciphertextHash = fileOutputStream.digest(),
+                        ),
+                    ),
+                )
+            } catch (ex: Exception) {
+                Log.e(TAG, "Failed to decrypt file $sourcePath: ${ex.message}")
+                callback(Result.success(null))
+            } finally {
+                // Clean up
+                inputStream.close()
+            }
+        }
+    }
+
+    override fun hashFile(
+        sourcePath: String,
+        hashSpec: String,
+        callback: (Result<ByteArray?>) -> Unit,
+    ) {
+        thread(start = true) {
+            val buffer = ByteArray(BUFFER_SIZE)
+            val inputStream = FileInputStream(sourcePath)
+            try {
+                val digest = MessageDigest.getInstance(hashSpec)
+                var length: Int
+                while (true) {
+                    length = inputStream.read(buffer)
+                    if (length <= 0) break
+
+                    // Only update the digest if we read more than 0 bytes
+                    digest.update(buffer, 0, length)
+                }
+
+                // Return success
+                callback(Result.success(digest.digest()))
+            } catch (ex: Exception) {
+                Log.e(TAG, "Failed to has file $sourcePath with $hashSpec: ${ex.message}")
+                callback(Result.success(null))
+            } finally {
+                // Clean up
+                inputStream.close()
+            }
+        }
+    }
+}

android/src/main/kotlin/org/moxxy/moxxy_native/cryptography/HashedFileOutputStream.kt

@@ -0,0 +1,25 @@
+package org.moxxy.moxxy_native.cryptography
+
+import java.io.FileOutputStream
+import java.security.MessageDigest
+
+/*
+ * A FileOutputStream that continuously hashes whatever it writes to the file.
+ */
+class HashedFileOutputStream(name: String, hashAlgorithm: String) : FileOutputStream(name) {
+    private val digest: MessageDigest
+
+    init {
+        this.digest = MessageDigest.getInstance(hashAlgorithm)
+    }
+
+    override fun write(buffer: ByteArray, offset: Int, length: Int) {
+        super.write(buffer, offset, length)
+
+        digest.update(buffer, offset, length)
+    }
+
+    fun digest(): ByteArray {
+        return digest.digest()
+    }
+}

example/lib/main.dart

@@ -1,3 +1,5 @@
+import 'dart:io';
+import 'dart:typed_data';
 import 'package:flutter/material.dart';
 import 'package:moxxy_native/moxxy_native.dart';
 
@@ -5,9 +7,16 @@ void main() {
   runApp(const MyApp());
 }
 
-class MyApp extends StatelessWidget {
+class MyApp extends StatefulWidget {
   const MyApp({super.key});
 
+  @override
+  MyAppState createState() => MyAppState();
+}
+
+class MyAppState extends State<MyApp> {
+  String? imagePath;
+
   @override
   Widget build(BuildContext context) {
     return MaterialApp(
@@ -44,6 +53,48 @@ class MyApp extends StatelessWidget {
               },
               child: const Text('Generic multi-picker'),
             ),
+            TextButton(
+              onPressed: () async {
+                final result = await MoxxyPickerApi().pickFiles(FilePickerType.image, false);
+                if (result.isEmpty) return;
+
+                final encDest = result.first! + '.enc';
+                final decDest = result.first! + '.dec';
+                final encResult = await MoxxyCryptographyApi().encryptFile(
+                  result.first!,
+                  encDest,
+                  Uint8List.fromList(List.filled(32, 1)),
+                  Uint8List.fromList(List.filled(16, 2)),
+                  CipherAlgorithm.aes256CbcPkcs7,
+                  'SHA-256',
+                );
+                if (encResult == null) {
+                  print('Failed to encrypt file');
+                  return;
+                }
+
+                final decResult = await MoxxyCryptographyApi().decryptFile(
+                  encDest,
+                  decDest,
+                  Uint8List.fromList(List.filled(32, 1)),
+                  Uint8List.fromList(List.filled(16, 2)),
+                  CipherAlgorithm.aes256CbcPkcs7,
+                  'SHA-256',
+                );
+                if (decResult == null) {
+                  print('Failed to decrypt file');
+                  return;
+                }
+
+                setState(() {
+                  imagePath = decDest;
+                });
+              },
+              child: Text('Test cryptography'),
+            ),
+
+            if (imagePath != null)
+              Image.file(File(imagePath!)),
           ],
         ),
       ),

example/pubspec.lock

@@ -130,54 +130,6 @@ packages:
       url: "https://pub.dev"
     source: hosted
     version: "1.8.2"
-  permission_handler:
-    dependency: "direct main"
-    description:
-      name: permission_handler
-      sha256: bc56bfe9d3f44c3c612d8d393bd9b174eb796d706759f9b495ac254e4294baa5
-      url: "https://pub.dev"
-    source: hosted
-    version: "10.4.5"
-  permission_handler_android:
-    dependency: transitive
-    description:
-      name: permission_handler_android
-      sha256: "59c6322171c29df93a22d150ad95f3aa19ed86542eaec409ab2691b8f35f9a47"
-      url: "https://pub.dev"
-    source: hosted
-    version: "10.3.6"
-  permission_handler_apple:
-    dependency: transitive
-    description:
-      name: permission_handler_apple
-      sha256: "99e220bce3f8877c78e4ace901082fb29fa1b4ebde529ad0932d8d664b34f3f5"
-      url: "https://pub.dev"
-    source: hosted
-    version: "9.1.4"
-  permission_handler_platform_interface:
-    dependency: transitive
-    description:
-      name: permission_handler_platform_interface
-      sha256: f2343e9fa9c22ae4fd92d4732755bfe452214e7189afcc097380950cf567b4b2
-      url: "https://pub.dev"
-    source: hosted
-    version: "3.11.5"
-  permission_handler_windows:
-    dependency: transitive
-    description:
-      name: permission_handler_windows
-      sha256: cc074aace208760f1eee6aa4fae766b45d947df85bc831cde77009cdb4720098
-      url: "https://pub.dev"
-    source: hosted
-    version: "0.1.3"
-  plugin_platform_interface:
-    dependency: transitive
-    description:
-      name: plugin_platform_interface
-      sha256: da3fdfeccc4d4ff2da8f8c556704c08f912542c5fb3cf2233ed75372384a034d
-      url: "https://pub.dev"
-    source: hosted
-    version: "2.1.6"
   sky_engine:
     dependency: transitive
     description: flutter
@@ -241,4 +193,4 @@ packages:
     version: "2.1.4"
 sdks:
   dart: ">=2.19.6 <3.0.0"
-  flutter: ">=2.8.0"
+  flutter: ">=2.5.0"

lib/moxxy_native.dart

@@ -1,2 +1,3 @@
+export 'pigeon/cryptography.g.dart';
 export 'pigeon/notifications.g.dart';
 export 'pigeon/picker.g.dart';

lib/pigeon/cryptography.g.dart

@@ -0,0 +1,141 @@
+// Autogenerated from Pigeon (v11.0.1), do not edit directly.
+// See also: https://pub.dev/packages/pigeon
+// ignore_for_file: public_member_api_docs, non_constant_identifier_names, avoid_as, unused_import, unnecessary_parenthesis, prefer_null_aware_operators, omit_local_variable_types, unused_shown_name, unnecessary_import
+
+import 'dart:async';
+import 'dart:typed_data' show Float64List, Int32List, Int64List, Uint8List;
+
+import 'package:flutter/foundation.dart' show ReadBuffer, WriteBuffer;
+import 'package:flutter/services.dart';
+
+enum CipherAlgorithm {
+  aes128GcmNoPadding,
+  aes256GcmNoPadding,
+  aes256CbcPkcs7,
+}
+
+class CryptographyResult {
+  CryptographyResult({
+    required this.plaintextHash,
+    required this.ciphertextHash,
+  });
+
+  Uint8List plaintextHash;
+
+  Uint8List ciphertextHash;
+
+  Object encode() {
+    return <Object?>[
+      plaintextHash,
+      ciphertextHash,
+    ];
+  }
+
+  static CryptographyResult decode(Object result) {
+    result as List<Object?>;
+    return CryptographyResult(
+      plaintextHash: result[0]! as Uint8List,
+      ciphertextHash: result[1]! as Uint8List,
+    );
+  }
+}
+
+class _MoxxyCryptographyApiCodec extends StandardMessageCodec {
+  const _MoxxyCryptographyApiCodec();
+  @override
+  void writeValue(WriteBuffer buffer, Object? value) {
+    if (value is CryptographyResult) {
+      buffer.putUint8(128);
+      writeValue(buffer, value.encode());
+    } else {
+      super.writeValue(buffer, value);
+    }
+  }
+
+  @override
+  Object? readValueOfType(int type, ReadBuffer buffer) {
+    switch (type) {
+      case 128: 
+        return CryptographyResult.decode(readValue(buffer)!);
+      default:
+        return super.readValueOfType(type, buffer);
+    }
+  }
+}
+
+class MoxxyCryptographyApi {
+  /// Constructor for [MoxxyCryptographyApi].  The [binaryMessenger] named argument is
+  /// available for dependency injection.  If it is left null, the default
+  /// BinaryMessenger will be used which routes to the host platform.
+  MoxxyCryptographyApi({BinaryMessenger? binaryMessenger})
+      : _binaryMessenger = binaryMessenger;
+  final BinaryMessenger? _binaryMessenger;
+
+  static const MessageCodec<Object?> codec = _MoxxyCryptographyApiCodec();
+
+  Future<CryptographyResult?> encryptFile(String arg_sourcePath, String arg_destPath, Uint8List arg_key, Uint8List arg_iv, CipherAlgorithm arg_algorithm, String arg_hashSpec) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.moxxy_native.MoxxyCryptographyApi.encryptFile', codec,
+        binaryMessenger: _binaryMessenger);
+    final List<Object?>? replyList =
+        await channel.send(<Object?>[arg_sourcePath, arg_destPath, arg_key, arg_iv, arg_algorithm.index, arg_hashSpec]) as List<Object?>?;
+    if (replyList == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyList.length > 1) {
+      throw PlatformException(
+        code: replyList[0]! as String,
+        message: replyList[1] as String?,
+        details: replyList[2],
+      );
+    } else {
+      return (replyList[0] as CryptographyResult?);
+    }
+  }
+
+  Future<CryptographyResult?> decryptFile(String arg_sourcePath, String arg_destPath, Uint8List arg_key, Uint8List arg_iv, CipherAlgorithm arg_algorithm, String arg_hashSpec) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.moxxy_native.MoxxyCryptographyApi.decryptFile', codec,
+        binaryMessenger: _binaryMessenger);
+    final List<Object?>? replyList =
+        await channel.send(<Object?>[arg_sourcePath, arg_destPath, arg_key, arg_iv, arg_algorithm.index, arg_hashSpec]) as List<Object?>?;
+    if (replyList == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyList.length > 1) {
+      throw PlatformException(
+        code: replyList[0]! as String,
+        message: replyList[1] as String?,
+        details: replyList[2],
+      );
+    } else {
+      return (replyList[0] as CryptographyResult?);
+    }
+  }
+
+  Future<Uint8List?> hashFile(String arg_sourcePath, String arg_hashSpec) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.moxxy_native.MoxxyCryptographyApi.hashFile', codec,
+        binaryMessenger: _binaryMessenger);
+    final List<Object?>? replyList =
+        await channel.send(<Object?>[arg_sourcePath, arg_hashSpec]) as List<Object?>?;
+    if (replyList == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyList.length > 1) {
+      throw PlatformException(
+        code: replyList[0]! as String,
+        message: replyList[1] as String?,
+        details: replyList[2],
+      );
+    } else {
+      return (replyList[0] as Uint8List?);
+    }
+  }
+}

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);
+}