refactor: (WIP) optimize exceptions and bytearray

packages/native_crypto/lib/native_crypto.dart

@@ -3,7 +3,7 @@
 // -----
 // File: native_crypto.dart
 // Created Date: 16/12/2021 16:28:00
-// Last Modified: 25/05/2022 10:48:20
+// Last Modified: 26/05/2022 12:10:42
 // -----
 // Copyright (c) 2021
 
@@ -23,7 +23,6 @@ export 'src/kdf/kdf.dart';
 export 'src/keys/keys.dart';
 // Utils
 export 'src/utils/cipher_algorithm.dart';
-export 'src/utils/convert.dart';
 export 'src/utils/hash_algorithm.dart';
 export 'src/utils/kdf_algorithm.dart';
 

packages/native_crypto/lib/src/core/cipher_text.dart

@@ -3,81 +3,144 @@
 // -----
 // File: cipher_text.dart
 // Created Date: 16/12/2021 16:59:53
-// Last Modified: 24/05/2022 21:27:44
+// Last Modified: 26/05/2022 16:22:49
 // -----
 // Copyright (c) 2021
 
 import 'dart:typed_data';
 
-import 'package:native_crypto/src/interfaces/byte_array.dart';
+import 'package:native_crypto/src/utils/cipher_algorithm.dart';
+import 'package:native_crypto/src/utils/extensions.dart';
+import 'package:native_crypto_platform_interface/native_crypto_platform_interface.dart';
 
-class CipherText extends ByteArray {
+/// Represents a cipher text in Native Crypto.
+///
+/// It is represented as a [List] of [Uint8List] like:
+/// ```txt
+/// [[NONCE], [MESSAGE + TAG]]
+/// ```
+/// where:
+/// - `[NONCE]` is a [Uint8List] of length [CipherText.ivLength]
+/// - `[MESSAGE + TAG]` is a [Uint8List] of length [CipherText.dataLength]
+/// 
+/// To 
+///
+/// So accessing just the Message or just the Tag is costly and should be 
+/// done only when needed.
+class CipherText {
   final int _ivLength;
-  final int _dataLength;
+  final int _messageLength;
   final int _tagLength;
 
-  final Uint8List _iv;
+  final CipherAlgorithm? _cipherAlgorithm;
 
-  CipherText(Uint8List iv, Uint8List data, Uint8List? tag)
+  final Uint8List? _iv;
-      : _ivLength = iv.length,
+  final Uint8List? _data; // Contains the message + tag (if any)
-        _dataLength = data.length,
-        _tagLength = tag?.length ?? 0,
-        _iv = iv,
-        super((tag != null) ? Uint8List.fromList(data + tag) : data);
 
-  CipherText.fromBytes(
+  CipherText._(
-    Uint8List bytes, {
+    this._ivLength,
-    required int ivLength,
+    this._messageLength,
-    required int dataLength,
+    this._tagLength,
-    int tagLength = 0,
+    this._cipherAlgorithm,
-  })  : _ivLength = ivLength,
+    this._iv,
-        _dataLength = dataLength,
+    this._data,
-        _tagLength = tagLength,
+  );
-        _iv = bytes.sublist(0, ivLength),
-        super(bytes.sublist(ivLength, bytes.length - tagLength));
 
-  const CipherText.fromIvAndBytes(
+  /// Gets the [CipherAlgorithm] used to encrypt the [CipherText].
-    Uint8List iv,
+  CipherAlgorithm get cipherAlgorithm {
-    super.data, {
+    if (_cipherAlgorithm.isNotNull) {
-    required int dataLength,
+      return _cipherAlgorithm!;
-    int tagLength = 0,
+    } else {
-  })  : _ivLength = iv.length,
+      throw NativeCryptoException(
-        _dataLength = dataLength,
+        message: 'Cipher algorithm is not specified',
-        _tagLength = tagLength,
+        code: NativeCryptoExceptionCode.invalid_cipher.code,
-        _iv = iv;
+      );
+    }
+  }
 
-  CipherText.fromPairIvAndBytes(
+  /// Gets the [Uint8List] of the [CipherText]'s IV.
-    List<Uint8List> pair, {
+  Uint8List get iv {
-    required int dataLength,
+    if (_iv.isNotNull) {
-    int tagLength = 0,
+      return _iv!;
-  })  : _ivLength = pair.first.length,
+    } else {
-        _dataLength = dataLength,
+      throw NativeCryptoException(
-        _tagLength = tagLength,
+        message: 'IV is not specified',
-        _iv = pair.first,
+        code: NativeCryptoExceptionCode.invalid_data.code,
-        super(pair.last);
+      );
+    }
+  }
 
-  /// Gets the CipherText IV.
+  /// Gets the length of the [CipherText]'s IV.
-  Uint8List get iv => _iv;
-
-  /// Gets the CipherText data.
-  Uint8List get data => _tagLength > 0
-      ? bytes.sublist(0, _dataLength - _tagLength)
-      : bytes;
-
-  /// Gets the CipherText tag.
-  Uint8List get tag => _tagLength > 0
-      ? bytes.sublist(_dataLength - _tagLength, _dataLength)
-      : Uint8List(0);
-
-  /// Gets the CipherText data and tag.
-  Uint8List get payload => bytes;
-
-  /// Gets the CipherText IV length.
   int get ivLength => _ivLength;
 
-  /// Gets the CipherText data length.
+  /// Gets the [Uint8List] of the [CipherText]'s data.
-  int get dataLength => _dataLength;
+  Uint8List get data {
+    if (_data.isNotNull) {
+      return _data!;
+    } else {
+      throw NativeCryptoException(
+        message: 'Data is not specified',
+        code: NativeCryptoExceptionCode.invalid_data.code,
+      );
+    }
+  }
 
-  /// Gets the CipherText tag length.
+  /// Gets the length of the [CipherText]'s data.
-  int get tagLength => _tagLength;
+  int get dataLength => _messageLength + _tagLength;
+
+  // CipherText.fromBytes(
+  //   Uint8List bytes, {
+  //   required int ivLength,
+  //   required int dataLength,
+  //   int tagLength = 0,
+  // })  : _ivLength = ivLength,
+  //       _dataLength = dataLength,
+  //       _tagLength = tagLength,
+  //       _iv = bytes.sublist(0, ivLength),
+  //       super(bytes.sublist(ivLength, bytes.length - tagLength));
+
+  // const CipherText.fromIvAndBytes(
+  //   Uint8List iv,
+  //   super.data, {
+  //   required int dataLength,
+  //   int tagLength = 0,
+  // })  : _ivLength = iv.length,
+  //       _dataLength = dataLength,
+  //       _tagLength = tagLength,
+  //       _iv = iv;
+
+  // CipherText.fromPairIvAndBytes(
+  //   List<Uint8List> pair, {
+  //   required int dataLength,
+  //   int tagLength = 0,
+  // })  : _ivLength = pair.first.length,
+  //       _dataLength = dataLength,
+  //       _tagLength = tagLength,
+  //       _iv = pair.first,
+  //       super(pair.last);
+
+  // /// Gets the CipherText IV.
+  // Uint8List get iv => _iv;
+
+  // /// Gets the CipherText data.
+  // Uint8List get data => _tagLength > 0
+  //     ? bytes.sublist(0, _dataLength - _tagLength)
+  //     : bytes;
+
+  // /// Gets the CipherText tag.
+  // Uint8List get tag => _tagLength > 0
+  //     ? bytes.sublist(_dataLength - _tagLength, _dataLength)
+  //     : Uint8List(0);
+
+  // /// Gets the CipherText data and tag.
+  // Uint8List get payload => bytes;
+
+  // /// Gets the CipherText IV length.
+  // int get ivLength => _ivLength;
+
+  // /// Gets the CipherText data length.
+  // int get dataLength => _dataLength;
+
+  // /// Gets the CipherText tag length.
+  // int get tagLength => _tagLength;
 }

packages/native_crypto/lib/src/core/cipher_text_wrapper.dart

@@ -0,0 +1,89 @@
+// Author: Hugo Pointcheval
+// Email: git@pcl.ovh
+// -----
+// File: cipher_text_wrapper.dart
+// Created Date: 26/05/2022 14:27:32
+// Last Modified: 26/05/2022 15:53:46
+// -----
+// Copyright (c) 2022
+
+import 'dart:typed_data';
+
+import 'package:native_crypto/native_crypto.dart';
+import 'package:native_crypto/src/utils/extensions.dart';
+
+class CipherTextWrapper {
+  final CipherText? _single;
+  final List<CipherText>? _list;
+
+  CipherTextWrapper._(this._single, this._list);
+
+  factory CipherTextWrapper.single(CipherText cipherText) =>
+      CipherTextWrapper._(cipherText, null);
+
+  factory CipherTextWrapper.list(List<CipherText> cipherTexts) =>
+      CipherTextWrapper._(null, cipherTexts);
+
+  factory CipherTextWrapper.fromBytes(
+      // Uint8List bytes, {
+      // required int ivLength,
+      // required int dataLength,
+      // int tagLength = 0,
+      // int? chunkSize,
+      // }
+      ) {
+        // TODO(hpcl): implement fromBytes
+    throw UnimplementedError();
+  }
+
+  bool get isSingle => _single.isNotNull;
+  bool get isList => _list.isNotNull;
+
+  /// Gets the [CipherText] if it's a single one.
+  ///
+  /// Throws [NativeCryptoException] with
+  /// [NativeCryptoExceptionCode.invalid_data] if it's not a single one.
+  CipherText get single {
+    if (isSingle) {
+      return _single!;
+    } else {
+      throw NativeCryptoException(
+        message: 'CipherTextWrapper is not single',
+        code: NativeCryptoExceptionCode.invalid_data.code,
+      );
+    }
+  }
+
+  /// Gets the [List] of [CipherText] if it's a list.
+  ///
+  /// Throws [NativeCryptoException] with
+  /// [NativeCryptoExceptionCode.invalid_data] if it's not a list.
+  List<CipherText> get list {
+    if (isList) {
+      return _list!;
+    } else {
+      throw NativeCryptoException(
+        message: 'CipherTextWrapper is not list',
+        code: NativeCryptoExceptionCode.invalid_data.code,
+      );
+    }
+  }
+
+  /// Gets the raw [Uint8List] of the [CipherText] or [List] of [CipherText].
+  Uint8List get raw {
+    if (isSingle) {
+      return single.bytes;
+    } else {
+      return list.map((cipherText) => cipherText.bytes).toList().sum();
+    }
+  }
+
+  int get chunkCount {
+    _single.isNull;
+    if (_single.isNotNull) {
+      return 1;
+    } else {
+      return _list?.length ?? 0;
+    }
+  }
+}

packages/native_crypto/lib/src/interfaces/byte_array.dart

@@ -3,47 +3,58 @@
 // -----
 // File: byte_array.dart
 // Created Date: 16/12/2021 17:54:16
-// Last Modified: 23/05/2022 23:07:03
+// Last Modified: 26/05/2022 14:25:05
 // -----
 // Copyright (c) 2021
 
-import 'dart:convert' as convert;
 import 'dart:typed_data';
 
 import 'package:flutter/foundation.dart';
-import 'package:native_crypto/src/utils/convert.dart';
+import 'package:native_crypto/src/utils/encoding.dart';
+import 'package:native_crypto/src/utils/extensions.dart';
 
 @immutable
 abstract class ByteArray {
   final Uint8List _bytes;
 
+  /// Creates a [ByteArray] from a [Uint8List].
   const ByteArray(this._bytes);
 
-  /// Creates an ByteArray object from a hexdecimal string.
+  /// Creates a [ByteArray] object from a hexdecimal string.
   ByteArray.fromBase16(String encoded)
-      : _bytes = Convert.decodeHexString(encoded);
+      : _bytes = encoded.toBytes(from: Encoding.base16);
 
-  /// Creates an ByteArray object from a Base64 string.
+  /// Creates a [ByteArray] object from a Base64 string.
   ByteArray.fromBase64(String encoded)
-      : _bytes = convert.base64.decode(encoded);
+      : _bytes = encoded.toBytes(from: Encoding.base64);
 
-  /// Creates an ByteArray object from a UTF-8 string.
+  /// Creates a [ByteArray] object from an UTF-8 string.
-  ByteArray.fromUtf8(String input)
+  ByteArray.fromUtf8(String encoded)
-      : _bytes = Uint8List.fromList(convert.utf8.encode(input));
+      : _bytes = encoded.toBytes(from: Encoding.utf8);
 
-  /// Creates an ByteArray object from a length.
+  /// Creates a [ByteArray] object from an UTF-16 string.
+  ByteArray.fromUtf16(String encoded) : _bytes = encoded.toBytes();
+
+  /// Creates an empty [ByteArray] object from a length.
   ByteArray.fromLength(int length) : _bytes = Uint8List(length);
 
-  /// Gets the ByteArray bytes.
+  /// Creates a [ByteArray] object from a [List] of [int].
-  // ignore: unnecessary_getters_setters
+  ByteArray.fromList(List<int> list) : _bytes = list.toTypedList();
+
+  /// Gets the [ByteArray] bytes.
   Uint8List get bytes => _bytes;
 
-  /// Gets the ByteArray bytes as a Hexadecimal representation.
+  /// Gets the [ByteArray] bytes as a Hexadecimal representation.
-  String get base16 =>
+  String get base16 => _bytes.toStr(to: Encoding.base16);
-      _bytes.map((byte) => byte.toRadixString(16).padLeft(2, '0')).join();
 
-  /// Gets the ByteArray bytes as a Base64 representation.
+  /// Gets the [ByteArray] bytes as a Base64 representation.
-  String get base64 => convert.base64.encode(_bytes);
+  String get base64 => _bytes.toStr(to: Encoding.base64);
+
+  /// Gets the [ByteArray] bytes as an UTF-8 representation.
+  String get utf8 => _bytes.toStr(to: Encoding.utf8);
+
+  /// Gets the [ByteArray] bytes as an UTF-16 representation.
+  String get utf16 => _bytes.toStr();
 
   @override
   bool operator ==(Object other) {

packages/native_crypto/lib/src/keys/secret_key.dart

@@ -3,7 +3,7 @@
 // -----
 // File: secret_key.dart
 // Created Date: 28/12/2021 13:36:54
-// Last Modified: 25/05/2022 10:45:55
+// Last Modified: 26/05/2022 11:56:06
 // -----
 // Copyright (c) 2021
 
@@ -24,13 +24,22 @@ class SecretKey extends Key {
 
   static Future<SecretKey> fromSecureRandom(int bitsCount) async {
     try {
-      final Uint8List _key =
+      final Uint8List? _key = await platform.generateSecretKey(bitsCount);
-          (await platform.generateSecretKey(bitsCount)) ?? Uint8List(0);
+
+      if (_key == null || _key.isEmpty) {
+        throw const KeyException(
+          message: 'Could not generate secret key, platform returned null',
+          code: 'platform_returned_null',
+        );
+      }
 
       return SecretKey(_key);
     } catch (e, s) {
+      if (e is KeyException) {
+        rethrow;
+      }
       throw KeyException(
-        message: 'Failed to generate a secret key!',
+        message: '$e',
         code: 'failed_to_generate_secret_key',
         stackTrace: s,
       );

packages/native_crypto/lib/src/utils/convert.dart

@@ -1,23 +0,0 @@
-// Author: Hugo Pointcheval
-// Email: git@pcl.ovh
-// -----
-// File: convert.dart
-// Created Date: 16/12/2021 16:28:00
-// Last Modified: 23/05/2022 22:39:19
-// -----
-// Copyright (c) 2021
-
-import 'dart:typed_data';
-
-abstract class Convert {
-  static Uint8List decodeHexString(String input) {
-    assert(input.length.isEven, 'Input needs to be an even length.');
-
-    return Uint8List.fromList(
-      List.generate(
-        input.length ~/ 2,
-        (i) => int.parse(input.substring(i * 2, (i * 2) + 2), radix: 16),
-      ).toList(),
-    );
-  }
-}

packages/native_crypto/lib/src/utils/encoding.dart

@@ -0,0 +1,10 @@
+// Author: Hugo Pointcheval
+// Email: git@pcl.ovh
+// -----
+// File: encoding.dart
+// Created Date: 26/05/2022 12:12:34
+// Last Modified: 26/05/2022 12:18:09
+// -----
+// Copyright (c) 2022
+
+enum Encoding { utf8, utf16, base64, base16 }

packages/native_crypto/lib/src/utils/extensions.dart

@@ -0,0 +1,95 @@
+// Author: Hugo Pointcheval
+// Email: git@pcl.ovh
+// -----
+// File: extensions.dart
+// Created Date: 26/05/2022 12:12:48
+// Last Modified: 26/05/2022 15:49:38
+// -----
+// Copyright (c) 2022
+
+import 'dart:convert';
+import 'dart:developer' as developer;
+import 'dart:typed_data';
+
+import 'package:native_crypto/src/utils/encoding.dart';
+
+extension ObjectX on Object? {
+  /// Returns `true` if the object is `null`.
+  bool get isNull => this == null;
+
+  /// Returns `true` if the object is **not** `null`.
+  bool get isNotNull => this != null;
+  
+  /// Prints the object to the console.
+  void log() => developer.log(toString());
+}
+
+extension ListIntX on List<int> {
+  /// Converts a [List] of int to a [Uint8List].
+  Uint8List toTypedList() => Uint8List.fromList(this);
+}
+
+extension ListUint8ListX on List<Uint8List> {
+  /// Reduce a [List] of [Uint8List] to a [Uint8List].
+
+  Uint8List sum() {
+    for (var i = 1; i < length; i++) {
+      first.addAll(this[i]);
+      removeAt(i);
+    }
+    return first;
+  }
+}
+
+extension StringX on String {
+  /// Converts a [String] to a [Uint8List] using the specified [Encoding].
+  Uint8List toBytes({final Encoding from = Encoding.utf16}) {
+    Uint8List bytes;
+    switch (from) {
+      case Encoding.utf8:
+        bytes = utf8.encode(this).toTypedList();
+        break;
+      case Encoding.utf16:
+        bytes = runes.toList().toTypedList();
+        break;
+      case Encoding.base64:
+        bytes = base64.decode(this);
+        break;
+      case Encoding.base16:
+        assert(length.isEven, 'String needs to be an even length.');
+        bytes = List.generate(
+          length ~/ 2,
+          (i) => int.parse(substring(i * 2, (i * 2) + 2), radix: 16),
+        ).toList().toTypedList();
+    }
+    return bytes;
+  }
+}
+
+extension Uint8ListX on Uint8List {
+  /// Converts a [Uint8List] to a [String] using the specified [Encoding].
+  String toStr({final Encoding to = Encoding.utf16}) {
+    String str;
+    switch (to) {
+      case Encoding.utf8:
+        str = utf8.decode(this);
+        break;
+      case Encoding.utf16:
+        str = String.fromCharCodes(this);
+        break;
+      case Encoding.base64:
+        str = base64.encode(this);
+        break;
+      case Encoding.base16:
+        str = List.generate(
+          length,
+          (i) => this[i].toRadixString(16).padLeft(2, '0'),
+        ).join();
+    }
+    return str;
+  }
+
+  /// Returns a concatenation of this with the other [Uint8List].
+  Uint8List operator +(final Uint8List other) =>
+      [...this, ...other].toTypedList();
+}

packages/native_crypto_platform_interface/lib/src/utils/exception.dart

@@ -3,21 +3,41 @@
 // -----
 // File: exception.dart
 // Created Date: 24/05/2022 18:54:48
-// Last Modified: 25/05/2022 10:43:29
+// Last Modified: 26/05/2022 15:36:56
 // -----
 // Copyright (c) 2022
 
+// ignore_for_file: constant_identifier_names
+
 import 'dart:developer';
 
 import 'package:flutter/services.dart';
 
+enum NativeCryptoExceptionCode {
+  unknown,
+  not_implemented,
+  invalid_argument,
+  invalid_key,
+  invalid_key_length,
+  invalid_algorithm,
+  invalid_padding,
+  invalid_mode,
+  invalid_cipher,
+  invalid_data,
+  platform_not_supported,
+  platform_returned_invalid_data,
+  platform_returned_empty_data,
+  platform_returned_null;
+
+  String get code => toString().split('.').last.toLowerCase();
+}
+
 class NativeCryptoException implements Exception {
-  const NativeCryptoException({
+  NativeCryptoException({
     this.message,
     String? code,
     this.stackTrace,
-    // ignore: unnecessary_this
+  }) : code = code ?? NativeCryptoExceptionCode.unknown.code;
-  }) : this.code = code ?? 'unknown';
 
   /// The long form message of the exception.
   final String? message;
@@ -73,7 +93,7 @@ class NativeCryptoException implements Exception {
           )
         : null;
 
-    String code = 'unknown';
+    String code = NativeCryptoExceptionCode.unknown.code;
     String message = platformException.message ?? '';
 
     if (details != null) {
@@ -103,51 +123,3 @@ class NativeCryptoException implements Exception {
   // ignore: avoid_equals_and_hash_code_on_mutable_classes
   int get hashCode => message.hashCode ^ code.hashCode ^ stackTrace.hashCode;
 }
-
-class KeyException extends NativeCryptoException {
-  const KeyException({
-    super.message,
-    super.code,
-    super.stackTrace,
-  });
-}
-
-class KeyDerivationException extends NativeCryptoException {
-  const KeyDerivationException({
-    super.message,
-    super.code,
-    super.stackTrace,
-  });
-}
-
-class CipherInitException extends NativeCryptoException {
-  const CipherInitException({
-    super.message,
-    super.code,
-    super.stackTrace,
-  });
-}
-
-class EncryptionException extends NativeCryptoException {
-  const EncryptionException({
-    super.message,
-    super.code,
-    super.stackTrace,
-  });
-}
-
-class DecryptionException extends NativeCryptoException {
-  const DecryptionException({
-    super.message,
-    super.code,
-    super.stackTrace,
-  });
-}
-
-class NotImplementedException extends NativeCryptoException {
-  const NotImplementedException({
-    super.message,
-    super.code,
-    super.stackTrace,
-  });
-}