feat: Add obfuscation option

packages/envied/lib/src/envied_base.dart

@@ -28,7 +28,16 @@ class Envied {
   /// ```
   final String? name;
 
-  const Envied({String? path, bool? requireEnvFile, this.name})
+  /// Allows all the values to be encrypted using a random
+  /// generated key that is then XOR'd with the encrypted
+  /// value when being accessed the first time.
+  /// Please note that the values can not be offered with
+  /// the const qualifier, but only with final.
+  /// **Can be overridden by the per-field obfuscate option!**
+  final bool obfuscate;
+
+  const Envied(
+      {String? path, bool? requireEnvFile, this.name, this.obfuscate = false})
       : path = path ?? '.env',
         requireEnvFile = requireEnvFile ?? false;
 }
@@ -38,5 +47,13 @@ class EnviedField {
   /// The environment variable name specified in the `.env` file to generate for the annotated variable
   final String? varName;
 
-  const EnviedField({this.varName});
+  /// Allows this values to be encrypted using a random
+  /// generated key that is then XOR'd with the encrypted
+  /// value when being accessed the first time.
+  /// Please note that the values can not be offered with
+  /// the const qualifier, but only with final.
+  /// **Overrides the per-class obfuscate option!**
+  final bool? obfuscate;
+
+  const EnviedField({this.varName, this.obfuscate});
 }

packages/envied/test/envy_test.dart

@@ -6,6 +6,8 @@ void main() {
     test('Empty constructor', () {
       final envied = Envied();
       expect(envied.path, '.env');
+      expect(envied.requireEnvFile, false);
+      expect(envied.obfuscate, false);
     });
 
     test('Specified path', () {
@@ -22,17 +24,28 @@ void main() {
       final envied = Envied(name: 'Foo');
       expect(envied.name, 'Foo');
     });
+
+    test('Specified obfuscate', () {
+      final envied = Envied(obfuscate: true);
+      expect(envied.obfuscate, true);
+    });
   });
 
   group('EnviedField Test Group', () {
     test('Empty constructor', () {
       final enviedField = EnviedField();
       expect(enviedField.varName, null);
+      expect(enviedField.obfuscate, null);
     });
 
     test('Specified path', () {
       final enviedField = EnviedField(varName: 'test');
       expect(enviedField.varName, 'test');
     });
+
+    test('Specified obfuscate', () {
+      final enviedField = EnviedField(obfuscate: true);
+      expect(enviedField.obfuscate, true);
+    });
   });
 }

packages/envied_generator/lib/src/generate_line_encrypted.dart

@@ -0,0 +1,77 @@
+import 'dart:math';
+
+import 'package:analyzer/dart/element/element.dart';
+import 'package:source_gen/source_gen.dart';
+
+/// Generate the line to be used in the generated class.
+/// If [value] is `null`, it means the variable definition doesn't exist
+/// and an [InvalidGenerationSourceError] will be thrown.
+///
+/// Since this function also does the type casting,
+/// an [InvalidGenerationSourceError] will also be thrown if
+/// the type can't be casted, or is not supported.
+String generateLineEncrypted(FieldElement field, String? value) {
+  if (value == null) {
+    throw InvalidGenerationSourceError(
+      'Environment variable not found for field `${field.name}`.',
+      element: field,
+    );
+  }
+
+  final rand = Random.secure();
+  final type = field.type.getDisplayString(withNullability: false);
+  final name = field.name;
+  final keyName = '_enviedkey$name';
+
+  switch (type) {
+    case "int":
+      final parsed = int.tryParse(value);
+      if (parsed == null) {
+        throw InvalidGenerationSourceError(
+          'Type `$type` does not align up to value `$value`.',
+          element: field,
+        );
+      } else {
+        final key = rand.nextInt(1 << 32);
+        final encValue = parsed ^ key;
+        return 'static final int $keyName = $key;\n'
+            'static final int $name = $keyName ^ $encValue;';
+      }
+    case "bool":
+      final lowercaseValue = value.toLowerCase();
+      if (['true', 'false'].contains(lowercaseValue)) {
+        final parsed = lowercaseValue == 'true';
+        final key = rand.nextBool();
+        final encValue = parsed ^ key;
+        return 'static final bool $keyName = $key;\n'
+            'static final bool $name = $keyName ^ $encValue;';
+      } else {
+        throw InvalidGenerationSourceError(
+          'Type `$type` does not align up to value `$value`.',
+          element: field,
+        );
+      }
+    case "String":
+    case "dynamic":
+      final parsed = value.codeUnits;
+      final key = parsed.map((e) => rand.nextInt(1 << 32)).toList(
+            growable: false,
+          );
+      final encValue = List.generate(parsed.length, (i) => i, growable: false)
+          .map((i) => parsed[i] ^ key[i])
+          .toList(growable: false);
+      final encName = '_envieddata$name';
+      return 'static const List<int> $keyName = [${key.join(", ")}];\n'
+          'static const List<int> $encName = [${encValue.join(", ")}];\n'
+          'static final ${type == 'dynamic' ? '' : 'String'} $name = String.fromCharCodes(\n'
+          '  List.generate($encName.length, (i) => i, growable: false)\n'
+          '      .map((i) => $encName[i] ^ $keyName[i])\n'
+          '      .toList(growable: false),\n'
+          ');';
+    default:
+      throw InvalidGenerationSourceError(
+        'Obfuscated envied can only handle types such as `int`, `bool` and `String`. Type `$type` is not one of them.',
+        element: field,
+      );
+  }
+}

packages/envied_generator/lib/src/generator.dart

@@ -5,6 +5,7 @@ import 'package:analyzer/dart/element/element.dart';
 import 'package:build/build.dart';
 import 'package:envied/envied.dart';
 import 'package:envied_generator/src/generate_line.dart';
+import 'package:envied_generator/src/generate_line_encrypted.dart';
 import 'package:envied_generator/src/load_envs.dart';
 import 'package:source_gen/source_gen.dart';
 
@@ -32,6 +33,7 @@ class EnviedGenerator extends GeneratorForAnnotation<Envied> {
       requireEnvFile:
           annotation.read('requireEnvFile').literalValue as bool? ?? false,
       name: annotation.read('name').literalValue as String?,
+      obfuscate: annotation.read('obfuscate').literalValue as bool,
     );
 
     final envs = await loadEnvs(config.path, (error) {
@@ -48,15 +50,21 @@ class EnviedGenerator extends GeneratorForAnnotation<Envied> {
       if (enviedFieldChecker.hasAnnotationOf(fieldEl)) {
         DartObject? dartObject = enviedFieldChecker.firstAnnotationOf(fieldEl);
         ConstantReader reader = ConstantReader(dartObject);
+
         String varName =
             reader.read('varName').literalValue as String? ?? fieldEl.name;
+
         String? varValue;
         if (envs.containsKey(varName)) {
           varValue = envs[varName];
         } else if (Platform.environment.containsKey(varName)) {
           varValue = Platform.environment[varName];
         }
-        return generateLine(
+
+        final bool obfuscate =
+            reader.read('obfuscate').literalValue as bool? ?? config.obfuscate;
+
+        return (obfuscate ? generateLineEncrypted : generateLine)(
           fieldEl,
           varValue,
         );

packages/envied_generator/test/src/generator_tests.dart

@@ -108,3 +108,33 @@ abstract class Env11 {
   @EnviedField(varName: 'test_string')
   static const String? testString = null;
 }
+
+@ShouldGenerate('static const List<int> _enviedkeytestString', contains: true)
+@ShouldGenerate('static const List<int> _envieddatatestString', contains: true)
+@ShouldGenerate('''
+  static final String testString = String.fromCharCodes(
+    List.generate(_envieddatatestString.length, (i) => i, growable: false)
+        .map((i) => _envieddatatestString[i] ^ _enviedkeytestString[i])
+        .toList(growable: false),
+  );
+''', contains: true)
+@Envied(path: 'test/.env.example', obfuscate: true)
+abstract class Env12 {
+  @EnviedField()
+  static const String? testString = null;
+}
+
+@ShouldGenerate('static const List<int> _enviedkeytestString', contains: true)
+@ShouldGenerate('static const List<int> _envieddatatestString', contains: true)
+@ShouldGenerate('''
+  static final String testString = String.fromCharCodes(
+    List.generate(_envieddatatestString.length, (i) => i, growable: false)
+        .map((i) => _envieddatatestString[i] ^ _enviedkeytestString[i])
+        .toList(growable: false),
+  );
+''', contains: true)
+@Envied(path: 'test/.env.example', obfuscate: false)
+abstract class Env13 {
+  @EnviedField(obfuscate: true)
+  static const String? testString = null;
+}