feat: Add obfuscation option

Author: ThexXTURBOXx

packages/envied/lib/src/envied_base.dart

@@ -28,7 +28,15 @@ 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.
+  final bool obfuscate;
+
+  const Envied(
+      {String? path, bool? requireEnvFile, this.name, this.obfuscate = false})
       : path = path ?? '.env',
         requireEnvFile = requireEnvFile ?? false;
 }

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) {
@@ -56,7 +58,7 @@ class EnviedGenerator extends GeneratorForAnnotation<Envied> {
         } else if (Platform.environment.containsKey(varName)) {
           varValue = Platform.environment[varName];
         }
-        return generateLine(
+        return (config.obfuscate ? generateLineEncrypted : generateLine)(
           fieldEl,
           varValue,
         );