Password Check

A Flutter package for password validation, strength checking, and security analysis

This package provides robust password validation with customizable rules, strength scoring, and common password detection.

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• ⭐ Starring the repository
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• 🐛 Reporting bugs and issues
• 💡 Suggesting new features
• 📢 Sharing with your network

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📸 Screenshots

Example App Screenshots

✨ Features

• ✅ Comprehensive Validation: Length, character types, patterns, and more
• ✅ Strength Scoring: 0-100 score with detailed strength levels
• ✅ Common Password Detection: Built-in dictionary of weak passwords
• ✅ Customizable Rules: Basic, strong, strict, or custom validation rules
• ✅ Pattern Detection: Sequential characters, keyboard patterns, repeated patterns
• ✅ Detailed Results: Validation errors, warnings, and strength analysis
• ✅ Secure Password Generation: Generate cryptographically secure passwords
• ✅ Generation History: Track generated passwords with timestamps
• ✅ Flutter Ready: Works seamlessly with Flutter and Dart applications
• ✅ Zero Dependencies: No external packages required
• ✅ Internationalization: 7 languages supported (EN, ES, FR, DE, PT, IT, FA)
• ✅ Advanced UI Widgets: 6 pre-built Flutter widgets
• ✅ Password History: Similarity detection and reuse prevention

📊 Package Statistics

Metric Value Tests 323 tests passing Coverage 92.1% code coverage Dependencies Zero external dependencies Languages 7 languages supported Widgets 6 pre-built Flutter widgets Platforms iOS, Android, Web, Desktop License MIT License

🚀 Quick Start

Add this package to your pubspec.yaml:

dependencies:
  password_checker_pro: ^1.0.2

Then run:

flutter pub get

⚡ 30-Second Setup

import 'package:password_checker_pro/password_checker_pro.dart';

void main() {
  // Create a password checker
  final checker = PasswordChecker.strong();
  
  // Validate a password
  final result = checker.validate('MySecurePassword123!');
  
  print('Valid: ${result.isValid}');
  print('Strength: ${result.strengthDescription}');
  print('Score: ${result.strengthScore}/100');
}

🆚 Why Choose Password Check?

Feature	Password Check	Other Packages
Dependencies	✅ Zero	❌ Multiple
UI Widgets	✅ 6 widgets	❌ Basic only
Languages	✅ 7 languages	❌ English only
Password History	✅ Advanced	❌ Not available
Test Coverage	✅ 92.1%	❌ Limited
Documentation	✅ Comprehensive	❌ Basic
Performance	✅ Optimized	❌ Varies

📖 Usage

🔧 Basic Usage

import 'package:password_checker_pro/password_checker_pro.dart';

void main() {
  // Create a password checker with default rules
  final checker = PasswordChecker();
  
  // Validate a password
  final result = checker.validate('MySecurePassword123!');
  
  if (result.isValid) {
    print('Password is valid!');
    print('Strength: ${result.strengthLevel.displayName}');
    print('Score: ${result.strengthScore}/100');
  } else {
    print('Password validation failed:');
    for (final error in result.errors) {
      print('- $error');
    }
  }
}

Using Different Validation Rules

// Basic validation (minimal requirements)
final basicChecker = PasswordChecker.basic();
final basicResult = basicChecker.validate('simple123');

// Strong validation (recommended for most apps)
final strongChecker = PasswordChecker.strong();
final strongResult = strongChecker.validate('MyStrongPassword123!');

// Strict validation (for high-security applications)
final strictChecker = PasswordChecker.strict();
final strictResult = strictChecker.validate('MyVeryStrictPassword123!@#');

// Custom validation rules
final customChecker = PasswordChecker(
  rules: ValidationRules(
    minLength: 10,
    requireUppercase: true,
    requireLowercase: true,
    requireNumbers: true,
    requireSpecialChars: false,
    allowSpaces: true,
  ),
);

Password Strength Analysis

final checker = PasswordChecker();
final result = checker.validate('MyPassword123!');

print('Is Valid: ${result.isValid}');
print('Strength Score: ${result.strengthScore}/100');
print('Strength Level: ${result.strengthLevel.displayName}');

// Check individual validation rules
print('Length Check: ${result.checks['minLength']}');
print('Uppercase Check: ${result.checks['uppercase']}');
print('Lowercase Check: ${result.checks['lowercase']}');
print('Numbers Check: ${result.checks['numbers']}');
print('Special Chars Check: ${result.checks['specialChars']}');

// Get warnings
for (final warning in result.warnings) {
  print('Warning: $warning');
}

Custom Validation Rules

const customRules = ValidationRules(
  minLength: 12,
  maxLength: 50,
  requireUppercase: true,
  requireLowercase: true,
  requireNumbers: true,
  requireSpecialChars: true,
  allowSpaces: false,
  checkCommonPasswords: true,
  checkRepeatedChars: true,
  maxRepeatedChars: 2,
  checkSequentialChars: true,
  maxSequentialLength: 3,
);

final checker = PasswordChecker(rules: customRules);

Password Generation

import 'package:password_checker_pro/password_checker_pro.dart';

void main() {
  // Create a password generator with default rules
  final generator = PasswordGenerator();
  
  // Generate a single password
  final result = generator.generate();
  
  print('Generated password: ${result.password}');
  print('Strength: ${result.strengthLevel.displayName}');
  print('Score: ${result.strengthScore}/100');
  print('Is valid: ${result.isValid}');
  
  // Generate multiple passwords
  final results = generator.generateMultiple(5);
  for (final result in results) {
    print('Password: ${result.password}');
  }
  
  // Generate with custom rules
  final customGenerator = PasswordGenerator(
    rules: const GenerationRules(
      length: 20,
      includeUppercase: true,
      includeLowercase: true,
      includeNumbers: true,
      includeSpecialChars: true,
      avoidSimilarChars: true,
      ensureCharacterVariety: true,
    ),
  );
  
  final strongPassword = customGenerator.generate();
  print('Strong password: ${strongPassword.password}');
}

Using Generation Presets

// Basic generation (8 chars, lowercase + numbers)
final basicGenerator = PasswordGenerator.basic();
final basicPassword = basicGenerator.generate();

// Strong generation (16 chars, all character types)
final strongGenerator = PasswordGenerator.strong();
final strongPassword = strongGenerator.generate();

// Strict generation (20 chars, all character types, avoid similar chars)
final strictGenerator = PasswordGenerator.strict();
final strictPassword = strictGenerator.generate();

Generation History

final generator = PasswordGenerator();

// Generate some passwords
generator.generate();
generator.generate();
generator.generate();

// Access generation history
print('Generated ${generator.historyCount} passwords');
print('Last password: ${generator.lastResult?.password}');

// View all generated passwords
for (final result in generator.history) {
  print('${result.timestamp}: ${result.password} (${result.strengthLevel.displayName})');
}

// Clear history
generator.clearHistory();

Using with PasswordChecker Extension

final checker = PasswordChecker.strong();

// Generate password using checker's validation rules
final result = checker.generatePassword(
  length: 16,
  includeUppercase: true,
  includeLowercase: true,
  includeNumbers: true,
  includeSpecialChars: true,
);

print('Generated: ${result.password}');
print('Valid: ${result.isValid}');

API Reference

PasswordChecker

Main class for password validation.

Constructors

• PasswordChecker({ValidationRules? rules}) - Creates with custom rules
• PasswordChecker.basic() - Creates with basic validation rules
• PasswordChecker.strong() - Creates with strong validation rules
• PasswordChecker.strict() - Creates with strict validation rules

Methods

• PasswordValidationResult validate(String password) - Validates a password

PasswordValidationResult

Result object containing validation information.

Properties

• bool isValid - Whether the password passed all validation rules
• List<String> errors - List of validation errors
• List<String> warnings - List of validation warnings
• int strengthScore - Password strength score (0-100)
• PasswordStrengthLevel strengthLevel - Password strength level
• Map<String, bool> checks - Detailed breakdown of validation checks

ValidationRules

Configuration class for password validation rules.

Properties

• int minLength - Minimum password length (default: 8)
• int maxLength - Maximum password length (default: 128)
• bool requireUppercase - Require uppercase letters (default: true)
• bool requireLowercase - Require lowercase letters (default: true)
• bool requireNumbers - Require numbers (default: true)
• bool requireSpecialChars - Require special characters (default: true)
• bool allowSpaces - Allow spaces in password (default: false)
• bool checkCommonPasswords - Check against common passwords (default: true)
• bool checkRepeatedChars - Check for repeated characters (default: true)
• int maxRepeatedChars - Maximum repeated characters allowed (default: 3)
• bool checkSequentialChars - Check for sequential characters (default: true)
• int maxSequentialLength - Maximum sequential length allowed (default: 3)

PasswordStrengthLevel

Enum representing password strength levels:

• veryWeak - Very weak password
• weak - Weak password
• fair - Fair password
• good - Good password
• strong - Strong password
• veryStrong - Very strong password

PasswordGenerator

Main class for generating secure passwords.

Constructors

• PasswordGenerator({GenerationRules? rules, String? language, CustomMessages? customMessages}) - Creates with custom rules
• PasswordGenerator.basic() - Creates with basic generation rules
• PasswordGenerator.strong() - Creates with strong generation rules
• PasswordGenerator.strict() - Creates with strict generation rules
• PasswordGenerator.auto() - Creates with automatic language detection
• PasswordGenerator.localized({required String language}) - Creates with specific language

Methods

• GenerationResult generate() - Generates a single password
• List<GenerationResult> generateMultiple(int count) - Generates multiple passwords
• GenerationResult generateValid({ValidationRules? validationRules}) - Generates a password that meets validation rules
• void clearHistory() - Clears generation history

Properties

• List<GenerationResult> history - List of generated passwords
• int historyCount - Number of generated passwords
• GenerationResult? lastResult - Most recent generation result
• String language - Current language code
• PasswordMessages messages - Current messages
• GenerationRules rules - Current generation rules

GenerationRules

Configuration class for password generation rules.

Properties

• int length - Length of generated password (default: 12)
• bool includeUppercase - Include uppercase letters (default: true)
• bool includeLowercase - Include lowercase letters (default: true)
• bool includeNumbers - Include numbers (default: true)
• bool includeSpecialChars - Include special characters (default: true)
• bool includeSpaces - Include spaces (default: false)
• bool avoidSimilarChars - Avoid similar characters like 0, O, l, 1 (default: true)
• bool avoidAmbiguousChars - Avoid ambiguous characters (default: true)
• String? customChars - Custom character set to include
• bool ensureCharacterVariety - Ensure at least one character from each included set (default: true)

Constructors

• GenerationRules() - Default rules
• GenerationRules.basic() - Basic rules (8 chars, lowercase + numbers)
• GenerationRules.strong() - Strong rules (16 chars, all character types)
• GenerationRules.strict() - Strict rules (20 chars, all character types, avoid similar chars)
• GenerationRules.custom() - Custom rules with specified parameters

GenerationResult

Result of password generation containing the password and metadata.

Properties

• String password - The generated password
• GenerationRules rules - Generation rules used
• PasswordValidationResult validation - Validation result of the generated password
• DateTime timestamp - When the password was generated
• bool isValid - Whether the password meets validation requirements

Examples

Flutter Form Validation

class PasswordForm extends StatefulWidget {
  @override
  _PasswordFormState createState() => _PasswordFormState();
}

class _PasswordFormState extends State<PasswordForm> {
  final _passwordController = TextEditingController();
  final _checker = PasswordChecker.strong();
  PasswordValidationResult? _validationResult;

  void _validatePassword(String password) {
    setState(() {
      _validationResult = _checker.validate(password);
    });
  }

  @override
  Widget build(BuildContext context) {
    return Column(
      children: [
        TextField(
          controller: _passwordController,
          onChanged: _validatePassword,
          obscureText: true,
          decoration: InputDecoration(
            labelText: 'Password',
            errorText: _validationResult?.isValid == false 
                ? _validationResult!.errors.first 
                : null,
          ),
        ),
        if (_validationResult != null) ...[
          LinearProgressIndicator(
            value: _validationResult!.strengthScore / 100,
            backgroundColor: Colors.grey,
            valueColor: AlwaysStoppedAnimation<Color>(
              _getStrengthColor(_validationResult!.strengthLevel),
            ),
          ),
          Text('Strength: ${_validationResult!.strengthLevel.displayName}'),
        ],
      ],
    );
  }

  Color _getStrengthColor(PasswordStrengthLevel level) {
    switch (level) {
      case PasswordStrengthLevel.veryWeak:
      case PasswordStrengthLevel.weak:
        return Colors.red;
      case PasswordStrengthLevel.fair:
        return Colors.orange;
      case PasswordStrengthLevel.good:
        return Colors.yellow;
      case PasswordStrengthLevel.strong:
      case PasswordStrengthLevel.veryStrong:
        return Colors.green;
    }
  }
}

🎨 Advanced UI Widgets

The package includes powerful pre-built widgets for comprehensive password visualization:

💡 Pro Tip: All widgets are fully customizable and support animations, theming, and responsive design.

🎯 Widget Overview

Widget	Purpose	Features
PasswordStrengthIndicator	Visual strength display	Animated progress, breakdown, suggestions
PasswordRequirementsChecklist	Requirements tracking	Interactive checklist, progress bar
PasswordStrengthMeter	Circular strength meter	Animated progress, customizable size
PasswordImprovementSuggestions	Smart suggestions	Contextual advice, priority levels
PasswordVisualizer	Comprehensive view	Tabbed interface, all features
PasswordHistoryWidget	History management	Similarity detection, reuse prevention

PasswordStrengthIndicator

Animated strength indicator with breakdown visualization and improvement suggestions.

PasswordStrengthIndicator(
  result: validationResult,
  showBreakdown: true,
  showSuggestions: true,
  animated: true,
)

PasswordRequirementsChecklist

Interactive checklist showing password requirements with progress tracking.

PasswordRequirementsChecklist(
  result: validationResult,
  rules: validationRules,
  showProgress: true,
  animated: true,
)

PasswordStrengthMeter

Circular strength meter with animated progress and customizable display.

PasswordStrengthMeter(
  result: validationResult,
  size: 120.0,
  animated: true,
  showScore: true,
  showLevel: true,
)

PasswordImprovementSuggestions

Smart improvement suggestions with contextual advice and priority levels.

PasswordImprovementSuggestions(
  result: validationResult,
  rules: validationRules,
  showIcons: true,
  showPriority: true,
)

PasswordVisualizer

Comprehensive visualization widget combining all indicators in a tabbed interface.

PasswordVisualizer(
  result: validationResult,
  rules: validationRules,
  animated: true,
)

📦 Installation

From pub.dev (Recommended)

flutter pub add password_checker_pro

From GitHub

dependencies:
  password_checker_pro:
    git:
      url: https://github.com/PasswordCheck/Password-Check.git

From Local Path

dependencies:
  password_checker_pro:
    path: ../path/to/password_checker_pro

🤝 Contributing

We welcome contributions! Please see our Contributing Guide for details.

Development Setup

# Clone the repository
git clone https://github.com/PasswordCheck/Password-Check.git

# Install dependencies
flutter pub get

# Run tests
flutter test

# Run example app
cd example && flutter run

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.

👥 Authors

• Mohsen Kashefi - LinkedIn - mohsenkashefi2000@gmail.com
• Mohammad Amin Rezaei Sepehr - LinkedIn - mohammadaminrez@gmail.com

🆘 Support

• 🐛 Issues: GitHub Issues
• 💬 Discussions: GitHub Discussions
• 📖 Documentation: Full Documentation

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Made with ❤️ by the youngDevs