PassLatch.Core 0.2.0-alpha

PassLatch.Core

Cross-platform password validation and generation library for .NET 8.0+ with comprehensive security features.

Features

• Password Strength Validation

  • Real-time entropy calculation
  • Six-level strength classification (Invalid, Weak, Fair, Good, Strong, Excellent)
  • Detailed validation feedback with actionable suggestions

• Pattern Detection

  • Repeating characters (e.g., "aaa", "111")
  • Keyboard patterns (e.g., "qwerty", "asdf")
  • Sequences (e.g., "abc", "123")

• Dictionary Checking

  • 76,000+ common passwords, words, and names (all license-compatible sources)
  • Leet-speak variant detection (e.g., "p@ssw0rd" → "password")
  • Embedded resources for zero-configuration deployment

• Secure Password Generation

  • Cryptographically secure random generation
  • Configurable length (8-64 characters)
  • Customizable character types
  • Automatic quality assurance
  • No repeated adjacent characters

Installation

Install via NuGet Package Manager:

dotnet add package PassLatch.Core

Or via Package Manager Console:

Install-Package PassLatch.Core

Quick Start

Password Validation

using PassLatch.Core;

var validator = new PasswordValidator();
var result = validator.ValidatePassword("MyP@ssw0rd!");

Console.WriteLine($"Strength: {result.OverallStrength}");
Console.WriteLine($"Summary: {result.Summary}");

foreach (var check in result.Checks)
{
    Console.WriteLine($"[{check.Severity}] {check.Message}");
}

Password Generation

using PassLatch.Core;

var generator = new PasswordGenerator();

// Generate with default settings (16 chars, all types)
string password = generator.GeneratePassword();

// Generate with custom settings
string customPassword = generator.GeneratePassword(
    length: 20,
    includeUppercase: true,
    includeLowercase: true,
    includeDigits: true,
    includeSymbols: true,
    excludeChars: "O0Il1"  // Avoid ambiguous characters
);

Console.WriteLine($"Generated: {customPassword}");

API Reference

PasswordValidator

Validates password strength and provides detailed feedback.

Methods

ValidationResult ValidatePassword(string password)

Validates a password and returns detailed results.

ValidationResult Properties

ValidationCheck Properties

PasswordGenerator

Generates cryptographically secure random passwords.

Methods

string GeneratePassword(int length = 16, bool includeUppercase = true, bool includeLowercase = true, bool includeDigits = true, bool includeSymbols = true, string excludeChars = null, int maxAttempts = 100)

Generates a password meeting the specified criteria.

Parameters

DictionaryChecker

Checks passwords against common dictionary words.

Methods

static (bool found, List<string> matches) CheckPassword(string password)

Checks if password contains dictionary words.

static (bool success, int count, string message) GetLoadStatus()

Returns dictionary loading status.

Examples

Complete Validation Example

using PassLatch.Core;

var validator = new PasswordValidator();
var password = "MySecureP@ssw0rd2024!";
var result = validator.ValidatePassword(password);

// Check overall strength
if (result.OverallStrength >= PasswordStrength.Strong)
{
    Console.WriteLine("✓ Password is strong enough");
}
else
{
    Console.WriteLine("✗ Password needs improvement");

    // Show specific issues
    foreach (var check in result.Checks.Where(c => c.Severity == CheckSeverity.Error))
    {
        Console.WriteLine($"  - {check.Message}");
    }
}

// Show entropy
Console.WriteLine($"Entropy: {result.EntropyBits:F1} bits");

Advanced Password Generation

using PassLatch.Core;

var generator = new PasswordGenerator();

try
{
    // Generate password excluding ambiguous characters
    string password = generator.GeneratePassword(
        length: 24,
        includeUppercase: true,
        includeLowercase: true,
        includeDigits: true,
        includeSymbols: true,
        excludeChars: "O0Il1|`~"  // Exclude confusing chars
    );

    Console.WriteLine($"Generated: {password}");

    // Validate the generated password
    var validator = new PasswordValidator();
    var result = validator.ValidatePassword(password);
    Console.WriteLine($"Strength: {result.OverallStrength}");
}
catch (ArgumentException ex)
{
    Console.WriteLine($"Error: {ex.Message}");
}

Dictionary Status Check

using PassLatch.Core;

var (success, count, message) = DictionaryChecker.GetLoadStatus();

Console.WriteLine($"Dictionary Status: {message}");
Console.WriteLine($"Entries Loaded: {count:N0}");

if (!success)
{
    Console.WriteLine("⚠ Using fallback dictionary");
}

Dictionary Details

The library includes three embedded dictionaries:

Dictionaries are embedded as resources for zero-configuration deployment.

Security Features

• Cryptographically Secure RNG: Uses System.Security.Cryptography.RandomNumberGenerator
• No Password Storage: All validation is in-memory only
• Thread-Safe: Dictionary loading uses lazy initialization with thread safety
• Embedded Resources: No external file dependencies
• Cross-Platform: Works on Windows, Linux, and macOS

Requirements

• .NET 8.0 or higher
• No external dependencies

Performance

• Dictionary Loading: ~50ms first time (lazy loaded)
• Validation: ~1-5ms per password
• Generation: ~5-15ms per password

Contributing

Contributions are welcome! Please see the main PassLatch repository for contribution guidelines.

License

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

For information about third-party dictionary source licenses, see the LICENSE file.

Related Projects

• PassLatch - Windows Forms UI application using this library

Changelog

v0.2.0-alpha (2025-12-18)

• BREAKING: Removed 446 words from dictionary (Google 10k source with licensing restrictions)
• All dictionaries now use license-compatible sources only (SecLists MIT, ENABLE1 Public Domain, US Census CC0)
• Total dictionary entries: 76,040 (down from 76,486)
• No functional changes to API or behavior
• Full release notes

v0.1.0-alpha (2025-12-16) - UNLISTED

• Initial release with 76K+ dictionary entries
• Unlisted due to licensing issues with Google 10k word list
• Full release notes

Support

• Issues: GitHub Issues
• Documentation: This README
• Main Project: PassLatch on GitHub

Made with ☕ by alatch