c - master - dashytka/PasswordStrengthChecker

70 строк2 KB
dashytka
create c#
05 ноя 2025, 08:44
05 ноя 2025, 08:4479e944c
// File: PasswordStrengthChecker.cs
using System;
using System.Linq;
using System.Text.RegularExpressions;

namespace SecurityTools
{
    public static class PasswordStrengthChecker
    {
        public static PasswordStrength EvaluatePassword(string password)
        {
            if (string.IsNullOrEmpty(password))
                return PasswordStrength.TooWeak;

            var score = 0;
            
            // Check length
            if (password.Length >= 8) score++;
            if (password.Length >= 12) score++;
            
            // Check character variety
            if (HasLowerCase(password)) score++;
            if (HasUpperCase(password)) score++;
            if (HasDigits(password)) score++;
            if (HasSpecialCharacters(password)) score++;
            
            // Check for common patterns
            if (IsCommonPassword(password)) score -= 2;
            if (HasRepeatingCharacters(password)) score--;
            
            return score switch
            {
                <= 2 => PasswordStrength.Weak,
                3 or 4 => PasswordStrength.Medium,
                5 or 6 => PasswordStrength.Strong,
                _ => PasswordStrength.VeryStrong
            };
        }

        private static bool HasLowerCase(string password) => password.Any(char.IsLower);
        private static bool HasUpperCase(string password) => password.Any(char.IsUpper);
        private static bool HasDigits(string password) => password.Any(char.IsDigit);
        
        private static bool HasSpecialCharacters(string password)
        {
            var specialCharPattern = new Regex(@"[!@#$%^&*()_+\-=\[\]{};':""\\|,.<>\/?]");
            return specialCharPattern.IsMatch(password);
        }

        private static bool IsCommonPassword(string password)
        {
            var commonPasswords = new[] { "password", "123456", "qwerty", "admin", "letmein" };
            return commonPasswords.Contains(password.ToLower());
        }

        private static bool HasRepeatingCharacters(string password)
        {
            return Regex.IsMatch(password, @"(.)\1{2,}");
        }
    }

    public enum PasswordStrength
    {
        TooWeak,
        Weak,
        Medium,
        Strong,
        VeryStrong
    }
}