Security type methods (helpers)

SecurityBits.cs

  using System;
	using System.Configuration;
	using System.Security.Cryptography;
	using System.Text;
	using System.Web;
	using BCrypt.Net;

  public static class Helper
  {
  	internal static T GetAppSetting<T>(string key, T Default)
		{
			if (key != null)
			{
				var value = ConfigurationManager.AppSettings[key];
				if (string.IsNullOrEmpty(value))
					return Default;
				if (typeof (T).BaseType == typeof (Enum))
					return (T) Enum.Parse(typeof (T), value);

				return (T) Convert.ChangeType(value, typeof (T));
			}
			return Default;
		}

		internal static bool CheckPassword(string password, string dbpassword, string salt)
		{
			return BCrypt.Verify(String.Concat(password, salt), dbpassword);
		}

		public static string EncodePassword(string password, string salt, int workFactor)
		{
			var pass = String.Concat(password, salt);
			string hash = BCrypt.HashPassword(pass, workFactor);

			return hash;
		}

		internal static string GetConfigValue(string configValue, string defaultValue)
		{
			if (String.IsNullOrEmpty(configValue))
				return defaultValue;

			return configValue;
		}

		/// <summary>
		/// Returns a random 64 character hex string (256 bits)
		/// </summary>		
		public static string CreateSalt()
		{
			var random = new RNGCryptoServiceProvider();
			var salt = new byte[32]; //256 bits
			random.GetBytes(salt);
			return BytesToHex(salt);
		}

		/// <summary>
		/// Converts a byte array to a hex string
		/// </summary>		
		internal static string BytesToHex(byte[] toConvert)
		{
			var s = new StringBuilder(toConvert.Length*2);
			foreach (byte b in toConvert)
			{
				s.Append(b.ToString("x2"));
			}
			return s.ToString();
		}

		/// <summary>
		/// returns the SHA512 hash of a string, formatted in hex
		/// </summary>		
		public static string SHA512Hex(string plainText)
		{
			var hash = new SHA512Managed();
			var utf8 = Encoding.UTF8.GetBytes(plainText);
			return BytesToHex(hash.ComputeHash(utf8));
		}

		public static string GetMD5Hash(string input)
		{
			var x = new MD5CryptoServiceProvider();
			byte[] bs = Encoding.UTF8.GetBytes(input);
			bs = x.ComputeHash(bs);
			var s = new StringBuilder();
			foreach (byte b in bs)
			{
				s.Append(b.ToString("x2").ToLower());
			}
			return s.ToString();
		}

		public static string GetClientIP()
		{
			HttpContext context = HttpContext.Current;

			string ipAddress = context.Request.ServerVariables["HTTP_X_FORWARDED_FOR"];

			if (!string.IsNullOrEmpty(ipAddress))
			{
				string[] addresses = ipAddress.Split(',');
				if (addresses.Length != 0)
				{
					return addresses[0];
				}
			}

			return context.Request.ServerVariables["REMOTE_ADDR"];
		}

		public static string PHPMd5Hash(string pass)
		{
			using (MD5 md5 = MD5.Create())
			{
				byte[] input = Encoding.UTF8.GetBytes(pass);
				byte[] hash = md5.ComputeHash(input);
				return BitConverter.ToString(hash).Replace("-", "");
			}
	  }
}