Base64Url C#

Base64Url.cs

public static class Base64Url
{
	public static string Encode(byte[] arg)
	{
		if (arg == null)
		{
			throw new ArgumentNullException("arg");
		}

		var s = Convert.ToBase64String(arg);
		return s
			.Replace("=", "")
			.Replace("/", "_")
			.Replace("+", "-");
	}

	public static string ToBase64(string arg)
	{
		if (arg == null)
		{
			throw new ArgumentNullException("arg");
		}

		var s = arg
				.PadRight(arg.Length + (4 - arg.Length % 4) % 4, '=')
				.Replace("_", "/")
				.Replace("-", "+");

		return s;
	}

	public static byte[] Decode(string arg)
	{
		var decrypted = ToBase64(arg);

		return Convert.FromBase64String(decrypted);
	}
}