unity3d的base64和MD5

 public static string Base64Decode(string str)  
    {  
        byte[] bytes = Convert.FromBase64String(str);  
        bytes = Convert.FromBase64String(Encoding.Default.GetString(bytes));  
        return Encoding.Default.GetString(bytes);  
    }  
  
    public static string Base64Encode(string str)  
    {  
        string go = Convert.ToBase64String(Encoding.Default.GetBytes(str));  
        return Convert.ToBase64String(Encoding.Default.GetBytes(go));  
    }  
 public string Md5Sum(string value)
   {
       System.Security.Cryptography.MD5 md5 = System.Security.Cryptography.MD5.Create();
       byte[] inputBytes = System.Text.Encoding.ASCII.GetBytes(value);
       byte[] hash = md5.ComputeHash(inputBytes);
       StringBuilder sb = new StringBuilder();
       for (int i = 0; i < hash.Length; i++)
       {
           sb.Append(hash[i].ToString("X2"));
       }
       return sb.ToString();
   }