KSIS2

using System.Net;
using System.Net.NetworkInformation;
using System.Net.Sockets;

internal class Lab2
{
    static byte[] IPv4ToBytes(string address)
    {
        byte[] bytes = new byte[4];
        string temp = "";
        int i = 0;
        int j = 0;
        while(i < address.Length)
        {
            if (address[i] == '.')
            {
                bytes[j++] = Convert.ToByte(temp);
                temp = "";
            }
            else
                temp += address[i];
            i++;
        }
        bytes[j] = Convert.ToByte(temp);
        return bytes;
    }

    static string bytesToIPv4(byte[] bytes)
    {
        string ip = "";
        for (int i = 0; i < 3; i++)
        {
            ip += bytes[i].ToString();
            ip += '.';
        }
        ip += bytes[3].ToString();
        return ip;
    }

    static string[] calcIPDiapason(string ip, string mask)
    {
        string[] diapason = new string[2];
        byte[] ipBytes = IPv4ToBytes(ip);
        byte[] maskBytes = IPv4ToBytes(mask);
        for(int i = 0;i < 4;i++)
            ipBytes[i] = (byte)(ipBytes[i] & maskBytes[i]);
        diapason[0] = bytesToIPv4(ipBytes);
        for(int i = 0;i < 4;i++)
            if (maskBytes[i] != 255)
                ipBytes[i] = (byte)(ipBytes[i] | ~maskBytes[i]);
        diapason[1] = bytesToIPv4(ipBytes);
        return diapason;
    }

    static bool isInDiapason(IPAddress address, string[] diapason)
    {
        if (address.ToString().CompareTo(diapason[0]) > 0 && address.ToString().CompareTo(diapason[1]) < 0)
            return true;
        else
            return false;
    }

    static string[] getDiapasonFromInput()
    {
        Console.Write("IP: ");
        string inputIP = Console.ReadLine();
        Console.Write("Mask: ");
        string inputMask = Console.ReadLine();
        string[] diapason = null;
        try
        {
            diapason = calcIPDiapason(inputIP, inputMask);
        }
        catch (Exception)
        {
            diapason = null;
        }
        return diapason;
    }

    static string getFirstMac()
    {
        string mac = "";
        foreach (NetworkInterface nic in NetworkInterface.GetAllNetworkInterfaces())
        {
            if (nic.OperationalStatus == OperationalStatus.Up)
            {
                mac = nic.GetPhysicalAddress().ToString();
                break;
            }
        }
        return mac;
    }

    static bool checkConfig()
    {
        const string OS = "Microsoft Windows NT 10.0.22621.0";
        const string mac = "7A791948F62B";
        const string cpuName = "Intel64 Family 6 Model 142 Stepping 12, GenuineIntel";
        string currOS = System.Environment.OSVersion.VersionString;
        string currMac = getFirstMac();
        string currCPU = System.Environment.GetEnvironmentVariable("PROCESSOR_IDENTIFIER").ToString();
        return currOS.Equals(OS) && currMac.Equals(mac) && currCPU.Equals(cpuName);
    }

    static void scanLAN(string[] diapason)
    {
        Console.WriteLine($"From {diapason[0]} to {diapason[1]}\n=================================");
        string macAddress = "";
        string ipAddress = "";
        string itemName = "";
        foreach (NetworkInterface item in NetworkInterface.GetAllNetworkInterfaces())
        {
            foreach (UnicastIPAddressInformation ip in item.GetIPProperties().UnicastAddresses)
            {
                if (ip.Address.AddressFamily == AddressFamily.InterNetwork && isInDiapason(ip.Address, diapason))
                {
                    IPInterfaceProperties props = item.GetIPProperties();
                    ipAddress = ip.Address.ToString();
                    macAddress = item.GetPhysicalAddress().ToString();
                    if (macAddress.Length == 0)
                        macAddress = "Не распознан";
                    itemName = item.Name;
                    Console.WriteLine("MAC: " + macAddress + "\nIP: " + ipAddress + '\n' + itemName + "\nDNS:");
                    for (int i = 0; i < props.DnsAddresses.Count; i++)
                    {
                        Console.WriteLine(props.DnsAddresses.ElementAt(i).ToString());
                    }
                    Console.WriteLine("Interface type: " + item.NetworkInterfaceType.ToString());
                    Console.WriteLine($"Mask: {ip.IPv4Mask}");
                    Console.WriteLine("========================");
                }
            }
        }
    }

    private static void Main(string[] args)
    {
        if (checkConfig())
        {
            string[] diapason = getDiapasonFromInput();
            if (diapason != null)
                scanLAN(diapason);
            else
                Console.WriteLine("An error occured while trying to convert the ip and the mask!");
        }
        else
            Console.WriteLine("Access denied!");

    }
}