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Generating Unique Key (Finger Print) for a Computer for Licensing Purposes

, 24 Jan 2011 CPOL
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Generating Unique Key(Finger Print) for a Computer for Licensing Purposes

Introduction

For licensing purposes, according to me, the best and secure way is to generate a unique key for the client's machine and provide a corresponding license key for that key. For this purpose, you can take help of the unique id of the client's computer motherboard, BIOS and processor. When you get these IDs, you can generate any key of your preferable format.

Year ago, I found a very handy and useful code in C# by searching the Internet to get these IDs. And it's serving me perfectly so far. Thanks to the original author of the code.

I added some additional code to generate a 128 bit key of a machine. The output is a nice looking key in hexadecimal format (eg. 4876-8DB5-EE85-69D3-FE52-8CF7-395D-2EA9).

Suggestions

I have a few suggestions in this regard:

  • Generate a key from only the Motherboard, Processor and BIOS since the user normally doesn't change these parts.
  • Don't use MAC ID, Graphics Card ID AND Disk ID since it's very common to change these devices.
  • It takes significant time to get IDs of devices. So make the finger print generating function static and save it in a static variable so that it generates the key only once in the whole application.

The Code

Here is the class. The code in the region "Original Device ID Getting Code" is from the original author.

using System;
using System.Management;
using System.Security.Cryptography;
using System.Security;
using System.Collections;
using System.Text;
namespace Security
{
    /// <summary>
    /// Generates a 16 byte Unique Identification code of a computer
    /// Example: 4876-8DB5-EE85-69D3-FE52-8CF7-395D-2EA9
    /// </summary>
    public class FingerPrint  
    {
        private static string fingerPrint = string.Empty;
        public static string Value()
        {
            if (string.IsNullOrEmpty(fingerPrint))
            {
                fingerPrint = GetHash("CPU >> " + cpuId() + "\nBIOS >> " + 
			biosId() + "\nBASE >> " + baseId()
                            //+"\nDISK >> "+ diskId() + "\nVIDEO >> " + 
			videoId() +"\nMAC >> "+ macId()
                                     );
            }
            return fingerPrint;
        }
        private static string GetHash(string s)
        {
            MD5 sec = new MD5CryptoServiceProvider();
            ASCIIEncoding enc = new ASCIIEncoding();
            byte[] bt = enc.GetBytes(s);
            return GetHexString(sec.ComputeHash(bt));
        }
        private static string GetHexString(byte[] bt)
        {
            string s = string.Empty;
            for (int i = 0; i < bt.Length; i++)
            {
                byte b = bt[i];
                int n, n1, n2;
                n = (int)b;
                n1 = n & 15;
                n2 = (n >> 4) & 15;
                if (n2 > 9)
                    s += ((char)(n2 - 10 + (int)'A')).ToString();
                else
                    s += n2.ToString();
                if (n1 > 9)
                    s += ((char)(n1 - 10 + (int)'A')).ToString();
                else
                    s += n1.ToString();
                if ((i + 1) != bt.Length && (i + 1) % 2 == 0) s += "-";
            }
            return s;
        }
        #region Original Device ID Getting Code
        //Return a hardware identifier
        private static string identifier
		(string wmiClass, string wmiProperty, string wmiMustBeTrue)
        {
            string result = "";
            System.Management.ManagementClass mc = 
		new System.Management.ManagementClass(wmiClass);
            System.Management.ManagementObjectCollection moc = mc.GetInstances();
            foreach (System.Management.ManagementObject mo in moc)
            {
                if (mo[wmiMustBeTrue].ToString() == "True")
                {
                    //Only get the first one
                    if (result == "")
                    {
                        try
                        {
                            result = mo[wmiProperty].ToString();
                            break;
                        }
                        catch
                        {
                        }
                    }
                }
            }
            return result;
        }
        //Return a hardware identifier
        private static string identifier(string wmiClass, string wmiProperty)
        {
            string result = "";
            System.Management.ManagementClass mc = 
		new System.Management.ManagementClass(wmiClass);
            System.Management.ManagementObjectCollection moc = mc.GetInstances();
            foreach (System.Management.ManagementObject mo in moc)
            {
                //Only get the first one
                if (result == "")
                {
                    try
                    {
                        result = mo[wmiProperty].ToString();
                        break;
                    }
                    catch
                    {
                    }
                }
            }
            return result;
        }
        private static string cpuId()
        {
            //Uses first CPU identifier available in order of preference
            //Don't get all identifiers, as it is very time consuming
            string retVal = identifier("Win32_Processor", "UniqueId");
            if (retVal == "") //If no UniqueID, use ProcessorID
            {
                retVal = identifier("Win32_Processor", "ProcessorId");
                if (retVal == "") //If no ProcessorId, use Name
                {
                    retVal = identifier("Win32_Processor", "Name");
                    if (retVal == "") //If no Name, use Manufacturer
                    {
                        retVal = identifier("Win32_Processor", "Manufacturer");
                    }
                    //Add clock speed for extra security
                    retVal += identifier("Win32_Processor", "MaxClockSpeed");
                }
            }
            return retVal;
        }
        //BIOS Identifier
        private static string biosId()
        {
            return identifier("Win32_BIOS", "Manufacturer")
            + identifier("Win32_BIOS", "SMBIOSBIOSVersion")
            + identifier("Win32_BIOS", "IdentificationCode")
            + identifier("Win32_BIOS", "SerialNumber")
            + identifier("Win32_BIOS", "ReleaseDate")
            + identifier("Win32_BIOS", "Version");
        }
        //Main physical hard drive ID
        private static string diskId()
        {
            return identifier("Win32_DiskDrive", "Model")
            + identifier("Win32_DiskDrive", "Manufacturer")
            + identifier("Win32_DiskDrive", "Signature")
            + identifier("Win32_DiskDrive", "TotalHeads");
        }
        //Motherboard ID
        private static string baseId()
        {
            return identifier("Win32_BaseBoard", "Model")
            + identifier("Win32_BaseBoard", "Manufacturer")
            + identifier("Win32_BaseBoard", "Name")
            + identifier("Win32_BaseBoard", "SerialNumber");
        }
        //Primary video controller ID
        private static string videoId()
        {
            return identifier("Win32_VideoController", "DriverVersion")
            + identifier("Win32_VideoController", "Name");
        }
        //First enabled network card ID
        private static string macId()
        {
            return identifier("Win32_NetworkAdapterConfiguration", 
				"MACAddress", "IPEnabled");
        }
        #endregion
    }
}

Upcoming Code

Later I'll show how I generated the license key from the unique machine key. The license key contains a lot of information like the Product Name, License Start Date, End Date and the Key.

Keep eyes on my blog (sowkot.blogspot.com).

History

  • 19th August, 2008: Initial post

My Other Articles

License

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)

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About the Author

Sowkot Osman
Software Developer (Senior)
Australia Australia
-7 years of extensive experience in devloping both desktop and web applications in C#.NET, VB.NET and ASP.NET, ASP.NET MVC 3.0/4.0
-5 years of experience in developing web applications in J2EE, Free Marker, JSP, Spring MVC, Spring Webflow.
-Expertise in Software Architecture and Framework design.
Blog: http://sowkot.blogspot.com


Comments and Discussions

 
Questionthe other article Pinmembervipz0071-Oct-14 17:52 
QuestionIs ther any chance of change in key after format even 0.01%? PinmemberKrishna Kapadia12-Aug-14 10:49 
QuestionWhen will you be explaining on how to create license keys Pinmembermukeshgmail4-Jun-14 8:21 
SuggestionMessage Automatically Removed Pinmemberkamleshgs15-May-14 8:06 
QuestionThanks! PinmemberbasarTurgut13-Jan-14 2:45 
QuestionCool! Pinmemberdiogopessoa29-Nov-13 6:05 
GeneralMy vote of 2 Pinprofessionalbobfox5-Nov-13 18:39 
BugWhat happen on cloning the harddisk? PinmemberXhek30-Oct-13 10:53 
GeneralMy vote of 5 PinmemberURVISH_SUTHAR128-Oct-13 4:25 
SuggestionGreat article but i prefer Usb Dongle PinmemberiProg72-Sep-13 9:00 
GeneralRe: Great article but i prefer Usb Dongle Pinmvpadriancs25-Sep-13 17:00 
QuestionREG: Reversing the hash string PinmemberMember 83233541-Jun-13 5:26 
AnswerRe: REG: Reversing the hash string Pinmvpadriancs25-Sep-13 17:06 
GeneralMy vote of 5 Pinmembercava4des4-Feb-13 19:40 
Question[My vote of 1] 99% of this was done by the "other" guy PinmemberJose A Pascoa2-Feb-13 22:47 
QuestionWould love to see the final part where reverse the hex string back Pinmemberearthit23-Jan-13 5:54 
GeneralRe: Would love to see the final part where reverse the hex string back Pinmemberpchinery12-Jun-13 6:40 
Questionjust my 0.01 cents :) PinmemberJayson Ragasa5-Dec-12 17:15 
Answerhow about this? Pinmvpadriancs25-Sep-13 17:11 
QuestionDon't forget to add your Reference! Haha Pinmemberandrogenic_human30-Nov-12 17:51 
QuestionMono Support? PinmemberEddie Y Chen2-Nov-12 22:39 
Questionget back original data PinmemberKrishna Kapadia28-Oct-12 21:16 
GeneralNot so easy Pinmembernumo25-Jun-12 4:23 
QuestionHack the key Pinmembernitin-aem16-Jun-12 2:42 
AnswerRe: Hack the key Pinmembersoftwaretry10-Jul-12 3:35 

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