Password Protection Example For .NET Apps It is copy protection for your software. It prevents software theft. It prevents unauthorized copies of your software from running. It stops people from stealing your software. It protects applications from illegal copying and unauthorized use.

To set password protection in .NET applications, follow these steps:

Step 1: Set ProtectKit code in your application.
Step 2: Set protection information using the "Set Password Protection Tool".
Step 3: Embed the protection file into your application.
Step 4: Obfuscate your application if desired.
Step 5: Digitally sign your application if desired.
Step 6: Deploy Application.
Step 7: Generate a password and send it to the user.

Here is an overview that explains how to set password protection in a .NET application.

.NET Example: (in Visual Basic .NET)

Step 1: Set ProtectKit code in your application

Check the ProtectKit status and the lockword:
You should do this when your application initializes. Here we chose to do this in the Form_Load event. That way, every time the application starts up, the passwordProtect Initialize function executes and checks whether the ProtectKit is running properly or not. Then the GetLockword function executes and retrieves the lockword from the application so you can check to see that it is correct.

Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
passwordProtect1.DllFileName = "ProFuncNET32.dll"

     Dim ret As Integer = passwordProtect1.Initialize("VB_Sample1.exe", "ProInfo32.dll")
     If (ret <> 0) Then
          Select Case (ret)
               Case -1 : MessageBox.Show("Unable to run application.")
               Case 1 : MessageBox.Show("Service is not running.")
               Case 2 : MessageBox.Show("Unable to load protection information file.")
               Case 3 : MessageBox.Show("Lockword is incorrect.")
               Case 4 : MessageBox.Show("Application must run on a local disk.")
               Case 5 : MessageBox.Show("An error has been generated")
          End Select
          Me.Close()
     End If

     Dim s As String = passwordProtect1.GetLockword()
     Dim ChkLockword() As String = "AbcdefgH"
     If (s <> ChkLockword) Then
          MessageBox.Show("Lockword is incorrect.")
          Me.Close()
     End If
     label1.Text = "OK"
End Sub

Retrieve the PC's Hardware Signature (PcID):
The QueryPcID function retrieves the hardware signature of the PC based on the requirements that set by the Set Password Protection Tool. This PcID is used to generate a password to unlock the application on this PC.

Private Sub button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button1.Click
textBox1.Text = passwordProtect1.QueryPcID()
End Sub

Set the Password: After a valid password has been generated, passing that password into the SetPassword function will unlock the application. Here we do that within a button click event.

Private Sub button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button2.Click
passwordProtect1.SetPassword(textBox2.Text)
End Sub

Check Protection Status: The QueryProtect function checks the protection status and returns a value based on that status. This allows you to set the appropriate action that will occur based on the protection status return values.

Private Sub button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles button3.Click
Dim ret As Integer = passwordProtect1.QueryProtect()
Select Case ret
Case -1 : label4.Text = "Unable to run application."
Case 0 : label4.Text = "Application is unlocked."
Case 1 : label4.Text = "Application is locked."
Case 2 : label4.Text = "Exceeded allowable number of uses."
Case 3 : label4.Text = "Exceeded allowable number of days."
Case 4 : label4.Text = "Exceeded allowable number of months."
Case 5 : label4.Text = "Application has expired."
Case 6 : label4.Text = "PC's clock has been turned back."
Case 7 : label4.Text = "PC is different."
Case 8 : label4.Text = "Protection file is incorrect."
Case 9 : label4.Text = "Lockword is incorrect."
Case 10 : label4.Text = "Password is incorrect."
Case 11 : label4.Text = "Other"
Case 12 : label4.Text = "Using an improper protection file."
End Select
'...Other programming code....
End Sub

Step 2: Set protection information

Use the Set Password Protection tool to set protection information into your application:

This tool writes protection information into a "protection information file" and also writes the same information into a file that is embedded into your application as a resource.

Password protection allows you to enable your applications in a variety of ways. Standard protection locks the application until it is unlocked. "Number of uses", "Number of days", and "Number of months" protection allow you to set how many times the application can be used, or for how many days, or months it will run. "Expiration date" protection sets a date after which the application stops running. The "renewable passwords" feature lets you enable an application that has stopped and it will be enabled again for the specified number of uses, days, or months.

Step 3: Embed the protection file into your application

In Step 2, the Set Password Protection tool, generated two files; a protection information file and another file containing the protection information that will be embedded in your application. To embed this file, use the Stream property of the PasswordProtect class.

How To Embed Protection Information:

There are two ways to embed the protection information into your application:

1. Open your application project, select the PasswordProtect class.
In the Properties window, click on button at the right of the Stream property (see image below) and set the path to the embedded protection file.

2. Open your application project and add the protection file to your project.
In the Properties Window, set the file's build action to "Embedded Resource".

After embedding the protection information, build the application.
Performing Steps 2 and 3, prior to Step 1, allows you to debug the protection portion of your code.

Step 4: Obfuscate your application

If you are obfuscating your compiled application, do that at this step. If you are not obfuscating your application, proceed to Step 5.

We highly recommend that you obfuscate your .NET applications. If your applications and resource files are not obfuscated, program code may be readable if your application is decompiled and your lockword and other protection information may be exposed. Obfuscating your .NET application and resource files using string encryption will prevent your programming code and protection information from being exposed.

Step 5: Digital signature

If you are digitally signing your application, do that at this step. If you are not digitally signing your application, proceed to Step 6.

Step 6: Deploy your application

Deploy your application and all its associated files to the target machine.

Step 7: Generate a password to unlock the application and send it the user

Three types of Password Generators

The ProtectKit3.5 includes three password generating programs. The runtime Password Generator (EXE) is an application that allows you to enter a lockword and a PcID to generate a password manually, without any need for programming. Using the lockword from Step 2 and the PcID retrieved from the enduser's PC, you can generate an unlock password, which you send to the enduser to unlock the application.

The Password Generator EXE

The Password Generator OCX and DLL files

These files provide the password generating functions in an easy to use API. This allows you to generate passwords programmatically using the lockword and retrieved PcID. You can also send the generated passwords to your users. These programming API allow you to do this seamlessly.

Below is sample code from a web application that uses VBScript to generate the password.

Set objCOM = Server.CreateObject("Pr3PassGen.PassGen")
objCOM.LockWord = varLockword
objCOM.PCID = varPCID
objCOM.PasswordType = varType
varUnlockword = objCOM.PS3GetPassword
Set objCOM = nothing

Here is Visual Basic code that uses the EMail API

ret = PS3SendMail("msv.newtone.co.jp", "info@newtone.co.jp", _
"NEWTONE", "paul@company.com", "Users", _
"PassWord Information", "Below is the password needed to unlock....")

Password Protection: Example For .NET Apps