Telnet Tool ActiveX control application instance code

During website construction, we can use Telnet Tool ActiveX for some programming. We have introduced the features of the Telnet Tool ActiveX control in the previous article. The following is an example of the application.

Programming example

The following is an ASP programming example of a simple Telnet Tool ActiveX control. The experiment environment is Windows 2000 Professional, IIS 5.0, SCO OpenServer 5.0.2, and Telnet Tool ActiveX control. Telnet Tool ActiveX control can download the 30-day trial version at www.dart.com, which only needs to be installed on the WEB server.

The program is not complex. After logging on to a sco unix system, two commands are executed and the command result is displayed on the browser page.

 
 

  
  
HTML  
  
  
HEADTITLEPowerTCP Telnet Tool Demo Page/TITLE/HEAD  
  
  
BODY  
  
  
*******************************************************************  
  
  
Program: PowerTCP Telnet Tool Demo  
  
  
Author: Yin  
  
  
Date: 07/16/2001  
  
  
Purpose: To demonstrate how to login into a SCO UNIX server.  
  
  
********************************************************************}  
  
  
Sub DoLogin()   
  
  
Session(RESULT) =   
  
  
On Error Resume Next   
  
  
Create a Telnet control   
  
  
Dim Telnet1   
  
  
Set Telnet1 = Server.CreateObject(Dart.Telnet.1)   
  
  
Use a 10 second timeout   
  
  
Telnet1.Timeout = 10000   
  
  
Specifies terminal type   
  
  
Telnet1.TermType = ansi   
  
  
AddResult Connecting to + txtHost + ... + vbCrLf   
  
  
Connect to the host on port 23   
  
  
Telnet1.Connect txtHost,23   
  
  
Dim a string to be used by the search method   
  
  
Dim Data   
  
  
Data =   
  
  
Search for login prompt   
  
  
Telnet1.Search Data, txtLoginPrompt   
  
  
AddResult Data   
  
  
Send username   
  
  
Telnet1.Send txtUser + vbCrLf   
  
  
Search for password prompt   
  
  
Telnet1.Search Data, txtPassPrompt   
  
  
AddResult Data   
  
  
Send password   
  
  
Telnet1.Send txtPass + vbCrLf + vbCrLf   
  
  
Search for command prompt   
  
  
Telnet1.Search Data, txtCommandPrompt   
  
  
AddResult Data   
  
  
Send command   
  
  
Telnet1.Send ps + vbCrLf   
  
  
Search for command prompt   
  
  
Telnet1.Search Data, txtCommandPrompt   
  
  
AddResult Data   
  
  
Send command   
  
  
Telnet1.Send netstat -rn + vbCrLf   
  
  
Search for command prompt   
  
  
Telnet1.Search Data, txtCommandPrompt   
  
  
AddResult Data   
  
  
Close the connection   
  
  
Telnet1.Close   
  
  
If Err.number = 0 then   
  
  
AddResult vbCrLf + Disconnecting... SUCCESS!   
  
  
Else   
  
  
Display info about the error   
  
  
AddResult vbcrlf + ERROR # + CStr(Err.number) + : + Err.Description   
  
  
End if   
  
  
Response.Write Session(RESULT)   
  
  
End Sub   
  
  
Private Sub AddResult(s)   
  
  
Session(RESULT) = Session(RESULT) + ReadyForHtml(s)   
  
  
End Sub   
  
  
Substitute escape codes for some of the HTML reserved characters   
  
  
Function ReadyForHtml(Data)   
  
  
On Error Resume Next   
  
  
ReadyForHtml = Data   
  
  
ReadyForHtml = Replace(ReadyForHtml, , gt;)   
  
  
ReadyForHtml = Replace(ReadyForHtml, , lt;)   
  
  
ReadyForHtml = Replace(ReadyForHtml, , nbsp;)   
  
  
ReadyForHtml = Replace(ReadyForHtml, vbCrLf , brnbsp;)   
  
  
ReadyForHtml = Replace(ReadyForHtml, vbCrLf, br)   
  
  
End Function   
  
  
Dim txtHost   
  
  
Dim txtLoginPrompt   
  
  
Dim txtUser   
  
  
Dim txtPassPrompt   
  
  
Dim txtPass   
  
  
Dim txtCommandPrompt   
  
  
txtHost = 192.0.1.6   
  
  
txtLoginPrompt = login:   
  
  
txtUser = root   
  
  
txtPassPrompt = Password   
  
  
txtPass = hp123   
  
  
txtCommandPrompt = #   
  
  
DoLogin() 
 
 

Summary

By using the Telnet Tool ActiveX control, we can log on to the UNIX System in the ASP program to easily complete many command line operations. Similarly, we can view the network configuration and running status in the CISCO router and switch through a browser.

Enterprise Firewall settings should generally prohibit direct remote logon from external networks to internal UNIX hosts, but we can simply click on a browser to select a specific operation, the ASP program on the WEB Server is used to log on to the UNIX host to complete the specified operation, which increases the system security while facilitating management.

Of course, we should always consider security issues in ASP programming, especially to avoid accidental leakage of ASP source code and UNIX passwords.