Packaging%20Zebedee%20and%20VNC%20with%20Delphi - PowerPoint PPT Presentation

Title: Packaging%20Zebedee%20and%20VNC%20with%20Delphi


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Packaging Zebedee and VNC with Delphi

• Zebedee Secure Tunnel
• VNC Remote Screen Viewer

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Plan

• Aim
• VNC
• Zebedee
• Delphi Wrap Application
• Hardware Firewalls
• Software Firewalls
• Database Access Via Zebedee
• Look at some Code

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Primary Aim

• To run PC support over the internet safely.
• Two free products
• Real VNC (Free Version)
• Allows remote screen control over TCP/IP
• http//www.realvnc.com/products/enterprise/4.1/
• Zebedee
• Secure TCP Tunnel software
• http//www.winton.org.uk/zebedee/
• Delphi application used as a coordinator.
• Starts and confirms servers
• Provides simple tools

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Free VNC

• Used alone
• No Encryption
• Could be Picked up by anyone on the Internet with
  a VNC Viewer by calling port 5900
• Password Authentication Only
• Suggested configuration with Zebedee
• Encrypted.
• Accepts only local (127.0.0.1) calls.
• Port 5900 should be blocked at firewalls
• Only activated when required Remove service
  mode
• Possible improvements
• Warn when service mode is present
• Change port used from 5900

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Zebedee

• An encrypted tunnel with compression
• Can provide authentication
• Can enable reverse call
• Only Zebedee port need be exposed through firewall

Internet
VNC alone
zbd
zbd
Zebedee Tunnel
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Zebedee

• Out of the box
• Sample Configuration files including one for VNC
• Typically Execute client or server
  configuration file
• No Filtering of permitted calls
• No Authentication
• Establish call by redirecting calling application
  to local Zebedee client port.
• Suggested Configuration
• Coded in the server and client configuration
  files.
• Can be extended in the command line .
• Make use of Zebedee public private key
  Authentication
• Carefully manage server filters to limit
  permitted calls
• Change port numbers
• Use Reverse mode

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Putting it all Together

• Wrapper programs attempt to ease the installation
  of the remote service and trouble shoot both
  before and after connection is established.
• Confirms connection to net and discovers network
  side IP address of machine
• Confirms VNC and Zebedee executables are
  installed
• If not install them from delivery files
• Starts programs and confirms servers are
  operating
• Basic status diagnostics
• Facilitates viewing of configuration and log
  files
• Anything else we think might be useful
• Single Inno Setup Install of all required files
  from URL
• http//www.innovasolutions.com.au/test/RmtSprt.htm
  l
• I think we need to deliver 3rd party installs as
  is
• including undesirable configuration files

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Hardware Firewall

• Best form of Firewall

Protected LAN
Internet
192.168.0.23-26
192.168.0.1
34.23.26.2
168.3.23.88
Controls access from Internet with clear rules
PCs are connected to safe local area
network. They can share files etc., contact LAN
servers and do not need firewall software
Corporate Fws, typically running on dedicated
boxes, will also control outgoing calls
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Hardware Firewalls

• The simple router based firewall generally
  requires no rules for a customer call home
  implementation.
• At the Support Center the incoming ports have to
  be forwarded to the specific server
• Could use broadcast I think
• Should use specific server
• Generally requires fixed IP address on the LAN

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Software Firewall

• A software program which intercepts calls to the
  IP stack to impose its rules.
• Essential when connected to a public LAN or dial
  up.
• Otherwise I am not a fan of these firewalls
• They are a major cause of network problems
• They are generally configured via an uninformed
  click
• They can manage installed software trying to
  initiating calls.

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Software Firewalls

• Firewall rules must be configured on a per
  connection basis

Internet Deny incoming Call anywhere (If
Authorised)
Intranet Share Directories Share Printers Share
Databases
Café Wireless
Wireless
Dial Up
Ethernet
Hotel Ethernet
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Database Via Zebedee

• Configuration file at server needs to allow
  access to the Db Server Port Number
• target MyDbServer3050
• Configuration file at client end needs to forward
  a specified port to the Db Server
• tunnel 1020192.168.0.763050
• MyDbServer fails here on version 2.4.1 as
  resolved locally
• The database client needs to be directed to that
  client port
• Firebird can be specified by port no
• Localhost/1020
• Interbase needs an entry in services
• Localhost/gds_zebedee
• Add gds_zebedee to C\WINDOWS\system32\drivers\et
  c\Services

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Look at Delphi CodeProcess Control

• Starting Process
• FZebedeeProc LaunchProcessAndReturnHandle(Cmd,
  FZebedeeTmpFile)
• gtgtgtgtgtgtgt
• if StdOut gt 0 then where StdOut
  FZebedeeTmpFile.Handle - Inheritable
• begin
• SI.hStdOutput StdOut
• SI.hStdError StdOut
• end
• if not CreateProcess(nil, PChar(Cmd), nil, nil,
  True,
• CreateFlag, nil, nil, SI, PI) then
• raise ..
• CloseHandle(PI.hThread)
• Proc PI.hProcess
• Terminating Process
• TerminateProcess(FZebedeeProc, 8)
  gtgtgtgtgtgt ExitProcess?????
• CloseHandle(FZebedeeProc)
• FZebedeeProc 0

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Look at Delphi CodeViewing Config and Log Files
function ViewFileInNotePad(const ALogFileName
string) Boolean var SystemRootDir string
NotePad string begin Result false if
FileExists(ALogFileName) then begin
SystemRootDir GetEnvironmentVariable('SystemRoo
t') NotePad ConcatToFullFileName(SystemRoo
tDir, '\system32\notepad.exe') Result
CreateProcessAndWait(NotePad ' "'
ALogFileName '"', 0, SW_Normal, '', '') gt 0
end end
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Look at Delphi CodeDos Commands
Example Do IPConfig ACmdIPConfig TmpFile
TTemporyFile.Create try Return
CreateProcessAndWait(ACmd, 30000, SW_SHOW,

'', '', true, 0, TmpFile.Handle)
if Return0 then ViewFileInNotePad(TmpFile
.Filename) else raise
Exception.Create('Command lt' ACmd 'gt
Failed
WindowsErrorString(0)) Sleep(1000)
finally TmpFile.Free end
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Look at Delphi CodeQuery or Probe A Port
In A Thread gtgt FSocket.Open Where FSocket
is a TClientSocket if FSocket.Active Connected
then Begin if not (FSocket.Socket.SendText
(FQuery) Length(FQuery)) then
FError 'Could not Send All Data' if
FSocket.Active Connected and not FProbe then
FResponse FSocket.Socket.ReceiveTex
t end else FError 'Failed to
Connect to ' FHost '' IntToStr(FSocket.Po
rt) FIpWait.SetEvent Suspend ltlt FSocket.Close
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Thank You