Script validation

spiceuser-e5za4 · 2021-09-29T13:47:48.000Z

Hi,

I have a script that I am using that I have no error checking.

do
{
$ip = Read-Host ‘Enter a valid IP address in the form of 193.62.66.x’
} while ($ip -notmatch $ipV4)

<##Testing Variables##>
[string]$IPAddress = $ip
[string]$Subnet = “255.255.255.0”
[string]$Gateway = “”
[string]$DNS1 = “”
[string]$DNS2 = “”

#Function to set IP Address"
function Set-StaticIPAddress ($IPAddress, $Subnet, $Gateway, $DNS1, $DNS2) {
$NewNetworkConfig = Get-WmiObject Win32_NetworkAdapterConfiguration -Filter “IpEnabled = ‘True’”
$NewNetworkConfig.EnableStatic($IPAddress, $Subnet)
$NewNetworkConfig.SetGateways($Gateway, 1)
$NewNetworkConfig.SetDNSServerSearchOrder(@($DNS1, $DNS2))
}

#Set new Configuration
Set-StaticIPAddress $IPAddress $Subnet $Gateway $DNS1 $DNS2
#Sleep to take wait effect
sleep -Seconds 10
#Test Connection
If (Test-Connection -ComputerName $env:COMPUTERNAME -Count 10) {
#If connection succeded…
Write-Host “IP address changed!” -ForegroundColor Green
#Set Task seqeunce Variable to False
#$TSENV.Value(“NetworkConfig”) = “Static”
#Exit 0
}
Else {
#If connection failed…
Write-Host “Configuration Failed! Setting back to DHCP!” -ForegroundColor Yellow
#Set Task seqeunce Variable to False
#$TSENV.Value(“NetworkConfig”) = “DHCP”
#Get current IP settings swap to DHCP
$CurrentNetworkConfig = Get-WmiObject Win32_NetworkAdapterConfiguration -Filter “IPEnabled = ‘True’”
#Set DNS Servers check switch
If ($RevDNSAuto -ne $true) {
#Set DNS to specified variable values
$CurrentNetworkConfig.SetDNSServerSearchOrder(@($REVDNS1,$REVDNS2))
}
Else {
#Set DNS to Auto
$CurrentNetworkConfig.SetDNSServerSearchOrder()
}
#Enable DHCP
$CurrentNetworkConfig.EnableDHCP()
#Wait for configuration to complete
Sleep -Seconds 10
#Exit 0
}

$validate = $true
}

Write-Host “Please enter your desired computer name: [Default $env:computername]”
$computername = Read-Host

Write-Host “If this computer object exists in AD, make sure the computer it is deleted or domain join will fail!” -ForegroundColor Yellow
Sleep -Seconds 2

$renamecomputer = $true
if ($computername -eq “” -or $computername -eq $env:computername) { $computername = $env:computername; $renamecomputer = $false }

I would like to make sure that the hostname doesn’t exist and if it does, then delete it.

Also, I would like it to throw an error such as no password, wrong password:

$dompassword = Read-Host “Enter the domain administrator password for the host to join the domain” -AsSecureString

$credentials = New-Object System.Management.Automation.PsCredential(“domain\administrator”, $dompassword )
Write-Host “Adding $computername to the domain”
Add-Computer -DomainName “” -Credential $credentials -OUPath $ou
if ($renamecomputer -eq $true) { Rename-Computer -NewName $computername -DomainCredential $credentials -Force }

What would be best way to error check the following:

acceptable subnet range
avoid using existing IP address
avoiding using existing hostname
incorrect password
blank password

Neally · 2021-09-29T13:55:12.000Z

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Neally Bot

mike9019 · 2021-09-29T19:33:36.000Z

Let’s break down your requests…

acceptable subnet range
avoid using existing IP address
avoiding using existing hostname (related? I would like to make sure that the hostname doesn’t exist and if it does, then delete it.)
incorrect password
blank password

1.) Will the subnet always be static - [string]$Subnet = “255.255.255.0” - or will you request the user input for that as well?

2.) Not entirely impossible but seems like a lot of effort. With a static IP address unless you make the IP static in your DHCP server then there’s no way to look it up via the lease table - assuming whatever DHCP server you’re using is able to be reached programmatically from PS and provides a way to do a lease table lookup. The only other option you’re left with, that I can think of is to ping (or Test-NetConnection) the inputted IP addresses prior to assigning it to the machine this script is run on but that could also provide false ‘negatives’ (ping failure doesn’t mean it’s not in use just means no echo response was provided).

3.) Existing hostname where? In AD? Delete it from where if it exists? AD? If you’re checking against AD for an existing computer object with the same name of this new computer it seems rather dangerous to delete it from AD if it already exists. Could also possibly run into issues where your OU is configured to not delete objects.

4.) Incorrect Domain Admin password? You’d have to perform an action to get the result - meaning once the user provides the password you’d have to do something that requires domain admin privileges to test if the password is incorrect. You can also attempt to start-process using runas to see if the process launches. Then again, that would create a local profile for that domain admin though.

5.) Easy enough just test if it’s blank. if password = ‘’ then what else what

Curiously, why are you even setting a static IP address?