$ipv4ListFile = "$PSScriptRoot\Ipv4.txt"

172.64.149.23
192.229.221.95
20.190.177.85
20.73.194.208

$ipArray = @()

# Script Version 1.3
 
<#
===========================================================================================
|                                                                                         |
|                                      User Settings                                      |
|                                                                                         |
===========================================================================================
#>
 
# Path to a plain text file containing IP addresses.
# Note: The file must contain a single IP address per line.
[string] `
$ipListFile = "$PSScriptRoot\Ipv4.txt"
 
# An Array with additional IP addresses to block.
[string[]] `
$ipArray = @()
 
<#
===========================================================================================
|                                                                                         |
|                                    Functions                                            |
|                                                                                         |
===========================================================================================
#>
 
function Show-WelcomeScreen {
    Clear-Host
    Write-Host ""
    Write-Host " $($host.ui.RawUI.WindowTitle)"
    Write-Host " +=======================================+"
    Write-Host " |                                       |"
    Write-Host " | This script will add firewall rules   |"
    Write-Host " | to block network traffic for the IP   |"
    Write-Host " | addresses specified in the input file |"
    Write-Host " | and/or defined in this script file.   |"
    Write-Host " |                                       |"
    Write-Host " +=======================================+"
    Write-Host ""
    Write-Host " Input File Path: $ipListFile" -ForegroundColor DarkGray
    Write-Host ""
    Write-Host " IP addresses hardcoded in this script: $($ipArray.Count)" -ForegroundColor DarkGray
    Write-Host ""
}
 
function Confirm-Continue {
    Write-Host " Press 'Y' key to continue or 'N' key to exit."
    Write-Host ""
    Write-Host " -Continue? (Y/N)"
    do {
        $key = $Host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown")
        $char = $key.Character.ToString().ToUpper()
        if ($char -ne "Y" -and $char -ne "N") {
            [console]::beep(1500, 500)
        }
    } while ($char -ne "Y" -and $char -ne "N")
    if ($char -eq "N") {Exit(1)} else {Clear-Host}
}
 
function Show-GoodbyeScreen {
    Write-Host "Operation Completed!" -BackgroundColor Black -ForegroundColor Green
    Write-Host ""
    Write-Host "Press any key to exit..."
    $key = $Host.UI.RawUI.ReadKey("NoEcho, IncludeKeyDown")
}
 
function Add-FirewallRules {
    param (
        [string]$ipListFile,
        [string[]]$ipArray
    )
 
    Write-Host "Compiling internal C# code..."
    # Natural Sorting C# Snippet
    Add-Type -TypeDefinition '
        using System;
        using System.Collections.Generic;
        using System.Runtime.InteropServices;
 
        public static class NativeMethods {
            [DllImport("shlwapi.dll", CharSet = CharSet.Unicode)]
            public static extern int StrCmpLogicalW(string first, string second);
        }
 
        public class NaturalStringComparer : IComparer<string> {
            public int Compare(string first, string second) {
                return NativeMethods.StrCmpLogicalW(first, second);
            }
        }
    '
 
    Write-Host "Fetching computer's firewall rules..."
    $ruleGroupName = "$env:COMPUTERNAME IP Blocks"
    [CimInstance[]]$currentRules = Get-NetFirewallRule -Group $ruleGroupName -ErrorAction SilentlyContinue
 
    Write-Host "Building IP address collection..."
    $comparer = [NaturalStringComparer]::new()
    $sortedSet = [System.Collections.Generic.SortedSet[string]]::new($ipArray, $comparer)
    if (Test-Path $ipListFile) {
        Write-Host "Fetching IP addresses from input file..."
        $ipList = Get-Content -Path $ipListFile | Where-Object { -not [string]::IsNullOrWhiteSpace($_) }
        foreach ($ip in $ipList) {
            $sortedSet.Add($ip) | Out-Null
        }
    }
    if ($sortedSet.Count -eq 0) {
        Write-Warning "There are no IP addresses to process."
        return
    }
    $totalItemCount   = $sortedSet.Count
    $currentItemIndex = 0
 
    Write-Host "Start processing IP address collection..."
    Write-Host ""
    foreach ($ip in $sortedSet) {
        $currentItemIndex +=1
        Write-Host "[$currentItemIndex of $totalItemCount] IP address: $ip"
 
        $ruleNameInbound = "IP Block (Inbound) ($ip)"
        $currentRules | Where-Object {
            $_.DisplayName -eq $ruleNameInbound
        } -ErrorAction SilentlyContinue | Remove-NetFirewallRule
 
        Write-Host "Adding firewall rule to block inbound traffic..." -ForegroundColor DarkGray
        [CimInstance]$ruleInbound = 
            New-NetFirewallRule `
                -DisplayName "$ruleNameInbound" `
                -Description "This rule disables incoming traffic for address: $ip" `
                -Group "$ruleGroupName" `
                -Direction "Inbound" `
                -Action "Block" `
                -RemoteAddress "$ip" `
                -Profile "Any" `
                -Enabled "True" `
                -LocalAddress "Any" `
                -InterfaceType "Any"
 
        $ruleNameOutbound = "IP Block (Outbound) ($ip)"
        $currentRules | Where-Object {
            $_.DisplayName -eq $ruleNameOutbound
        } -ErrorAction SilentlyContinue | Remove-NetFirewallRule
 
        Write-Host "Adding firewall rule to block outbound traffic..." -ForegroundColor DarkGray
        [CimInstance]$ruleOutbound = 
            New-NetFirewallRule `
                -DisplayName "$ruleNameOutbound" `
                -Description "This rule disables outgoing traffic for address: $ip" `
                -Group "$ruleGroupName" `
                -Direction "Outbound" `
                -Action "Block" `
                -RemoteAddress "$ip" `
                -Profile "Any" `
                -Enabled "True" `
                -LocalAddress "Any" `
                -InterfaceType "Any"
 
        Write-Host ""
    }
}
 
<#
===========================================================================================
|                                                                                         |
|                                         Main                                            |
|                                                                                         |
===========================================================================================
#>
 
[System.Console]::Title = "Block IP addresses - by Elektro"
[CultureInfo]::CurrentUICulture = "en-US"
 
try { Set-ExecutionPolicy -ExecutionPolicy "Unrestricted" -Scope "Process" } catch { }
 
Show-WelcomeScreen
Confirm-Continue
Add-FirewallRules -ipListFile $ipListFile -ipArray $ipArray
Show-GoodbyeScreen
Exit(0)