#Requires -Version 5.1
<#
    JbTecWiz Support Centre -- generated fix script

    Fault : LDAP channel binding and signing enforcement breaks applications
    Fix   : Find every unsigned bind before enforcing anything
    Source: https://jbtecwiz.com/support/srv-id-ldap-signing

    Run as     : Elevated PowerShell on each domain controller
    Expect     : 1 week of logging
    Risk       : low
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    Before enabling enforcement. This is the step that prevents the outage.

    HOW TO UNDO IT
    Set the diagnostic value back to 0 to stop the logging.

    This script walks the fix one step at a time and asks before each
    one. Steps with no command are things you do yourself -- it prints
    those and waits. Run with -DryRun to print without executing.

    --------------------------------------------------------------------
    NO WARRANTY - USE AT YOUR OWN RISK

    This script is provided by JbTecWiz as-is and with no warranty of any
    kind, express or implied. You run it entirely at your own risk.

    JbTecWiz accepts no liability for any loss or damage arising from its
    use, including but not limited to data loss, downtime, or configuration
    changes that turn out to be wrong for your system.

    You are responsible for reading this script before running it, for
    satisfying yourself that it suits the machine in front of you, and for
    having a working backup first. Some steps cannot be undone.
    --------------------------------------------------------------------
#>

[CmdletBinding()]
param(
    # Print every step and command without running anything.
    [switch]$DryRun,
    # Do not ask before each step. Read the script first if you use this.
    [switch]$Unattended
)

$ErrorActionPreference = 'Stop'
$script:Failed = 0

function Write-Rule { param([string]$Text)
    Write-Host ''
    Write-Host ('-' * 70) -ForegroundColor DarkGray
    if ($Text) { Write-Host $Text -ForegroundColor Cyan }
}

function Show-Prose { param([string]$Text, [string]$Colour = "Gray")
    if (-not $Text) { return }
    $words = $Text -split "\s+"; $line = "  "
    foreach ($w in $words) {
        if (($line.Length + $w.Length) -gt 74) { Write-Host $line -ForegroundColor $Colour; $line = "  " }
        $line += "$w "
    }
    if ($line.Trim()) { Write-Host $line -ForegroundColor $Colour }
}

function Invoke-Step {
    param(
        [int]$Number, [string]$Do, [string]$Why,
        [scriptblock]$Command, [switch]$Manual, [string]$Shell = "powershell"
    )
    Write-Rule "  Step $Number of 5"
    Show-Prose $Do "White"
    if ($Why) { Write-Host ""; Show-Prose $Why "DarkGray" }

    if ($Manual) {
        Write-Host ''
        Write-Host '  -> Do this yourself, then press Enter to carry on.' -ForegroundColor Yellow
        if (-not $Unattended -and -not $DryRun) { [void](Read-Host) }
        return
    }

    Write-Host ''
    foreach ($l in ($Command.ToString().Trim() -split "`n")) {
        Write-Host ("    " + $l.Trim()) -ForegroundColor Green
    }
    Write-Host ''

    if ($DryRun) { Write-Host "  (dry run -- not executed)" -ForegroundColor DarkGray; return }
    if (-not $Unattended) {
        $a = Read-Host "  Run this step? [Y]es / [S]kip / [Q]uit"
        if ($a -match "^[Qq]") { Write-Host "  Stopped at your request."; exit 0 }
        if ($a -match "^[Ss]") { Write-Host "  Skipped." -ForegroundColor DarkGray; return }
    }
    try { & $Command }
    catch {
        $script:Failed++
        Write-Host ("  Step $Number failed: " + $_.Exception.Message) -ForegroundColor Red
        Show-Prose "The rest of the fix may depend on this. Read the write-up before carrying on." "Red"
        if (-not $Unattended) {
            $c = Read-Host "  Carry on anyway? [y/N]"
            if ($c -notmatch "^[Yy]") { exit 1 }
        }
    }
}

Write-Rule
Write-Host '  LDAP channel binding and signing enforcement breaks applications' -ForegroundColor White
Write-Host '  Find every unsigned bind before enforcing anything' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: low   Reversible   1 week of logging'
Write-Host ''
Show-Prose 'No warranty. Use at your own risk - JbTecWiz accepts no liability. Read it before you run it, and have a backup.' 'DarkYellow'
Write-Rule

if (-not $Unattended -and -not $DryRun) {
    $go = Read-Host '  Ready? [y/N]'
    if ($go -notmatch "^[Yy]") { Write-Host "  Nothing was changed."; exit 0 }
}

Invoke-Step -Number 1 -Do 'Turn on the diagnostic logging that records unsigned binds.' -Why 'Event 2889 records the client address and the account for every unsigned bind. Left running for a week it produces the complete list of what will break -- which is the only way to do this without an outage.' -Command {
    Set-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\NTDS\Diagnostics' -Name '16 LDAP Interface Events' -Value 2 -Type DWord
}

Invoke-Step -Number 2 -Do 'Collect the events after several days, covering month-end and any weekly jobs.' -Command {
    Get-WinEvent -LogName 'Directory Service' -MaxEvents 2000 |
      Where-Object Id -eq 2889 |
      ForEach-Object { ($_.Message -split "`n" | Select-String 'Client IP|Identity') -join ' ' } |
      Group-Object | Sort-Object Count -Descending | Format-Table Count,Name -AutoSize
}

Invoke-Step -Number 3 -Do 'Work through the list: multifunction printers, monitoring systems, backup appliances and older line-of-business applications are the usual occupants.' -Manual

Invoke-Step -Number 4 -Do 'Reconfigure each to use LDAPS on port 636, or LDAP with sign and seal. Most support it and simply were not configured for it.' -Manual

Invoke-Step -Number 5 -Do 'Only when the 2889 events have stopped, enable enforcement.' -Command {
    Set-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\NTDS\Parameters' -Name LdapEnforceChannelBinding -Value 2 -Type DWord
    Set-ItemProperty 'HKLM:\SYSTEM\CurrentControlSet\Services\NTDS\Parameters' -Name 'LDAPServerIntegrity' -Value 2 -Type DWord
}

Write-Rule "  Confirm it worked"
Show-Prose 'No 2889 events for a full week, then enforcement enabled with no support calls.' 'White'

Write-Rule
if ($script:Failed -gt 0) {
    Write-Host ("  Finished with " + $script:Failed + " failed step(s).") -ForegroundColor Yellow
    Show-Prose 'Read the full write-up at https://jbtecwiz.com/support/srv-id-ldap-signing' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Set the diagnostic value back to 0 to stop the logging.' 'DarkGray'
Write-Rule