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

    Fault : Certificate enrolment fails -- template permissions and CA errors
    Fix   : Publish the template and confirm the CA is reachable
    Source: https://jbtecwiz.com/support/srv-app-ca-enrollment

    Run as     : Elevated PowerShell on the CA
    Expect     : 30 minutes
    Risk       : medium
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    The template does not appear to the requester.

    HOW TO UNDO IT
    Remove-CATemplate unpublishes it again.

    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 '  Certificate enrolment fails -- template permissions and CA errors' -ForegroundColor White
Write-Host '  Publish the template and confirm the CA is reachable' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: medium   Reversible   30 minutes'
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 'List which templates the CA is issuing. A template that exists in the directory but is not published here cannot be requested.' -Command {
    certutil -CATemplates
    Get-CATemplate | Format-Table Name,OID
}

Invoke-Step -Number 2 -Do 'Publish it.' -Command {
    Add-CATemplate -Name 'WorkstationAuthV2' -Force
    certutil -CATemplates
}

Invoke-Step -Number 3 -Do 'Check the CA service is healthy and the client can reach it.' -Command {
    certutil -ping
    Get-Service CertSvc | Format-List Status,StartType
    certutil -config "CA01\Example Issuing CA" -ping
}

Invoke-Step -Number 4 -Do 'Confirm the client''s autoenrolment policy is enabled -- the template being published means nothing if the client is not told to enrol.' -Why 'Auto-enrolment has to be enabled by Group Policy for computers and users separately. Publishing the template and setting the permissions is only two thirds of the job.' -Command {
    Get-ItemProperty 'HKLM:\SOFTWARE\Policies\Microsoft\Cryptography\AutoEnrollment' -ErrorAction SilentlyContinue | Format-List AEPolicy
}

Invoke-Step -Number 5 -Do 'Trigger enrolment on a client and read the result.' -Command {
    certutil -pulse
    Get-WinEvent -LogName Application -MaxEvents 30 | Where-Object ProviderName -like '*CertificateServicesClient*' | Format-List TimeCreated,Id,Message
}

Write-Rule "  Confirm it worked"
Show-Prose 'The certificate is issued and appears in the client''s store.' 'White'
Write-Host ''
if (-not $DryRun) {
    Get-ChildItem Cert:\LocalMachine\My | Format-Table Subject,NotAfter,Template
}

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-app-ca-enrollment' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Remove-CATemplate unpublishes it again.' 'DarkGray'
Write-Rule