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

    Fault : Certificate errors on every site -- NET::ERR_CERT_AUTHORITY_INVALID
    Fix   : Inspect the trust store for what should not be there
    Source: https://jbtecwiz.com/support/win-app-browser-cert

    Run as     : Elevated PowerShell
    Expect     : 25 minutes
    Risk       : high
    Reversible : yes

    WHEN THIS IS THE RIGHT FIX
    The clock is right. Look at what the machine trusts before changing
    anything.

    HOW TO UNDO IT
    Export any certificate with Export-Certificate before removing it, and
    re-import with Import-Certificate.

    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 errors on every site -- NET::ERR_CERT_AUTHORITY_INVALID' -ForegroundColor White
Write-Host '  Inspect the trust store for what should not be there' -ForegroundColor Cyan
Write-Host ''
Write-Host '  Risk: high   Reversible   25 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 'Look at the certificate the browser is actually being offered. Click the warning, view the certificate, and read the issuer -- that name is the answer.' -Why 'If the issuer is your antivirus or your employer''s firewall, this is TLS inspection and expected. If it is a name you do not recognise, treat the machine as compromised and act accordingly.' -Manual

Invoke-Step -Number 2 -Do 'List roots that are not from Microsoft''s program, sorted by when they were installed.' -Command {
    Get-ChildItem Cert:\LocalMachine\Root |
      Sort-Object NotBefore -Descending |
      Select-Object -First 25 Subject,Issuer,NotAfter,Thumbprint |
      Format-Table -Wrap
}

Invoke-Step -Number 3 -Do 'Check the per-user store as well -- malware frequently installs there because it needs no elevation.' -Command {
    Get-ChildItem Cert:\CurrentUser\Root | Where-Object { $_.Subject -ne $_.Issuer -or $_.NotBefore -gt (Get-Date).AddYears(-2) } | Format-Table Subject,NotAfter,Thumbprint
}

Invoke-Step -Number 4 -Do 'Remove a root only when you are certain what it is. Removing a legitimate corporate root breaks every internal site on the machine.' -Command {
    Remove-Item -Path 'Cert:\CurrentUser\Root\THUMBPRINT' -Force
}

Invoke-Step -Number 5 -Do 'Refresh the trusted root list from Microsoft on a machine that has been offline a long time.' -Command {
    certutil -generateSSTFromWU C:\roots.sst
    certutil -addstore -f Root C:\roots.sst
}

Write-Rule "  Confirm it worked"
Show-Prose 'Well-known sites load without a warning and the corporate sites still work.' 'White'
Write-Host ''
if (-not $DryRun) {
    Test-NetConnection www.microsoft.com -Port 443 -InformationLevel Quiet
}

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/win-app-browser-cert' 'Yellow'
} else {
    Write-Host '  Finished.' -ForegroundColor Green
}
Write-Host ''
Show-Prose 'To undo: Export any certificate with Export-Certificate before removing it, and re-import with Import-Certificate.' 'DarkGray'
Write-Rule