<#
.TITLE
    Check Certificate Profile Expiry

.SYNOPSIS
    Audits SCEP, PKCS, and trusted root certificate profiles: validity settings, deployment errors, and root certificates nearing expiry.

.DESCRIPTION
    This script inventories all certificate-related configuration profiles (SCEP,
    PKCS, and trusted certificate profiles) across platforms, reports their validity
    period settings and assignment state, and pulls per-profile deployment status to
    surface devices where certificate delivery is failing. For trusted certificate
    profiles it decodes the embedded root certificate and reports its actual expiry
    date, catching root or issuing CA certificates that will silently break SCEP
    enrollment when they lapse.

.TAGS
    Monitoring,Security

.MINROLE
    Intune Administrator

.PERMISSIONS
    DeviceManagementConfiguration.Read.All

.AUTHOR
    Ugur Koc

.VERSION
    1.2

.CHANGELOG
    1.2 - Added Azure Automation contract validation, portal-safe boolean parameters, beta Graph endpoints, and terminating paging errors
    1.1 - Azure Automation now records script progress, outcomes, and summaries in job history
    1.0 - Initial release

.LASTUPDATE
    2026-07-30

.EXAMPLE
    .\check-certificate-profile-expiry.ps1
    Audits all certificate profiles with a 90-day expiry warning window

.EXAMPLE
    .\check-certificate-profile-expiry.ps1 -ExpiryWarningDays 180 -ExportToCsv "true"
    Uses a 180-day warning window for embedded root certificates and exports to CSV

.NOTES
    - Requires Microsoft.Graph.Authentication module
    - Individual issued device certificates are not exposed via Graph; this script audits the profiles, their embedded CA certificates, and delivery status
    - Trusted certificate payloads are decoded locally to read the real certificate expiry
    - Uses beta Graph endpoints for the device configuration surface
    - Local interactive sign-in uses the MgGraphCommunity module to avoid the Graph SDK's mandatory WAM broker on Windows
#>

[CmdletBinding()]
param(
    [Parameter(Mandatory = $false, HelpMessage = "Days before an embedded certificate expiry to raise a warning")]
    [ValidateRange(1, 730)]
    [int]$ExpiryWarningDays = 90,

    [Parameter(Mandatory = $false, HelpMessage = "Export results to CSV")]
    [ValidateSet("true", "false", "1", "0", '$true', '$false')]
    [string]$ExportToCsv,

    [Parameter(Mandatory = $false, HelpMessage = "Output path for exports")]
    [string]$OutputPath = ".",

    [Parameter(Mandatory = $false, HelpMessage = "Force module installation without prompting")]
    [ValidateSet("true", "false", "1", "0", '$true', '$false')]
    [string]$ForceModuleInstall
)

# Normalize the local module-install override for Azure Automation parameter binding.
$forceModuleInstallRaw = [string]$ForceModuleInstall
Remove-Variable -Name ForceModuleInstall
if ([string]::IsNullOrWhiteSpace($forceModuleInstallRaw)) {
    $ForceModuleInstall = $false
}
elseif ($forceModuleInstallRaw.Trim().ToLowerInvariant() -in @("true", "1", '$true')) {
    $ForceModuleInstall = $true
}
elseif ($forceModuleInstallRaw.Trim().ToLowerInvariant() -in @("false", "0", '$false')) {
    $ForceModuleInstall = $false
}
else {
    throw "Parameter 'ForceModuleInstall' accepts only true, false, 1, 0, $true, or $false."
}

# Azure Automation supplies portal parameter values as strings. Normalize the
# public boolean parameters once so local and runbook execution use real booleans.
foreach ($runbookBooleanParameter in @('ExportToCsv')) {
    $runbookBooleanRaw = [string](Get-Variable -Name $runbookBooleanParameter -ValueOnly)
    Remove-Variable -Name $runbookBooleanParameter

    if ([string]::IsNullOrWhiteSpace($runbookBooleanRaw)) {
        Set-Variable -Name $runbookBooleanParameter -Value $false
        continue
    }

    switch ($runbookBooleanRaw.Trim().ToLowerInvariant()) {
        { $_ -in @("true", "1", '$true') } {
            Set-Variable -Name $runbookBooleanParameter -Value $true
        }
        { $_ -in @("false", "0", '$false') } {
            Set-Variable -Name $runbookBooleanParameter -Value $false
        }
        default {
            throw "Parameter '$runbookBooleanParameter' accepts only true, false, 1, 0, $true, or $false."
        }
    }
}

# ============================================================================
# ENVIRONMENT DETECTION AND SETUP
# ============================================================================

function Initialize-RequiredModule {
    param(
        [string[]]$ModuleNames,
        [bool]$IsAutomationEnvironment,
        [bool]$ForceInstall = $false
    )

    foreach ($ModuleName in $ModuleNames) {
        Write-Verbose "Checking module: $ModuleName"

        $module = Get-Module -ListAvailable -Name $ModuleName | Select-Object -First 1

        if (-not $module) {
            if ($IsAutomationEnvironment) {
                throw "Module '$ModuleName' is not available in Azure Automation"
            }
            else {
                Write-Information "Module '$ModuleName' not found. Installing..." -InformationAction Continue

                if (-not $ForceInstall) {
                    $response = Read-Host "Install module '$ModuleName'? (Y/N)"
                    if ($response -notmatch '^[Yy]') {
                        throw "Module '$ModuleName' is required but installation was declined."
                    }
                }

                try {
                    $isAdmin = ([Security.Principal.WindowsPrincipal] [Security.Principal.WindowsIdentity]::GetCurrent()).IsInRole([Security.Principal.WindowsBuiltInRole] "Administrator")
                    $scope = if ($isAdmin) { "AllUsers" } else { "CurrentUser" }

                    Install-Module -Name $ModuleName -Scope $scope -Force -AllowClobber -Repository PSGallery
                    Write-Information "✓ Successfully installed '$ModuleName'" -InformationAction Continue
                }
                catch {
                    throw "Failed to install module '$ModuleName': $($_.Exception.Message)"
                }
            }
        }

        Import-Module -Name $ModuleName -Force -ErrorAction Stop
    }
}

# Detect execution environment
$IsAzureAutomation = $null -ne $PSPrivateMetadata.JobId.Guid

# Initialize required modules
$RequiredModules = @("Microsoft.Graph.Authentication")

# MgGraphCommunity gives WAM-free interactive sign-in for local runs
if (-not $IsAzureAutomation) {
    $RequiredModules += "MgGraphCommunity"
}

try {
    Initialize-RequiredModule -ModuleNames $RequiredModules -IsAutomationEnvironment $IsAzureAutomation -ForceInstall $ForceModuleInstall
    Write-Verbose "✓ All required modules are available"
}
catch {
    Write-Error "Module initialization failed: $_"
    exit 1
}

# ============================================================================
# AUTHENTICATION
# ============================================================================

try {
    if ($IsAzureAutomation) {
        Write-Output "Connecting to Microsoft Graph using Managed Identity..."
        Connect-MgGraph -Identity -NoWelcome -ErrorAction Stop
    }
    else {
        Write-Output "Connecting to Microsoft Graph..."
        $Scopes = @(
            "DeviceManagementConfiguration.Read.All"
        )
        Connect-MgGraphCommunity -Scopes $Scopes -NoWelcome -ErrorAction Stop
    }
    Write-Output "✓ Successfully connected to Microsoft Graph"
}
catch {
    Write-Error "Failed to connect to Microsoft Graph: $($_.Exception.Message)"
    exit 1
}

# ============================================================================
# HELPER FUNCTIONS
# ============================================================================

function Get-MgGraphAllPage {
    param(
        [string]$Uri,
        [int]$DelayMs = 100
    )

    $allResults = @()
    $nextLink = $Uri

    do {
        try {
            if ($allResults.Count -gt 0) {
                Start-Sleep -Milliseconds $DelayMs
            }

            $response = Invoke-MgGraphRequest -Uri $nextLink -Method GET

            if ($null -ne $response.value) {
                $allResults += $response.value
            }
            else {
                $allResults += $response
            }

            $nextLink = $response.'@odata.nextLink'
        }
        catch {
            if ($_.Exception.Message -like "*429*") {
                Write-Information "Rate limit hit, waiting 60 seconds..." -InformationAction Continue
                Start-Sleep -Seconds 60
                continue
            }
            throw "Error fetching data: $($_.Exception.Message)"
        }
    } while ($nextLink)

    return $allResults
}

function Get-EmbeddedCertificateExpiry {
    param([object]$CertProfile)

    # Trusted cert profiles embed the certificate as base64 in trustedRootCertificate
    if (-not $CertProfile.trustedRootCertificate) { return $null }

    try {
        $certBytes = [Convert]::FromBase64String($CertProfile.trustedRootCertificate)
        $cert = [System.Security.Cryptography.X509Certificates.X509Certificate2]::new($certBytes)
        return [PSCustomObject]@{
            Subject   = $cert.Subject
            NotAfter  = $cert.NotAfter
            Thumbprint = $cert.Thumbprint
        }
    }
    catch {
        Write-Verbose "Could not decode certificate in '$($CertProfile.displayName)': $($_.Exception.Message)"
        return $null
    }
}

# ============================================================================
# MAIN SCRIPT LOGIC
# ============================================================================

try {
    Write-Output "Retrieving configuration profiles..."
    $allConfigurations = Get-MgGraphAllPage -Uri "https://graph.microsoft.com/beta/deviceManagement/deviceConfigurations?`$expand=assignments"

    # Certificate-related profile types across all platforms
    $certificateProfiles = @($allConfigurations | Where-Object {
            $_.'@odata.type' -match "ScepCertificateProfile|PkcsCertificateProfile|TrustedRootCertificate|TrustedCertificate"
        })

    if ($certificateProfiles.Count -eq 0) {
        Write-Output "`nNo SCEP, PKCS, or trusted certificate profiles found in this tenant."
        return
    }
    Write-Output "✓ Found $($certificateProfiles.Count) certificate profiles"

    $now = Get-Date
    [System.Collections.Generic.List[Object]]$report = @()

    foreach ($certProfile in $certificateProfiles) {
        $typeName = ([string]$certProfile.'@odata.type') -replace "#microsoft.graph.", ""

        $kind = if ($typeName -match "Scep") { "SCEP" }
        elseif ($typeName -match "Pkcs") { "PKCS" }
        else { "Trusted Certificate" }

        # Deployment health per profile
        $deviceStatuses = Get-MgGraphAllPage -Uri "https://graph.microsoft.com/beta/deviceManagement/deviceConfigurations/$($certProfile.id)/deviceStatuses"
        $errorCount = @($deviceStatuses | Where-Object { $_.status -in @("error", "conflict", "nonCompliant") }).Count
        $okCount = @($deviceStatuses | Where-Object { $_.status -in @("compliant", "succeeded") }).Count

        # Real certificate expiry for trusted cert profiles
        $embedded = if ($kind -eq "Trusted Certificate") { Get-EmbeddedCertificateExpiry -CertProfile $certProfile } else { $null }
        $embeddedExpiry = ""
        $flag = ""

        if ($embedded) {
            $daysLeft = [math]::Round(($embedded.NotAfter - $now).TotalDays, 0)
            $embeddedExpiry = "$($embedded.NotAfter.ToString('yyyy-MM-dd')) ($daysLeft days)"
            if ($daysLeft -lt 0) { $flag = "CertificateExpired" }
            elseif ($daysLeft -le $ExpiryWarningDays) { $flag = "CertificateExpiring" }
        }

        if (-not $flag) {
            if (@($certProfile.assignments).Count -eq 0) { $flag = "NotAssigned" }
            elseif ($errorCount -gt 0) { $flag = "DeploymentErrors" }
        }

        $validity = ""
        if ($certProfile.certificateValidityPeriodValue) {
            $validity = "$($certProfile.certificateValidityPeriodValue) $($certProfile.certificateValidityPeriodScale)"
        }

        $report.Add([PSCustomObject]@{
                ProfileName     = $certProfile.displayName
                Kind            = $kind
                ProfileType     = $typeName
                IsAssigned      = (@($certProfile.assignments).Count -gt 0)
                ValiditySetting = $validity
                EmbeddedCertExpiry = $embeddedExpiry
                DevicesOk       = $okCount
                DevicesError    = $errorCount
                Flag            = $flag
                ProfileId       = $certProfile.id
            })
    }

    # ----- Display results -----
    Write-Output "`nCERTIFICATE PROFILE AUDIT"
    Write-Output ("=" * 50)
    Write-Output "Expiry warning window: $ExpiryWarningDays days | Generated: $(Get-Date -Format 'yyyy-MM-dd HH:mm:ss')"
    Write-Output ("=" * 50)

    foreach ($kindGroup in ($report | Group-Object -Property Kind | Sort-Object Name)) {
        Write-Output "`n$($kindGroup.Name) profiles ($($kindGroup.Count)):"
        foreach ($row in ($kindGroup.Group | Sort-Object ProfileName)) {
            $assignedLabel = if ($row.IsAssigned) { "assigned" } else { "NOT ASSIGNED" }
            $line = "  $($row.ProfileName) [$assignedLabel]"
            if ($row.Flag) { $line += " [$($row.Flag)]" }
            Write-Output $line

            if ($row.ValiditySetting) {
                Write-Output "    Issued cert validity: $($row.ValiditySetting)"
            }
            if ($row.EmbeddedCertExpiry) {
                Write-Output "    Embedded certificate expires: $($row.EmbeddedCertExpiry)"
            }
            Write-Output "    Deployment: $($row.DevicesOk) ok, $($row.DevicesError) errors"
        }
    }

    # Summary
    $flagged = @($report | Where-Object { $_.Flag })
    Write-Output "`n"
    Write-Output ("=" * 50)
    Write-Output "Summary: $($report.Count) certificate profiles | $($flagged.Count) flagged"
    foreach ($row in $flagged) {
        Write-Output "  [$($row.Flag)] $($row.ProfileName)"
    }
    Write-Output ("=" * 50)

    # Export to CSV if requested
    if ($ExportToCsv) {
        $timestamp = Get-Date -Format "yyyy-MM-dd_HH-mm-ss"
        $csvPath = Join-Path $OutputPath "Certificate_Profile_Audit_$timestamp.csv"
        $report | Export-Csv -Path $csvPath -NoTypeInformation -Encoding UTF8
        Write-Output "✓ CSV report saved: $csvPath"
    }
}
catch {
    Write-Error "Script execution failed: $($_.Exception.Message)"
    exit 1
}
finally {
    try {
        $null = Disconnect-MgGraph
        Write-Output "✓ Disconnected from Microsoft Graph"
    }
    catch {
        Write-Verbose "Graph disconnection completed"
    }
}

# Copia sin cambios de https://github.com/ugurkocde/IntuneAutomation (commit 797bb2e).
# MIT License
#
# Copyright (c) 2025 Ugur Koc | Microsoft MVP
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in all
# copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
# SOFTWARE.