xExchange

1.23.0.0

DSCResources/MSFT_xExchAntiMalwareScanning/MSFT_xExchAntiMalwareScanning.psm1

function Get-TargetResource
{
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSDSCUseVerboseMessageInDSCResource", "")]
    [CmdletBinding()]
    [OutputType([System.Collections.Hashtable])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.Boolean]
        $Enabled,

        [Parameter(Mandatory = $true)]
        [System.Management.Automation.PSCredential]
        [System.Management.Automation.Credential()]
        $Credential,

        [Parameter()]
        [System.Boolean]
        $AllowServiceRestart = $false
    )

    LogFunctionEntry -Parameters @{"Enabled" = $Enabled} -Verbose:$VerbosePreference

    #Establish remote Powershell session
    GetRemoteExchangeSession -Credential $Credential -CommandsToLoad 'Get-TransportAgent' -Verbose:$VerbosePreference

    $agent = Get-TransportAgent -Identity "Malware Agent"

    if ($null -ne $agent)
    {
        $returnValue = @{
            Enabled = [System.Boolean] $agent.Enabled
        }
    }

    $returnValue
}

function Set-TargetResource
{
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSDSCUseVerboseMessageInDSCResource", "")]
    [CmdletBinding()]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.Boolean]
        $Enabled,

        [Parameter(Mandatory = $true)]
        [System.Management.Automation.PSCredential]
        [System.Management.Automation.Credential()]
        $Credential,

        [Parameter()]
        [System.Boolean]
        $AllowServiceRestart = $false
    )

    LogFunctionEntry -Parameters @{"Enabled" = $Enabled} -Verbose:$VerbosePreference

    $scriptsRoot = Join-Path -Path ((Get-ItemProperty HKLM:\SOFTWARE\Microsoft\ExchangeServer\v15\Setup).MsiInstallPath) -ChildPath "Scripts"


    if ($Enabled -eq $true)
    {
        $scriptPath = Join-Path -Path "$($scriptsRoot)" -ChildPath "Enable-AntimalwareScanning.ps1"
    }
    else
    {
        $scriptPath = Join-Path -Path "$($scriptsRoot)" -ChildPath "Disable-AntimalwareScanning.ps1"
    }

    #Override Write-Host, as it is used by the target scripts, and causes a DSC error since the session is not interactive
    New-Alias Write-Host Write-Verbose

    if($AllowServiceRestart -eq $true)
    {
        . $scriptPath -ForceRestart
    }
    else
    {
        . $scriptPath

        Write-Warning -Message 'The configuration will not take effect until the MSExchangeTransport service is manually restarted.'
    }

    Remove-HelperSnapin

    Remove-Item Alias:Write-Host
}

function Test-TargetResource
{
    [Diagnostics.CodeAnalysis.SuppressMessageAttribute("PSDSCUseVerboseMessageInDSCResource", "")]
    [CmdletBinding()]
    [OutputType([System.Boolean])]
    param
    (
        [Parameter(Mandatory = $true)]
        [System.Boolean]
        $Enabled,

        [Parameter(Mandatory = $true)]
        [System.Management.Automation.PSCredential]
        [System.Management.Automation.Credential()]
        $Credential,

        [Parameter()]
        [System.Boolean]
        $AllowServiceRestart = $false
    )

    LogFunctionEntry -Parameters @{"Enabled" = $Enabled} -Verbose:$VerbosePreference

    $agentStatus = Get-TargetResource @PSBoundParameters

    $testResults = $true

    if ($null -eq $agentStatus)
    {
        Write-Verbose -Message 'Unable to retrieve AntiMalware Agent Status for server'

        $testResults = $false
    }
    else
    {
        if (!(VerifySetting -Name "Enabled" -Type "Boolean" -ExpectedValue $Enabled -ActualValue $agentStatus.Enabled -PSBoundParametersIn $PSBoundParameters -Verbose:$VerbosePreference))
        {
            $testResults = $false
        }
    }

    Remove-HelperSnapin

    return $testResults
}

<#
    .SYNOPSIS
        Removes the Exchange and ForeFront snapins, which are loaded by the
        Enable/Disable-AntimalwareScanning.ps1 scripts in the $Exscripts
        directory. Prevents an issue where if a snapin is added by multiple
        modules during the same session, subsequent additions of the same
        module fail with 'An item with the same key has already been added'.
 
    .NOTES
        This similar function exists in the files
        MSFT_xExchAntiMalwareScanning.psm1 and MSFT_xExchMaintenanceMode.psm1.
        This was initially attempted to be put in xExchangeHelper.psm1 instead.
        However when xExchangeHelper.psm1 is loaded as a NestedModule from
        xExchange.psd1, functions within xExchangeHelper.psm1 do not appear to
        be able to detect added snapins loaded by scripts called from other
        modules. The added snapins were only detectable when running
        Get-PSSnapin directly from functions within
        MSFT_xExchAntiMalwareScanning.psm1 and MSFT_xExchMaintenanceMode.psm1.
#>
function Remove-HelperSnapin
{
    [CmdletBinding()]
    param()

    $snapinsToRemove = @('Microsoft.Exchange.Management.Powershell.E2010', 'Microsoft.Forefront.Filtering.Management.PowerShell')

    foreach ($snapin in $snapinsToRemove)
    {
        if ($null -ne (Get-PSSnapin -Name $snapin -ErrorAction SilentlyContinue))
        {
            Write-Verbose -Message "'$snapin' snapin is currently loaded. Removing."

            Remove-PSSnapin -Name $snapin -ErrorAction SilentlyContinue -Confirm:$false
        }
    }
}

Export-ModuleMember -Function *-TargetResource