AzSKPreview

4.0.0

Framework/Core/SVT/SVTControlAttestation.ps1

using namespace System.Management.Automation
Set-StrictMode -Version Latest 
class SVTControlAttestation 
{
    [SVTEventContext[]] $ControlResults = $null
    hidden [bool] $dirtyCommitState = $false;
    hidden [bool] $abortProcess = $false;
    hidden [ControlStateExtension] $controlStateExtension = $null;
    hidden [AttestControls] $AttestControlsChoice;
    hidden [bool] $bulkAttestMode = $false;
    [AttestationOptions] $attestOptions;
    hidden [PSObject] $ControlSettings ; 
    hidden [SubscriptionContext] $SubscriptionContext;
    hidden [InvocationInfo] $InvocationContext;

    SVTControlAttestation([SVTEventContext[]] $ctrlResults, [AttestationOptions] $attestationOptions, [SubscriptionContext] $subscriptionContext, [InvocationInfo] $invocationContext)
    {
        $this.SubscriptionContext = $subscriptionContext;
        $this.InvocationContext = $invocationContext;
        $this.ControlResults = $ctrlResults;
        $this.AttestControlsChoice = $attestationOptions.AttestControls;
        $this.attestOptions = $attestationOptions;
        $this.controlStateExtension = [ControlStateExtension]::new($this.SubscriptionContext, $this.InvocationContext)
        $this.controlStateExtension.UniqueRunId = $(Get-Date -format "yyyyMMdd_HHmmss");
        $this.controlStateExtension.Initialize($true)
        $this.ControlSettings=$ControlSettingsJson = [ConfigurationManager]::LoadServerConfigFile("ControlSettings.json");
    }

    [AttestationStatus] GetAttestationValue([string] $AttestationCode)
    {
        switch($AttestationCode.ToUpper())
        {
            "1" { return [AttestationStatus]::NotAnIssue;}
            "2" { return [AttestationStatus]::WillNotFix;}
            "3" { return [AttestationStatus]::WillFixLater;}
            "4" { return [AttestationStatus]::ApprovedException;}
            "5" { return [AttestationStatus]::NotApplicable;}
            "6" { return [AttestationStatus]::StateConfirmed;}            
            "9" { 
                    $this.abortProcess = $true;
                    return [AttestationStatus]::None;
                }            
            Default { return [AttestationStatus]::None;}
        }
        return [AttestationStatus]::None
    }

    [ControlState] ComputeEffectiveControlState([ControlState] $controlState, [string] $ControlSeverity, [bool] $isSubscriptionControl, [SVTEventContext] $controlItem, [ControlResult] $controlResult)
    {
        Write-Host "$([Constants]::SingleDashLine)" -ForegroundColor Cyan
        Write-Host "ControlId : $($controlState.ControlId)`nControlSeverity : $ControlSeverity`nDescription : $($controlItem.ControlItem.Description)`nCurrentControlStatus : $($controlState.ActualVerificationResult)`n"        
        if(-not $controlResult.CurrentSessionContext.Permissions.HasRequiredAccess)
        {
            Write-Host "Skipping attestation process for this control. You do not have required permissions to evaluate this control. `nNote: If your permissions were elevated recently, please run the 'Disconnect-AzAccount' command to clear the Azure cache and try again." -ForegroundColor Yellow
            if($controlItem.ControlItem.Tags.Contains("KeySecretPermissions"))
            {
                Write-Host "(Please note that you must have access permissions to the keys & secrets in the key vault for successful attestation of this control)" -ForegroundColor Yellow
            }
            Write-Host ([Constants]::CoAdminElevatePermissionMsg) -ForegroundColor Yellow
            return $controlState;
        }
        if(-not $this.isControlAttestable($controlItem, $controlResult))
        {
            Write-Host "This control cannot be attested by policy. Please follow the steps in 'Recommendation' for the control in order to fix the control and minimize exposure to attacks." -ForegroundColor Yellow
            return $controlState;
        }
        $userChoice = ""
        $isPrevAttested = $false;
        if($controlResult.AttestationStatus -ne [AttestationStatus]::None)
        {
            $isPrevAttested = $true;
        }
        $tempCurrentStateObject = $null;
        if($null -ne $controlResult.StateManagement -and $null -ne $controlResult.StateManagement.CurrentStateData)
        {
            $tempCurrentStateObject  = $controlResult.StateManagement.CurrentStateData;
        }

        #display the current state only if the state object is not empty
        if($null -ne $tempCurrentStateObject -and $null -ne $tempCurrentStateObject.DataObject)
        {
            Write-Host "Configuration data to be attested:" -ForegroundColor Cyan
            Write-Host "$([JsonHelper]::ConvertToPson($tempCurrentStateObject.DataObject))"
        }

        if($isPrevAttested -and ($this.AttestControlsChoice -eq [AttestControls]::All -or $this.AttestControlsChoice -eq [AttestControls]::AlreadyAttested))
        {
            #Compute the effective attestation status for support backward compatibility
            $tempAttestationStatus = $controlState.AttestationStatus
            #ToDo: Check in DB if 'NotFixed' exists; Capture Timestamp; Remove following if condition code
            if($controlState.AttestationStatus -eq [AttestationStatus]::NotFixed)
            {
                $tempAttestationStatus = [AttestationStatus]::WillNotFix;
            }
            while($userChoice -ne '0' -and $userChoice -ne '1' -and $userChoice -ne '2' -and $userChoice -ne '9' )
            {
                Write-Host "Existing attestation details:" -ForegroundColor Cyan
                Write-Host "Attestation Status: $tempAttestationStatus`nVerificationResult: $($controlState.EffectiveVerificationResult)`nAttested By : $($controlState.State.AttestedBy)`nJustification : $($controlState.State.Justification)`n"
                Write-Host "Please select an action from below: `n[0]: Skip`n[1]: Attest`n[2]: Clear Attestation" -ForegroundColor Cyan
                $userChoice = Read-Host "User Choice"
                if(-not [string]::IsNullOrWhiteSpace($userChoice))
                {
                    $userChoice = $userChoice.Trim();
                }
            }
        }
        else
        {
            while($userChoice -ne '0' -and $userChoice -ne '1' -and $userChoice -ne '9' )
            {
                Write-Host "Please select an action from below: `n[0]: Skip`n[1]: Attest" -ForegroundColor Cyan
                $userChoice = Read-Host "User Choice"
                if(-not [string]::IsNullOrWhiteSpace($userChoice))
                {
                    $userChoice = $userChoice.Trim();
                }
            }
        }
        $Justification=""
        $Attestationstate=""
        $message = ""
        [PSObject] $ValidAttestationStatesHashTable = $this.ComputeEligibleAttestationStates($controlItem, $controlResult);
        [String[]]$ValidAttestationKey = @(0)
        #Sort attestation status based on key value
        if($null -ne $ValidAttestationStatesHashTable)
        {
            $ValidAttestationStatesHashTable | ForEach-Object {
                $message += "`n[{0}]: {1}" -f $_.Value,$_.Name;
                $ValidAttestationKey += $_.Value
            }
        }
        switch ($userChoice.ToUpper()){
            "0" #None
            {                
                            
            }
            "1" #Attest
            {
                $attestationState = ""
                while($attestationState -notin [String[]]($ValidAttestationKey) -and $attestationState -ne '9' )
                {
                    Write-Host "`nPlease select an attestation status from below: `n[0]: Skip$message" -ForegroundColor Cyan
                    $attestationState = Read-Host "User Choice"
                    $attestationState = $attestationState.Trim();
                }
                $attestValue = $this.GetAttestationValue($attestationState);
                if($attestValue -ne [AttestationStatus]::None)
                {
                    $controlState.AttestationStatus = $attestValue;
                }
                elseif($this.abortProcess)
                {
                    return $null;
                }
                elseif($attestValue -eq [AttestationStatus]::None)
                {
                    return $controlState;
                }

                #In case when the user selects ApprovedException as the reason for attesting,
                #they'll be prompted to provide the number of days till that approval expires.
                $exceptionApprovalExpiryDate = ""
                if($controlState.AttestationStatus -eq [AttestationStatus]::ApprovedException)
                {
                    Write-Host "`nPlease provide the number of days for which the exception has been approved (default is 6 months):" -ForegroundColor Cyan
                    Write-Host "`nNote: The number of days should fall in the next 6 months." -ForegroundColor Yellow
                    $numberOfDays = Read-Host "No. of Days"

                    $maxAllowedExceptionApprovalExpiryDate = ([DateTime]::UtcNow).AddMonths(6)                    

                    try
                    {                        
                        if(-not [string]::IsNullOrWhiteSpace($numberOfDays))
                        {
                            #$controlItem.ControlItem.AttestationExpiryPeriodInDays = $numberOfDays.Trim()
                            $proposedExceptionApprovalExpiryDate = ([DateTime]::UtcNow).AddDays($numberOfDays.Trim())

                            if($proposedExceptionApprovalExpiryDate -gt $maxAllowedExceptionApprovalExpiryDate)
                            {
                                Write-Host "`nNote: The exception approval expiry will be set to 6 months.`n" -ForegroundColor Yellow
                                $exceptionApprovalExpiryDate = $maxAllowedExceptionApprovalExpiryDate                                
                            }
                            else
                            {
                                $exceptionApprovalExpiryDate = $proposedExceptionApprovalExpiryDate
                            }
                        }
                        else
                        {
                            Write-Host "`nNote: The exception approval expiry will be set to 6 months.`n" -ForegroundColor Yellow
                            $exceptionApprovalExpiryDate = $maxAllowedExceptionApprovalExpiryDate
                        }
                    }
                    catch
                    {
                        Write-Host "`nThe days need to be an integer value." -ForegroundColor Red
                        throw $_.Exception
                    }
                }
                
                if($controlState.AttestationStatus -ne [AttestationStatus]::None)
                {
                    $Justification = ""
                    while([string]::IsNullOrWhiteSpace($Justification))
                    {
                        $Justification = Read-Host "Justification"
                        try
                        {
                            $SanitizedJustification = [System.Text.UTF8Encoding]::ASCII.GetString([System.Text.UTF8Encoding]::ASCII.GetBytes($Justification));
                            $Justification = $SanitizedJustification;
                        }
                        catch
                        { 
                            # If the justification text is empty then prompting message again to provide justification text.
                        }
                        if([string]::IsNullOrWhiteSpace($Justification))
                        {
                            Write-Host "`nEmpty space or blank justification is not allowed."
                        }
                    }                    
                    $this.dirtyCommitState = $true
                }
                $controlState.EffectiveVerificationResult = [Helpers]::EvaluateVerificationResult($controlState.ActualVerificationResult,$controlState.AttestationStatus);
                
                $controlState.State = $tempCurrentStateObject

                if($null -eq $controlState.State)
                {
                    $controlState.State = [StateData]::new();
                }

                $controlState.State.AttestedBy = [ContextHelper]::GetCurrentSessionUser();
                $controlState.State.AttestedDate = [DateTime]::UtcNow;
                $controlState.State.Justification = $Justification    

                #In case of control exemption, calculating the exception approval(attestation) expiry date beforehand,
                #based on the days entered by the user (default 6 months)
                if($controlState.AttestationStatus -eq [AttestationStatus]::ApprovedException)
                {
                    $controlState.State.ExpiryDate = $exceptionApprovalExpiryDate.ToString("MM/dd/yyyy");
                }
                break;
            }
            "2" #Clear Attestation
            {
                $this.dirtyCommitState = $true
                #Clears the control state. This overrides the previous attested controlstate.
                $controlState.State = $null;
                $controlState.EffectiveVerificationResult = $controlState.ActualVerificationResult
                $controlState.AttestationStatus = [AttestationStatus]::None
            }
            "9" #Abort
            {
                $this.abortProcess = $true;
                return $null;
            }
            Default
            {

            }
        }

        return $controlState;
    }

    [ControlState] ComputeEffectiveControlStateInBulkMode([ControlState] $controlState, [string] $ControlSeverity, [bool] $isSubscriptionControl, [SVTEventContext] $controlItem, [ControlResult] $controlResult)
    {
        Write-Host "$([Constants]::SingleDashLine)" -ForegroundColor Cyan        
        Write-Host "ControlId : $($controlState.ControlId)`nControlSeverity : $ControlSeverity`nDescription : $($controlItem.ControlItem.Description)`nCurrentControlStatus : $($controlState.ActualVerificationResult)`n"
        if(-not $controlResult.CurrentSessionContext.Permissions.HasRequiredAccess)
        {
            Write-Host "Skipping attestation process for this control. You do not have required permissions to evaluate this control. `nNote: If your permissions were elevated recently, please run the 'Disconnect-AzAccount' command to clear the Azure cache and try again." -ForegroundColor Yellow
            if($controlItem.ControlItem.Tags.Contains("KeySecretPermissions"))
            {
                Write-Host "(Please note that you must have access permissions to the keys & secrets in the key vault for successful attestation of this control)" -ForegroundColor Yellow
            }
            Write-Host ([Constants]::CoAdminElevatePermissionMsg) -ForegroundColor Yellow
            return $controlState;
        }
        $userChoice = ""
        if($null -ne $this.attestOptions -and $this.attestOptions.IsBulkClearModeOn)
        {
            if($controlState.AttestationStatus -ne [AttestationStatus]::None)
            {                
                $this.dirtyCommitState = $true
                #Compute the effective attestation status for support backward compatibility
                $tempAttestationStatus = $controlState.AttestationStatus
                if($controlState.AttestationStatus -eq [AttestationStatus]::NotFixed)
                {
                    $tempAttestationStatus = [AttestationStatus]::WillNotFix;
                }
                Write-Host "Existing attestation details:" -ForegroundColor Cyan
                Write-Host "Attestation Status: $tempAttestationStatus`nVerificationResult: $($controlState.EffectiveVerificationResult)`nAttested By : $($controlState.State.AttestedBy)`nJustification : $($controlState.State.Justification)`n"
            }            
            #Clears the control state. This overrides the previous attested controlstate.
            $controlState.State = $null;
            $controlState.EffectiveVerificationResult = $controlState.ActualVerificationResult
            $controlState.AttestationStatus = [AttestationStatus]::None
            return $controlState;
        }
        $ValidAttestationStatesHashTable = $this.ComputeEligibleAttestationStates($controlItem, $controlResult);
        #Checking if control is attestable
        if($this.isControlAttestable($controlItem, $controlResult))
        {    # Checking if the attestation state provided in command parameter is valid for the control
            if( $this.attestOptions.AttestationStatus -in $ValidAttestationStatesHashTable.Name)
            {
            
                        $controlState.AttestationStatus = $this.attestOptions.AttestationStatus;
                        $controlState.EffectiveVerificationResult = [Helpers]::EvaluateVerificationResult($controlState.ActualVerificationResult,$controlState.AttestationStatus);
                
                        if($null -ne $controlResult.StateManagement -and $null -ne $controlResult.StateManagement.CurrentStateData)
                        {
                            $controlState.State = $controlResult.StateManagement.CurrentStateData;
                        }

                        if($null -eq $controlState.State)
                        {
                            $controlState.State = [StateData]::new();
                        }
                        $this.dirtyCommitState = $true
                        $controlState.State.AttestedBy = [ContextHelper]::GetCurrentSessionUser();
                        $controlState.State.AttestedDate = [DateTime]::UtcNow;
                        $controlState.State.Justification = $this.attestOptions.JustificationText                
            }
            #if attestation state provided in command parameter is not valid for the control then print warning
            else
            {
                $outvalidSet=$ValidAttestationStatesHashTable.Name -join "," ;
                Write-Host "The chosen attestation state is not applicable to this control. Valid attestation choices are: $outvalidSet" -ForegroundColor Yellow;
                return $controlState ;
            }
        }
        #If control is not attestable then print warning
        else
        {
            Write-Host "This control cannot be attested by policy. Please follow the steps in 'Recommendation' for the control in order to fix the control and minimize exposure to attacks." -ForegroundColor Yellow;
        }
        return $controlState;
    }
    
    [void] StartControlAttestation()
    {
    
        
        try
        {
            #user provided justification text would be available only in bulk attestation mode.
            if($null -ne $this.attestOptions -and  (-not [string]::IsNullOrWhiteSpace($this.attestOptions.JustificationText) -or $this.attestOptions.IsBulkClearModeOn))
            {
                $this.bulkAttestMode = $true;                
                    Write-Host "$([Constants]::SingleDashLine)" -ForegroundColor Yellow                
            }
            else
            {
                Write-Host ("$([Constants]::SingleDashLine)`nNote: Enter 9 during any stage to exit the attestation workflow. This will abort attestation process for the current resource and remaining resources.`n$([Constants]::SingleDashLine)") -ForegroundColor Yellow
            }
            
            if($null -eq $this.ControlResults)
            {
                Write-Host "No control results found." -ForegroundColor Yellow
            }
            $this.abortProcess = $false;
            #filtering the controls - Removing all the passed controls
            #Step1 Group By IDs

            $filteredControlResults = @()
            $filteredControlResults += $this.ControlResults | Group-Object { $_.GetUniqueId() }

            if((($filteredControlResults | Measure-Object).Count -eq 1 -and ($filteredControlResults[0].Group | Measure-Object).Count -gt 0 -and $null -ne $filteredControlResults[0].Group[0].ResourceContext) `
                -or ($filteredControlResults | Measure-Object).Count -gt 1)
            {
                Write-Host "No. of candidate resources for the attestation: $($filteredControlResults.Count)" -ForegroundColor Cyan
            }
        
            #show warning if the keys count is greater than certain number.
            $counter = 0
            #start iterating resource after resource
            foreach($resource in  $filteredControlResults)
            {
                $resourceValueKey = $resource.Name
                $this.dirtyCommitState = $false;
                $resourceValue = $resource.Group;        
                $isSubscriptionScan = $false;
                $counter = $counter + 1
                if(($resourceValue | Measure-Object).Count -gt 0)
                {
                    $SubscriptionId = $resourceValue[0].SubscriptionContext.SubscriptionId
                    if($null -ne $resourceValue[0].ResourceContext)
                    {
                        $ResourceId = $resourceValue[0].ResourceContext.ResourceId
                        Write-Host $([String]::Format([Constants]::ModuleAttestStartHeading, $resourceValue[0].FeatureName, $resourceValue[0].ResourceContext.ResourceGroupName, $resourceValue[0].ResourceContext.ResourceName, $counter, $filteredControlResults.Count)) -ForegroundColor Cyan
                    }
                    else
                    {
                        $isSubscriptionScan = $true;
                        Write-Host $([String]::Format([Constants]::ModuleAttestStartHeadingSub, $resourceValue[0].FeatureName, $resourceValue[0].SubscriptionContext.SubscriptionName, $resourceValue[0].SubscriptionContext.SubscriptionId)) -ForegroundColor Cyan
                    }    
                    
                    [ControlState[]] $resourceControlStates = @()
                    $count = 0;
                    [SVTEventContext[]] $filteredControlItems = @()
                    $resourceValue | ForEach-Object { 
                        $controlItem = $_;
                        $matchedControlItem = $false;
                        if(($controlItem.ControlResults | Measure-Object).Count -gt 0)
                        {
                            [ControlResult[]] $matchedControlResults = @();
                            $controlItem.ControlResults | ForEach-Object {
                                $controlResult = $_
                                if($controlResult.ActualVerificationResult -ne [VerificationResult]::Passed -and $controlResult.ActualVerificationResult -ne [VerificationResult]::Error)
                                {
                                    if($this.AttestControlsChoice -eq [AttestControls]::All)
                                    {
                                        $matchedControlItem = $true;
                                        $matchedControlResults += $controlResult;
                                        $count++;
                                    }
                                    elseif($this.AttestControlsChoice -eq [AttestControls]::AlreadyAttested -and $controlResult.AttestationStatus -ne [AttestationStatus]::None)
                                    {
                                        $matchedControlItem = $true;
                                        $matchedControlResults += $controlResult;
                                        $count++;
                                    }
                                    elseif($this.AttestControlsChoice -eq [AttestControls]::NotAttested -and  $controlResult.AttestationStatus -eq [AttestationStatus]::None)
                                    {
                                        $matchedControlItem = $true;
                                        $matchedControlResults += $controlResult;
                                        $count++;
                                    }                                    
                                }
                            }
                        }
                        if($matchedControlItem)
                        {
                            $controlItem.ControlResults = $matchedControlResults;
                            $filteredControlItems += $controlItem;
                        }
                    }
                    if($count -gt 0)
                    {
                        Write-Host "No. of controls that need to be attested: $count" -ForegroundColor Cyan

                         foreach( $controlItem in $filteredControlItems)
                         {
                            $controlId = $controlItem.ControlItem.ControlID
                            $controlSeverity = $controlItem.ControlItem.ControlSeverity
                            $controlResult = $null;
                            $controlStatus = "";
                            $isPrevAttested = $false;
                            if(($controlItem.ControlResults | Measure-Object).Count -gt 0)
                            {                                
                                foreach( $controlResult in $controlItem.ControlResults)
                                {
                                    $controlStatus = $controlResult.ActualVerificationResult;
                                
                                    [ControlState] $controlState = [ControlState]::new($controlId,$controlItem.ControlItem.Id,$controlResult.ChildResourceName,$controlStatus,"1.0");
                                    if($null -ne $controlResult.StateManagement -and $null -ne $controlResult.StateManagement.AttestedStateData)
                                    {                                
                                        $controlState.State = $controlResult.StateManagement.AttestedStateData
                                    }                        
                        
                                    $controlState.AttestationStatus = $controlResult.AttestationStatus
                                    $controlState.EffectiveVerificationResult = $controlResult.VerificationResult
                                    $controlState.HashId = [Helpers]::ComputeHash($resourceValueKey.ToLower());
                                    $controlState.ResourceId = $resourceValueKey;
                                    if($this.bulkAttestMode)
                                    {
                                        $controlState = $this.ComputeEffectiveControlStateInBulkMode($controlState, $controlSeverity, $isSubscriptionScan, $controlItem, $controlResult)                                        
                                    }
                                    else
                                    {
                                        $controlState = $this.ComputeEffectiveControlState($controlState, $controlSeverity, $isSubscriptionScan, $controlItem, $controlResult)                                        
                                    }                                    
                                    $resourceControlStates +=$controlState;
                                    if($this.abortProcess)
                                    {
                                        Write-Host "Aborted the attestation workflow." -ForegroundColor Yellow
                                        return;
                                    }
                                }
                            }
                            Write-Host $([Constants]::SingleDashLine) -ForegroundColor Cyan
                        }
                    }
                    else
                    {
                        Write-Host "No attestable controls found.`n$([Constants]::SingleDashLine)" -ForegroundColor Yellow
                    }
                    
                    #remove the entries which doesn't have any state
                    #$resourceControlStates = $resourceControlStates | Where-Object {$_.State}
                    #persist the value back to state
                    if($this.dirtyCommitState)
                    {
                        if(($resourceControlStates | Measure-Object).Count -gt 0)
                        {
                            Write-Host "Attestation summary for this resource:" -ForegroundColor Cyan
                            $output = @()
                            $resourceControlStates | ForEach-Object {
                                $out = "" | Select-Object ControlId, EvaluatedResult, EffectiveResult, AttestationChoice
                                $out.ControlId = $_.ControlId
                                $out.EvaluatedResult = $_.ActualVerificationResult
                                $out.EffectiveResult = $_.EffectiveVerificationResult
                                $out.AttestationChoice = $_.AttestationStatus.ToString()
                                $output += $out
                            }
                            Write-Host ($output | Format-Table ControlId, EvaluatedResult, EffectiveResult, AttestationChoice | Out-String) -ForegroundColor Cyan
                        }

                        Write-Host "Committing the attestation details for this resource..." -ForegroundColor Cyan
                        $this.controlStateExtension.SetControlState($resourceValueKey, $resourceControlStates, $false)
                        Write-Host "Commit succeeded." -ForegroundColor Cyan
                    }
                    
                    if($null -ne $resourceValue[0].ResourceContext)
                    {
                        $ResourceId = $resourceValue[0].ResourceContext.ResourceId
                        Write-Host $([String]::Format([Constants]::CompletedAttestAnalysis, $resourceValue[0].FeatureName, $resourceValue[0].ResourceContext.ResourceGroupName, $resourceValue[0].ResourceContext.ResourceName)) -ForegroundColor Cyan
                    }
                    else
                    {
                        $isSubscriptionScan = $true;
                        Write-Host $([String]::Format([Constants]::CompletedAttestAnalysisSub, $resourceValue[0].FeatureName, $resourceValue[0].SubscriptionContext.SubscriptionName, $resourceValue[0].SubscriptionContext.SubscriptionId)) -ForegroundColor Cyan
                    }    
                }
            
            }
        }
        finally
        {
            $folderPath = Join-Path $([Constants]::AzSKAppFolderPath) "Temp" | Join-Path -ChildPath $($this.controlStateExtension.UniqueRunId)
            [Helpers]::CleanupLocalFolder($folderPath);
        }
    }    

    [bool] isControlAttestable([SVTEventContext] $controlItem, [ControlResult] $controlResult)
    {
        # If None is found in array along with other attestation status, 'None' will get precedence.
        if(($controlItem.ControlItem.ValidAttestationStates | Measure-Object).Count -gt 0 -and ($controlItem.ControlItem.ValidAttestationStates | Where-Object { $_.Trim() -eq [AttestationStatus]::None } | Measure-Object).Count -gt 0)
        { 
            return $false
        }
        else
        {
            return $true
        }
    }

    [PSObject] ComputeEligibleAttestationStates([SVTEventContext] $controlItem, [ControlResult] $controlResult)
    {
        [System.Collections.ArrayList] $ValidAttestationStates = $null
        #Default attestation state
        if($null -ne $this.ControlSettings.DefaultValidAttestationStates){
            $ValidAttestationStates = $this.ControlSettings.DefaultValidAttestationStates | Select-Object -Unique
        }
        #Additional attestation state
        if($null -ne $controlItem.ControlItem.ValidAttestationStates)
        { 
            $ValidAttestationStates += $controlItem.ControlItem.ValidAttestationStates | Select-Object -Unique
        }
        $ValidAttestationStates = $ValidAttestationStates.Trim() | Select-Object -Unique
        #if control not in grace, disable WillFixLater option
        if(-not $controlResult.IsControlInGrace)
        {
            if(($ValidAttestationStates | Where-Object { $_ -eq [AttestationStatus]::WillFixLater} | Measure-Object).Count -gt 0)
            {
                $ValidAttestationStates.Remove("WillFixLater")
            }
        }
        $ValidAttestationStatesHashTable = [Constants]::AttestationStatusHashMap.GetEnumerator() | Where-Object { $_.Name -in $ValidAttestationStates } | Sort-Object value
        
        if($this.attestOptions.IsExemptModeOn)
        {
            $ValidAttestationStatesHashTable += [Constants]::AttestationStatusHashMap.GetEnumerator() | Where-Object { $_.Name -eq [AttestationStatus]::ApprovedException }
        }
        
        return $ValidAttestationStatesHashTable;
    }
}