Module/Rule.SecurityOption/Convert/SecurityOptionRule.Convert.psm1
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# Copyright (c) Microsoft Corporation. All rights reserved. # Licensed under the MIT License. using module .\..\..\Common\Common.psm1 using module .\..\SecurityOptionRule.psm1 using namespace System.Text # Header <# .SYNOPSIS Identifies and extracts the Security Option details from an xccdf rule. .DESCRIPTION The class is used to convert the rule check-content element into an Security Option object. The rule content is parsed to identify it as a Security Option rule. The configuration details are then extracted and validated before returning the object. #> class SecurityOptionRuleConvert : SecurityOptionRule { <# .SYNOPSIS Empty constructor for SplitFactory #> SecurityOptionRuleConvert () { } <# .SYNOPSIS Converts a xccdf stig rule element into a Security Option Rule .PARAMETER XccdfRule The STIG rule to convert #> SecurityOptionRuleConvert ([xml.xmlelement] $XccdfRule) : base ($XccdfRule, $true) { [System.Text.RegularExpressions.Match] $tokens = $this.ExtractProperties() $this.SetOptionName($tokens) $this.SetOptionValue($tokens) $this.SetDuplicateRule() $this.SetDscResource() } #region Methods <# .SYNOPSIS Extracts and returns the Security Option settings from the check-content. .DESCRIPTION This match looks for the following patterns 1. If "OptionName" * "Value" 2. If the value for "OptionName" * "Value" This has only been found in the SQL instance STIG .NOTES If any rule does not match this pattern, please update the xccdf change log file to align to one of these options. #> [System.Text.RegularExpressions.Match] ExtractProperties () { return [regex]::Match( $this.RawString, '(?:If\s(?:the\svalue\sfor\s)?")(?<optionName>[^"]+)(?:")[^"]+(?:")(?<optionValue>[^"]+)(?:")' ) } <# .SYNOPSIS Sets the Security Option name that was extracted from the xccdf. .DESCRIPTION Gets the Security Option name token from the regular expression match group and sets the policy Name. If the named group is null, the convert status is set to fail. #> [void] SetOptionName ([System.Text.RegularExpressions.Match] $Regex) { $thisOptionName = $Regex.Groups.Where( {$_.Name -eq 'OptionName'}).Value if (-not $this.SetStatus($thisOptionName)) { $this.set_OptionName($thisOptionName) } } <# .SYNOPSIS Sets the Security Option value that was extracted from the xccdf. .DESCRIPTION Gets the Security Option value token from the regular expression match group and sets the policy value. If the named group is null, the convert status is set to fail. #> [void] SetOptionValue ([System.Text.RegularExpressions.Match] $Regex) { if ($this.OptionValueContainsRange()) { $this.SetOptionOrganizationValue() } else { $thisOptionValue = $Regex.Groups.Where( {$_.Name -eq 'OptionValue'}).Value if (-not $this.SetStatus($thisOptionValue)) { $this.set_OptionValue($thisOptionValue) } } } <# .SYNOPSIS Looks for a range of values defined in the rule. .DESCRIPTION A regular expression is applied to the rule to look for key words and sentence structures that define a list of valid values. If a range is detected the test returns true and false if not. #> [bool] OptionValueContainsRange () { if (Test-SecurityPolicyContainsRange -CheckContent $this.SplitCheckContent) { return $true } return $false } <# .SYNOPSIS Sets the organizational value with the correct range. .DESCRIPTION The range of valid values is enforced in the organizational settings with a PowerShell expression. The range of values are extracted and converted into a PS expression that is evaluated when the rule is loaded. For example, if a value is allowed to be between 1 and 3, the user provided org setting will be evaluated to ensure that they are within policy guide lines and throw an error if not. #> [void] SetOptionOrganizationValue () { $this.set_OrganizationValueRequired($true) $thisPolicyValueTestString = Get-SecurityPolicyOrganizationValueTestString -CheckContent $this.SplitCheckContent if (-not $this.SetStatus($thisPolicyValueTestString)) { $this.set_OrganizationValueTestString($thisPolicyValueTestString) } } hidden [void] SetDscResource () { if ($null -eq $this.DuplicateOf) { $this.DscResource = 'SecurityOption' } else { $this.DscResource = 'None' } } <# .SYNOPSIS looks for the Security Option path to determine if the rule is configuring an Security Option. #> static [bool] Match ([string] $CheckContent) { <# .Net does not appear to support regex subroutines, so we add and expand a variable before the match is evaluated. #> $delimiter = '(?:(?:-|>)>)' return ($CheckContent -Match "(?:Local Security Policy|Security Settings) $delimiter Local Policies $delimiter Security Options" ) } #endregion } |