Framework/Helpers/ConfigurationHelper.ps1

Set-StrictMode -Version Latest
#
# ConfigurationHelper.ps1
#
class ConfigurationHelper {
    hidden static [bool] $IsIssueLogged = $false
    hidden static [PSObject] $ServerConfigMetadata = $null
    hidden static [bool] $OfflineMode = $false;
    hidden static [string] $ConfigVersion = ""
    hidden static [bool] $LocalPolicyEnabled = $false
    hidden static [string] $ConfigPath = [string]::Empty
    hidden static [Policy[]] $PolicyCacheContent = @()
    hidden static $NotExtendedTypes = @{} #Used to remember Types we have checked already as to whether they are extended (e.g., Build.ext.ps1) or not.
    hidden static [PSObject] LoadOfflineConfigFile([string] $fileName) {
        return [ConfigurationHelper]::LoadOfflineConfigFile($fileName, $true);
    }
    hidden static [PSObject] LoadOfflineConfigFile([string] $fileName, [bool] $parseJson) {
        $rootConfigPath = [Constants]::AzSKAppFolderPath  ;
        return [ConfigurationHelper]::LoadOfflineConfigFile($fileName, $true, $rootConfigPath);
    }
    hidden static [PSObject] LoadOfflineConfigFile([string] $fileName, [bool] $parseJson, $path) {
        #Load file from AzSK App folder"
        $rootConfigPath = $path ;    
        
        $extension = [System.IO.Path]::GetExtension($fileName);

        $filePath = $null
        if (Test-Path -Path $rootConfigPath) {
            $filePath = (Get-ChildItem $rootConfigPath -Name -Recurse -Include $fileName) | Select-Object -First 1 
        }
        #If file not present in App folder load settings from Configurations in Module folder
        if (!$filePath) {

            $basePath = [ConfigurationHelper]::GetBaseFrameworkPath()
            $rootConfigPath = $basePath | Join-Path -ChildPath "Configurations";
            
            $filePath = (Get-ChildItem $rootConfigPath -Name -Recurse -Include $fileName) | Select-Object -First 1 
        }

        if ($filePath) {
            if ($parseJson) {
                if ($extension -eq ".json" -or $extension -eq ".lawsview") {
                    $fileContent = (Get-Content -Raw -Path (Join-Path $rootConfigPath $filePath)) | ConvertFrom-Json
                }
                else {
                    $fileContent = (Get-Content -Raw -Path (Join-Path $rootConfigPath $filePath)) 
                }
            }
            else {
                $fileContent = (Get-Content -Raw -Path (Join-Path $rootConfigPath $filePath)) 
            }
        }
        else {
            throw "Unable to find the specified file '$fileName'"          
        }
        if (-not $fileContent) {
            throw "The specified file '$fileName' is empty"                                  
        }

        return $fileContent;
    }    

    hidden static [PSObject] LoadServerConfigFile([string] $policyFileName, [bool] $useOnlinePolicyStore, [string] $onlineStoreUri, [bool] $enableAADAuthForOnlinePolicyStore) {
        [PSObject] $fileContent = "";
        if ([string]::IsNullOrWhiteSpace($policyFileName)) {
            throw [System.ArgumentException] ("The argument 'policyFileName' is null");
        } 


        #Check if policy is present in cache and fetch the same if present
        $cachedPolicyContent = [ConfigurationHelper]::PolicyCacheContent | Where-Object { $_.Name -eq $policyFileName }
        if ($cachedPolicyContent)
        {
            $fileContent = $cachedPolicyContent.Content
            if ($fileContent)
            {
                return $fileContent                                  
            }
        }

        <#
        if ($onlineStoreUri -match "\{0\}.*\{1\}" -and $useOnlinePolicyStore -eq $true)
        {
            #[EventBase]::PublishGenericCustomMessage(" Org Policy URL not set yet: $onlineStoreUri", [MessageType]::Warning);
        }
        #>


        if ($useOnlinePolicyStore) {
            
            if ([string]::IsNullOrWhiteSpace($onlineStoreUri)) {
                throw [System.ArgumentException] ("The argument 'onlineStoreUri' is null");
            } 
            
            #Remember if the file we are attempting is SCMD.json
            $bFetchingSCMD = ($policyFileName -eq [Constants]::ServerConfigMetadataFileName)
            if ($bFetchingSCMD -and $null -ne [ConfigurationHelper]::ServerConfigMetadata) {
                return [ConfigurationHelper]::ServerConfigMetadata;
            }
            #First load offline OSS Content
            $fileContent = [ConfigurationHelper]::LoadOfflineConfigFile($policyFileName)

            #Check if policy is listed as present in server config metadata file
            if (-not [ConfigurationHelper]::OfflineMode -and [ConfigurationHelper]::IsPolicyPresentOnServer($policyFileName, $useOnlinePolicyStore, $onlineStoreUri, $enableAADAuthForOnlinePolicyStore)) {
                #Write-Host -ForegroundColor Yellow "**NOT FOUND** $policyFileName"
                try {
                    if ([String]::IsNullOrWhiteSpace([ConfigurationHelper]::ConfigVersion) -and -not [ConfigurationHelper]::LocalPolicyEnabled) {
                        try {
                            $Version = [System.Version] ($global:ExecutionContext.SessionState.Module.Version);
                            $serverFileContent = [ConfigurationHelper]::InvokeControlsAPI($onlineStoreUri, $Version, $policyFileName, $enableAADAuthForOnlinePolicyStore);
                            [ConfigurationHelper]::ConfigVersion = $Version;
                        }
                        catch {
                            try {
                                $Version = ([ConfigurationHelper]::LoadOfflineConfigFile("AzSK.json")).ConfigSchemaBaseVersion;
                                $serverFileContent = [ConfigurationHelper]::InvokeControlsAPI($onlineStoreUri, $Version, $policyFileName, $enableAADAuthForOnlinePolicyStore);
                                [ConfigurationHelper]::ConfigVersion = $Version;
                            }
                            catch {
                                if (Test-Path $onlineStoreUri) {    
                                    [EventBase]::PublishGenericCustomMessage("Running Org-Policy from local policy store location: [$onlineStoreUri]", [MessageType]::Warning);
                                    $serverFileContent = [ConfigurationHelper]::LoadOfflineConfigFile($policyFileName, $true, $onlineStoreUri)
                                    [ConfigurationHelper]::LocalPolicyEnabled = $true
                                }
                                else {
                                    throw $_
                                }
                            }
                        }
                    }
                    elseif ([ConfigurationHelper]::LocalPolicyEnabled) {
                        $serverFileContent = [ConfigurationHelper]::LoadOfflineConfigFile($policyFileName, $true, $onlineStoreUri)
                    }
                    else {
                        $Version = [ConfigurationHelper]::ConfigVersion ;
                        $serverFileContent = [ConfigurationHelper]::InvokeControlsAPI($onlineStoreUri, $Version, $policyFileName, $enableAADAuthForOnlinePolicyStore);
                    }

                    #Completely override offline config if Server Override flag is enabled
                    if ([ConfigurationHelper]::IsOverrideOfflineEnabled($policyFileName)) {
                        $fileContent = $serverFileContent
                    }
                    else {
                        $fileContent = [Helpers]::MergeObjects($fileContent, $serverFileContent)    
                    }
                    #Write-Host -ForegroundColor Green "**ADDING TO CACHE** $policyFileName"
                }
                catch {
                    [ConfigurationHelper]::OfflineMode = $true;

                    if (-not [ConfigurationHelper]::IsIssueLogged) {
                        if ([Helpers]::CheckMember($_, "Exception.Response.StatusCode") -and $_.Exception.Response.StatusCode.ToString().ToLower() -eq "unauthorized") {
                            [EventBase]::PublishGenericCustomMessage(("Not able to fetch org-specific policy. The current Azure subscription is not linked to your org tenant."), [MessageType]::Warning);
                            [ConfigurationHelper]::IsIssueLogged = $true
                        }
                        elseif ($bFetchingSCMD ) {
                            [EventBase]::PublishGenericCustomMessage(("Not able to fetch org-specific policy. Validate if org policy URL is correct."), [MessageType]::Warning);
                            [ConfigurationHelper]::IsIssueLogged = $true
                        }
                        else {
                            [EventBase]::PublishGenericCustomMessage(("Error while fetching the policy [$policyFileName] from online store. " + [Constants]::OfflineModeWarning), [MessageType]::Warning);
                            [EventBase]::PublishGenericException($_);
                            [ConfigurationHelper]::IsIssueLogged = $true
                        }
                    }            
                }                    
            }

            #If we were trying to fetch SCMD and the returned JSON does not have 'OnlinePolicyList' something is wrong!
            #In ADO this happens if ADOScanner_Policy_<ProjName> repo does not exist.
            #ADOTOD: Perhaps we should query for repo being present when the OnlinePolicyURL is formed (or first used)
            if ($bFetchingSCMD -and -not [Helpers]::CheckMember($fileContent, "OnlinePolicyList"))
            {
                [EventBase]::PublishGenericCustomMessage(("Org policy URL may be incorrect or policy-repo does not exist!`r`nReverting to local policy."), [MessageType]::Warning);
                $fileContent = [ConfigurationHelper]::LoadOfflineConfigFile($policyFileName)
            }

            if (-not $fileContent) {
                #Fire special event to notify user about switching to offline policy
                [EventBase]::PublishGenericCustomMessage(([Constants]::OfflineModeWarning + " Policy: $policyFileName"), [MessageType]::Warning);
                $fileContent = [ConfigurationHelper]::LoadOfflineConfigFile($policyFileName)
            }
            # return $updateResult
        }
        else {
            [EventBase]::PublishGenericCustomMessage(([Constants]::OfflineModeWarning + " Policy: $policyFileName"), [MessageType]::Warning);
            $fileContent = [ConfigurationHelper]::LoadOfflineConfigFile($policyFileName)
        }        
        if (-not $fileContent) {
            throw "The specified file '$policyFileName' is empty"                                  
        }

        #Store policy file content into cache.
        #Note: This will happen only once per file (whether found on server or not).
        #In case of SVT config JSONs, we will overwrite this (only once) right after resolving baselines/dynamic parameters in control recos, etc. (in LoadSVTConfig)

        #ADOTODO: by Sep2020. Do any controlSettings processing here. Revisit after Asim's policy cache changes are integrated.
        if ($policyFileName -match "ControlSettings.json")
        {    
            #Compile regex-s once upon load. The Env setting is just to compare perf during dev-test.
            #This code will overwrite the text regex with compiled version. (At point of usage, no change is needed.)
            if ((@($fileContent.Patterns)).Count -gt 0 -and -not $env:AzSKNoCompileRegex)
            {
                $iPat = 0
                $rgxOpt = [Text.RegularExpressions.RegexOptions]::Compiled; #default: case-sensitive match!
                $fileContent.Patterns | % {
                    $regExList = @($_.RegexList)
                    $iReg=0
                    $regExList | % {
                        $txtRegex = $_
                        $compiledRegex = [Text.RegularExpressions.Regex]::new($txtRegex, $rgxOpt)
                        $fileContent.Patterns[$iPat].RegexList[$iReg] = $compiledRegex
                        $iReg++
                    }
                    $iPat++
                }
            }
        }

        $policy = [Policy]@{
            Name    = $policyFileName
            Content = $fileContent
        }
        [ConfigurationHelper]::PolicyCacheContent += $policy

        return $fileContent;
    }

    hidden static [PSObject] LoadServerFileRaw([string] $fileName, [bool] $useOnlinePolicyStore, [string] $onlineStoreUri, [bool] $enableAADAuthForOnlinePolicyStore) {
        [PSObject] $fileContent = "";
        if ([string]::IsNullOrWhiteSpace($fileName)) {
            throw [System.ArgumentException] ("The argument 'fileName' is null");
        } 

        if ($useOnlinePolicyStore) {
            
            if ([string]::IsNullOrWhiteSpace($onlineStoreUri)) {
                throw [System.ArgumentException] ("The argument 'onlineStoreUri' is null");
            } 

            #Check if policy present in server using metadata file
            if (-not [ConfigurationHelper]::OfflineMode -and [ConfigurationHelper]::IsPolicyPresentOnServer($fileName, $useOnlinePolicyStore, $onlineStoreUri, $enableAADAuthForOnlinePolicyStore)) {
                try {
                    if ([String]::IsNullOrWhiteSpace([ConfigurationHelper]::ConfigVersion)) {                            
                        try {
                            $Version = [System.Version] ($global:ExecutionContext.SessionState.Module.Version);
                            $serverFileContent = [ConfigurationHelper]::InvokeControlsAPI($onlineStoreUri, $Version, $fileName, $enableAADAuthForOnlinePolicyStore);
                            [ConfigurationHelper]::ConfigVersion = $Version;
                        }
                        catch {
                            $Version = ([ConfigurationHelper]::LoadOfflineConfigFile("AzSK.json")).ConfigSchemaBaseVersion;
                            $serverFileContent = [ConfigurationHelper]::InvokeControlsAPI($onlineStoreUri, $Version, $fileName, $enableAADAuthForOnlinePolicyStore);
                            [ConfigurationHelper]::ConfigVersion = $Version;
                        }
                    }
                    else {
                        $Version = [ConfigurationHelper]::ConfigVersion ;
                        $serverFileContent = [ConfigurationHelper]::InvokeControlsAPI($onlineStoreUri, $Version, $fileName, $enableAADAuthForOnlinePolicyStore);
                    }
                        
                    $fileContent = $serverFileContent
                }
                catch {
                    [ConfigurationHelper]::OfflineMode = $true;

                    if (-not [ConfigurationHelper]::IsIssueLogged) {
                        if ([Helpers]::CheckMember($_, "Exception.Response.StatusCode") -and $_.Exception.Response.StatusCode.ToString().ToLower() -eq "unauthorized") {
                            [EventBase]::PublishGenericCustomMessage(("Not able to fetch org-specific policy. The current Azure subscription is not linked to your org tenant."), [MessageType]::Warning);
                            [ConfigurationHelper]::IsIssueLogged = $true
                        }
                        elseif ($fileName -eq [Constants]::ServerConfigMetadataFileName) {
                            [EventBase]::PublishGenericCustomMessage(("Not able to fetch org-specific policy. Validate if org policy URL is correct."), [MessageType]::Warning);
                            [ConfigurationHelper]::IsIssueLogged = $true
                        }
                        else {
                            [EventBase]::PublishGenericCustomMessage(("Error while fetching the policy [$fileName] from online store. " + [Constants]::OfflineModeWarning), [MessageType]::Warning);
                            [EventBase]::PublishGenericException($_);
                            [ConfigurationHelper]::IsIssueLogged = $true
                        }
                    }            
                }
                
                
            }

        }
        else {
            [EventBase]::PublishGenericCustomMessage(([Constants]::OfflineModeWarning + " Policy: $fileName"), [MessageType]::Warning);            
        }        

        return $fileContent;
    }

    hidden static [PSObject] InvokeControlsAPI([string] $onlineStoreUri, [string] $configVersion, [string] $policyFileName, [bool] $enableAADAuthForOnlinePolicyStore) {
        #Evaluate all code block in onlineStoreUri.
        #Can use '$FileName' in uri to fill dynamic file name.
        #Revisit
        # We are adding this code in AzSK.Framework for time-being. Need to revisit our strategy to update this code in framework later. This is ADO specific.
        $rmContext = [ContextHelper]::GetCurrentContext();
        $user = "";
        $base64AuthInfo = [Convert]::ToBase64String([Text.Encoding]::ASCII.GetBytes(("{0}:{1}" -f $user, $rmContext.AccessToken)))
        try {
            $FileName = $policyFileName;
            #$ResponseHeaders = $null #The '-ResponseHeadersVariable' param is supported in PS core, we should enable after moving to PS core. Will allow us to check response content-type etc.
            $uri = $global:ExecutionContext.InvokeCommand.ExpandString($onlineStoreUri)
            $webRequestResult = Invoke-RestMethod -Uri $uri -Method Get -ContentType "application/json" -Headers @{Authorization = ("Basic {0}" -f $base64AuthInfo) } #-ResponseHeadersVariable 'ResponseHeaders'
            return $webRequestResult;
        }
        catch {
            return $null;
        }
        return $null;
    }

    #Need to rethink on this function logic
    hidden static [PSObject] LoadModuleJsonFile([string] $fileName) {
     $basePath = [ConfigurationHelper]::GetBaseFrameworkPath()
     $rootConfigPath = Join-Path $basePath | Join-Path -ChildPath "Configurations";
        $filePath = (Get-ChildItem $rootConfigPath -Name -Recurse -Include $fileName) | Select-Object -First 1 
     if ($filePath) {
            $fileContent = (Get-Content -Raw -Path (Join-Path $rootConfigPath $filePath)) | ConvertFrom-Json
        }
        else {
            throw "Unable to find the specified file '$fileName'"          
        }
        return $fileContent;
    }

    hidden static [PSObject] LoadModuleRawFile([string] $fileName) {
    
     $basePath = [ConfigurationHelper]::GetBaseFrameworkPath()
     $rootConfigPath = Join-Path $basePath | Join-Path -ChildPath "Configurations";

        $filePath = (Get-ChildItem $rootConfigPath -Name -Recurse -Include $fileName) | Select-Object -First 1 
     if ($filePath) {
            $fileContent = (Get-Content -Raw -Path (Join-Path $rootConfigPath $filePath)) 
        }
        else {
            throw "Unable to find the specified file '$fileName'"          
        }
        return $fileContent;
    }

    hidden static [bool] IsPolicyPresentOnServer([string] $fileName, [bool] $useOnlinePolicyStore, [string] $onlineStoreUri, [bool] $enableAADAuthForOnlinePolicyStore) {
        #Check if Config meta data is null and load the meta data from server
        if ($null -eq [ConfigurationHelper]::ServerConfigMetadata) {
            #if File is meta data file then return true
            if ($fileName -eq [Constants]::ServerConfigMetadataFileName) {
                return $true
            }
            else {                
                $filecontent = [ConfigurationHelper]::LoadServerConfigFile([Constants]::ServerConfigMetadataFileName, $useOnlinePolicyStore, $onlineStoreUri, $enableAADAuthForOnlinePolicyStore);                            
                [ConfigurationHelper]::ServerConfigMetadata = $filecontent;
            }
        }
        
        if ($null -ne [ConfigurationHelper]::ServerConfigMetadata) {
            if ([ConfigurationHelper]::ServerConfigMetadata.OnlinePolicyList | Where-Object { $_.Name -eq $fileName }) {
                return $true
            }
            else {
                return $false
            }
        }
        else {
            #If Metadata file is not present on server then set offline default meta data..
            [ConfigurationHelper]::ServerConfigMetadata = [ConfigurationHelper]::LoadOfflineConfigFile([Constants]::ServerConfigMetadataFileName);
            return $false            
        }
    }

    #Function to check if Override Offline flag is enabled
    hidden static [bool] IsOverrideOfflineEnabled([string] $fileName) {
        if ($fileName -eq [Constants]::ServerConfigMetadataFileName) {
            return $true
        }

        $PolicyMetadata = [ConfigurationHelper]::ServerConfigMetadata.OnlinePolicyList | Where-Object { $_.Name -eq $fileName }
        if (($PolicyMetadata -and [Helpers]::CheckMember($PolicyMetadata, "OverrideOffline") -and $PolicyMetadata.OverrideOffline -eq $true) ) {
            return $true
        }
        else {
            return $false
        }
    }
    
    #Helper function to get base Framework folder path

    hidden static [PSObject] GetBaseFrameworkPath() {
        $moduleName = $([Constants]::AzSKModuleName)
        $isDebugModeOn = $([Constants]::AzSKDebugModeOn)
        #Remove Staging from module name before forming config base path
        $moduleName = $moduleName -replace "Staging", ""
        if ($true -eq $isDebugModeOn) { # If Dev-Test mode is on, here the \Framework folder is parallel to \ModuleName folder
            $basePath = Join-Path (Get-Item $PSScriptRoot).Parent.Parent.FullName $moduleName | Join-Path -ChildPath "Framework"
            
        }
        else { #In installed modules folder, the basepath is different.
            $basePath = (Get-Item $PSScriptRoot).Parent.FullName    
        }
        return $basePath
    }
}

#Model to store online policy file content with name.
#Used in ConfigurationHelper to cache online policy files
class Policy {
    [string] $Name
    [PSObject] $Content
}