Merging the changes from Windows Source Depot.

Change details:
- Add metadata to the PowerShellGet.psd1
- Fixed special chars in PSGet.Resource.psd1
- Catalog signing verification changes from Windows Source Depot

src/Modules/Shared/PowerShellGet/PSGet.Resource.psd1

@@ -174,8 +174,8 @@ ConvertFrom-StringData @'
         ShouldIncludeDscResourcesToExport=This module '{0}' has exported DscResources. As a best practice, include exported DSC resources in the module manifest file(.psd1). If your PowerShell version is higher than 5.0, run Update-ModuleManifest -DscResourcesToExport to update the manifest with ExportedDscResources field.
         UpdateModuleManifestPathCannotFound=Cannot load the manifest file '{0}' properly. Please specify the correct manifest path.
         UpdatedModuleManifestNotValid=Cannot update the manifest file '{0}' because the manifest is not valid. Verify that the manifest file is valid, and then try again.'{1}'
-        ExportedDscResourcesNotSupportedOnLowerPowerShellVersion=The ExportedDscResources property is not supported in module manifests on PowerShell versions that are older than 5.0. Remove the value for the parameter ‘DscResourcesToExport’, and then try again.
-        CompatiblePSEditionsNotSupportedOnLowerPowerShellVersion=The CompatiblePSEditions property is not supported in module manifests on PowerShell versions that are older than 5.1. Remove the value for the parameter ‘CompatiblePSEditions’, and then try again.
+        ExportedDscResourcesNotSupportedOnLowerPowerShellVersion=The ExportedDscResources property is not supported in module manifests on PowerShell versions that are older than 5.0. Remove the value for the parameter 'DscResourcesToExport', and then try again.
+        CompatiblePSEditionsNotSupportedOnLowerPowerShellVersion=The CompatiblePSEditions property is not supported in module manifests on PowerShell versions that are older than 5.1. Remove the value for the parameter 'CompatiblePSEditions', and then try again.
         ExternalModuleDependenciesNotSpecifiedInRequiredOrNestedModules='{0}' is listed in ExternalModuleDependencies, but it is not found in either the RequiredModules or NestedModules properties. Verify that this module is required for ExternalModuleDependencies, and then add it to NestedModules or RequiredModules.
         TestModuleManifestFail=Cannot update the manifest properly. '{0}'
         PackageManagementProvidersNotInModuleBaseFolder=PackageManagementProvider '{0}' is not found in the module base '{1}'. Verify that the PackageManagementProvider specified is within the module base.

src/Modules/Shared/PowerShellGet/PSModule.psm1

@@ -14,13 +14,13 @@ Microsoft.PowerShell.Core\Set-StrictMode -Version Latest
 # Check if this is nano server. [System.Runtime.Loader.AssemblyLoadContext] is only available on NanoServer
 $script:isNanoServer = $null -ne ('System.Runtime.Loader.AssemblyLoadContext' -as [Type])
 
-function IsInbox { $PSHOME.EndsWith('\WindowsPowerShell\v1.0', [System.StringComparison]::OrdinalIgnoreCase) }
-function IsWindows { $PSVariable = Get-Variable -Name IsWindows -ErrorAction Ignore; return (-not $PSVariable -or $PSVariable.Value) }
-function IsLinux { $PSVariable = Get-Variable -Name IsLinux -ErrorAction Ignore; return ($PSVariable -and $PSVariable.Value) }
-function IsOSX { $PSVariable = Get-Variable -Name IsOSX -ErrorAction Ignore; return ($PSVariable -and $PSVariable.Value) }
-function IsCoreCLR { $PSVariable = Get-Variable -Name IsCoreCLR -ErrorAction Ignore; return ($PSVariable -and $PSVariable.Value) }
+$script:IsInbox = $PSHOME.EndsWith('\WindowsPowerShell\v1.0', [System.StringComparison]::OrdinalIgnoreCase)
+$script:IsWindows = (-not (Get-Variable -Name IsWindows -ErrorAction Ignore)) -or $IsWindows
+$script:IsLinux = (Get-Variable -Name IsLinux -ErrorAction Ignore) -and $IsLinux
+$script:IsOSX = (Get-Variable -Name IsOSX -ErrorAction Ignore) -and $IsOSX
+$script:IsCoreCLR = (Get-Variable -Name IsCoreCLR -ErrorAction Ignore) -and $IsCoreCLR
 
-if(IsInbox)
+if($script:IsInbox)
 {
     $script:ProgramFilesPSPath = Microsoft.PowerShell.Management\Join-Path -Path $env:ProgramFiles -ChildPath "WindowsPowerShell"
 }
@@ -29,7 +29,7 @@ else
     $script:ProgramFilesPSPath = $PSHome
 }
 
-if(IsInbox)
+if($script:IsInbox)
 {
     try
     {
@@ -49,7 +49,7 @@ if(IsInbox)
                                     Microsoft.PowerShell.Management\Join-Path -Path $env:USERPROFILE -ChildPath "Documents\WindowsPowerShell"
                                 }
 }
-elseif(IsWindows)
+elseif($script:IsWindows)
 {
     $script:MyDocumentsPSPath = Microsoft.PowerShell.Management\Join-Path -Path $HOME -ChildPath 'Documents\PowerShell'
 }
@@ -65,10 +65,10 @@ $script:ProgramFilesScriptsPath = Microsoft.PowerShell.Management\Join-Path -Pat
 
 $script:MyDocumentsScriptsPath = Microsoft.PowerShell.Management\Join-Path -Path $script:MyDocumentsPSPath -ChildPath "Scripts"
 
-$script:TempPath = if(IsWindows){ ([System.IO.DirectoryInfo]$env:TEMP).FullName } else { '/tmp' }
+$script:TempPath = if($script:IsWindows){ ([System.IO.DirectoryInfo]$env:TEMP).FullName } else { '/tmp' }
 $script:PSGetItemInfoFileName = "PSGetModuleInfo.xml"
 
-if(IsWindows)
+if($script:IsWindows)
 {
     $script:PSGetProgramDataPath = Microsoft.PowerShell.Management\Join-Path -Path $env:ProgramData -ChildPath 'Microsoft\Windows\PowerShell\PowerShellGet\'
     $script:PSGetAppLocalPath = Microsoft.PowerShell.Management\Join-Path -Path $env:LOCALAPPDATA -ChildPath 'Microsoft\Windows\PowerShell\PowerShellGet\'
@@ -123,8 +123,8 @@ $script:NuGetProviderVersion  = [Version]'2.8.5.201'
 
 $script:SupportsPSModulesFeatureName="supports-powershell-modules"
 $script:FastPackRefHashtable = @{}
-$script:NuGetBinaryProgramDataPath=if(IsWindows) {"$env:ProgramFiles\PackageManagement\ProviderAssemblies"}
-$script:NuGetBinaryLocalAppDataPath=if(IsWindows) {"$env:LOCALAPPDATA\PackageManagement\ProviderAssemblies"}
+$script:NuGetBinaryProgramDataPath=if($script:IsWindows) {"$env:ProgramFiles\PackageManagement\ProviderAssemblies"}
+$script:NuGetBinaryLocalAppDataPath=if($script:IsWindows) {"$env:LOCALAPPDATA\PackageManagement\ProviderAssemblies"}
 # go fwlink for 'https://nuget.org/nuget.exe'
 $script:NuGetClientSourceURL = 'https://go.microsoft.com/fwlink/?LinkID=690216&clcid=0x409'
 $script:NuGetExeName = 'NuGet.exe'
@@ -430,7 +430,28 @@ Microsoft.PowerShell.Utility\Import-LocalizedData  LocalizedData -filename PSGet
 # This code is required to add a .Net type and call the Telemetry APIs 
 # This is required since PowerShell does not support generation of .Net Anonymous types
 #
-$requiredAssembly = @( "system.management.automation, Version=3.0.0.0, Culture=neutral, PublicKeyToken=31bf3856ad364e35" )
+$requiredAssembly = @( [System.Management.Automation.PSCmdlet].Assembly.FullName )
+
+$script:IsSafeX509ChainHandleAvailable = ($null -ne ('Microsoft.Win32.SafeHandles.SafeX509ChainHandle' -as [Type]))
+
+if($script:IsSafeX509ChainHandleAvailable)
+{  
+   # It is not possible to define a single internal SafeHandle class in PowerShellGet namespace for all the supported versions of .Net Framework including .Net Core.
+   # SafeHandleZeroOrMinusOneIsInvalid is not a public class on .Net Core,
+   # therefore SafeX509ChainHandle will be used if it is available otherwise InternalSafeX509ChainHandle is defined below.
+   #
+   # ChainContext is not available on .Net Core, we must have to use SafeX509ChainHandle on .Net Core.
+   #
+   $SafeX509ChainHandleClassName = 'SafeX509ChainHandle'      
+   $requiredAssembly += [Microsoft.Win32.SafeHandles.SafeX509ChainHandle].Assembly.FullName
+}
+else
+{
+   # SafeX509ChainHandle is not available on .Net Framework 4.5 or older versions,
+   # therefore InternalSafeX509ChainHandle is defined below.
+   #
+   $SafeX509ChainHandleClassName = 'InternalSafeX509ChainHandle'
+}
 
 $source = @" 
 using System; 
@@ -439,6 +460,9 @@ using System.Management.Automation;
 using Microsoft.Win32.SafeHandles;
 using System.Security.Cryptography;
 using System.Runtime.InteropServices;
+using System.Runtime.ConstrainedExecution;
+using System.Runtime.Versioning;
+using System.Security;
 
 namespace Microsoft.PowerShell.Commands.PowerShellGet 
 { 
@@ -484,22 +508,87 @@ namespace Microsoft.PowerShell.Commands.PowerShellGet
         public IntPtr pvExtraPolicyStatus; 
     }
 
+    // Internal SafeHandleZeroOrMinusOneIsInvalid class to remove the dependency on .Net Framework 4.6.
+    public abstract class InternalSafeHandleZeroOrMinusOneIsInvalid : SafeHandle
+    {
+        protected InternalSafeHandleZeroOrMinusOneIsInvalid(bool ownsHandle)
+            : base(IntPtr.Zero, ownsHandle)
+        {
+        }
+
+        public override bool IsInvalid
+        {
+            get
+            {
+                return handle == IntPtr.Zero || handle == new IntPtr(-1);
+            }
+        }
+    }
+
+    // Internal SafeX509ChainHandle class to remove the dependency on .Net Framework 4.6.
+    [SecurityCritical]
+    public sealed class InternalSafeX509ChainHandle : InternalSafeHandleZeroOrMinusOneIsInvalid { 
+        private InternalSafeX509ChainHandle () : base(true) {}
+ 
+        internal InternalSafeX509ChainHandle (IntPtr handle) : base (true) {
+            SetHandle(handle); 
+        }
+  
+        internal static InternalSafeX509ChainHandle InvalidHandle { 
+            get { return new InternalSafeX509ChainHandle(IntPtr.Zero); }
+        } 
+ 
+        [SecurityCritical]
+        override protected bool ReleaseHandle() 
+        {
+            CertFreeCertificateChain(handle);
+            return true;
+        } 
+
+        [DllImport("Crypt32.dll", SetLastError=true)]
+$(if(-not $script:isNanoServer)
+{
+        '
+        [SuppressUnmanagedCodeSecurity,
+         ResourceExposure(ResourceScope.None),
+         ReliabilityContract(Consistency.WillNotCorruptState, Cer.Success)]
+        '
+})
+        private static extern void CertFreeCertificateChain(IntPtr handle); 
+    }
+
     public class Win32Helpers
     {
         [DllImport("Crypt32.dll", CharSet=CharSet.Auto, SetLastError=true)]
         public extern static 
         bool CertVerifyCertificateChainPolicy(
             [In]     IntPtr                       pszPolicyOID,
-            [In]     SafeX509ChainHandle pChainContext,
+            [In]     $SafeX509ChainHandleClassName  pChainContext,
             [In]     ref CERT_CHAIN_POLICY_PARA   pPolicyPara,
             [In,Out] ref CERT_CHAIN_POLICY_STATUS pPolicyStatus);
 
         [DllImport("Crypt32.dll", CharSet=CharSet.Auto, SetLastError=true)]
         public static extern
-        SafeX509ChainHandle CertDuplicateCertificateChain(
+        $SafeX509ChainHandleClassName CertDuplicateCertificateChain(
             [In]     IntPtr pChainContext);
 
-        public static bool IsMicrosoftCertificate([In] SafeX509ChainHandle pChainContext)
+$(if($script:IsSafeX509ChainHandleAvailable)
+{
+@"
+        [DllImport("Crypt32.dll", CharSet=CharSet.Auto, SetLastError=true)]
+    $(if(-not $script:isNanoServer)
+    {
+    '
+        [ResourceExposure(ResourceScope.None)]
+    '
+    })
+        public static extern
+        SafeX509ChainHandle CertDuplicateCertificateChain(
+            [In]     SafeX509ChainHandle pChainContext);
+"@
+})
+
+        public static bool IsMicrosoftCertificate([In] $SafeX509ChainHandleClassName pChainContext)
         {
             //-------------------------------------------------------------------------
             //  CERT_CHAIN_POLICY_MICROSOFT_ROOT  
@@ -525,7 +614,7 @@ namespace Microsoft.PowerShell.Commands.PowerShellGet
             //  to NULL.  
             //--------------------------------------------------------------------------  
             const uint MICROSOFT_ROOT_CERT_CHAIN_POLICY_ENABLE_TEST_ROOT_FLAG       = 0x00010000;
-            //const uint MICROSOFT_ROOT_CERT_CHAIN_POLICY_CHECK_APPLICATION_ROOT_FLAG = 0x00020000;
+            const uint MICROSOFT_ROOT_CERT_CHAIN_POLICY_CHECK_APPLICATION_ROOT_FLAG = 0x00020000;
             //const uint MICROSOFT_ROOT_CERT_CHAIN_POLICY_DISABLE_FLIGHT_ROOT_FLAG    = 0x00040000;
 
             CERT_CHAIN_POLICY_PARA PolicyPara = new CERT_CHAIN_POLICY_PARA(Marshal.SizeOf(typeof(CERT_CHAIN_POLICY_PARA)));
@@ -533,16 +622,39 @@ namespace Microsoft.PowerShell.Commands.PowerShellGet
             int CERT_CHAIN_POLICY_MICROSOFT_ROOT = 7;
             
             PolicyPara.dwFlags = (uint) MICROSOFT_ROOT_CERT_CHAIN_POLICY_ENABLE_TEST_ROOT_FLAG;
-            
-            if(!CertVerifyCertificateChainPolicy(new IntPtr(CERT_CHAIN_POLICY_MICROSOFT_ROOT),
-                                                 pChainContext,
-                                                 ref PolicyPara,
-                                                 ref PolicyStatus))
+            bool isMicrosoftRoot = false;
+
+            if(CertVerifyCertificateChainPolicy(new IntPtr(CERT_CHAIN_POLICY_MICROSOFT_ROOT),
+                                                pChainContext,
+                                                ref PolicyPara,
+                                                ref PolicyStatus))
             {
-                return false;
+                isMicrosoftRoot = (PolicyStatus.dwError == 0);
             }
 
-            return (PolicyStatus.dwError == 0);
+            // Also check for the Microsoft root for application signing if the Microsoft product root verification is unsuccessful.
+            if(!isMicrosoftRoot)
+            {
+                // Some Microsoft modules can be signed with Microsoft Application Root instead of Microsoft Product Root,
+                // So we need to use the MICROSOFT_ROOT_CERT_CHAIN_POLICY_CHECK_APPLICATION_ROOT_FLAG for the certificate verification.
+                // MICROSOFT_ROOT_CERT_CHAIN_POLICY_CHECK_APPLICATION_ROOT_FLAG can not be used
+                // with MICROSOFT_ROOT_CERT_CHAIN_POLICY_ENABLE_TEST_ROOT_FLAG,
+                // so additional CertVerifyCertificateChainPolicy call is required to verify the given certificate is in Microsoft Application Root.
+                //
+                CERT_CHAIN_POLICY_PARA PolicyPara2 = new CERT_CHAIN_POLICY_PARA(Marshal.SizeOf(typeof(CERT_CHAIN_POLICY_PARA)));
+                CERT_CHAIN_POLICY_STATUS PolicyStatus2 = new CERT_CHAIN_POLICY_STATUS(Marshal.SizeOf(typeof(CERT_CHAIN_POLICY_STATUS)));
+                PolicyPara2.dwFlags = (uint) MICROSOFT_ROOT_CERT_CHAIN_POLICY_CHECK_APPLICATION_ROOT_FLAG;
+
+                if(CertVerifyCertificateChainPolicy(new IntPtr(CERT_CHAIN_POLICY_MICROSOFT_ROOT),
+                                                    pChainContext,
+                                                    ref PolicyPara2,
+                                                    ref PolicyStatus2))
+                {
+                    isMicrosoftRoot = (PolicyStatus2.dwError == 0);
+                }
+            }
+
+            return isMicrosoftRoot;
         }
     }
 } 
@@ -567,7 +679,7 @@ catch
     # Ignore the error and try adding the type below
 }
 
-if(-not $script:TelemetryEnabled -and (IsWindows))
+if(-not $script:TelemetryEnabled -and $script:IsWindows)
 {
     try
     {
@@ -589,8 +701,8 @@ if(-not $script:TelemetryEnabled -and (IsWindows))
     }
 }
 
-$RequiredAssembliesForInternalWebProxy = @( "$([System.Net.IWebProxy].AssemblyQualifiedName)".Substring('System.Net.IWebProxy'.Length+1).Trim(), 
-                                            "$([System.Uri].AssemblyQualifiedName)".Substring('System.Uri'.Length+1).Trim() )
+$RequiredAssembliesForInternalWebProxy = @( [System.Net.IWebProxy].Assembly.FullName, 
+                                            [System.Uri].Assembly.FullName )
 
 $SourceForInternalWebProxy = @" 
 using System; 
@@ -732,7 +844,7 @@ function Publish-Module
 
     Begin
     {
-        if($script:isNanoServer -or (IsCoreCLR)) {
+        if($script:isNanoServer -or $script:IsCoreCLR) {
             $message = $LocalizedData.PublishPSArtifactUnsupportedOnNano -f "Module"
             ThrowError -ExceptionName "System.InvalidOperationException" `
                         -ExceptionMessage $message `
@@ -2531,7 +2643,7 @@ function Publish-Script
 
     Begin
     {
-        if($script:isNanoServer -or (IsCoreCLR)) {
+        if($script:isNanoServer -or $script:IsCoreCLR) {
             $message = $LocalizedData.PublishPSArtifactUnsupportedOnNano -f "Script"
             ThrowError -ExceptionName "System.InvalidOperationException" `
                         -ExceptionMessage $message `
@@ -4931,7 +5043,7 @@ function New-ScriptFileInfo
 
         if(-not $Author)
         {
-            if(IsWindows)
+            if($script:IsWindows)
             {
                 $Author = (Get-EnvironmentVariable -Name 'USERNAME' -Target $script:EnvironmentVariableTarget.Process -ErrorAction SilentlyContinue)
             }
@@ -5219,7 +5331,7 @@ function Update-ScriptFileInfo
 
             if(-not $Author)
             {
-                if(IsWindows)
+                if($script:IsWindows)
                 {
                     $Author = (Get-EnvironmentVariable -Name 'USERNAME' -Target $script:EnvironmentVariableTarget.Process -ErrorAction SilentlyContinue)
                 }
@@ -6194,7 +6306,7 @@ function Ping-Endpoint
     $results = @{}
 
     $WebProxy = $null
-    if($Proxy -and (IsWindows))
+    if($Proxy -and $script:IsWindows)
     {
         $ProxyNetworkCredential = $null
         if($ProxyCredential)
@@ -6424,7 +6536,7 @@ function ValidateAndSet-PATHVariableIfUserAccepts
         $Request
     )
 
-    if(-not (IsWindows))
+    if(-not $script:IsWindows)
     {
         return
     }
@@ -7224,7 +7336,7 @@ function Install-NuGetClientBinaries
         $Force
     )
 
-    if(-not (IsWindows) -or
+    if(-not $script:IsWindows -or
        ($script:NuGetProvider -and 
         (-not $BootstrapNuGetExe -or 
         ($script:NuGetExePath -and (Microsoft.PowerShell.Management\Test-Path -Path $script:NuGetExePath)))))
@@ -7327,7 +7439,7 @@ function Install-NuGetClientBinaries
     }
     
     # On Nano server we don't need NuGet.exe
-    if(-not $bootstrapNuGetProvider -and ($script:isNanoServer -or (IsCoreCLR) -or -not $BootstrapNuGetExe))
+    if(-not $bootstrapNuGetProvider -and ($script:isNanoServer -or $script:IsCoreCLR -or -not $BootstrapNuGetExe))
     {
         return
     }
@@ -7384,7 +7496,7 @@ function Install-NuGetClientBinaries
             }
         }
 
-        if($BootstrapNuGetExe -and -not $script:isNanoServer -and -not (IsCoreCLR))
+        if($BootstrapNuGetExe -and -not $script:isNanoServer -and -not $script:IsCoreCLR)
         {
             Write-Verbose -Message $LocalizedData.DownloadingNugetExe
 
@@ -7468,14 +7580,14 @@ function Test-RunningAsElevated
     [OutputType([bool])]
     Param()
 
-    if(IsWindows)
+    if($script:IsWindows)
     {
         $wid=[System.Security.Principal.WindowsIdentity]::GetCurrent()
         $prp=new-object System.Security.Principal.WindowsPrincipal($wid)
         $adm=[System.Security.Principal.WindowsBuiltInRole]::Administrator
         return $prp.IsInRole($adm)
     }
-    elseif((IsLinux) -or (IsOSX))
+    elseif($script:IsCoreCLR)
     {
         # Permission models on *nix can be very complex, to the point that you could never possibly guess without simply trying what you need to try;
         # This is totally different from Windows where you can know what you can or cannot do with/without admin rights.
@@ -11728,7 +11840,7 @@ function Set-InstalledModulesVariable
             WarningAction = 'SilentlyContinue'
         }
 
-        if(IsWindows)
+        if($script:IsWindows)
         {
             $GetChildItemParams['Attributes'] = 'Hidden'
         }
@@ -13914,7 +14026,7 @@ function Validate-ModuleCommandAlreadyAvailable
                                                                       -ErrorAction SilentlyContinue `
                                                                       -WarningAction SilentlyContinue | 
                                     Microsoft.PowerShell.Core\Where-Object { ($CommandNames -contains $_.Name) -and 
-                                                                             ($_.Source -ne $CurrentModuleInfo.Name) } |
+                                                                             ($_.ModuleName -ne $CurrentModuleInfo.Name) } |
                                         Microsoft.PowerShell.Utility\Select-Object -First 1 -ErrorAction Ignore
             if($AvailableCommand)
             {
@@ -13979,7 +14091,7 @@ function ValidateAndGet-AuthenticodeSignature
             # Skip the PSGetModuleInfo.xml and ModuleName.cat files in the catalog validation
             $TestFileCatalogResult = Microsoft.PowerShell.Security\Test-FileCatalog -Path $ModuleBasePath `
                                                                                     -CatalogFilePath $CatalogFilePath `
-                                                                                    -FilesToSkip $script:PSGetItemInfoFileName,'*.cat' `
+                                                                                    -FilesToSkip $script:PSGetItemInfoFileName,'*.cat','*.nupkg','*.nuspec' `
                                                                                     -Detailed `
                                                                                     -ErrorAction SilentlyContinue
             if(-not $TestFileCatalogResult -or 
@@ -14152,23 +14264,45 @@ function Test-MicrosoftCertificate
         $AuthenticodeSignature
     )
 
+    $IsMicrosoftCertificate = $false
+
     if($AuthenticodeSignature.SignerCertificate)
     {
+        $X509Chain = $null
+        $SafeX509ChainHandle = $null
+
         try
         {
             $X509Chain = New-Object System.Security.Cryptography.X509Certificates.X509Chain
             $null = $X509Chain.Build($AuthenticodeSignature.SignerCertificate)
+            
+            if($script:IsSafeX509ChainHandleAvailable)
+            {
+                $SafeX509ChainHandle = [Microsoft.PowerShell.Commands.PowerShellGet.Win32Helpers]::CertDuplicateCertificateChain($X509Chain.SafeHandle)
+            }
+            else
+            {
+                $SafeX509ChainHandle = [Microsoft.PowerShell.Commands.PowerShellGet.Win32Helpers]::CertDuplicateCertificateChain($X509Chain.ChainContext)
+            }
+
+            $IsMicrosoftCertificate = [Microsoft.PowerShell.Commands.PowerShellGet.Win32Helpers]::IsMicrosoftCertificate($SafeX509ChainHandle)
         }
         catch
         {
-            return $false
+            Write-Debug "Exception in Test-MicrosoftCertificate function:  $_"
         }
+        finally
+        {
+            if($SafeX509ChainHandle) { $SafeX509ChainHandle.Dispose() }
 
-        $SafeX509ChainHandle = [Microsoft.PowerShell.Commands.PowerShellGet.Win32Helpers]::CertDuplicateCertificateChain($X509Chain.ChainContext)
-        return [Microsoft.PowerShell.Commands.PowerShellGet.Win32Helpers]::IsMicrosoftCertificate($SafeX509ChainHandle)
+            # On .NET Framework 4.5.2 and earlier versions, 
+            # the X509Chain class does not implement the IDisposable interface and 
+            # therefore does not have a Dispose method.
+            if($X509Chain -and (Get-Member -InputObject $X509Chain -Name Dispose -ErrorAction SilentlyContinue)) { $X509Chain.Dispose() }
+        }
     }
 
-    return $false
+    return $IsMicrosoftCertificate
 }
 
 function Test-ValidManifestModule
@@ -14217,7 +14351,7 @@ function Test-ValidManifestModule
                        -CallerPSCmdlet $PSCmdlet `
                        -ErrorCategory InvalidOperation
         }
-        elseif(IsWindows)
+        elseif($script:IsWindows)
         {
             $ValidationResult = Validate-ModuleAuthenticodeSignature -CurrentModuleInfo $PSModuleInfo `
                                                                      -InstallLocation $InstallLocation `

src/Modules/Shared/PowerShellGet/PowerShellGet.psd1

@@ -45,6 +45,24 @@ RequiredModules = @(@{ModuleName='PackageManagement';ModuleVersion='1.0.0.1'})
 PrivateData = @{
                 "PackageManagementProviders" = 'PSModule.psm1'
                 "SupportedPowerShellGetFormatVersions" = @('1.x')
-               }
+    PSData = @{
+        Tags = @('Packagemanagement',
+                 'Provider',
+                 'PSEdition_Desktop',
+                 'PSEdition_Core',
+                 'Linux',
+                 'Mac')
+        ProjectUri = 'https://go.microsoft.com/fwlink/?LinkId=828955'
+        LicenseUri = 'https://go.microsoft.com/fwlink/?LinkId=829061'
+        ReleaseNotes = @'
+- PowerShellCore support
+- Security enhancements including the enforcement of catalog-signed modules during installation
+- Authenticated Repository support
+- Proxy Authentication support
+- Responses to a number of user requests and issues
+'@
+    }
+}
+
 HelpInfoURI = 'https://go.microsoft.com/fwlink/?LinkId=393271'
 }