Credentials in Desired State Configuration

Question

I have the following Desired State Configuration (DSC)

Configuration Cert
{
    param (
        [Parameter(Mandatory=$true)] 
        [ValidateNotNullorEmpty()] 
        [System.String] $machineName,

        [Parameter(Mandatory = $true)]
        [ValidateNotNullorEmpty()]
        [PSCredential]
        $certCredential
    )

    Import-DscResource -ModuleName xPSDesiredStateConfiguration, xCertificate

    Node $machineName 
    {
        xPfxImport cert
        {
            Ensure = 'Present'
            Path = 'C:\certificate.pfx'
            Thumbprint = 'abcdefg'
            Location = 'LocalMachine'
            Store = 'My'
            Exportable = $true
            Credential = $certCredential
        }
    } 
}  
$cd = @{
    AllNodes = @(
    @{
        NodeName = 'localhost'
        PSDscAllowPlainTextPassword = $true
    }
)

}

$secpasswd = ConvertTo-SecureString 'password' -AsPlainText -Force
$mycreds = New-Object System.Management.Automation.PSCredential ('x', $secpasswd)

Cert -machineName MyPC -certCredential $mycreds -ConfigurationData $cd

Start-DscConfiguration –Path .\Cert –Wait –Verbose -Force

When I try to execute this I get the following error:

ConvertTo-MOFInstance : System.InvalidOperationException error processing property 'Credential' OF TYPE 'xPfxImport': Converting and storing encrypted passwords as plain text is not recommended. For more information on securing credentials in MOF file, please refer to MSDN blog: http://go.microsoft.com/fwlink/?LinkId=393729 At C:\Users\x\Desktop\script.ps1:18 char:9 + xPfxImport At line:341 char:16 + $aliasId = ConvertTo-MOFInstance $keywordName $canonicalizedValue + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: (:) [Write-Error], InvalidOperationException + FullyQualifiedErrorId : FailToProcessProperty,ConvertTo-MOFInstance Compilation errors occurred while processing configuration 'Cert'. Please review the errors reported in error stream and modify your configuration code appropriately. At C:\Windows\system32\WindowsPowerShell\v1.0\Modules\PSDesiredStateConfiguration\PSDesiredStateConfiguration.psm1:3917 char:5 + throw $ErrorRecord + ~~~~~~~~~~~~~~~~~~ + CategoryInfo : InvalidOperation: (Cert:String) [], InvalidOperationException + FullyQualifiedErrorId : FailToProcessConfiguration

I realize that the password must be encrypted and saving it as plain is not allowed or at least not recommended. I have tried many things suggested in the internet and I am still not able to make this working properly.

I am looking for a way to install a certificate and give certain set certificate permissions after that.

Answer 1

You need to allow for plaintextcredentials (link)

Configuration DomainCredentialExample
{
param(
    [PSCredential]$DomainCredential
)
    Import-DscResource -ModuleName PSDesiredStateConfiguration

    Node $AllNodes.NodeName
    {
        Group DomainUserToLocalGroup
        {
            GroupName        = 'InfoSecBackDoor'
            MembersToInclude = 'contoso\notyouraccount'
            Credential       = $DomainCredential
        }
    }
}

$cd = @{
    AllNodes = @(
        @{
            NodeName="localhost"
            PSDscAllowPlainTextPassword=$true
        }
    )
}

$cred = Get-Credential -UserName contoso\genericuser -Message "Password please"
DomainCredentialExample -DomainCredential $cred -ConfigurationData $cd

Answer 2

Having found myself facing the same issue, and I just thought I would re-iterate the actual cause of the issue (which is actually tucked away in the comments):

The last comment led me to the real problem. I did not realize that the nodename is actually what causing the issue. Please change node localhost line (8) to Node $AllNodes.NodeName and NodeName="*" back to NodeName="localhost"

Picking through the framework code inside PSDesiredStateConfiguration.psm1, the PSDscAllowPlainTextPassword flag won't get seen unless $machineName = localhost (in our case it was actually a case of fully-qualified vs. non-fully-qualified machine names).

I did also stumble across an undocumented workaround (not that I necessarily recommend using it) - it is actually possible to turn off the check for plaintext credentials using the following registry keys:

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\PowerShell\3\DSC]
"PSDscAllowPlainTextPassword"="True"
"PSDscAllowDomainUser"="True"

Hopefully this might save someone else some head-scratching!