functions/Remove-DbaNetworkCertificate.ps1

#ValidationTags#Messaging,FlowControl,Pipeline,CodeStyle#

function Remove-DbaNetworkCertificate {
<#
    .SYNOPSIS
        Removes the network certificate for SQL Server instance
     
    .DESCRIPTION
        Removes the network certificate for SQL Server instance. This setting is found in Configuration Manager.
     
    .PARAMETER SqlInstance
        The target SQL Server - defaults to localhost. If target is a cluster, you must also specify InstanceClusterName (see below)
     
    .PARAMETER Credential
        Allows you to login to the computer (not sql instance) using alternative credentials.
     
    .PARAMETER Silent
        Use this switch to disable any kind of verbose messages
     
    .PARAMETER WhatIf
        Shows what would happen if the command were to run. No actions are actually performed.
     
    .PARAMETER Confirm
        Prompts you for confirmation before executing any changing operations within the command.
     
    .EXAMPLE
        Remove-DbaNetworkCertificate
         
        Removes the Network Certificate for the default instance (MSSQLSERVER) on localhost
     
    .EXAMPLE
        Remove-DbaNetworkCertificate -SqlInstance sql1\SQL2008R2SP2
         
        Removes the Network Certificate for the SQL2008R2SP2 instance on sql1
     
    .EXAMPLE
        Remove-DbaNetworkCertificate -SqlInstance localhost\SQL2008R2SP2 -WhatIf
         
        Shows what would happen if the command were run
     
    .NOTES
        Tags: Certificate
         
        Website: https://dbatools.io
        Copyright: (C) Chrissy LeMaire, clemaire@gmail.com
        License: GNU GPL v3 https://opensource.org/licenses/GPL-3.0
#>

    [CmdletBinding(SupportsShouldProcess, ConfirmImpact = "Low", DefaultParameterSetName = 'Default')]
    param (
        [Parameter(ValueFromPipeline = $true)]
        [Alias("ServerInstance", "SqlServer", "ComputerName")]
        [DbaInstanceParameter[]]
        $SqlInstance = $env:COMPUTERNAME,
        
        [PSCredential]
        
        $Credential,
        
        [switch]
        $Silent
    )
    process {
        foreach ($instance in $sqlinstance) {
            Write-Message -Level VeryVerbose -Message "Processing $instance" -Target $instance
            $null = Test-ElevationRequirement -ComputerName $instance -Continue
            
            Write-Message -Level Verbose -Message "Resolving hostname"
            $resolved = $null
            $resolved = Resolve-DbaNetworkName -ComputerName $instance -Turbo
            
            if ($null -eq $resolved) {
                Stop-Function -Message "Can't resolve $instance" -Target $instance -Continue -Category InvalidArgument
            }
            
            Write-Message -Level Output -Message "Connecting to SQL WMI on $($instance.ComputerName)"
            try {
                $sqlwmi = Invoke-ManagedComputerCommand -ComputerName $resolved.FQDN -ScriptBlock { $wmi.Services } -Credential $Credential -ErrorAction Stop | Where-Object DisplayName -eq "SQL Server ($($instance.InstanceName))"
            }
            catch {
                Stop-Function -Message "Failed to access $instance" -Target $instance -Continue -ErrorRecord $_
            }
            
            $regroot = ($sqlwmi.AdvancedProperties | Where-Object Name -eq REGROOT).Value
            $vsname = ($sqlwmi.AdvancedProperties | Where-Object Name -eq VSNAME).Value
            $instancename = $sqlwmi.DisplayName.Replace('SQL Server (', '').Replace(')', '') # Don't clown, I don't know regex :(
            $serviceaccount = $sqlwmi.ServiceAccount
            
            if ([System.String]::IsNullOrEmpty($regroot)) {
                $regroot = $sqlwmi.AdvancedProperties | Where-Object { $_ -match 'REGROOT' }
                $vsname = $sqlwmi.AdvancedProperties | Where-Object { $_ -match 'VSNAME' }
                
                if (![System.String]::IsNullOrEmpty($regroot)) {
                    $regroot = ($regroot -Split 'Value\=')[1]
                    $vsname = ($vsname -Split 'Value\=')[1]
                }
                else {
                    Stop-Function -Message "Can't find instance $vsname on $instance" -Continue -Category ObjectNotFound -Target $instance
                }
            }
            
            if ([System.String]::IsNullOrEmpty($vsname)) { $vsname = $instance }
            
            Write-Message -Level Output -Message "Regroot: $regroot" -Target $instance
            Write-Message -Level Output -Message "ServiceAcct: $serviceaccount" -Target $instance
            Write-Message -Level Output -Message "InstanceName: $instancename" -Target $instance
            Write-Message -Level Output -Message "VSNAME: $vsname" -Target $instance
            
            $scriptblock = {
                $regroot = $args[0]
                $serviceaccount = $args[1]
                $instancename = $args[2]
                $vsname = $args[3]
                
                $regpath = "Registry::HKEY_LOCAL_MACHINE\$($args[0])\MSSQLServer\SuperSocketNetLib"
                $cert = (Get-ItemProperty -Path $regpath -Name Certificate).Certificate
                Set-ItemProperty -Path $regpath -Name Certificate -Value $null
                
                [pscustomobject]@{
                    ComputerName      = $env:COMPUTERNAME
                    InstanceName      = $instancename
                    SqlInstance          = $vsname
                    ServiceAccount    = $serviceaccount
                    RemovedThumbprint = $cert.Thumbprint
                }
            }
            
            if ($PScmdlet.ShouldProcess("local", "Connecting to $ComputerName to remove the cert")) {
                try {
                    Invoke-Command2 -ComputerName $resolved.fqdn -Credential $Credential -ArgumentList $regroot, $serviceaccount, $instancename, $vsname -ScriptBlock $scriptblock -ErrorAction Stop
                }
                catch {
                    Stop-Function -Message "Failed to connect to $($resolved.fqdn) using PowerShell remoting!" -ErrorRecord $_ -Target $instance -Continue
                }
            }
        }
    }
}