function Get-Cert {
<#
.SYNOPSIS
    Fetches a Certificate.
#>
    [CmdletBinding()]
    param(
        [string]$Thumbprint,
        [string]$StoreName,
        [string]$FriendlyName
    )

    $certStore = @{ }
    $certStores = Get-ChildItem Cert:\LocalMachine\ | ForEach-Object { "Cert:\LocalMachine\$($_.Name)" }
    if ($StoreName) {
        $certStores = $certStores | Where-Object { $_ -Match "\\$StoreName" }
    }
    foreach ($store in $certStores) {
        Get-ChildItem $store | Where-Object { $_.NotAfter -gt (Get-Date) } | ForEach-Object {
            if ($certStore.ContainsKey($_.Thumbprint)) {
                $certStore[$_.Thumbprint].Add($_)
            } else {
                $list = [System.Collections.Generic.List[System.Security.Cryptography.X509Certificates.X509Certificate]]::new()
                $list.Add($_)
                $certStore.Add($_.Thumbprint, $list)
            }
        }
    }

    if ($Thumbprint) {
        return $certStore[$Thumbprint]
    } elseif ($FriendlyName) {
        return $certStore.Values | Where-Object { $_.FriendlyName -match $FriendlyName }
    }
    return $certStore.Values
}