<#
.SYNOPSIS
    A short one-line action-based description, e.g. 'Tests if a function is valid'
.DESCRIPTION
    A longer description of the function, its purpose, common use cases, etc.
.NOTES
    Information or caveats about the function e.g. 'This function is not supported in Linux'
.LINK
    Specify a URI to a help page, this will show when Get-Help -Online is used.
.EXAMPLE
    Test-MyTestFunction -Verbose
    Explanation of the function or its result. You can include multiple examples with additional .EXAMPLE lines
#>

function Get-SslCertificate {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory)]
        [string]$DNSName
    )

    process {
        Write-Verbose "Checking certificate for $DNSName"

        $tcp = [Net.Sockets.TcpClient]::new($DNSName, 443)
        $ssl = [Net.Security.SslStream]::new(
            $tcp.GetStream(),
            $false,
            { $true }
        )

        $ssl.AuthenticateAsClient($DNSName)

        $cert = [Security.Cryptography.X509Certificates.X509Certificate2]::new(
            $ssl.RemoteCertificate
        )

        $ssl.Dispose()
        $tcp.Dispose()

        $cert
    }
}