TestSSL.ps1

function Test-SslProtocols {
   param(
     [Parameter(Mandatory=$true,ValueFromPipelineByPropertyName=$true,ValueFromPipeline=$true)]
     $ComputerName,
     
     [Parameter(ValueFromPipelineByPropertyName=$true)]
     [int]$Port = 443
   )
   begin {
     $ProtocolNames = [System.Security.Authentication.SslProtocols] | gm -static -MemberType Property | ?{$_.Name -notin @("Default","None")} | %{$_.Name}
   }
   process {
     $ProtocolStatus = [Ordered]@{}
     $ProtocolStatus.Add("ComputerName", $ComputerName)
     $ProtocolStatus.Add("Port", $Port)
     $ProtocolStatus.Add("KeyLength", $null)
     $ProtocolStatus.Add("SignatureAlgorithm", $null)
     
     $ProtocolNames | %{
       $ProtocolName = $_
       $Socket = New-Object System.Net.Sockets.Socket([System.Net.Sockets.SocketType]::Stream, [System.Net.Sockets.ProtocolType]::Tcp)
       $Socket.Connect($ComputerName, $Port)
       try {
         $NetStream = New-Object System.Net.Sockets.NetworkStream($Socket, $true)
         $SslStream = New-Object System.Net.Security.SslStream($NetStream, $true)
         $SslStream.AuthenticateAsClient($ComputerName,  $null, $ProtocolName, $false )
         $RemoteCertificate = [System.Security.Cryptography.X509Certificates.X509Certificate2]$SslStream.RemoteCertificate
         $ProtocolStatus["KeyLength"] = $RemoteCertificate.PublicKey.Key.KeySize
         $ProtocolStatus["SignatureAlgorithm"] = $RemoteCertificate.SignatureAlgorithm.FriendlyName
         $ProtocolStatus["Certificate"] = $RemoteCertificate
         $ProtocolStatus.Add($ProtocolName, $true)
       } catch  {
         $ProtocolStatus.Add($ProtocolName, $false)
       } finally {
         $SslStream.Close()
       }
     }
     [PSCustomObject]$ProtocolStatus
   }
 }
 
 $FQDN = ""
 Test-SslProtocols -ComputerName $FQDN