Modifying SSL cert check Powershell script to loop through multiple sites - powershell

Question

I'm a Powershell newb, but I am trying to write a script to check the SSL certificate expiration dates for multiple remote websites.
I found this script (http://www.zerrouki.com/checkssl/) that does what I want, but only for a single site.
I am trying to modify it to allow for multiple sites/checks, but am getting an error when I do so. I've removed all of the email functionality from the script as I'll be using another to tool to alert on expiring certs. And I've hardcoded the URLs to check.
<#
Modified from Fabrice ZERROUKI - fabricezerrouki#hotmail.com Check-SSL.ps1
#>
$WebsiteURLs= #("URL1.com","URL2.com","URL3.com")
$WebsitePort=443
$CommonName=$WebsiteURL
$Threshold=120
foreach ($WebsiteURL in $WebsiteURLs){
Try{
$Conn = New-Object System.Net.Sockets.TcpClient($WebsiteURL,$WebsitePort)
Try {
$Stream = New-Object System.Net.Security.SslStream($Conn.GetStream())
$Stream.AuthenticateAsClient($CommonName)
$Cert = $Stream.Get_RemoteCertificate()
$ValidTo = [datetime]::Parse($Cert.GetExpirationDatestring())
Write-Host "`nConnection Successfull" -ForegroundColor DarkGreen
Write-Host "Website: $WebsiteURL"
$ValidDays = $($ValidTo - [datetime]::Now).Days
if ($ValidDays -lt $Threshold)
{
Write-Host "`nStatus: Warning (Expires in $ValidDays days)" -ForegroundColor Yellow
Write-Host "CertExpiration: $ValidTo`n" -ForegroundColor Yellow
}
else
{
Write-Host "`nStatus: OK" -ForegroundColor DarkGreen
Write-Host "CertExpiration: $ValidTo`n" -ForegroundColor DarkGreen
}
}
Catch { Throw $_ }
Finally { $Conn.close() }
}
Catch {
Write-Host "`nError occurred connecting to $($WebsiteURL)" -ForegroundColor Yellow
Write-Host "Website: $WebsiteURL"
Write-Host "Status:" $_.exception.innerexception.message -ForegroundColor Yellow
Write-Host ""
}
}
When I run this (with valid sites in the $WebsiteURLs variable) every site returns: Status: Authentication failed because the remote party has closed the transport stream.
If I only put one site in the $WebsiteURLs variable and remove the foreach function it runs ok.
Any idea what I can do to make this loop through each site in the variable?

Answer 1

Problem lies here:
$WebsiteURLs= #("URL1.com","URL2.com","URL3.com")
$WebsitePort=443
$CommonName=$WebsiteURL
When you call $Stream.AuthenticateAsClient($CommonName) it doesn't work, because $CommonName=$WebsiteURL is setting $commonName to null. When you remove the loop I assume you did as I did and changed $WebsiteURLs to $WebsiteURL so then you had a value to assign $CommonName.
If you move the declaration of $CommonName to within your loop it works.
$WebsiteURLs= #("URL1.com","URL2.com","URL3.com")
$WebsitePort=443
$Threshold=120
foreach ($WebsiteURL in $WebsiteURLs){
$CommonName=$WebsiteURL
Try{
$Conn = New-Object System.Net.Sockets.TcpClient($WebsiteURL,$WebsitePort)
Try {
$Stream = New-Object System.Net.Security.SslStream($Conn.GetStream())
$Stream.AuthenticateAsClient($CommonName)
$Cert = $Stream.Get_RemoteCertificate()
$ValidTo = [datetime]::Parse($Cert.GetExpirationDatestring())
Write-Host "`nConnection Successfull" -ForegroundColor DarkGreen
Write-Host "Website: $WebsiteURL"
$ValidDays = $($ValidTo - [datetime]::Now).Days
if ($ValidDays -lt $Threshold)
{
Write-Host "`nStatus: Warning (Expires in $ValidDays days)" -ForegroundColor Yellow
Write-Host "CertExpiration: $ValidTo`n" -ForegroundColor Yellow
}
else
{
Write-Host "`nStatus: OK" -ForegroundColor DarkGreen
Write-Host "CertExpiration: $ValidTo`n" -ForegroundColor DarkGreen
}
}
Catch { Throw $_ }
Finally { $Conn.close() }
}
Catch {
Write-Host "`nError occurred connecting to $($WebsiteURL)" -ForegroundColor Yellow
Write-Host "Website: $WebsiteURL"
Write-Host "Status:" $_.exception.innerexception.message -ForegroundColor Yellow
Write-Host ""
}
}