Create a self-signed certificate for your web server with PowerShell

By Tomica Kaniski in Other 0 Comment

Sometimes you may need SSL certificate just for testing your (local) web application. Of course, for public and trusted purposes, you’ll probably use free Let’s Encrypt certificate or something similar (or, of course, any of the paid options).

And this is OK as long as you have publicly resolvable domain name.

But what if you need certificate for, let’s say, “localhost” or “webserver.local”?

Then you’ll probably use your internal PKI infrastructure or a simple self-signed certificate.

Second one can be easily achieved with PowerShell, by using the New-SelfSignedCertificate cmdlet (or with OpenSSL, yes 🙂).

So, let me show you how.

We have a simple IIS setup hosting a single (default) website, responding to http://localhost/:

We’ll issue a new self-signed certificate, make it trusted (important!) and then attach it to our test website, with following:

If everything goes well, we will see another binding created in our IIS console:

And if we open https://localhost/, all should be good as well:

Cheers!

Add a route to your VPN connection via PowerShell

By Tomica Kaniski in Other 2 Comments

I’m sure that you’re using some VPN somewhere, and you’re having “trouble” with split tunneling and routing, right?

Well, I had. 😀

As I’m “here and there” most of the time, I’ve setup an “anchor” location (no, it’s not in the cloud… yet) which is always available via VPN, and which has few machines that I’m, more or less, using regularly. When I’m not there, I connect there via my precious Windows 10/11 laptop and work as I’m there locally. I know – you know what VPNs are used for… bear with me a bit longer. 😀

So, all good – I have a VPN client (Windows built-in), a VPN server and Internet connection, and I can work.

One thing that I like to have is Internet access which is not routed via my “anchor” location, so that “the work stuff” goes through VPN and “the fun stuff” not.

It’s really easy to set this up – in properties of your VPN connection, just untick the “Use default gateway on remote network” checkbox:

But then you’ll have an issue with connecting to “the work stuff” – your current default gateway doesn’t know where “the work stuff” network is and how to get there.

It needs a route.

No problem, it’s easy to add a route in Windows (my “the work stuff” network is 192.168.13.0/24 and my VPN gateway is 192.168.14.1, or publicly 141.138.55.154):

And now you have access to “the work stuff” network again! And Internet access works as it should (not via the “anchor” location)!

Great.

But then you disconnect. And reconnect. And route you’ve added is gone. So, you repeat the procedure. Or script it. Or…

What if I tell you there is actually a better way?

I’m not really sure in which release this came out, but now you have an updated set of PowerShell cmdlets in (Windows 10/11) (which is cool!). For this story, the one we’re interested the most is Add-VpnConnectionRoute.

“So, doest that mean that, with it, I can configure my VPN connection to always have the route I need, whenever I connect to VPN? No more adding routes manually?!”

Exactly.

If I use the discussed Add-VpnConnectionRoute on my existing VPN connection, I can add the route I need and it will be written in the connection configuration and made active when the tunnel comes up, while still using the split tunneling.

Let’s see:

  • connected to “the work stuff” VPN and this is (part of) routing table prior the route configuration:

  • adding route configuration:

  • checking routes again:

As you can see, I’ve got new routes in my route table (it would be the same by using route add command above) and now I can access “the work stuff” without any issue:

And if I disconnect and connect again – it still works! 😊

Hope it helps someone!

Cheers!

Checking certificate expiration with PowerShell

By Tomica Kaniski in Other 4 Comments

Had an idea to write some (PowerShell) script which will check and maybe notify me of certificates that are nearing expiration for a bunch of (public) sites that… somewhat matter to me. 😊

As it turns out, someone already had this idea and wrote very nice PowerShell script that does just that, available here – thank you!

While testing it, there were sites on which the script worked just fine, and there were sites on which I got errors like this one (Error: “String was not recognized as a valid DateTime.”):

Seems to be connected to my regional settings (I know… who would ever use hr-HR instead of en-US, but… 😊) and date/time formatting:

I’ve tried to fix it in a couple of ways, but the one that finally did it (for me) was explained on Dan Sheehan’s blog (thanks!), implemented on lines 25-26 below.

So, my adapted script looks like this (and works with my hr-HR culture):

It provides the following output (which can be further customized per your needs, of course… and I know – need to insert some line breaks, convert output to HTML, send it via e-mail, … it’s a start! 😊):

Note that I’m returning expiration date “the Croatian way”, by using the following formatting:

Hope it helps someone (and #kudos to original authors)!

Cheers!