HTTPS on Windows with IIS certificate using Let's Encrypt

In order to enable HTTPS for a website you need to get a certificate from a Certificate Authority (CA).
Most of the CA authorities offers paid certificates.

But Let's Enrcrypt is a free CA .

To be able to use free certificates from Let's Encrypt you need  to demonstrate that you are in control of the domain for which you want a certificate.
This is done using software which use ACME protocol.

How you can do this on windows machines running IIS :

• ACMESharp

           A Powershell library that provides access to many (but not yet all) commands of the ACME                API.

• letsencrypt-win-simple

          This is a ACME windows CLI client built in native .net and aims to be as simple as possible to           use.

• Certify - SSL Certificate Manager 

           Certify is a visual GUI based tool built on top of ACMESharp library.
It is still in alpha version , but is a promising tool.

The easiest to use , from my point of view , is letsencrypt-win-simple .

Why ?

Easy to install and easy to run .

Before running it make sure that you do the next in IIS :

1. Go to IIS manager and on the server select Handler Mappings , then View ordered list from the right menu .  Scroll down to find StaticFile handler and make sure it is above the Extensionless handlers, like in the bellow picture.

2. In case you have a custom  HTTP module running in IIS which is removing the Server header from the response , disable it while you are setting up the certificate and also when you are renewing it .

3. On the bindings of the web site for which the certificate is requested , make sure that the host name is filled in the binding settings section

After running the tool you will get the certificate in IIS .

Update : 21/03/20017

After you get the certificate you might wan to :

1. Revert StaticFile handler to it's original position .
    Why ? If you have an application under your website in iis,  which for example  is an web api , it      will no longer work until you revert the Staticfile handler to it's original position.