11 January 2020
I use LetsEncrypt for my SSL needs on my websites (including this one!). It works seamlessly with my hosting provider (GoDaddy) but sometimes I generate a certificate to use on a local Windows box for testing purposes. However, the certificates that LetsEncrypt gives you aren't readily importable into IIS. Fortunately, there is a way to do it.
The web interface to generate a cert (www.zerossl.com) gives you four files:
But you can’t import this directly into IIS in Windows. To do that, install the OpenSSL for Windows Light version from:
Then add the OpenSSL directory (ie: C:\Program Files\OpenSSL\bin) to your Path environment variable.
Finally, run the following command in a command prompt while in the folder with your .txt files:
openssl pkcs12 -inkey domain-key.txt -in domain-crt.txt -export -out yourdomainname.pfx
The program will prompt you for a password and make you confirm it. Once you are done, you’ll have a .pfx file that you can import directly into IIS!