Generate a pfx using p7s and key

It’s the end of 2019 and I can’t believe I am dealing with this again.

I can’t remember the last time I had to generate a pfx for installation in IIS but it has been frustrating enough for me to blog about so I remember for next time.

Pre-requisites

OpenSSL. A quick way to install in on Windows is via chocolatey

choco install OpenSSL.Light

Files form client

• my_domain.p7s
• my_domain.key

Generate the PKS

# First generate a cer file
openssl pkcs7 -print_certs -in my_domain.p7s -out my_domain.cer

# Second generate a cer file
openssl pkcs12 -export -inkey my_domain.key -in my_domain.cer -out my_domain.pfx

You can now install the pfx on the windows server!