Using a .pfx to install an SSL certificate

Got a .pfx file and need to install an SSL certificate with this? Here’s how I did it. You’ll need to extract the signed public certificate (public key) and the private key without passphrase.

cd /etc/nginx/
mkdir ssl
cd ssl
mv /path/to/pfx/file.pfx .
chmod 400 file.fpx

First extract the public certificate. You might be asked for a password.

openssl pkcs12 -in ./file.pfx -clcerts -nokeys -out public.crt

And extract the private key:

openssl pkcs12 -in ./file.pfx -nocerts -nodes -out private.rsa

Now you can test the server on an arbitrary port, using openssl:

openssl s_server -www -accept 443 -cert ./public.crt -key ./private.rsa

Make sure no one can read the files other than you:

chmod 400 /etc/nginx/ssl/*

With NginX it is now easy to fire up the server. I used a proxy for this, because from an architecture perspective, this is the easiest:

server {
    server_name example.org;

    listen 443 ssl;
    ssl_certificate /etc/nginx/ssl/public.crt;
    ssl_certificate_key /etc/nginx/ssl/private.rsa;

    location / {
        proxy_pass http://example.org/;
        proxy_set_header Host $host;
        proxy_set_header X-Ssl on;
    }
}

I pass an additional X-Ssl header to the backend so they know we’re publicly serving through the SSL proxy (e.g. for building absolute URL’s). Once you actually know how to do it, it is easy as pie.

With thanks to Yadab Das and Berk D. Demir

9 Comments

  • Thank you, this was very helpful.

    but there is a small typo …

    In the command line, you’ve called the private key file ‘private.rsa’

    openssl pkcs12 -in ./file.pfx -nocerts -nodes -out private.rsa openssl s_server -www -accept 443 -cert ./public.crt -key ./private.rsa

    and in the nginx conf you’ve called it ‘private.key’

    ssl_certificate_key /etc/nginx/ssl/private.key;

  • Thanks, I updated the post 🙂

  • I found that your “extract public certificates” step omitted the intermediate certificates, which in turn prevented the PEM file from working.

    You can include the intermediate certificates in the output file if you do include the -nodes flag: openssl pkcs12 -in wildcard_intenvdemo_com_140715_export.pfx -out intenvdemo_public.pem -nodes -nokeys

  • Thanks!

  • thanks so much.

    although when i installed it said it missed intermediate certificate.

  • Chri.s wrote:

    Bro, you mixed up chmod 400 file.fpx with chmod 400 file.pfx 😉

    But thanks!

  • Giovanni wrote:

    Thank you very much. I used this technique to extract valid .crt and .key (I like .key instead of .rsa) files from a .pfx file for use with python/django/apache SSLCertificateFile and SSLCertificateKeyFile configuration.

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