Skip to content

Instantly share code, notes, and snippets.

Show Gist options
  • Star 1 You must be signed in to star a gist
  • Fork 0 You must be signed in to fork a gist
  • Save ionutzp/14cb3086f1748664af4ca513ee97db43 to your computer and use it in GitHub Desktop.
Save ionutzp/14cb3086f1748664af4ca513ee97db43 to your computer and use it in GitHub Desktop.
How to convert a .pfx SSL certificate to .crt/key (pem) formats. Useful for NGINX.md

source: http://www.markbrilman.nl/2011/08/howto-convert-a-pfx-to-a-seperate-key-crt-file/

openssl pkcs12 -in [yourfile.pfx] -nocerts -out [keyfile-encrypted.key]

What this command does is extract the private key from the .pfx file. Once entered you need to type in the importpassword of the .pfx file. This is the password that you used to protect your keypair when you created your .pfx file. If you cannot remember it anymore you can just throw your .pfx file away, cause you won’t be able to import it again, anywhere!. Once you entered the import password OpenSSL requests you to type in another password, twice!. This new password will protect your .key file.

Now let’s extract the certificate:

openssl pkcs12 -in [yourfile.pfx] -clcerts -nokeys -out [certificate.crt]

Just press enter and your certificate appears.

Now as I mentioned in the intro of this article you sometimes need to have an unencrypted .key file to import on some devices. I probably don’t need to mention that you should be carefully. If you store your unencrypted keypair somewhere on an unsafe location anyone can have a go with it and impersonate for instance a website or a person of your company. So always be extra careful when it comes to private keys! Just throw the unencrypted keyfile away when you’re done with it, saving just the encrypted one.

The command:

openssl rsa -in [keyfile-encrypted.key] -out [keyfile-decrypted.key]

Notes:

  • When you first extract the key, apply a new password (probably the same as you used to extract it) and then create an unencrypted key with the rsa command above
  • Use an encrypted key file for NGINX otherwise it'll ask for the password every time it is restarted.
  • Check the top of the extract .crt file for extra bits above the ----BEING... line and remove if necessary
  • This certificated needs to be concatenated with the full chain of certificate authorities cat domain.crt CA_bundle.crt > final.crt
  • test the cert with openssl s_client -showcerts -connect www.domain.com:443

=============================

With following procedure you can change your password on an .pfx certificate using openssl.

Export you current certificate to a passwordless pem type: [user@hostname]>openssl pkcs12 -in mycert.pfx -out tmpmycert.pem -nodes Enter Import Password: MAC verified OK

Convert the passwordless pem to a new pfx file with password: [user@hostname]openssl pkcs12 -export -out mycert2.pfx -in tmpmycert.pem Enter Export Password: Verifying - Enter Export Password:

Remove the temporary file: [user@hostname]rm tmpmycert.pem

Now you are done and can use the new mycert2.pfx file with your new password.

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment