Создание pfx

openssl pkcs12 -export -out ssl.pfx -inkey ssl_name.key -in ssl_name.crt -CAfile ca.crt

openssl pkcs12 -export -out .p12 -inkey .key -in .crt

Из pfx получить private key

Procedure

1. Take the file you exported (e.g. certname.pfx) and copy it to a system where you have OpenSSL installed. Note: the *.pfx file is in PKCS#12 format and includes both the certificate and the private key.
2. Run the following command to export the private key: openssl pkcs12 -in certname.pfx -nocerts -out key.pem -nodes
3. Run the following command to export the certificate: openssl pkcs12 -in certname.pfx -nokeys -out cert.pem
4. Run the following command to remove the passphrase from the private key: openssl rsa -in key.pem -out server.key 

http://office.microsoft.com/en-us/sharepoint-portal-server-it/step-4-export-the-client-certificate-with-a-private-key-pfx-file-for-use-on-additional-client-computers-and-index-management-servers-HA001164784.aspx



Из pfx получить crt

https://support.stackpath.com/hc/en-us/articles/230841967-Converting-pfx-to-a-crt-key-files