Converting pfx to pem using openssl

How to generate a .pem CA certificate and client certificate from a PFX file using OpenSSL.

Solution 1:

Another perspective for doing it on Linux... here is how to do it so that the resulting single file contains the decrypted private key so that something like HAProxy can use it without prompting you for passphrase.

openssl pkcs12 -in file.pfx -out file.pem -nodes

Then you can configure HAProxy to use the file.pem file.

This is an EDIT from previous version where I had these multiple steps until I realized the -nodes option just simply bypasses the private key encryption. But I'm leaving it here as it may just help with teaching.

openssl pkcs12 -in file.pfx -out file.nokey.pem -nokeys
openssl pkcs12 -in file.pfx -out file.withkey.pem
openssl rsa -in file.withkey.pem -out file.key
cat file.nokey.pem file.key > file.combo.pem

1. The 1st step prompts you for the password to open the PFX.
2. The 2nd step prompts you for that plus also to make up a passphrase for the key.
3. The 3rd step prompts you to enter the passphrase you just made up to store decrypted.
4. The 4th puts it all together into 1 file.

Then you can configure HAProxy to use the file.combo.pem file.

The reason why you need 2 separate steps where you indicate a file with the key and another without the key, is because if you have a file which has both the encrypted and decrypted key, something like HAProxy still prompts you to type in the passphrase when it uses it.

Solution 2:

You can use the OpenSSL Command line tool. The following commands should do the trick

openssl pkcs12 -in client_ssl.pfx -out client_ssl.pem -clcerts

openssl pkcs12 -in client_ssl.pfx -out root.pem -cacerts

If you want your file to be password protected etc, then there are additional options.

You can read the entire documentation here.