Understanding the Basics of PEM and PFX Certificates
Before we dive into the OpenSSL command to convert PEM to PFX, it’s important to understand what these certificate formats are and how they differ.
What is a PEM Certificate?
PEM stands for “Privacy Enhanced Mail,” which is a file format used to store digital certificates and private keys. PEM certificates are Base64-encoded ASCII files that contain a public key, private key, and certificate chain. They are commonly used in web servers, email servers, and other applications that require secure communication.
What is a PFX Certificate?
PFX (Personal Information Exchange) is a binary format used to store a certificate and its associated private key. PFX certificates are password-protected and are commonly used in Windows-based systems.
Converting PEM to PFX using OpenSSL
Now that we have a basic understanding of what PEM and PFX certificates are, let’s look at how to convert PEM to PFX using OpenSSL.
Step 1: Install OpenSSL
OpenSSL is a widely used open-source software library that provides cryptographic functions. If you don’t already have OpenSSL installed on your system, you can download it from the official website.
Step 2: Convert PEM Certificate to PKCS12 format
The first step in converting a PEM certificate to PFX is to convert it to PKCS12 format. PKCS12 is a binary format used to store a certificate and its associated private key.
To convert a PEM certificate to PKCS12 format using OpenSSL, use the following command:
Here, “cert.pem” is the name of the PEM certificate file, and “key.pem” is the name of the private key file. The “cert.pfx” file is the output file in PKCS12 format.
Step 3: Enter a Password
When you enter the above command, OpenSSL will prompt you to enter a password for the PFX file. This password is used to protect the private key in the PFX file.
Step 4: Verify the PFX File
Once the conversion is complete, you can verify the PFX file using the following command:
This command will display information about the PFX file, including the certificate and private key information.
FAQs for openssl command to convert pem to pfx
What is pem and pfx format?
PEM stands for Privacy Enhanced Mail, which is a base64-encoded ASCII certificate format. It contains the private key, public key, and certification authority (CA) certificate. PFX, on the other hand, is a binary file format that combines the private key and related certificate into a single encrypted file. It is typically used in Windows environments.
Why would I need to convert pem to pfx?
You may need to convert a PEM certificate to PFX format so that it can be used on a Windows server. Microsoft IIS servers typically require PFX SSL certificates. Additionally, you may need to convert a PEM format SSL certificate to a PFX file to import it into the Windows Certificate Store.
How can I convert pem to pfx using openssl?
To convert pem to pfx using OpenSSL, you need to execute the following command:
openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt
privateKey.key with the filename of your private key,
certificate.crt with the filename of your certificate, and
CACert.crt with the filename of the CA certificate. You can also use
.pem files instead of
.crt, as they contain the same certificate data.
Can I encrypt the PFX output?
Yes, you can encrypt the PFX output by adding the
-aes256 option to the command. For example:
openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.crt -certfile CACert.crt -aes256
This will encrypt the PFX file with the AES 256-bit encryption algorithm. When you run the command, you will be prompted to enter a password to use for the encryption.
Is there any other tool I can use to convert pem to pfx?
Yes, there are many other tools that you can use to convert PEM to PFX format, including Windows Certificate Manager, DigiCert Certificate Utility, and GlobalSign SSL Configuration Checker. However, using OpenSSL is the most common method and it is available on most platforms, including Windows, Linux, and macOS.