News, Information and Resources about SSL Certificates
Authorized Reseller

How to Convert CRT to PEM, DER to PEM, CER to PEM, and CER to PFX

Get a Step-by-step easy guide on how to convert your SSL from CER to PEM, CRT to PEM, DER to PEM, and CER to PFX format effortlessly.

Did you know that more than 5 billion people are regular internet users, a good number of whom frequently access websites that are secured by SSL certificates.

These SSL (Secure Socket Layer) certificates serve dual purposes: they keep the user safe while also boosting the website’s overall reputation.

To make certificate management easier, an SSL converter can come in extremely handy.

This blog will guide you to convert CRT to PEM, DER to PEM, CER to PEM, and CER to PFX format effortlessly.

Types of SSL Certificate Formats

When it comes to securing your website, understanding SSL certificate formats is crucial.

Whether you want to convert CRT to PEM or switch between other formats, a good understanding of the types of formats is essential.

Below are some commonly used formats:

  • CER/CET: Often used on Windows-based systems.
  • PEM: Widely adopted and easy to edit using text editors.
  • DER: Binary form commonly used in Java-based systems.
  • PKCS#7: Holds the certificate and its entire trust chain.
  • PKCS#12: Personal Information Exchange Syntax: Often used to store a certificate file with its private key.
  • PFX: PFX is password protected file which contains both certificate and private key information.

What is a PEM File?

In the late 20th century, an innovative approach to securing e-mail communication was devised naming “Privacy Enhanced Mail” or PEM.

Though initially invented to make email secure, it has today evolved into an Internet security standard cherished by many.

The PEM format is characterized by its ‘BEGIN CERTIFICATE’ and ‘END CERTIFICATE’ delimiters.

When you aim to convert CRT to PEM, you’re essentially transitioning your certificate into a widely accepted, versatile format, amplifying its compatibility and ease of use.

How to Convert CRT, CER, DER to PEM Format?

Managing SSL certificates often involves dealing with different formats, each having its specific requirements and use cases.

If you’re curious about how to convert CRT, CER, DER to PEM format, you’re in the right spot.

Before you can successfully switch SSL files to PEM format, you’ll need to satisfy certain preliminary requirements.

  • The SSL certificate should be in format as .crt, .der, or .cer
  • A Windows Server machine where the certificate and its private key pair are installed and marked as exportable.
  • OpenSSL module for PowerShell installed on your system.

Now that you’ve checked these off your list, let’s go into the conversion process.

Convert CER to PEM

Have a digital certificate in CER format and wish to switch it to PEM?

No worries. With the aid of OpenSSL, the transition can be executed smoothly.

Below is the simple command you should input:

openssl x509 -in certificate.cer -out certificate.pem

Remember to substitute ‘certificate.cer’ with the actual name of your SSL certificate.

Once the command runs successfully, a new file titled ‘certificate.pem,’ will be created. This new file houses your SSL certificate but is now in the easily readable PEM format.

Convert CRT to PEM

If you’re aiming to convert .crt to .pem file, the method is pretty straightforward. Just start up your OpenSSL tool and type in:

openssl x509 -in certificate.crt -out certificate.pem

Upon executing this command, your CRT certificate will be transformed into a PEM variant, streamlining its management and application.

Convert DER to PEM

In case your digital certificate is in the DER format, the switch to PEM remains uncomplicated.

To facilitate this, utilize a command that’s similar to the previous ones via OpenSSL:

openssl x509 -inform der -in certificate.cer -out certificate.pem

Make sure to replace ‘certificate.der’ with the appropriate name of your SSL certificate in the DER format. The result? A fresh PEM-style file labelled ‘certificate.pem.’

The PEM format is a widely supported, base64-encoded standard used for storing SSL certificates and other X509 public key certificates.

Convert CER to PFX

PFX being a format that uses public key and a private key. To convert a CER file into PFX, you need to use private key first.

Now, use OpenSSL and PKCS 12 command to change file format to PFX.

Below is a command to convert CER to PFX file format.

openssl pkcs12 -export -out certificate.pfx -inkey privateKey.key -in certificate.cer -certfile CACert.cer

In this command, you need to swap privateKey.key with private key file and replace certificate.cer file with CER certificate file.

The output will be a certificate.pfx, which contains both the certificate and a private key.

Basic Standard of SSL Format: X.509

When it comes to digital certification standards, X.509 stands out. Its primary purpose is to verify the certificate holder’s identity and guarantee safe web data exchanges. Distributed by trusted Certificate Authorities (CA), X.509 certifications are pivotal for maintaining online safety.

They include essential details such as the certificate owner’s identity, its validity period, and a unique digital signature for validation. They also incorporate a public key for data encryption and decryption and a private counterpart for digital signing purposes.

You might often find a need to convert PEM to CRT to match the standard requirement of your specific application.

Final Thoughts

It is essential to recognize the significance and value of having an SSL converter. SSL certificate file converter is helpful during the installation of a certificate as different servers accept different file formats.

Moreover, it also increases the compatibility of an SSL certificate to the server type. Hope that the above suggestion regarding converting file format will help you during SSL related tasks.

Having the correct certificate ensures both a secure online space and demonstrates your dedication to respecting user privacy.

SSL Tools

SSL Converter

Free SSL Checker

Why No Padlock

SSL Certificate Decoder

CSR Decoder

About the Author

Apurva Barve

Apurva holds a master’s in Computer Science and has spent over 6 years immersing in SaaS Customer Services with a focus on SSL technologies. With a natural ability to understand customer needs, she has thrived in highly competitive markets, showcasing her adaptability and prowess in the ever-evolving SSL industry. When not decoding tech jargon, you'll find her sipping on coffee and enjoying the digital landscape.