Understanding the Basics of PEM and DER Private Keys
Before diving into the process of converting PEM to DER private keys, it’s essential to understand the basics of these two key formats.
What is a PEM Private Key?
PEM (Privacy Enhanced Mail) is a widely used format for storing private keys. It’s a Base64 encoded text file that contains a private key encrypted with a password. PEM files usually have a .pem or .key extension.
What is a DER Private Key?
DER (Distinguished Encoding Rules) is another format for storing private keys. It’s a binary format, and unlike PEM, it can’t be encrypted. DER files usually have a .der or .key extension.
Why Convert PEM to DER Private Key?
There are several reasons why you might need to convert a PEM private key to a DER private key. One of the most common reasons is to use the DER format for SSL certificate installation on certain web servers like IIS, which require a DER format.
Understanding the basics of PEM and DER private keys is crucial before attempting to convert them. PEM files are text files containing an encrypted private key, while DER files are binary files that cannot be encrypted. Converting PEM to DER is necessary in cases where a DER format is required, such as with certain web servers. OpenSSL is used in the process, and the conversion can be verified by checking the contents of the DER file.
How to Convert PEM to DER Private Key
The process of converting PEM to DER private key is relatively straightforward and can be accomplished using OpenSSL, a command-line tool for working with SSL/TLS certificates.
Step 1: Open the Terminal
Open the terminal on your Linux machine and type the following command to access OpenSSL:
Step 2: Convert PEM to DER
Once you’ve accessed OpenSSL, you can use the following command to convert a PEM private key to a DER private key:
In this command, replace private_key.pem with the name of your PEM file, and private_key.der with the name of the output DER file.
Step 3: Verify the Conversion
To verify that the conversion was successful, you can use the following command to view the contents of the DER file:
If you see the binary contents of the private key, the conversion was successful.
FAQs for converting PEM to DER private key
PEM stands for Privacy Enhanced Mail, and it is a format for storing cryptographic keys and certificates. A PEM private key is a plaintext file that contains a private key formatted in base64 encoding, which is commonly used by many cryptographic systems, including OpenSSL. The key is enclosed in a pair of header and footer lines, which indicate the type of the key and whether it is encrypted or not.
DER stands for Distinguished Encoding Rules and it is a binary-encoded format for storing cryptographic keys and certificates. A DER private key is a binary file that contains a private key in a serialized ASN.1 (Abstract Syntax Notation One) format. The key is not encrypted and can be read by any software that understands the DER format.
Why would I want to convert a PEM private key to a DER format?
There are several reasons why you might want to convert a PEM private key to a DER format. One reason is that some software or systems only accept keys in a specific format, such as DER. Another reason is that DER keys are generally smaller in size than PEM keys, which can be advantageous in certain situations, such as when transferring keys over a low-bandwidth network.
How can I convert a PEM private key to a DER format?
You can convert a PEM private key to a DER format using the OpenSSL command-line tool. First, you need to have OpenSSL installed on your computer. Then, open a terminal or command prompt and navigate to the directory where your PEM private key is stored. Then, run the following command:
openssl pkcs8 -topk8 -nocrypt -in privatekey.pem -outform der -out privatekey.der
This command will take the PEM private key stored in the file “privatekey.pem,” convert it to a DER format, and store the resulting key in the file “privatekey.der.”
Can I convert a password-protected PEM private key to a DER format?
Yes, you can convert a password-protected PEM private key to a DER format using the same command as above. However, you will need to provide the passphrase for the key when prompted by OpenSSL. If you forget the passphrase, you will not be able to convert the key to a DER format or use it in any other way.