Understanding PEM and SSH Keys
Before we dive into the process of converting PEM to SSH key, let’s first understand what PEM and SSH keys are. PEM stands for Privacy Enhanced Mail, and it is a Base64 encoded format that is used for handling SSL certificates, private keys, and public keys. On the other hand, SSH stands for Secure Shell, and it is a cryptographic network protocol used for secure data communication. An SSH key is a pair of cryptographic keys that are used to authenticate a user to a remote server.
Differences between PEM and SSH Keys
PEM and SSH keys have some differences, despite serving similar purposes. Firstly, PEM keys are used primarily in SSL certificates, while SSH keys are used for remote server access. Additionally, PEM keys are in a text format, while SSH keys are binary files.
Converting PEM to SSH Key
To convert a PEM file to an SSH key, you need to use the OpenSSL command-line tool. Here are the steps to follow:
Step 1: Install OpenSSL
If you do not have OpenSSL installed on your system, you need to install it first. Here is how to install OpenSSL on Ubuntu:
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Step 2: Convert PEM to Private Key
To convert a PEM to an SSH key, you first need to convert the PEM to a private key. Here is the command to use:
Replace example.pem with the name of your PEM file.
Step 3: Convert Private Key to SSH Key
Now that you have the private key in a PEM format, you can convert it to an SSH key using the following command:
Replace example.key with the name of your private key file.
FAQs for Convert PEM to SSH Key
What is a PEM file and SSH Key?
PEM stands for Privacy Enhanced Mail, which is a Base64 encoded X.509 certificate that contains public and private keys. On the other hand, SSH (Secure Shell) is a cryptographic network protocol used for secure communication between remote computers. The SSH key is a pair of cryptographic keys that are used to authenticate the user and establish a secure connection between two systems.
Why would I need to convert a PEM file to an SSH key?
You may need to convert a PEM file to an SSH key to establish a secure connection between two systems and authenticate the user. SSH keys are widely used for accessing remote servers and cloud computing instances, whereas PEM files are mostly used for SSL/TLS certificates for enabling HTTPS connections. Some cloud services like Amazon Web Services and Google Cloud Platform only allow SSH key-based authentication, and you may need to convert your PEM file to an SSH key to manage your cloud instances.
How can I convert a PEM file to an SSH key?
To convert a PEM file to an SSH key, you can use the following command in your terminal:
ssh-keygen -y -f path/to/pem/file.pem > path/to/ssh/key.pem
This command uses the ssh-keygen utility that is built into most Unix-based systems to extract the public key from the PEM file and save it in the SSH key format. Here, the -y option specifies that the SSH public key should be generated, and the -f option specifies the path to the PEM file. Finally, the > symbol is used to redirect the output to the SSH key file.
Are there any tools to automate the conversion process?
Yes, there are several tools that can automate the conversion process, especially if you need to convert multiple PEM files to SSH keys. Some popular tools include PuTTYgen, OpenSSL, and ssh-keygen. These tools can easily convert PEM files to SSH keys and vice versa, allowing you to manage your keys and certificates more efficiently.
Can I use the same SSH key for multiple systems?
It is generally not recommended to use the same SSH key for multiple systems, as this can increase the risk of unauthorized access if the key is compromised. Instead, it is best practice to generate a separate SSH key for each system or user that you need to access. This way, even if one key is compromised, your other systems will still be secure.