SSH Key Generation and Management

The ssh-keygen command is a powerful utility for creating, managing, and converting SSH keys. This cheatsheet provides common usage examples for generating and manipulating SSH key pairs.

Key Generation and Usage

Create a SSH Private Key

This command generates a new SSH private key pair. It specifies the output file path, the key type (RSA), a comment for identification, and suppresses output and passphrase prompts for automation.

$ ssh-keygen -f ~/.ssh/mykey -t rsa -C "MyKey" -q -N ""

Generate a SSH Public Key from a Private Key

This command extracts the public key component from an existing private key file. The -y flag indicates that you want to output the public key.

$ ssh-keygen -y -f ~/.ssh/id_rsa > ~/.ssh/id_rsa.pub

Convert a Multiline Public SSH Key to a Normal Public Key

This is useful when dealing with public keys that have been formatted with newlines. The -i flag is used for importing a key, and -f specifies the input file.

$ ssh-keygen -i -f ~/Downloads/key.multiline_pub > ~/Downloads/key.pub

View the Public SSH Key from a Private Key

This command directly displays the public key associated with a given private key file without saving it to a new file. It's a quick way to inspect your public key.

$ ssh-keygen -y -f ~/.ssh/id_rsa

Further Resources

• OpenSSH Keygen Manual Page
• MDN Web Docs: SSH
• SSH Key Generation Guide