ssh-keygen
Generate SSH keys used for authentication, password-less logins, and other things.
More information: https://man.openbsd.org/ssh-keygen.
- Generate a key interactively:
ssh-keygen
- Generate an ed25519 key with 32 key derivation function rounds and save the key to a specific file:
ssh-keygen -t ed25519 -a 32 -f ~/.ssh/filename
- Generate an RSA 4096-bit key with email as a comment:
ssh-keygen -t rsa -b 4096 -C "comment|email"
- Remove the keys of a host from the known_hosts file (useful when a known host has a new key):
ssh-keygen -R remote_host
- Retrieve the fingerprint of a key in MD5 Hex:
ssh-keygen -l -E md5 -f ~/.ssh/filename
- Change the password of a key:
ssh-keygen -p -f ~/.ssh/filename
- Change the type of the key format (for example from OPENSSH format to PEM), the file will be rewritten in-place:
ssh-keygen -p -N "" -m PEM -f ~/.ssh/OpenSSH_private_key
- Retrieve public key from secret key:
ssh-keygen -y -f ~/.ssh/OpenSSH_private_key