tldr/pages/common/ssh-keygen.md

ssh-keygen

Generate ssh keys used for authentication, password-less logins, and other things.

• Generate a key interactively:

ssh-keygen

• Specify file in which to save the key:

ssh-keygen -f ~/.ssh/{{filename}}

• Generate an ed25519 key with 100 key derivation function rounds:

ssh-keygen -t ed25519 -a 100

• Generate an RSA 4096 bit key with email as a comment:

ssh-keygen -t rsa -b 4096 -C "{{email}}"

• Retrieve the key fingerprint from a host (useful for confirming the authenticity of the host when first connecting to it via SSH):

ssh-keygen -l -F {{remote_host}}

• 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}}