cheat:ssh-keygen
---
tags: [ ssh ]
---
# To generate an SSH key:
ssh-keygen -t rsa
# To generate a 4096-bit SSH key:
ssh-keygen -t rsa -b 4096
# To generate a FIDO/U2F token-backed key:
ssh-keygen -t ed25519-sk
# To generate a FIDO2 resident key:
ssh-keygen -t ed25519-sk -O resident
# To update a passphrase on a key:
ssh-keygen -p -P <old-passphrase> -N <new-passphrase> -f <keyfile>
# To remove a passphrase on a key:
ssh-keygen -p -P <old-passphrase> -N '' -f <keyfile>
# To generate a 4096 bit RSA key with a passphase and comment containing the user and hostname:
ssh-keygen -t rsa -b 4096 -C "$USER@$HOSTNAME" -P <passphrase>
# To print the fingerprint of a public key:
ssh-keygen -lf <keyfile>
# To print the Github-style (MD5) fingerprint of a public key:
ssh-keygen -E md5 -lf <keyfile>
# To download resident keys from a FIDO2 authenticator to the current directory:
ssh-keygen -K
# To view the public key associated with a private key:
ssh-keygen -y -f <private-key-file> > <public-key-file>
ssh-keygen -y -f ~/.ssh/private-key > ~/.ssh/public-key.pub
tldr:ssh-keygen
# 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
# 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 dsa|ecdsa|ed25519|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
$
cheat.sh