= SSH KeyGen =

'''`ssh-keygen(1)`''' is used to generate public-private keypairs.

<<TableOfContents>>

----



== Installation ==

`ssh-keygen(1)` is bundled with `openssl`.

----



== Usage ==

To generate a new SSH key, try:

{{{
ssh-keygen -t rsa -b 4096 -C "me@example.com"
}}}

Note that standards are always shifting. In the past, Github recommended a 2048 bits long key. Github now recommends the `ed25519` algorithm, instead of `rsa`.



=== Legacy Format ===

OpenSSH 7.8+ uses a new format of SSH keys, which begin with `-----BEGIN OPENSSH PRIVATE KEY-----`. Some software are not prepared to parse this key format.

To generate a new key using the old format, add the `-m PEM` option.

To convert an existing key to the old format, try:

{{{
ssh-keygen -p -f ~/.ssh/id_rsa -m pem -P "" -N ""
}}}



=== Commercial Services ===

[[https://docs.github.com/en/free-pro-team@latest/github/authenticating-to-github/adding-a-new-ssh-key-to-your-github-account|Github]] and [[https://docs.gitlab.com/ee/ssh/#adding-an-ssh-key-to-your-gitlab-account|Gitlab]] both allow SSH key authentication.

----



== See also ==

[[https://man.archlinux.org/man/core/openssh/ssh-keygen.1.en|ssh-keygen(1)]]

[[Encryption/OpenSSH|OpenSSH]]

[[Encryption/SSH|SSH]]



----
CategoryRicottone