# keygen

    ssh-keygen -b 4096
    ssh-keygen -R host  # remove host from `known_hosts`
    ssh-keygen -p       # change password for existing key


# ssh-agent

    ssh-add     # add identity to agent
    ssh-add -l  # list identities in agent, `-L` gives actual keys
    ssh-add -D  # remove all identities from agent


# master connection

`<login>` is how connection was made, usually it is `user@host`.

    ssh -O check <login>
    ssh -O cancel <login>
    ssh -O exit <login>
    ssh -O stop <login>  # stop accepting new connections without killing current ones


# x forwarding

    ssh -CY

- -C enables compression
- -Y disables X11 SECURITY extension restrictions


# socks proxy

    ssh -D 9999 hbschr@hbschr.de

configure firefox to use network SOCKS 5 proxy on `localhost:9999`


# sshfs via fuse

mount point should belong to user.
will be mounted as fs `fuse.sshfs`, specific options like btrfs subvolumes are not accessible.

    sshfs heiko@loki:/ /mnt/loki/

# host based identity

    # in config
    Host host
        IdentityFile ~/.ssh/id_host

# misc

- cipher: symmetric key, f.e. aes
- mac: message authentication code
- kex: key exchange, f.e. dh
- key: asymmetric key

```
ssh -Q cipher
ssh -Q mac
ssh -Q kex
ssh -Q key
```