sshset

This is a simple Bash script sshset.sh that can be used to set up stuff needed for OpenSSH Server and Client (such as configuration files, keys, etc.) starting from a (configurable) data directory and some environment variables.

Warning: this tool assumes the data directory and the environment variables are trusted! It is NOT suitable for use in environments with untrusted input.

Supported content of the data directory when running as root:

Path	Category	Files extensions	Configures
`sshd-config/`	Server	`*.conf` (suggestion)	`/etc/ssh/sshd_config.d/`
`host-keys/`	Server	private keys: none, public keys: `*.pub`	Host keys in `/etc/ssh/`
`sshrc/`	Server	`*.sh` (suggestion)	`/etc/ssh/sshrc`
`ssh-config/`	Client	`*.conf` (suggestion)	`/etc/ssh/ssh_config.d/`
`known-hosts/`	Client	`*.txt` (suggestion)	`/etc/ssh/ssh_known_hosts`
`users/*/authorized-keys/`	Server	private keys: none, public keys: `*.pub`	`~/.ssh/authorized_keys` for each user
`users/*/sshrc/`	Server	`*.sh` (suggestion)	`~/.ssh/rc` for each user
`users/*/ssh-config/`	Client	`*.conf` (suggestion)	`~/.ssh/config` for each user
`users/*/known-hosts/`	Client	`*.txt` (suggestion)	`~/.ssh/known_hosts` for each user
`users/*/identity-keys/`	Client	private keys: none, public keys: `*.pub`	Identity keys in `~/.ssh/` for each user

Note: the /etc/ssh/ssh_config and /etc/ssh/sshd_config files are not touched at all.

Supported content of the data directory when running as unprivileged user:

Path	Category	Files extensions	Configures
`sshd-config/`	Server	`*.conf` (suggestion)	`~/.ssh/sshd_config.d/`
`host-keys/`	Server	private keys: none, public keys: `*.pub`	Host keys in `~/.ssh/`
`authorized-keys/`	Server	private keys: none, public keys: `*.pub`	`~/.ssh/authorized_keys`
`sshrc/`	Server	`*.sh` (suggestion)	`~/.ssh/rc`
`ssh-config/`	Client	`*.conf` (suggestion)	`~/.ssh/config`
`known-hosts/`	Client	`*.txt` (suggestion)	`~/.ssh/known_hosts`
`identity-keys/`	Client	private keys: none, public keys: `*.pub`	Identity keys in `~/.ssh/`

Note: when setting up the SSH server as unprivileged user, an ~/.ssh/sshd_config file is created automatically, which can then be used with the -f option of the sshd command.

Tip: in general, where files processing order matters, it is recommended to prefix filenames with numbers (e.g. 50-myfile.conf).

For a list of the supported environment variables, see the top section of the script itself.

Examples

See app.sh and the Dockerfiles in this directory for usage examples. They are also useful for development.

To build the example images:

Bash
for i in {alpine,debian}-{root,unpriv}; do
    docker build -t "img-sshset-$i" -f "test-$i.Dockerfile" .
done

Then you can run them like this:

Bash
mkdir -pv data-root data-unpriv

docker run -it --rm -p2222:22 -v"$PWD/data-root:/opt/sshset/data" -eSSHSET_{SETUP_{SERVER,CLIENT}=true,GEN_{HOSTKEYS,AUTHKEY,IDKEY}=true} img-sshset-debian-root

docker run -it --rm -p2222:2222 -v"$PWD/data-unpriv:/opt/sshset/data" -eSSHSET_{SETUP_{SERVER,CLIENT}=true,GEN_{HOSTKEYS,AUTHKEY,IDKEY}=true} img-sshset-debian-unpriv