qubes-network-server/doc/Setting up an SSH server.md
Manuel Amador (Rudd-O) 644763bbba Improvements to docs.
2016-10-12 17:21:24 +00:00

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# Setting up an SSH server
This tutorial will teach you how to set up an SSH server on your Qubes network server.
We assume:
1. That you have a desktop or laptop *manager* machine.
2. That you have a Qubes OS *server*.
3. That both machines share a physical network link (e.g. Wi-Fi or Ethernet).
## Set up Qubes network server
First of all, [install Qubes network server](https://github.com/Rudd-O/qubes-network-server#installation) on your Qubes OS server.
## Set up needed VMs
You'll need three VMs on the network server:
1. A NetVM which will be attached to the network interface mentioned above.
For the purposes of this example, we'll call this `exp-net`.
2. A ProxyVM which will be attached to the NetVM.
This we'll call `exp-firewall`.
3. A StandaloneVM which will be attached to the ProxyVM. The role of this
machine is to give you control over `dom0` and other VMs on the system.
This we'call `exp-manager`.
Create them if you do not already have them. Once you have created them,
start the StandaloneVM `exp-manager` you created, and then verify that you
can ping your manager machine from it.
Power off `exp-manager` when your test is complete.
## Set static address on `exp-manager`
On your server's `dom0`, run the command:
```
qvm-static-ip -s exp-manager static_ip x.y.z.w
```
`x.y.z.w` must be an IP address available on the same network that both
your `exp-net` and your manager machine share.
Power `exp-manager` back on, and verify that you can still ping your
manager machine from it.
Verify that you can ping the new IP address you gave to `exp-manager`
from your manager machine. This should work fine.
## Harden the firewall on `exp-manager`
At this point, `exp-manager` is accessible on your network, so it's best
to set up a firewall rule permitting only SSH access from the manager
machine, and denying all other access to anyone.
If you are new to firewall rules in Qubes, [check out this quite
good overview of them](https://www.qubes-os.org/doc/qubes-firewall/).
Launch the Qubes Manager preferences window for the `exp-manager` VM.
Go to the *Firewall rules* tab and select *Deny network access
except...* from the top area.
Add a new network rule (use the plus button). On the *Address* box,
you're going to write `from-a.b.c.d`, where `a.b.c.d` is the IP address
of your manager machine. Select the *TCP* protocol, and type `22`
(the SSH port) on the *Service* box. Click OK.
([See the documentation for qubes-network-server](https://github.com/Rudd-O/qubes-network-server)
to understand more about firewalling rules in Qubes network server.)
Back on the main dialog, click *OK*.
## Enable and start SSH on the `exp-manager` VM
In a terminal window of `exp-manager`, run:
```
sudo systemctl enable sshd.service
sudo systemctl start sshd.service
```
This will start the OpenSSH server on the `exp-manager` VM.
Test that you can connect via SSH from the manager machine to
the `exp-manager` VM. You will not be able to log in, because
no password is set up, but we will fix that shortly.
## Set up SSH authentication
On the `exp-manager` VM, set a password on the `user` user:
```
sudo passwd user
```
On the manager machine, copy your SSH public key to `exp-manager`:
```
ssh-copy-id user@x.y.z.w
```
This will prompt you for the password you set up. Enter it.
Now kill the `user` password on `exp-manager`:
```
sudo passwd -d user
sudo passwd -l user
```
Good news! You can now remotely log in, from your manager machine,
to your Qubes OS server. You are also able to run commands on the
`exp-manager` VM, directly from your manager machine.
Should you want to run commands on *other* VMs of your Qubes OS server,
then learn how to [enable remote management of your Qubes network server](https://github.com/Rudd-O/ansible-qubes/tree/master/doc/Remote management of Qubes OS servers.md).