YunoHost has been developed to provide the best security without too much complication. Every protocol used in YunoHost are encrypted, only password's hash are stored and by default each user is able to access to his personal directory only.

Two things remain important to note:

• Installing additional apps can increase significantly the number of potential security flaws. Do not hesitate to get information about them before using it, and try to install only those which will suit your needs.

• The fact that YunoHost is a well-spread software increase chances to face an attack. If a flaw is discovered, it could potentially affect all the YunoHost instances at once. Keep your system up-to-date to remain safe.

If you need some advises, do not hesitate to ask us.

If your YunoHost server is used in a critical production environment, or if you want to improve its safety, you may want to follow those good practices.

Attention: Following those instructions requires advanced knowledges in system administration.

By default, the SSH authentication uses the administration password. Deactivation this kind of authentication and replacing it by a key mechanism is advised.

On your client:

ssh-keygen
ssh-copy-id -i ~/.ssh/id_rsa.pub <your_yunohost_server>

Type your admnistration password and your key will be copied on your server.

Note: If you get Agent admitted failure to sign using the key. while login from ssh, run bash ssh-add to fix the message.

On your server, edit the SSH configuration file, in order to deactivate the password authentication.

nano /etc/ssh/sshd_config

# Modify or add the following line
PasswordAuthentication no

Save and restart SSH daemon.

YunoHost administration is accessible through an HTTP API, served on the 6787 port by default. It can be used to administrate a lot of things on your server, thus to break many things between malicious hands. The best thing to do, if you know how to use the command-line interface, is to deactivate the yunohost-api service.

sudo service yunohost-api stop