1 Abstract
As there are two different types of certificates, there are two individual tasks as well in order to setup a hosts. If one would like to use only one certificate, execute the corresponding task.
Configuration paths
There are two different options to tell the ssh daemon about the certificate: 'user based' (recommended) or 'global'
'user based': The certificate is valid for one specific user on the client.SSH_CERTIFICATES=$HOME/.ssh/netdef SSH_CONFIG=$HOME/.ssh/config SSH_KNOWNHOSTS=$HOME/.ssh/known_hosts
'global': The certificate is valid for each user on the client.SSH_CERTIFICATES=/etc/ssh/netdef SSH_CONFIG=/etc/ssh/ssh_config SSH_KNOWNHOSTS=/etc/ssh/ssh_known_hosts
2 Host certificate
To setup the host certificate the public key of the CA authority is needed. There are three public keys called 'yubikey1.pub', 'yubikey2.pub' and 'yubikey3.pub'.
Add the following line to '$SSH_KNOWNHOSTS' where 'yubikeyX.pub' must be replaced with the public key stored in 'yubikeyX.pub'.
@cert-authority *.netdef.org `yubikey1.pub` @cert-authority *.netdef.org `yubikey2.pub` @cert-authority *.netdef.org `yubikey3.pub`
3 Client Certificate
Step 1 - Sign client's public key
One can either use the public key file that is stored on github or one can manually copy the id_rsa.pub file to the CA authority.
The instructions how to singed a clients public key can be found here.
The CA provides a zip file where all signed keys are stored.
helloworld-1234567890-1-cert.pub helloworld-1234567890-2-cert.pub ... helloworld-1234567890-N-cert.pub
Step 2 - copy all certificates to netdef folder
Copy all certificates that can be found in the provided tar file to the folder '$SSH_CERTIFICATES'.
mkdir -p $SSH_CERTIFICATES cp *cert.pub $SSH_CERTIFICATES
Step 3 - edit the config file
Add the following lines to '$SSH_CONFIG''$SSH_CERTIFICATES' must be replaced with the correct file name and the correct path to the folder respectively.
Host *.netdef.org CertificateFile `$SSH_CERTIFICATES`/helloworld-1234567890-1-cert.pub CertificateFile `$SSH_CERTIFICATES`/helloworld-1234567890-2-cert.pub ... CertificateFile `$SSH_CERTIFICATES`/helloworld-1234567890-N-cert.pub