Abstract
There are two different things needed to setup the certificate authentification.
user certificates: There are N user certifiactes, one for each public key provided for signing.
helloworld-1234567890-1-cert.pub helloworld-1234567890-2-cert.pub ... helloworld-1234567890-N-cert.pub
host certificate public key: There is one public key to authenticate servers.
yubikeyX.pub
Tell the SSH daemon about the certificate.
There are two different options to tell the ssh daemon about the certificate: global
or user based
.
global
: The certificate is valid for each user on the client.user based
: The certificate is valid for one specific user on the client.
To work correctly there are two things that need to be done:
- provide the certificate such that the client can authentificate itsself on the server side. To do so, the ssh daemon needs to knwo where the certificate is stroed and that it is need to login to *.netdef.org
- provide the public host key such that the client can authenticate the host's certificate. This is done by adding a new entrie in the known_hosts file.
The certificates can be installed for a single user or for all users in a machine.
user based configuration paths
SSH_CERTIFICATES=$HOME/.ssh/netdef SSH_CONFIG=$HOME/.ssh/config SSH_KNOWNHOSTS=$HOME/.ssh/known_hosts
global configuration paths
SSH_CERTIFICATES=/etc/ssh/netdef SSH_CONFIG=/etc/ssh/ssh_config SSH_KNOWNHOSTS=/etc/ssh/ssh_known_hosts
Step 1 - 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 2 - edit the config file
Add the following lines to $SSH_CONFIG
. The name of the certificate as well as $SSH_CERTIFICATES
must be replaced with the correct file name and the correct path to the folder respectively.
Host *.netdef.org CertificateFile `$SSH_CERTIFICATES`/helloworld-1234567890-1-cert.pub CertificateFile `$SSH_CERTIFICATES`/helloworld-1234567890-2-cert.pub ... CertificateFile `$SSH_CERTIFICATES`/helloworld-1234567890-N-cert.pub
Step 3 - edit known hosts file.
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 `yubikeyX.pub`