gocsaf/docs/client-certificate-setup.md

Client-Certificate based authentication

Assuming the userA.pfx file is available, which can be imported into a web browser.

Configure nginx

Assuming the relevant server block is in /etc/nginx/sites-enabled/default and the CA used to verify the client certificates is under /etc/ssl/, adjust it like shown in the following example:

server {
    # Other Config
    # ...

    ssl_client_certificate /etc/ssl/rootca-cert.pem;
    ssl_verify_client optional;
    ssl_verify_depth 2;

    # This example allows access to all three TLP locations for all certs.
    location ~ /.well-known/csaf/(red|green|amber)/{
        autoindex on;
        # in this location access is only allowed with client certs
        if  ($ssl_client_verify != SUCCESS){
            # we use status code 404 == "Not Found", because we do not
            # want to reveal if this location exists or not.
            return 404;
        }
    }
}

This will restrict the access to the defined paths in the location directive to only authenticated client certificates issued by the CAs which are configured with ssl_client_certificate.

If you want to restrict each path of green, amber and red differently, you could use several location blocks each which a single if that matches the $ssl_client_i_dn variable to CAs that you would want to allow for that location.

If you want to restrict the writing permission and the accessing to the web-interface of the csaf_provider to only some TLS client certificates, the CA issuer of these certificates should be assigned to the issuer config option in the /user/lib/csaf/config.toml file e.g. issuer = "C=DE,O=CSAF Tools Development (internal),CN=Tester" . To inspect the accepted format for this field you can check the value of the ca: in the nginx log file /var/log/nginx/error.log.

Reload or restart nginx to apply the changes (e.g. systemctl reload nginx on Debian or Ubuntu.)

To test this see development-client-certs.md and

• From the browser after importing the testclient1.p12: nagivate to the protected directories.
• With curl: curl https://{serverURL}/.well-known/csaf/red/ --cert-type p12 --cert testclient1.p12. (If the server uses self-signed certifcate one of the following options should be added to the curl command: --insecure to disable the verification, --cacert {CA-Certificate-File} to pass the CA-Certificate that verifies the server).