security-doc/security-guide/source/compute/checklist.rst

Checklist

Check-Compute-01: Is user/group ownership of config files set to root/nova?

Configuration files contain critical parameters and information required for smooth functioning of the component. If an unprivileged user, either intentionally or accidentally, modifies or deletes any of the parameters or the file itself then it would cause severe availability issues causing a denial of service to the other end users. User ownership of such critical configuration files must be set to root and group ownership must be set to nova. Additionally, the containing directory should have the same ownership to ensure that new files are owned correctly.

Run the following commands:

$ stat -L -c "%U %G" /etc/nova/nova.conf | egrep "root nova"
$ stat -L -c "%U %G" /etc/nova/api-paste.ini | egrep "root nova"
$ stat -L -c "%U %G" /etc/nova/policy.json | egrep "root nova"
$ stat -L -c "%U %G" /etc/nova/rootwrap.conf | egrep "root nova"
$ stat -L -c "%U %G" /etc/nova | egrep "root nova"

Pass: If user and group ownership of all these config files is set to root and nova respectively. The above commands show output of root nova.

Fail: If the above commands do not return any output, the user and group ownership might have set to any user other than root or any group other than nova.

Recommended in: ../compute.

Check-Compute-02: Are strict permissions set for configuration files?

Similar to the previous check, we recommend to set strict access permissions for such configuration files.

Run the following commands:

$ stat -L -c "%a" /etc/nova/nova.conf
$ stat -L -c "%a" /etc/nova/api-paste.ini
$ stat -L -c "%a" /etc/nova/policy.json
$ stat -L -c "%a" /etc/nova/rootwrap.conf

A broader restriction is also possible: if the containing directory is set to 750, the guarantee is made that newly created files inside this directory would have the desired permissions.

Pass: If permissions are set to 640 or stricter, or the containing directory is set to 750. The permissions of 640/750 translates into owner r/w, group r, and no rights to others. For example, "u=rw,g=r,o=".

Note

If check_compute_01 and permissions set to 640, root has read/write access and nova has read access to these configuration files. The access rights can also be validated using the following command. This command will only be available on your system if it supports ACLs.

$ getfacl --tabular -a /etc/nova/nova.conf
getfacl: Removing leading '/' from absolute path names
# file: etc/nova/nova.conf
USER   root  rw-
GROUP  nova  r--
mask         r--
other        ---

Fail: If permissions are not set to at least 640/750.

Recommended in: ../compute.

Check-Compute-03: Is keystone used for authentication?

Note

This item only applies to OpenStack releases Rocky and before as auth_strategy was deprecated in Stein.

OpenStack supports various authentication strategies like noauth, and keystone. If the noauth strategy is used, then the users could interact with OpenStack services without any authentication. This could be a potential risk since an attacker might gain unauthorized access to the OpenStack components. We strongly recommend that all services must be authenticated with keystone using their service accounts.

Before Ocata:

Pass: If value of parameter auth_strategy under [DEFAULT] section in /etc/nova/nova.conf is set to keystone.

Fail: If value of parameter auth_strategy under [DEFAULT] section is set to noauth or noauth2.

After Ocata:

Pass: If value of parameter auth_strategy under [api] or [DEFAULT] section in /etc/nova/nova.conf is set to keystone.

Fail: If value of parameter auth_strategy under [api] or [DEFAULT] section is set to noauth or noauth2.

Check-Compute-04: Is secure protocol used for authentication?

OpenStack components communicate with each other using various protocols and the communication might involve sensitive or confidential data. An attacker may try to eavesdrop on the channel in order to get access to sensitive information. All the components must communicate with each other using a secured communication protocol.

Pass: If value of parameter www_authenticate_uri under [keystone_authtoken] section in /etc/nova/nova.conf is set to Identity API endpoint starting with https:// and value of parameter insecure under the same [keystone_authtoken] section in the same /etc/nova/nova.conf is set to False.

Fail: If value of parameter www_authenticate_uri under [keystone_authtoken] section in /etc/nova/nova.conf is not set to Identity API endpoint starting with https:// or value of parameter insecure under the same [keystone_authtoken] section in the same /etc/nova/nova.conf is set to True.

Check-Compute-05: Does Nova communicate with Glance securely?

OpenStack components communicate with each other using various protocols and the communication might involve sensitive or confidential data. An attacker may try to eavesdrop on the channel in order to get access to sensitive information. All the components must communicate with each other using a secured communication protocol.

Pass: If value of parameter api_insecure under [glance] section in /etc/nova/nova.conf is set to False and value of parameter api_servers under [glance] section in /etc/nova/nova.conf is set to a value starting with https://.

Fail: If value of parameter api_insecure under [glance] section in /etc/nova/nova.conf is set to True, or if value of parameter api_servers under [glance] section in /etc/nova/nova.conf is set to a value that does not start with https://.