Add webvirtcloud/test_authorization_matrix.py, which walks every named URL
and checks that a user without any VM/compute relation only reaches an
explicit allowlist, and that the global view_instances permission does not
open consoles. It found:
- /computes/<id>/... views without any check (compute_graph,
get_compute_*, get_dom_capabilities, storages.get_volumes): the whole
computes URL namespace is now wrapped with superuser_only, so a view
added there later cannot be exposed by a missing decorator.
- guess_mac_address (leaks dhcpd.conf host/MAC pairs), random_mac_address
and guess_clone_name: superuser-only, like the buttons that use them.
- check_instance: cross-tenant VM name lookup with no caller; removed.
- getvvfile and get_vdi_url: reachable with only view_instances, and the
.vv file contains the VNC password.
Console access now follows one rule, instances.utils.can_open_console:
an active superuser or an active owner of the VM. The global
view_instances permission is read-only. It is used by the console page,
novncd, getvvfile and get_vdi_url (getvvfile and the VDI tab are kept for
virt-viewer users). The console page answers 403 instead of 500 when
access is denied, with the same answer for a missing VM.
