Master Key Encryption
Encrypt the master key to secure it against being compromised
and enabling an attacker to decrypt your keys and other sensitive
data.
On physical and virtual Palo Alto Networks devices,
you can configure the master key to use the AES-256-CBC or the AES-256-GCM
(introduced in PAN-OS 10.0) encryption algorithm to encrypt data
such as keys and passwords. AES-256-GCM provides stronger encryption
than AES-256-CBC and improves your security posture. It also includes
a built-in integrity check. The master key uses the configured encryption
algorithm to encrypt sensitive data stored on the firewall and on
Panorama. When you set the encryption algorithm to AES-256-GCM,
you can still
use an HSM to encrypt the master
key with an encryption key that is stored on the HSM.
The default encryption algorithm that the master key uses to encrypt data is AES-256-CBC—the same
algorithm that the master key used prior to PAN-OS 10.0. AES-256-CBC is the default
encryption level because when you manage firewalls with Panorama, the managed firewalls
may be on different PAN-OS releases, and firewalls on PAN-OS releases earlier than
PAN-OS 10.0 do not support AES-256-GCM. This is why Panorama must use the lowest level
of encryption that its managed devices can use. For example, if some managed devices run
PAN-OS 10.0 and some run earlier versions, Panorama must use AES-256-CBC. However, if
all managed devices run PAN-OS 10.0 or later, then Panorama and all of its managed
devices can use AES-256-GCM.
Palo Alto Networks recommends using AES-256-GCM level 2 for master key
encryption.
Use the same encryption level on Panorama
and its managed devices and use the same encryption level on firewall
pairs. Upgrade devices to use the strongest possible encryption
algorithm. If all Panorama-managed devices run PAN-OS 10.0, use
AES-256-GCM on all devices. The configuration of managed or paired
devices that use different encryption levels may become out of sync.
When you change the encryption algorithm to AES-256-GCM, devices
use it instead of AES-256-CBC to encrypt sensitive data. When you
change from one algorithm to another, you can also specify whether
to:
By default, when you change the encryption algorithm, the device
uses the new algorithm to re-encrypt existing encrypted data as
well as to encrypt new data. If you manage devices with Panorama,
they may be on different versions of PAN-OS and may not support
the newest encryption algorithms. Be sure you understand which encryption
algorithms Panorama and its managed devices support before you change
the encryption algorithm or re-encrypt data that has already been
encrypted.
