Enforce Device Trust

Resources protected by the device mode "required" will enforce the use of a trusted device, in addition to establishing the user's identity and enforcing the necessary roles. Furthermore, users using a trusted device leave audit trails that include the device's information.

Device Trust enforcement can be configured with the following three modes of operation, represented by the device_trust_mode authentication setting:

• off - disables device trust. Device authentication is not performed and device-aware audit logs are absent.
• optional - enables device authentication and device-aware audit, but does not require a trusted device to access resources.
• required - enables device authentication and device-aware audit. Additionally, it requires a trusted device for all SSH, Database and Kubernetes connections.

Prerequisites

• To enroll a macOS device, you need:
  • A signed and notarized tsh binary for enrollment. Download the macOS tsh installer.
  • A Teleport version newer than v12.0.0.
• To enroll a Windows device, you need:
  • A device that includes a TPM with 2.0 support.
  • tsh installed on the device. Download the Windows tsh installer.
  • Credentials for a user with administrator privileges for the device. This is only required during enrollment.
  • A Teleport version newer than v13.1.2.

Role-based trusted device enforcement

Role-based configuration enforces trusted device access at the role level. It can be configured with the spec.options.device_trust_mode option and applies to the resources in its allow rules. It works similarly to require_session_mfa.

To enforce authenticated device checks for a specific role, update the role with the following:

kind: role
version: v7
metadata:
  name: require-trusted-device
spec:
  options:
    # require authenticated device check for this role
+   device_trust_mode: "required" # add this line
  allow:
    logins: ['admin']
    kubernetes_groups: ['edit']
    node_labels:
      '*': '*'
    ...

tctl create -f device-enforcement.yaml

Cluster-wide trusted device enforcement

Cluster-wide configuration enforces trusted device access at the cluster level. Enterprise clusters run in optional mode by default. Changing the mode to required will enforce a trusted device for all SSH, Database and Kubernetes accesses.

To enable device mode required update your configuration as follows:

kind: cluster_auth_preference
version: v2
metadata:
  name: cluster-auth-preference
spec:
  type: local
  second_factor: "on"
  webauthn:
    rp_id: teleport.example.com
  device_trust:
+   mode: "required" # add this line

tctl create -f cap.yaml
cluster auth preference has been updated

tctl edit cluster_auth_preference

auth_service:
  authentication:
    type: local
    second_factor: "on"
    webauthn:
      rp_id: teleport.example.com
    device_trust:
+     mode: "required" # add this line

Once the config is updated, SSH, Database and Kubernetes access without a trusted device will be forbidden. For example, SSH access without a trusted device fails with the following error:

tsh ssh ip-172-31-35-170
ERROR: ssh: rejected: administratively prohibited (unauthorized device)

Locking a device

Similar to session and identity locking, a device can be locked using tctl lock.

Locking blocks certificate issuance and ongoing or future accesses originating from a locked device. Locking a device only works if device trust is enabled and if the device is enrolled to Teleport.

Find a device ID to lock:

tctl devices ls
Asset Tag     OS    Enroll Status   Device ID------------ -----  ------------- ------------------------------------C00AA0AAAA0A  macOS  enrolled     9cdfc0ad-64b7-4d9c-this-is-an-example

Lock a device:

tctl lock --device=9cdfc0ad-64b7-4d9c-this-is-an-example --ttl=12h
Created a lock with name "5444970a-39a0-4814-968d-e58b4a8fa686".

Now, if a user on that device tries to access an SSH server for example, Teleport will deny access:

tsh ssh ip-172-31-35-170
ERROR: ssh: rejected: administratively prohibited (lock targeting Device:"9cdfc0ad-64b7-4d9c-this-is-an-example" is in force)

Troubleshooting

"binary missing signature or entitlements" on tsh device enroll

A signed and notarized tsh binary is necessary to enroll and use a a trusted device. Download the macOS tsh installer to fix the problem.

"unauthorized device" errors using a trusted device

A trusted device needs to be registered and enrolled before it is recognized by Teleport as such. Follow the registration and enrollment steps and make sure to tsh logout and tsh login after enrollment is done.

Next steps

• Device Management
• Jamf Pro Integration