How to Control Thunderbolt Devices with 'boltctl' (with examples)

Boltctl is a command-line utility for managing Thunderbolt devices connected to your system. Thunderbolt technology, commonly used in Mac and certain PC environments, allows for fast data transfer and connectivity between computers and external devices such as hard drives, monitors, and video capture devices. The boltctl command helps list, authorize, deauthorize, and get detailed information about these devices.

Understanding and managing Thunderbolt devices is crucial for maintaining system security and ensuring that only trusted devices can connect and communicate with your hardware. Below, we cover several common use cases of boltctl with examples highlighting how to effectively use this command.

Use Case 1: List Connected (and Authorized) Thunderbolt Devices

Code:

boltctl

Motivation:

You may want to quickly check which Thunderbolt devices are currently connected and have been authorized for use on your system. This is especially important for auditing connected devices to prevent unauthorized access or data transfer.

Explanation:

The boltctl command without any additional arguments lists all the connected devices that your system has previously authorized. This implies that these devices have been deemed trustworthy in a previous session or during the current session with the appropriate credentials.

Example Output:

○ Apple Inc. Thunderbolt 3 Display
  ├─ Type:           peripheral
  ├─ Status:         authorized
  ├─ Authorized:     yes
  └─ Store:          yes

Use Case 2: List All Connected Devices, Including Unauthorized Ones

Code:

boltctl list

Motivation:

To perform a thorough inspection of all Thunderbolt devices connected to your system, you need to see both authorized and unauthorized devices. This helps identify any potential security threats or new devices that require your attention.

Explanation:

The list argument for boltctl expands the listing to include devices that are connected but not yet authorized. This ensures you have a comprehensive view of all peripherals currently interfacing with your system.

Example Output:

○ Apple Inc. Thunderbolt 3 Display
  ├─ Type:           peripheral
  ├─ Status:         unauthorized
  ├─ Authorized:     no
  └─ Store:          no

Use Case 3: Authorize a Device Temporarily

Code:

boltctl authorize device_uuid

Motivation:

In scenarios where you need to grant a temporary access to a Thunderbolt device, such as testing or one-time use of unfamiliar hardware, you can authorize it temporarily to maintain security.

Explanation:

• authorize: This command authorizes a device for the current session but doesn’t save it as a trusted device.
• device_uuid: A unique identifier for the Thunderbolt device you want to authorize. This identifier is usually a string or number uniquely assigned to the device.

Example Output:

Device device_uuid is now temporarily authorized.

Use Case 4: Authorize and Remember a Device

Code:

boltctl enroll device_uuid

Motivation:

For devices you frequently use and trust, enrolling them saves their credentials, allowing automatic authorization upon subsequent connections, thus simplifying usability without repeated permissions.

Explanation:

• enroll: This command tells boltctl to not only authorize the device but also remember it for future sessions.
• device_uuid: This is the unique identifier for the device you are authorizing and storing.

Example Output:

Device device_uuid has been enrolled and is now remembered.

Use Case 5: Revoke a Previously Authorized Device

Code:

boltctl forget device_uuid

Motivation:

When a previously authorized device is no longer in use or poses a security risk, forgetting it ensures it won’t automatically reauthorize upon future connections, enforcing better control over connected devices.

Explanation:

• forget: This action removes the device from the trusted list, meaning it will need to be reauthorized if connected again.
• device_uuid: The unique identifier of the device you wish to deauthorize and remove from memory.

Example Output:

Device device_uuid has been forgotten and will not be automatically reauthorized.

Use Case 6: Show More Information About a Device

Code:

boltctl info device_uuid

Motivation:

When troubleshooting or verifying device specifications, obtaining detailed information about a connected Thunderbolt device helps identify its capabilities, status, and permissions.

Explanation:

• info: A command that returns a detailed description of the device’s capabilities, status, authorization level, and other pertinent information.
• device_uuid: The identifier for the specific device you want more information on.

Example Output:

○ Apple Inc. Thunderbolt 3 Display
  ├─ Type:           peripheral
  ├─ Status:         connected
  ├─ Authorized:     no
  ├─ Store:          no
  ├─ Model:          27-Inch 5K
  ├─ Vendor:         Apple Inc
  ├─ UUID:           device_uuid

Conclusion:

The boltctl command is an indispensable tool for managing Thunderbolt devices on your machine. Using the various options it provides ensures greater security and control over the high-speed, high-performance Thunderbolt architecture, which is an essential component of modern connectivity. Familiarizing yourself with these commands enriches not only security but also usability, giving you the flexibility to efficiently manage peripheral connections as needs evolve.