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Share2Us

Devices and trust

Your devices

Section titled “Your devices”
Terminal window
s2u login          # authenticate this machine
s2u devices        # list the machines signed in to your account

A device is a machine that has signed in. It has its own key pair, which is what lets someone send you something only that machine can open.

Trusting a device on your network

Section titled “Trusting a device on your network”

When a direct transfer prompt asks about a sender, answering t trusts it. You then choose what trust means:

  • Ask every time, the default. No code to compare, but you stay in the loop.
  • Automatic, where its files are saved without a prompt.

Trust is an account feature, not a local one. The list lives on your account, signed by the server and synced to your signed-in machines. Nothing on the local disk can widen it, and neither can automation or an agent driving the CLI on your behalf. That is the point: the machine running the commands is exactly the thing you might not trust.

Why it asks for a code

Section titled “Why it asks for a code”

Adding a trusted device requires a second factor. Share2Us emails a six-digit code to your account address, or asks for your authenticator code once you have set one up under Account → Security in the portal.

Before you enter it, the prompt and the email both show the device’s safety number: five groups of four digits. Run s2u lan id on the device you think you are trusting and compare. If they differ, cancel. That comparison is the step that catches an impostor, and skipping it is what an attacker is counting on.

Managing the list

Section titled “Managing the list”
Terminal window
s2u lan trusted list
s2u lan trusted mode <fingerprint> ask|auto
s2u lan trusted revoke <fingerprint>
s2u lan trusted reset

Switching a device to automatic asks for a code. Revoking does not, because removing access should never be the harder direction.