Clipboard and file transfer

During a remote desktop session you can sync the clipboard with the endpoint, type your clipboard as keystrokes, send files and folders to the endpoint, and copy them back. Everything you transfer is encrypted end to end between your browser and the endpoint, and every transfer is audited. This page shows how to use each one and how policy shapes them.

How it works

Transfers travel inside the session, on channels of their own beside the video. Before anything moves, your browser and the endpoint agree a set of keys that your Outpost cannot work out, and the endpoint signs the exchange with an identity key that never leaves it. From then on your Outpost relays only ciphertext. Keys exist in memory for the session only, and a change of signed-in user at the endpoint starts a fresh exchange. The cryptography is P-256, SHA-256, HKDF, and AES-256-GCM, all FIPS-approved algorithms.

Your browser remembers each endpoint’s identity key the first time it connects. If the key is different next time, for example after the agent is reinstalled, the viewer stops transfers until you confirm the code with the person at the endpoint. The memory is per browser, so a different browser or a private window counts as a first connection.

The screen video and ordinary keystrokes are not end-to-end encrypted. See the security model.

Before you begin

• The endpoint’s agent must support transfers. If it does not, the viewer says Update the agent to use clipboard and file transfer.
• Sending anything to the endpoint needs Control on. With Control off, the viewer says View only. Turn on Control to send to the endpoint.
• Clipboard sync works on Windows, macOS, and Linux X11 sessions. On Wayland, a text console, or the sign-in screen, the viewer says Clipboard sync is not available for this session type. Type clipboard still works there.
• On the sign-in screen, before anyone has signed in, only Type clipboard works. Files need a signed-in user.
• Policy decides which directions are allowed. See Directions and limits.

Check the secure transfer code

Select File transfers in the viewer’s toolbar to open the Transfers panel. The top of the panel shows the Secure transfer code, six digits, and the Outpost tray app at the endpoint shows the same code. If the two match, nothing sits between you and the endpoint.

The endpoint does not pop the code up. The person at the endpoint finds it in the tray app’s card and, on Windows, in the tooltip of the Outpost icon in the notification area. Ask them to open the tray app and read it to you.

Under the code, the panel says one of these:

Message	Meaning
First session with this endpoint, key pinned.	Your browser had not seen this endpoint and has remembered its key.
Endpoint key matches your last session.	The key is the one your browser remembered.
Code confirmed.	You, or policy, confirmed the code.
The secure transfer key for the endpoint changed since your last session.	Transfers are stopped. Ask the person at the endpoint to open the tray app and read you the code. If it matches, select Confirm code matches.
Policy requires you to confirm this code matches the one on the endpoint screen.	remote_access.e2e_require_verification is on. Confirm the code with the person at the endpoint, and select Confirm code matches. You are asked again at every change of signed-in user.

Setting up a secure channel… means the exchange has not finished yet. Transfers wait for it.

Copy and paste text and images

With Control on, press Ctrl+V (or Shift+Insert) in the viewer. The viewer sends your clipboard to the endpoint first, then the keystroke, so the endpoint pastes what you copied. Selecting the viewer window also sends your clipboard.

When someone copies text or an image on the endpoint, it arrives on your clipboard while the viewer window has focus, or the next time you select it.

The clipboard button in the toolbar shows the state when you point at it, and at the top of its menu:

State	Meaning
Clipboard sync on	Clipboard sync is working.
Clipboard connecting	The secure channel is being set up.
Clipboard waiting for focus	The endpoint copied something. Select the viewer window to receive it.
Clipboard sync off	You turned off Sync clipboard.
Clipboard off	Policy, the session type, or the agent version rules out clipboard sync.

Your browser asks for permission to read the clipboard the first time. Allow it. A clipboard larger than 64 MB is not sent.

The Clipboard tab of the Transfers panel lists text, images, and files in each direction with On or the reason they are blocked.

Turn clipboard sync off

To keep what you copy on your own computer, and what is copied on the endpoint on the endpoint, open the clipboard menu in the toolbar and turn off Sync clipboard. The button is struck through while sync is off, and the Clipboard tab of the Transfers panel shows Clipboard sync is off. Select Sync clipboard again to turn it back on. Anything copied while sync was off is not sent afterwards.

Turning sync off affects only the clipboard. Type clipboard and file transfers keep working. The choice applies to this viewer window and stays across reconnects.

Type the clipboard

Type clipboard, in the clipboard menu in the toolbar, types the text on your clipboard into the endpoint as keystrokes, up to 4,096 characters. Use it where a paste does not work: the sign-in screen, a password field that refuses paste, or a session with no clipboard sync. It counts as text sent to the endpoint, so it follows remote_access.clipboard_text.

Send files and folders to the endpoint

1. Drag files or folders from your computer onto the endpoint’s screen in the viewer. Alternatively, open Transfers > Queue, and select Upload or Upload folder.
2. Wait for the transfer to finish in the queue. The files land in a transfer folder on the endpoint and on the endpoint’s clipboard.
3. On the endpoint, paste them where they belong with Ctrl+V, or Cmd+V on a Mac.

Caution

The transfer folder is deleted when the session ends. Paste or move the files out of it before you disconnect.

To put files straight into a folder of your choice, open Transfers > Files, browse to the folder, and select Upload here. Files written this way stay after the session ends.

On Windows, files you send are marked as downloaded from the internet, so Windows treats them as it would a browser download.

Copy files from the endpoint

• From the endpoint’s clipboard. Copy files on the endpoint. The Queue tab shows Remote clipboard has the number of items, with Download.
• From any folder. Open Transfers > Files, browse to the folder, select the files, and select Download selected. On a Mac, shortcuts to Home, Desktop, Documents, and Downloads are listed.

Your browser asks where to save. Choose or create a folder: browsers do not let a page save straight into your Downloads or Desktop folder itself. Browsers that cannot save into a folder receive a single zip file instead.

Each transfer in the Queue shows its progress, and Cancel stops it. Transfers yield to the video and input, so a large copy does not freeze the session on a slow link.

Files on the endpoint are read and written as the signed-in user, so a transfer cannot reach a file that user cannot open. On a Mac, macOS can ask the user to allow access to protected folders. The transfer stops until they select Allow. See macOS agent.

Verify a file against the audit log

By default, the audit log records each file’s hash as a keyed hash that only the endpoint can reproduce. To check whether a file on your computer is the one that was transferred:

1. Open Transfers > Verify, and select Verify a file.
2. Choose the file. Your browser computes its SHA-256, and the endpoint returns the keyed hash.
3. Compare Audit hash with the hash in the audit entry.

A keyed hash cannot be checked once the endpoint’s key is lost, for example after the agent is reinstalled. Where a permanent match matters, set the hash settings to plain.

Directions and limits

Each kind of transfer has its own setting, and each setting lists the allowed directions: to_endpoint (technician to endpoint) and to_technician (endpoint to technician). An empty list turns that kind off. A direction is allowed only where every applicable profile allows it.

Setting	Controls	Default
remote_access.clipboard_text	Plain and rich text in the clipboard, and Type clipboard	Both directions
remote_access.clipboard_images	Images in the clipboard	Both directions
remote_access.file_transfer	Files and folders by drop, paste, upload, or download, and the Files browser	Both directions
remote_access.file_transfer_max_file_mb	Largest single file, in MiB	0, no limit
remote_access.file_transfer_max_session_mb	Total file data in one session, both directions together, in MiB	0, no limit

Browsing folders on the endpoint shows their contents, so the Files tab needs to_technician. Uploading into a browsed folder needs both directions.

Framework baselines set floors on these settings:

Framework	Clipboard text and images	Files
CJIS	Off	Off
PCI DSS, ISO 27001	To the endpoint only	To the endpoint only
HIPAA, SOC 2, NIST 800-53, NIST 800-171, CMMC Level 2	No floor	To the endpoint only
DISA STIG, Microsoft security baseline	Recommends to the endpoint only	Recommends to the endpoint only

A setting a baseline locked is shown in the viewer as, for example, Locked by PCI DSS baseline. See Compliance framework baselines.

What is audited

Every clipboard sync, file transfer, folder listing, refusal, and code confirmation is recorded in the audit log against the session and the technician. See Audit logs.

• Clipboard events record the direction, the formats, and the total size, never the content or a hash of it.
• File transfers record the direction, the outcome, the number of files, the total size, and, for each file, its name, size, and hash as policy allows.

Six settings decide how much each file event reveals, separately for each direction:

Settings	Choices, most revealing first	Default
remote_access.audit_file_names_to_endpoint, remote_access.audit_file_names_to_technician	full_path, file_name, path_hash, name_hash	full_path
remote_access.audit_file_sizes_to_endpoint, remote_access.audit_file_sizes_to_technician	exact, summary (rounded, such as 2.1 MB)	exact
remote_access.audit_file_hash_to_endpoint, remote_access.audit_file_hash_to_technician	plain (SHA-256), keyed, none	keyed

When profiles disagree, the least revealing choice wins. Keyed hashes use a key that never leaves the endpoint.

The tray app at the endpoint also lists each transfer of the session, newest first with its time, such as “Technician copied text from this PC”. The list appears only in the tray app’s card: the endpoint shows no pop-up or notification for a transfer, in any session mode. See Consent prompts and session notices.

If something goes wrong

The viewer gives a reason wherever a transfer is unavailable or fails:

Reason	Cause	Fix
Blocked by profile: and a direction	A profile does not allow that direction.	Change remote_access.clipboard_text, clipboard_images, or file_transfer in the profile.
Locked by a framework baseline	A framework floor forbids it.	Not changeable while the framework applies to the endpoint.
Over the transfer size limit	A file, or the session total, is over the limit policy sets.	Send less, or raise the limit.
Confirm the secure transfer code first	Policy requires the code check, or the endpoint’s key changed.	Confirm the code with the person at the endpoint.
Not available on the sign-in screen	Nobody is signed in at the endpoint.	Use Type clipboard, or sign in first.
The session is paused because no input reached it for a while.	The session paused for technician inactivity.	Turn on Control and select the screen to resume.
The Windows user changed	The signed-in user changed during the transfer.	Start the transfer again.
The endpoint user cannot open this	The signed-in user has no access to that file or folder.	Use a location the user can open.

Next steps

• Remote access policy settings
• Troubleshoot remote access