SSH terminal, SFTP and FTPS on iPhone

When something on the network needs a quick look, a server’s disk, a switch’s port status, a config file to fetch, NetBlade lets you do it from the phone. This article covers the SSH terminal and the file transfer screen: how to connect, how saved hosts work, where your passwords are kept, and the limits iOS sets.

Before you start

NetBlade Pro. The SSH terminal and File transfer are Pro features; Settings › «See NetBlade Pro» shows the plans.
A server, switch or router that accepts SSH (usually port 22), or an FTP/FTPS server.
An account on it. The SSH terminal signs in with a user name and a password.

1. Connect over SSH

Open Tools › SSH.
Enter «Host», «Port», «Username» and «Password».
If you will come back to this machine, turn on «Save this host». To skip typing the password next time, also turn on «Remember password».
Tap «Connect».

On the first connection NetBlade stores the server’s host key. On every later connection it checks that the key is the same, before sending your password.

Warning: If the key has changed, NetBlade stops with “The host key for … has changed” and shows the old and new fingerprints. Nothing is sent. That is what an interception attempt looks like, and also what a reinstalled server looks like: check with whoever runs the machine before assuming the harmless explanation.

2. Run commands

Type a command in the field and send it. The «Complete» button works like the Tab key, suggesting commands you already typed in this session and the built-in ones.

Above the field there is a row of one-tap commands. NetBlade guesses on connect whether it is talking to a Linux machine or to a switch or router, and offers the matching set; the first chip switches between “Linux” and “Switch / router”. Every shortcut only reads, and the label is the exact command that will be sent. Touch and hold a shortcut and choose «Edit before running» to adjust it first, for example to add an interface name.

Tap «Disconnect» when you are done.

Note: iOS offers apps no full interactive terminal, so commands run one at a time. Programs that take over the screen, such as top, vi or less, do not work. Use their non-interactive forms: top -bn1, journalctl --no-pager, tail -n 50.

3. Move files with SFTP, FTP or FTPS

Open Tools › File transfer.
Choose the «Protocol»: SFTP, FTP or FTPS. The port changes to the usual default (22, 21 or 990).
Enter «Host», «Port», «Username» and «Password», or turn on «Anonymous» for FTP servers that allow it.
Turn on «Save this connection» and, if you want, «Remember password».
Tap «Connect» and browse the folders.

From the folder view you can «Upload», «Download», «Rename», «Delete» and create a «New folder». Deleting asks for confirmation, because it cannot be undone.

Which protocol to choose

SFTP runs over SSH, so any machine you can SSH into usually offers it with no extra service. Prefer it.
FTPS is FTP with TLS. NetBlade pins the server’s certificate on the first connection and checks it on later ones, including on the data connection.
FTP sends the password and the files in clear text, and the app reminds you. Use it only on a network you trust, and only when nothing else is available.

Note: On iPhone the host key check described in step 1 applies to the SSH terminal. The file transfer screen does not verify the SFTP server’s host key, so connect to machines you know, on a network you trust.

4. Manage saved hosts

Saved hosts appear at the top of each screen, under “Saved” in SSH and “Saved connections” in File transfer. Tap one to fill in the connection; a key icon means its password is remembered.

To remove one, touch and hold it and choose «Forget». This deletes the saved entry and its remembered password.

Tip: Touch and hold the NetBlade icon on the Home Screen: the last four saved SSH and file transfer hosts appear as quick actions. Tapping one opens the tool already connecting.

5. Know where your passwords live

Remembered passwords are stored in the iOS Keychain, on this device only. They are not synced to other devices and never go into NetBlade’s backup file.
The rest of a saved host (address, port, user name, label) is kept in the app’s local data.
If you restore NetBlade on a new device, the saved hosts come back but the passwords do not: you enter them again.

This is deliberate. A password that stays on one device cannot leak through a backup file you forgot about.

Check that it worked

After «Connect», the output area shows “Connected to” with the host and your user name.
A shortcut such as uptime returns a line from the server.
In File transfer, the folder list of your home directory appears.
Leaving the screen and coming back, the host is listed among the saved ones.

If something goes wrong

The handshake fails with no algorithm in common. Old devices, and some hardened ones, offer algorithms the app does not share. NetBlade prints what the server offers so you can see which; on old gear an SSH firmware update is usually the fix.
Login refused. Check user name and password. The SSH terminal signs in with a password; accounts that only accept keys cannot be used here.
A command seems to hang or prints nothing. It is probably waiting for a terminal. Use a non-interactive form.
“The TLS certificate … changed since the first connection”. The FTPS server now presents a different certificate, and NetBlade does not connect. It may be a renewed certificate or an interception: confirm with whoever runs the server.

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