SSH Over USB

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SSH over USB using usbmuxd

You can either download a binary and run that or use a python script. The python script is a lot slower than the binary version. On Linux the python method is mostly deprecated, use the binary version provided by libimobiledevice. There is also a newer solution called gandalf.

Using binary

  • Download the zip file from OS X or Windows (32 bits).
  • on Linux usbmux is provided by libimobiledevice, install it using your distro's package manager.
  • If you're on Windows, install iTunes
  • Unzip to a directory of choice.
    • Windows: Run path/to/itunnel_mux.exe --iport 22 --lport 2222
    • OS X: Run sudo path/to/itnl --iport 22 --lport 2222
    • Linux: iproxy 2222 22

Connect to localhost as you would over wifi.

Making itunnel mux run automatically in the background on OS X

  • Save the unzipped folder (containing both itnl and libmd.dylib) somewhere (eg. /Library/itunnel)
  • Create the file /Library/LaunchDaemons/com.usbmux.itunnel.plist with the contents:
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
	<key>Label</key>
	<string>com.usbmux.itunnel</string>
	<key>ProgramArguments</key>
	<array>
		<string>/path/to/itnl</string>
		<string>--iport</string>
		<string>22</string>
		<string>--lport</string>
		<string>2222</string>
	</array>
	<key>RunAtLoad</key>
	<true/>
	<key>KeepAlive</key>
	<true/>
</dict>
</plist>
  • (replacing /path/to/ with the path to where you have itnl stored, eg. /Library/itunnel/)
  • run sudo launchctl load /Library/LaunchDaemons/com.usbmux.itunnel.plist
  • You now don't have to run the itunnel binary every time you want to SSH over USB as the itunnel software is always running in the background

Using python

Tested on OS X and Windows.

You will need to have Python installed on your system.

  • Get usbmuxd source package and unpack. (Or if the linked usbmuxd package doesn't work, try libusbmuxd.)
  • Go into folder python-client
  • chmod +x tcprelay.py
  • Run ./tcprelay.py -t 22:2222

Now you can log into your device via ssh mobile@localhost -p 2222

The -t switch tells tcprelay to run threaded and allow more than one ssh over the same port.

See ./tcprelay.py --help for further options.


Using gandalf

Tested on OS X and Linux, each with up to 29 devices connected at the same time. The advantage of using gandalf is that it is written in a functional programming language, which practically means that it won't give you seg faults and it is actively maintained.

  • Installation

You need to have opam installed, it is OCaml's package manager.

On OS X you can do:

$ brew install opam

(If on Linux, then get opam via your package manager, details available https://opam.ocaml.org/doc/Install.html, Ubuntu users please pay attention, need to use a ppa for opam). It is important that your compiler is up to date, you can check with opam switch, make sure its at least >= 4.02.0

then

$ opam install usbmux

This will install the command line tool gandalf and an OCaml library.

  • gandalf usage.

The following are a series of usages of gandalf, all short form arguments have long-forms as well and -v can be added at any time.

1) See with realtime updates what devices are connected

$ gandalf

This will start up gandalf in listen mode, that is it will print out whenever a device connects or disconnects.

2) Start with a mapping file which is of the form

  <udid>:<local_port>:<device_port>. The ~#~ character starts comments

So an example mapping file would be:

# the phone1 udid, local port 2000, phone's port 22 aka ssh
123456dfg213423453456123dfg:2000:22
# phone 2, same deal but note different local port 
frgfg2345345123jifgidfug123:2001:22

and the gandalf invocation is:

$ gandalf -m mapping

2.1) You can also daemonize gandalf with the -d flag. *NOTE*: You might need to end up doing that under sudo as gandalf needs to make a pid file under /var/run.

3) To see a pretty JSON representation of devices and their ports that are currently connected, do:

$ gandalf -s

4) To reload gandalf with a new set of mappings, do:

$ gandalf -r

This will cancel all running threads and reload from the original mappings file, so make your changes there.

5) To cleanly exit gandalf, do: *NOTE* This might require super user permissions.

$ gandalf -e

Check out the man page, accessible with:

$ gandalf --help

or

$ man gandalf

Simple invocation:

$ sudo `which gandalf` --mappings etc/mapping --daemonize --verbose
  • Important Notes and Catches

1) If you are running this on Linux, then you might get issues with usbmuxd having issues when more than around 7 devices are plugged in. This is because multiple threads are trying to call various libxml2 freeing functions. I have a forked version of libplist that usbmuxd uses, sans the memory freeing calls. Its available [[1][here]]. Compile and install that, then compile and install usbmuxd from source. This will leak memory but its not that much at all and I believe it to be a fixed amount.

2) Another issue you might have is USB3.0. The Linux kernel might crap out on you after 13 devices. This is a combination of the kernel not giving enough resources and the host controller on your motherboard being crappy. The solution to this problem is to disable USB3.0 in your BIOS. To verify that USB3.0 isn't working check with lsusb

SSH over USB using the iFunBox GUI (Windows only)

This feature only exists in the Windows build of iFunBox.

  • Get the latest Windows build of iFunBox and install it.
  • Click on "Quick Toolbox," then "USB Tunnel."
  • Assign ports as you see fit.

Theos usage

Export the following variables in your shell in order to deploy builds to the connected device:

export THEOS_DEVICE_IP=localhost

export THEOS_DEVICE_PORT=2222

SSH without password

Run the following command one time and you will not be asked to type your password again.

ssh-copy-id root@DEVICE_IP