yarest 0.5.0 (beta)

Yet Another REmote Support Tool

Features

• Extremely simple GUI for both your end-users and technicians
• Core yarest package exports all of the functionality independent of the GUI
• Usable with most any VNC variant, RDP, and likely other port based desktop sharing programs
• Requires only outbound connectivity for both technician and end-user when the SSH server is on a 3rd machine
• Supports multiple "connection profiles" to enable use of multiple SSH servers
• Supports executing your own custom code during sessions via the "SupportExtender" interface
• Includes an NSIS installer for Windows that can download and install the necessary Python dependencies

How It Works

The basic premise is simply this:

1. First entity starts the overall process by establishing a reverse SSH tunnel from a random server port number to their pre-configured local port number.
2. First entity delivers random port number, aka "access code", to the second entity. This could occur over the phone, e-mail, your own custom software, really fast courier pigeons, morse code, telepathy...anything you choose.
3. Second entity establishes a forward SSH tunnel from their pre-configured local port number to the "access code" server port, which links up the two tunnels.
4. Either or both entities disconnect the session when finished.

Code Example

The following two "connection profiles" and code snippets are intended to represent the basic code needed for the scenario described directly above, whereby the second entity is providing support to the first entity via RDP.

>>> [First Entity]
>>> ssh_server = my.support.server
>>> ssh_port = 22
>>> ssh_allow_unknown = True
>>> ssh_hostkeys =
>>> ssh_compression = True
>>> support_port = 3389
>>> support_tunnel = reverse

>>> [Second Entity]
>>> ssh_server = my.support.server
>>> ssh_port = 22
>>> ssh_allow_unknown = True
>>> ssh_hostkeys =
>>> ssh_compression = True
>>> support_port = 9999
>>> support_tunnel = forward
>>> support_exec = %SYSTEMROOT%\system32\mstsc.exe
>>> support_args = /v:localhost:%d /f

In the below code snippet assume:

• your_config_file contains exactly one connection profile, the "First Entity" one above
• your_password comes from the end-user in some manner
• send_access_code_to_your_provider delivers the "access code" to the other entity
• user_clicked_disconnect is some flag you set from elsewhere to end the session

>>> from yarest import ConnectionProfile, SupportEntity
>>>
>>> profiles = ConnectionProfile.read_from_file(your_config_file)
>>>
>>> firstentity = SupportEntity(profiles[0])
>>> firstentity.connect(your_password)
>>>
>>> access_code = firstentity.start_session()
>>> send_access_code_to_your_provider(access_code)
>>>
>>> user_clicked_disconnect = False
>>> while not user_clicked_disconnect:
>>>     continue
>>>
>>> firstentity.stop_session()

In the below code snippet assume:

• your_config_file contains exactly one connection profile, the "Second Entity" one above
• your_password comes from the end-user in some manner
• access_code was received from the first entity
• user_clicked_disconnect is some flag you set from elsewhere to end the session

>>> from yarest import ConnectionProfile, SupportEntity
>>>
>>> profiles = ConnectionProfile.read_from_file(your_config_file)
>>>
>>> secondentity = SupportEntity(profiles[0])
>>> secondentity.connect(your_password)
>>> secondentity.start_session(access_code)
>>>
>>> user_clicked_disconnect = False
>>> while not user_clicked_disconnect:
>>>     continue
>>>
>>> secondentity.stop_session()

SSH Server Security Considerations

Only the main SSH port needs to be accessible on any server(s) used, and ideally such is the only port open on any server(s) firewall(s).

Unless you have a need otherwise, the simplest option is usually to chroot the entire SSH server to the bare-minimum environment.

If you do need the SSH server for other purposes, then setup groups for your technicians and end-users and confine them to their own chroot environments.

Dependencies

• Python >= 2.6 (Tested with 2.6 and 2.7, untested on 3.x)
• ssh
• pycrypto (Required by ssh)
• configObj (Tested with 4.7.2)
• psutil (Tested with 0.4 and 0.5)
• wxPython (Tested with 2.8.10 and 2.8.12) [Only required by the yarest.gui package]
• setuptools [If you don't have it already we'll install the included Distribute]

Installation

Providers should consider creating their own simple installation package to automate these steps and include their own pre-configured profile(s). On Linux that could be done an infinite number of ways, for a countless number of distros, so nothing is provided beyond this documentation. On Windows the included NSIS installer should be a good starting point for most needs.

Steps for a functionally complete installation are as follows:

Bugs

Can be submitted via the issue tracker.

http://code.google.com/p/yarest/issues

Changelog