Teleport is software which provides an SSH Jump Host (or Bastion host) service in a secure, modern way, with support for role-based access control and single sign-on.

It is a replacement for the ecAccess SSH service, and is operated by the CD Apps team and User Services.

Overview

The Teleport service provides:

• Single SSH hop from client systems anywhere on the internet to servers inside ECMWF (ecGate, HPC, etc)
• Web single sign-on using ECMWF's website and the HID token
• Re-authentication required only every 12 hours (once per day)
• Integration with standard tools such as the OpenSSH ssh client, scp, and ssh-agent
• X11 and Port forwarding

The single sign-on step is performed using an application called "tsh", every 12 hours.

After that you use standard ssh or scp to connect to systems inside ECMWF.

Downloading tsh 

tsh application is required to perform user authentication once every 12 hours.

tsh is open source, very portable, and has minimal dependencies.

• Download from the Gravitational website and place into your $PATH 

The binary is available for Linux 32-bit, 64-bit, and ARM, as well as Windows 64-bit and a signed package for MacOS.

MacOS users can also use homebrew for installation (brew install teleport).

User Authentication

Once every 12 hours, you will need to refresh your tokens by logging in to the ECMWF website.

First Time

Run tsh, giving the location of our gateway:

tsh login --proxy=shell.ecmwf.int:443

Your default web browser will open and you should login with your email address, workstation password, and then HID Token code.

Subsequent Occasions

tsh login

Connecting to hosts through the gateway

OpenSSH 7.3 or later has a simple command line option to connect via our gateway (shell.ecmwf.int) to the destination-host:

ssh -J username@shell.ecmwf.int username@destination-host

For example, if your username is ab0 and you wish to connect to ecgate:

ssh -J ab0@shell.ecmwf.int ab0@ecgate

The OpenSSH configuration setting for this is named ProxyJump:

Host ecgate
  User ab0
  ProxyJump ab0@shell.ecmwf.int

See the Legacy Configuration note below if your ssh client is older than 7.3.

If your connection fails after working for some time, it could be because your tokens have expired. You can check them:

$ tsh status
> Profile URL:  https://shell.ecmwf.int:443
  Logged in as: firstname.lastname@ecmwf.int
  Cluster:      shell.ecmwf.int
  Roles:        *
  Logins:       ab0
  Valid until:  2020-06-22 23:26:30 +0100 BST [EXPIRED]
  Extensions:   permit-agent-forwarding, permit-port-forwarding, permit-pty

Destination Hosts available

The hosts directly available through the Teleport gateway are:

• Linux VDI (both legacy OpenSUSE and CENTOS 8 beta)
• Physical office workstations
• ecGate
• HPC2020 TEMS

To access any other host, the ProxyJump feature allows chaining by using a comma, like so:

ssh -J ab0@shell.ecmwf.int,ab0@workstation ab0@lxc

Configuring passwordless login

With the initial configuration you may be prompted for a password at the destination-host.

For login without a password, add the Teleport certificate authority to your ~/.ssh/authorized_keys file:

curl -fs https://nexus.ecmwf.int/repository/internal-teleport-configs/prod/teleport_user_ca.pub >> ~/.ssh/authorized_keys

Windows Clients

There are various ways to initiate SSH from Windows 10, so it depends on your system and your preferences.

Alternatively, you can use:

Host ecgate
  User ab0
  ProxyCommand ssh -q -i c:/users/ab0/.tsh/keys/shell.ecmwf.int/firstname.lastname@ecmwf.int -W %h:%p ab0@shell.ecmwf.int
  IdentityFile c:/users/ab0/.tsh/keys/shell.ecmwf.int/firstname.lastname@ecmwf.int

# Windows currently has a bug, you need the full path to ssh or you will get:
# posix_spawn: No such file or directory

Host *.ecmwf.int
  User ab0
  ProxyCommand C:\Windows\System32\OpenSSH\ssh.exe -q -W %h:%p ab0@shell.ecmwf.int

# this assumes the SSH Agent is running, otherwise add:
# Host shell.ecmwf.int
#   IdentityFile ~/.tsh/keys/shell.ecmwf.int/firstname.lastname@ecmwf.int

{
  "guid": "{717406b0-06cb-454c-a0c4-875267fa373d}", # run "[guid]::NewGuid()" in a PowerShell to generate this
  "name": "ecGate",
  "commandline": "ssh ab0@ecgate.ecmwf.int"
  "suppressApplicationTitle": true,
  "hidden": false,
  "fontSize": 10,
  "fontFace": "Fira Code",
  "cursorShape": "filledBox",
  "cursorColor": "#073642",
  "colorScheme": "Solarized Dark",
},

Other Notes

SSH Agent is required

If you have logged in but ssh fails to connect, it may be that your SSH agent is not running.

The Agent can be started and tokens refreshed this way:

eval $(ssh-agent -s)
tsh logout
tsh login

And this will make sure the Agent continues to run in your environment:

echo 'eval $(ssh-agent -s)' >> ~/.bash_profile

SCP, X11, Agent, and Port Forwarding

SCP, Agent forwarding, X11 forwarding, and Port forwarding (including SOCKS proxy), all work through the Teleport gateway.

Legacy Configuration

For OpenSSH clients older than 7.3, the following configuration can be used:

# ~/.ssh/config file:
Host ecgate
  User ab0
  ProxyCommand /usr/bin/ssh -q -W %h:%p ab0@shell.ecmwf.int

Difficult client environments

You might not be able to download and run tsh, or access our web login service, or run the SSH Agent, from where you wish to use ssh.

Instead you can use (or copy) the identity files which tsh stores in $HOME:

# ~/.ssh/config file:
Host ecgate
  User ab0
  IdentityFile ~/.tsh/keys/shell.ecmwf.int/firstname.lastname@ecmwf.int
  ProxyCommand /usr/bin/ssh -q -i ~/.tsh/keys/shell.ecmwf.int/firstname.lastname@ecmwf.int -W %h:%p ab0@shell.ecmwf.int

This is a good way to access Teleport credentials via a shared file system from any host.