Access to Biological Sciences Computers
=======================================

From Outside the Department
----------------------------

.. highlight:: none

This includes if you are in the department but using WiFi.

Access from outside the department is only available through our "gateway" server. 

This server is **ssh.cryst.bbk.ac.uk**

You can 'ssh' to the gateway server using the following:

If you are using a Linux terminal:


   **ssh -X <userid>@ssh.cryst.bbk.ac.uk**


If you are using a Mac OSX terminal:

   **ssh -Y <userid>@ssh.cryst.bbk.ac.uk**
   
You can also use our web-based portal:

   https://login.cryst.bbk.ac.uk/
   
The initial login to the site is dependent on whether you are a MSc Student, PhD, Post Doc or staff. Theses details will be given to you by your Tutor/Line Manager/Project Supervisor.


From Within the Department
--------------------------

Using a department computer you can access most server/workstations directly with **ssh**.

If you are using a Linux terminal:


   **ssh -X <server name>.cryst.bbk.ac.uk**

If you are using a Mac OSX terminal:

   **ssh -Y <server name>.cryst.bbk.ac.uk**
   
In both cases you will be logged into the server with the same userid and the computer you are logged into.
   
The <server name> will depend on whose research group you are in, not all research groups have dedicated servers.

**The only 'general' server that anyone can use is ssh.cryst.bbk.ac.uk, but it should not be used for data processing.**

Your Tutor/Line Manager/Project Supervisor will inform you which servers you can use.


Setting up 'password-free' login
--------------------------------

Every time you 'ssh' to a server it will ask for a password, it is possible to configure your account so that this does not happen.

To do this you need to create some authentication keys. Log into ssh.cryst.bbk.ac.uk, by default you will be in your home directory, run the following commands::

   mkdir .ssh
   chmod 700 .ssh
   cd .ssh
   ssh-keygen -t rsa

and hit return a number of times accepting the defaults, an example is below::

   pandora:~/.ssh-104> ssh-keygen -t rsa
   Generating public/private rsa key pair.
   Enter file in which to save the key (/d/user5/software/.ssh/id_rsa): 
   Enter passphrase (empty for no passphrase): 
   Enter same passphrase again: 
   Your identification has been saved in /d/user5/software/.ssh/id_rsa.
   Your public key has been saved in /d/user5/software/.ssh/id_rsa.pub.
   The key fingerprint is:
   SHA256:gt4QAAy36N6xddJR8pa/dYTKLTQzMMcmPZgn51Z7nPw software@pandora.cryst.bbk.ac.uk
   The key's randomart image is:
   +---[RSA 2048]----+
   |=.o    . +=.     |
   | + o    +==B ..  |
   |. . .  . +B=o.+..|
   |.	 o. o +o*..= |
   | . .oo.oS .= o...|
   |. ..+oo.	+ . E|
   | . o. .    .     |
   |		     |
   |		     |
   +----[SHA256]-----+

Two files will be created::

   id_rsa
   id_rsa.pub
   
id_rsa should be kept private and readable only by your own account.
 
Next, the authentication key has to copied into a authorized_keys file::

   ssh-copy-id <userid>@ssh.cryst.bbk.ac.uk
   
where <userid> is your **Departmental** UserID.

Answer **"yes"** to the question::

   The authenticity of host 'ssh.cryst.bbk.ac.uk (193.61.32.118)' can't be established.
   ECDSA key fingerprint is SHA256:Z1wNGr15rhEdIyGseQCcd6aKoZTm71R5o51ioEypbf8.
   ECDSA key fingerprint is MD5:07:19:36:1a:b6:d8:da:45:66:30:ee:fb:cb:96:7f:fa.
   Are you sure you want to continue connecting (yes/no)? yes

and then use your **departmental** password to finish.

The first time you log into another server it will ask a question::

   >ssh minos
   The authenticity of host 'minos (193.61.35.203)' can't be established.
   ECDSA key fingerprint is SHA256:XhHYcziGBrSSREm7ySX7x72jK6+it5ntHSM9iE8wCoY.
   ECDSA key fingerprint is MD5:4c:35:5a:bb:05:d2:4f:d4:a1:45:c1:cb:f4:35:90:af.
   Are you sure you want to continue connecting (yes/no)? 

Type **"yes"** and you will be logged in, this will only happen once for each new server.
 

'password-free' login from outside
----------------------------------

Using similar commands above, password free login into the gateway server can be setup.

On your home/private/outside computer in a linux/Mac terminal::

   cd
   mkdir .ssh  (if it does not already exist)
   chmod 700 .ssh
   ssh-keygen -t rsa
   ssh-copy-id <userid>@ssh.cryst.bbk.ac.uk
   
where <userid> is your **Departmental** UserID.

If you are on the College WiFi (e.g. eduroam) you are considered an outside computer.