On Sunday 04 January 2009 11:32:24 Mike Cloaked wrote:
Anne Wilson-4 wrote:
> Is a ssh key specific to a computer, or to a user? That is, does my key
> pertain to any box on the lan, as long as I'm the user? Or is it machine
ssh keys are specific to the user - they are in the users .ssh directory in
their home user directory. Root also has its own .ssh
On the server side you can choose who to allow to connect and also whether
to allow password connections and many other options in
/etc/ssh/sshd_config and you can find more in "man sshd_config"
On my server I set that up to allow only connection with keys. I presume that
any box that might need to be monitored by ssh will need the same treatment.
You need to look up how to generate ssh keys and store them. It is
possible
to replicate the .ssh directory for your own user area and put it on the
user area of the same name on a different computer to save the need to
generate new keys.
I feel unsafe about storing keys on a laptop that is going to travel, so I'll
need to read up on storing them on a usb stick. At least losing the stick
will not make the connection unsafe :-) - I'm unlikely to lose the laptop and
stick at the same time.
However you also need to be aware that the system will know if the
remote
machine you are connecting to is upgraded - and then when you try to ssh in
you will get a warning saying there is a possible man-in-the middle attack.
In this instance if the remote machine is known to have been reinstalled
for example then in the user area from which you are trying to connect need
to have the entry in .ssh/known_hosts removed by editing (or remove the
known_hosts file) and accept prompts the first time you then subsequently
ssh into another machine.
OK - this is probably not an issue on the server, which runs CentOS, but would
be much more so on workstations and laptops.
There are tutorials on the net and a google search will find them
fairly
easily.
Yes, I set it up from such a tutorial, but sometimes I need to check that I
have understood/remembered something correctly. Especially when it concerns
something relevant to security.
Anne