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The Hacker's Utility Belt: SSH

21 points by apgwoz 18y ago

jf 18y ago
Another cool feature of SSH: Escape Characters (The following is an excerpt from the manpage for ssh(1) with the same title) ~. Disconnect. ~? Display a list of escape characters. The ~. escape character is useful for getting back to your prompt when your SSH session has hung or died.
Bjoern 18y ago
Not to be overly critical but - why - is this in the TOP3 of HN? It's a totally^Wrather incomplete^Wnice `intro` to SSH, ok. Aside from this...... ~/.ssh/config: # This is maybe useful if you get dropped all the time # due to stricter SSHd rules. ServerAliveInterval 60 # Instead of tunneling always with the CLI directly why not # make a entry in your ssh config to make it easy, e.g. HostName your.companies.host User username LocalForward 9999 clients.oracle.server.name:1521 # You can also use "Port" if the SSHd is on a non 22 port On the CLI: # Does all the tunneling automatically ssh your.companies.host
- apgwoz 18y ago
  I agree completely. The post is nothing more than a "hey, if you're not using ssh for these two things, maybe take a look." I went this route because there are so many other full fledged introductions to ssh, that I thought it'd almost be a waste of my time. I'm sorry that reading it wasted yours.
tannerburson 18y ago
I'm a big fan of the ForwardAgent option. It allows you to, based on destination, pass your SSH key forward and have it used as the private key on the destination server as well. This allows me to ssh into a remote server, but keep my key based access rights on other servers (or github).
- thristian 18y ago
  The standard warning about agent-forwarding: ssh-agent works by exposing your private keys to any process running as you, or any process running with root permissions. You have to trust your laptop or workstation (if you didn't, you wouldn't be typing passwords at the keyboard) so ssh-agent is pretty safe locally, but you should be careful about extending that level of trust to other hosts. For example, I use agent-forwarding all the time at $EMPLOYER, because the same sysad is responsible for my workstation and the production systems, so every host is equally trustworthy. I might use agent-forwarding when connecting to a shell-server run by a friend, I wouldn't use it while connecting to an anonymous service like github or gitorious.

21 points by apgwoz 18y ago

jf 18y ago

Another cool feature of SSH: Escape Characters (The following is an excerpt from the manpage for ssh(1) with the same title) ~. Disconnect. ~? Display a list of escape characters. The ~. escape character is useful for getting back to your prompt when your SSH session has hung or died.

Bjoern 18y ago

Not to be overly critical but - why - is this in the TOP3 of HN? It's a totally^Wrather incomplete^Wnice `intro` to SSH, ok. Aside from this...... ~/.ssh/config: # This is maybe useful if you get dropped all the time # due to stricter SSHd rules. ServerAliveInterval 60 # Instead of tunneling always with the CLI directly why not # make a entry in your ssh config to make it easy, e.g. HostName your.companies.host User username LocalForward 9999 clients.oracle.server.name:1521 # You can also use "Port" if the SSHd is on a non 22 port On the CLI: # Does all the tunneling automatically ssh your.companies.host

apgwoz 18y ago
I agree completely. The post is nothing more than a "hey, if you're not using ssh for these two things, maybe take a look." I went this route because there are so many other full fledged introductions to ssh, that I thought it'd almost be a waste of my time. I'm sorry that reading it wasted yours.

tannerburson 18y ago

I'm a big fan of the ForwardAgent option. It allows you to, based on destination, pass your SSH key forward and have it used as the private key on the destination server as well. This allows me to ssh into a remote server, but keep my key based access rights on other servers (or github).

thristian 18y ago
The standard warning about agent-forwarding: ssh-agent works by exposing your private keys to any process running as you, or any process running with root permissions. You have to trust your laptop or workstation (if you didn't, you wouldn't be typing passwords at the keyboard) so ssh-agent is pretty safe locally, but you should be careful about extending that level of trust to other hosts. For example, I use agent-forwarding all the time at $EMPLOYER, because the same sysad is responsible for my workstation and the production systems, so every host is equally trustworthy. I might use agent-forwarding when connecting to a shell-server run by a friend, I wouldn't use it while connecting to an anonymous service like github or gitorious.