As of the Leopard release of OS X, ssh-agent is more tightly integrated with Keychain. It is possible to store the passphrases of all of your SSH keys securely in Keychain, from which ssh-agent will read them on startup. The bottom line is that it is simple to secure your keys with passphrases, but never have to type the passphrase to use them! Here is how:

Add the pass phrase to each ssh key to keychain:

ssh-add -K [path/to/private SSH key]
Whenever you reboot your Mac, all the SSH keys in your keychain will be automatically loaded. You should be able to see the keys in the Keychain Access app, as well as from the command line via:

ssh-add -l

I didn’t find one clear and con­cise place explain­ing how to setup pri­vate keys on OS-X. This is my attempt to rem­edy that.

First, you need to gen­er­ate the Pri­vate (id_dsa or id_rsa) and Pub­lic (id_dsa.pub or id_rsa.pub) Key pair. Prop­erly secured machines don’t accept RSA encryp­tion (rsa1) which was used by SSH v1 pro­to­col, but they do accept RSA v2 and DSA, with DSA being arguably more secure. For the –t option use either rsa or dsa, with dsa being pref­fered. The rest of this arti­cle assumes you’re using dsa. You are able to choose a passphrase, so pick some­thing easy to remem­ber and suf­fi­ciently complex.

SSH has many features which are helpful when working regularly with files on remote servers; together they can give a vast increase in productivity over the bare use of SSH. If you regularly use SSH, it’s worth spending a little time learning about these and configuring your environment to make your life easier.

Accessing Plex/Nine as a Remote Library

Currently, there are two methods you can use to access your Plex/Nine library remotely from another computer outside your home or local network.

The standard procedure to upgrade Drupal to the latest release is to download it from drupal.org and follow the included UPGRADE.txt.
For administrators using the UNIX shell it may be easier using the attached patch files below instead of downloading and installing the newest complete Drupal release.

SCP
The scp command allows you to copy files over ssh connections. This is pretty useful if you want to transport files between computers, for example to backup something. The scp command uses the ssh command and they are very much alike. However, there are some important differences.

The scp command can be used in three* ways: to copy from a (remote) server to your computer, to copy from your computer to a (remote) server, and to copy from a (remote) server to another (remote) server. In the third case, the data is transferred directly between the servers; your own computer will only tell the servers what to do.

I was at work the other week, doing a repetitive task of the sort that provides an opportunity to listen to music. I’d recently purchased an album and had stored it in the iTunes library on my home computer, but had not yet loaded the new songs onto my iPhone. There had to be a way to make iTunes at home share its music to my work computer so that I could listen to the new music. A few internet searches turned up some interesting information as well as a solution.

find will find files recursively in sub directories, if any. If that's what you want, great. If you only want files in the current directory, you can use:

for i in *.tar.gz; do tar xzvf $i; done

If you are going to do this kind of thing often, you should edit the file ~/.ssh/config and put something like this in it

You're at home, and you want to mount a disk from a Mac at work onto your Mac at home, but work has a firewall. Your attempts to use the afp file serving protocol are thwarted because the afp port (548) is blocked.

It's a treasured geek secret that ssh can tunnel TCP connections like ssh all over the internet. What does that mean? It means that you can access machines and ports from your local machine that you never thought you could, including git repositories that are behind firewalls or inside VPNs.

A few corrections.

You can't simply cat the public key over to a server if you haven't created the ~/.ssh directory first. You have to create the directory first. Also, simply catting it over isn't overly smart, and you could have it refuse to use the key due to insecure permissions. You should be doing:

scp ~/.ssh/id_rsa.pub user@server.com:~/
ssh user@server.com
mkdir .ssh && chown 0700 .ssh
mv id_rsa.pub .ssh/authorized_keys && chmod 0600 .ssh/authorized_keys
And you're right, the key needs to be on the other end first, before you get this dialog because this is add the key to the running ssh-agent. If there is no pubkey negotiation, ssh-agent isn't consulted at all, you're providing a straight password to the remote sshd server.