easy ssh with ssh-agent

[parsim]

I ssh into four different remote machines fairly often, so I went through the process of generating ssh-keys so I could do this without typing in a password every time.

However, the end result doesn't seem as useful as it should be. Am I doing something wrong, or is this the way it's meant to work?

I'm currently doing this every time I need to ssh:

1. Think whether I've already sshed to this host since the machine's been booted. If I don't think I have, go to Step 2. Otherwise, if I'm confident, I just 'ssh user@host', but if I'm wrong, it will sit there for a while, then prompt me for "Password:". I need to Control-C this and go to Step 2. If I'm not sure whether I have or haven't, I run "ssh-add -l" and see if the host is on the list.
   
2. Execute "ssh-add ~/.ssh/identity.hostname". This asks me for a passphrase (which is long and easy to mistype).
   
3. "ssh user@host" and passwordlessly enter the account

Instead, what I'd like to do is this:

1. "ssh user@host". If I've previously sshed, then I enter passwordlessly. If not, then I'm prompted for a passphrase. Upon entering it, the ssh connection is established. The passphrase will not be required again.

I could ssh-add all four ~/.ssh/identity.host keys at the start of each session, but I don't want to type in four long passphrases when I may not even want to do any sshing that day.

[adaptr]

If you have set a different passphrase on every private key you use, then you will indeed have to type in all of them.
The usefulness of ssh-agent comes into play when you trust it to handle your private keys, obviating the need for you to type in more than one passphrase for a complete set of keys you intend to use during a session.

There is generally no need to generate a different key for each host - one key pair will do, just upload the public key to multiple machines.
Use the same passphrase for all of them, just make sure it is strong enough.
ssh-add will try to re-use the last passphrase,so this does make sense.

When you follow this, you type your passphrase once at the beginning of the session, and ssh-agent takes care of the rest.

I would personally put the shh-add sequence in a small script or in bash_login.
Then you will only have to type your passphrase when you log in, and you're set.
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>>> emerge (3 of 7) mcse/70-293 to /
Essential tools: gentoolkit eix profuse screen

[parsim]

Aha, thanks! I thought you needed separate passphrases for security reasons.

I've set my passphrases to the same thing, written a little script "ssh-startup":