Initialize Your SSH Agent From the Apple Keychain
Starting in Mac OS X 10.5, Apple provides built-in
integration of ssh-agent with the Keychain, and SSHChain is
no longer needed. See here for details.
The SSH package provided with Mac OS X includes a utility called
ssh-agent. The purpose of ssh-agent is to
hold your SSH identities in memory, so that you don't have to repeatedly
enter your passphrase for every SSH-related command. You run
ssh-agent once, enter your passphrase(s) once, and it
takes care of the rest.
Unfortunately, the usual provisions for starting ssh-agent
are designed for X11-based windowing systems, and don't integrate too
well with Mac OS X. (In particular, they assume that you have a root
session which can run user-specified programs, and from which all other
processes will inherit their environment. There is also the problem of
how to get your passphrases to ssh-agent.)
With the SSHChain utility, you can add your SSH identities and
passphrases to the Apple Keychain, and have ssh-agent load
automatically each time you log in. The agent will then be available
to whatever processes you launch. SSHChain will also terminate the
agent when you log out, so that unused agents are not left running.
Because SSHChain requires access to your Keychain, it is being released as free software, licensed under the GNU GPL. The source code and project files are available here.