Load your SSH key from USB stick. Forked from http://tammersaleh.com/posts/building-an-encrypted-usb-drive-for-your-ssh-keys-in-os-x/

load

#!/usr/bin/env bash

# Script to load keys and (force) eject.
# If no hour value is given for the key's lifetime, it defaults to 4 hours.
#
# Usage (OS X):
#   /Volumes/keys/load <optional hour value>
#   <enter decryption password>

HOURS="$1"
DIR="/Volumes/keys"
KEY="$DIR/id_rsa"

if [ -z $HOURS ]; then
  HOURS=4
fi

/usr/bin/ssh-add -D  # Delete all identities on the machine.
/usr/bin/ssh-add -t ${HOURS}H $KEY
/usr/sbin/diskutil umount force $DIR

Deprecated. See https://github.com/dideler/usb-ssh-key