sshlp_addagent

#!/bin/sh
#
# Get a key pair from LastPass and set up the ssh agent
#

if [ $# -lt 2 ]; then
  echo "$0: get a key pair from LastPass and set up the ssh agent" >&2
  echo "Syntax: $0 <client> <server>" >&2
  echo "  where <client> is the name of the ssh 'client' side" >&2
  echo "  and <server> is the name of the ssh 'server' side" >&2
  exit 4
fi

export CLIENT="$1"
export SERVER="$2"

MYDIR=$( cd $( dirname "$0" ) ; echo $PWD)
CLOUD_FN="${MYDIR}/sshlp.fn"

if [ -f "${CLOUD_FN}" ]; then
  . "${CLOUD_FN}"
fi

if ! private_key=$( lpass show --field="Private Key" ssh/${CLIENT}^${SERVER} ) ; then
  echo "Unable to find ${CLIENT} ${SERVER}" >&2
  exit 4
fi

if ! eval "$(ssh-agent -s)" >/dev/null 2>&1 ; then
  echo "Unable to start ssh-agent" >&2
  exit 4
fi

private_keydir="${TMPDIR}/$$ssh"
private_keyfile="${private_keydir}/$$_priv"
if ! mkdir -p "${private_keydir}" ; then
  echo "Unable to make temporary directory to store private key" >&2
  exit 4
fi
if ! printf "%s\n" "${private_key}" >"${private_keyfile}" ; then
  echo "Unable to write private key to add" >&2
  exit 4
fi
if ! chmod 0700 "${private_keydir}" ; then
  echo "Unable to chmod private key directory to reduced settings" >&2
  exit 4
fi
if ! chmod 0600 "${private_keyfile}" ; then
  echo "Unable to chmod private key file to reduced settings" >&2
  exit 4
fi

export SSH_ASKPASS="${MYDIR}/sshlp_passphrase" 
export SSH_ASKPASS_REQUIRE=force

if ! ssh-add "${private_keyfile}" >/dev/null 2>&1 ; then
  echo "Unable to add private key to ssh-agent" >&2
fi

if ! rm -rf "${private_keydir}" ; then
  echo "Unable to remove tempory private key file ${private_keyfile}. You should remove this yourself!" >&2
  exit 4
fi