#!/bin/bash
#
# Copyright Hank Leininger <hlein@korelogic.com>, <hlein@progressive-comp.com>

VERSION='$Id: imap-login,v 1.2 2005/05/11 16:28:10 hlein Exp $'
VERSION=`echo "$VERSION" | sed 's/.*,v //; s/ .*//;'`

# Log in to an SSL-IMAP server and drop the connection.
# (Just enough to prove to any auth-before-Something tool that we are allowed.)
# Turns off local-echo when prompting for password, so it will not print.
# Requires stunnel 3.x

# IP address of the server to log into;
# you must change this, or use the -s option
SERVER=127.255.255.254

# Default username will be read from the environment;
# update this if your remote name is different
##USER=foo

# Default timeout.  You might have to increase this
# if you are behind a very very slow link
TIMEOUT=8

# Default port to use for the local stunnel listener
LOCAL_PORT=1430

BASENAME=`echo "$0" | sed 's%.*/%%'`

USAGE="
  Usage: $BASENAME [-s serverip] [-u username] [-t timeout] [-p localport]

      All arguments are optional, to override defaults in the script.
	-s current default: $SERVER
	-u current default: $USER
	-t current default: $TIMEOUT
	-p current default: $LOCAL_PORT

$BASENAME v$VERSION
"

while getopts s:u:t:p:vh? c ; do
  case $c in
	s)	SERVER="$OPTARG" ;;
	u)	USER="$OPTARG" ;;
	t)	TIMEOUT="$OPTARG" ;;
	p)	LOCAL_PORT="$OPTARG" ;;
	*)	echo "$USAGE" >&2 ; exit 1 ;;
  esac
done

if [ -z "$SERVER" -o "$SERVER" = "127.255.255.254" ]; then
  echo "Not a valid server: '$SERVER'" >&2
  echo "$USAGE" >&2 ; exit 1
fi

PORT_LISTENING=`netstat -an | egrep "tcp.*[.:]${LOCAL_PORT}[^0-9.:].*LISTEN"`

if [ -n "$PORT_LISTENING" ]; then
  echo "Port ${LOCAL_PORT} in use, please specify an alternate one." >&2
  echo "$USAGE" >&2 ; exit 1
fi

# We should probably respect TMPDIR if set to a
# private tempdir, but oh well
mkdir -p ~/tmp
stty -echo
stunnel -c -D crit -d "127.0.0.1:${LOCAL_PORT}" -r "${SERVER}:993" \
	-P ~/tmp/imap-stunnel.$$
echo -n "Password: "
read PASSWORD
stty echo
echo
cat <<EOF | nc -w "${TIMEOUT}" -v -v -n 127.0.0.1 "${LOCAL_PORT}"
a01 login $USER $PASSWORD
EOF
kill `cat ~/tmp/imap-stunnel.$$ 2>/dev/null` 2>/dev/null
sleep 1
rm -f ~/tmp/imap-stunnel.$$ 2>/dev/null