#!/bin/sh

########################################################
## ez-pine-gpg-incoming                               ##
## part of ez-pine-gpg v0.4h // gpg filters for pine  ##
## http://Business-PHP.com/opensource/ez-pine-gpg/    ##
## (c) 13 Feb 2004, Atom Emet                         ##
## (c) 16 Dec 2004, Atom Emet                         ##
## Atom {at} Business-PHP.com                         ##
## Distributed under the GNU General Public License   ##
## http://www.gnu.org/copyleft/gpl.html               ##
##                                                    ##
##  ################################################  ##
##                                                    ##
## This program is free software; you can             ##
## redistribute it and/or modify it under the terms   ##
## of the GNU General Public License as published by  ##
## the Free Software Foundation; either version 2 of  ##
## the License, or (at your option) any later         ##
## version.                                           ##
##                                                    ##
## This program is distributed in the hope that it    ##
## will be useful, but WITHOUT ANY WARRANTY; without  ##
## even the implied warranty of MERCHANTABILITY or    ##
## FITNESS FOR A PARTICULAR PURPOSE.  See the GNU     ##
## General Public License for more details.           ##
##                                                    ##
## You should have received a copy of the GNU         ##
## General Public License along with this program;    ##
## if not, write to the                               ##
## Free Software Foundation, Inc.,                    ##
## 59 Temple Place - Suite 330,                       ##
## Boston, MA  02111-1307, USA.                       ##
########################################################

#########################################
## PATH is configured during installation
PATH=/bin:/usr/bin:/home/bnewbold/bin

###################
## clear the screen
clear 1>&2

echo '#########################################################################' 1>&2
echo '## This message is being processed by ez-pine-gpg v0.4h                ##' 1>&2
echo '## http://Business-PHP.com/opensource/ez-pine-gpg/                     ##' 1>&2
echo '## (c) 13 Feb 2004, Atom Emet                                          ##' 1>&2
echo '## (c) 16 Dec 2004, Atom Emet                                          ##' 1>&2
echo '## Distributed under the GNU General Public License                    ##' 1>&2
echo '## See source for details                                              ##' 1>&2
echo '#########################################################################' 1>&2

####################################################
## if things go wrong, this notice will be displayed
## along with the incoming message
##
gpg_failed () {
    echo '%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%'
    echo '%%%%%%%%%%%% Something went wrong --- See above for more info %%%%%%%%%%%%'
    echo '%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%'
    #############################
    ## if the message is textmode
    if [ "${textmode}" = 'yes' ]
    then
        ############################################################
        ## display the input and un-dash-escape any clearsigned text
        echo "${input}" | sed '/^-----BEGIN PGP SIGNED MESSAGE-----/,/^-----BEGIN PGP SIGNATURE-----/ s/^- -/-/'
    elif [ "${textmode}" = 'no' ] && [ "${stdout}" ]
    then
	#######################################
	## if the message seems to be encrypted
	## and gpg produces STDOUT display the decrypted message
	echo "${stdout}"
    else
	##############################################################################
	## if we're here then the message was encrypted but not successfully decrypted
	## just display the input
	echo "${input}"
    fi
    #############################################
    ## unset variables that we don't need anymore
    input= ; stdout= ; textmode=
    ############################################
    ## just because something went wrong doesn't
    ## mean that pine needs to know about it.
    ## a zero exit status makes pine happy
    clear 1>&2
    exit 0
}

###########################################
## do the right thing even if ^C is pressed
##
trap 'gpg_failed' 2

############################################################
## create a variable "input" containing STDIN to this script
##
input="`cat`"

#####################################################
## test if the message in textmode or binary/armored?
if echo "${input}" | gpg --list-only --list-packets 2>&1 | egrep -q '^[[:space:]]+mode t'
then
    export textmode=yes
else
    export textmode=no
fi

##############################################################
## echo a message that let's us know ez-pine-gpg is being used
## and display the machine name and current date/time
##
echo '##########################################################################'
echo '## ez-pine-gpg v0.4h ## http://Business-PHP.com/opensource/ez-pine-gpg/'
echo "## `date` ## `uname -n`"
echo '##########################################################################'

#################################################
## display some information about the the message
## we're only concerned with STDERR
echo "${input}" | gpg --list-only > /dev/null

###############################################
## the variable "stdout" is the output from gpg
## notices from gpg STDERR are redirected to STDOUT and displayed
## if gpg fails then bail out with an error message
##
{ stdout="`echo "${input}" | gpg --decrypt`" || gpg_failed ; } 2>&1

#############################################
## figure out how to best display the message
##
if [ "${textmode}" = 'no' ]
then
    ########################################################
    ## if the message is armored display the output from gpg
    echo '%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%'
    echo '%%%%%%%%%%%%%%%%%%%%%%%% OpenPGP ENCODED MESSAGE %%%%%%%%%%%%%%%%%%%%%%%%%'
    echo '%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%'
    echo "${stdout}"
else
    ##########################################################################################
    ## if the message is clearsigned (or malformed?) display the input and un-dash-escape text
    echo '%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%'
    echo '%%%%%%%%%%%%%%%%%%%%%%%%% OpenPGP SIGNED MESSAGE %%%%%%%%%%%%%%%%%%%%%%%%%'
    echo '%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%'
    echo "${input}" | sed '/^-----BEGIN PGP SIGNED MESSAGE-----/,/^-----BEGIN PGP SIGNATURE-----/ s/^- -/-/'
fi

###########################
## get rid of the variables
## containing the message
input= ; stdout= ; textmode=

#############
## we're done
##
exit 0