# -*- mode: sh; -*-
#
# $HeadURL: https://tstotts.net/pubvc/bash-snippets/gpg.sh $
# $Id: gpg.sh 624 2007-07-07 02:08:52Z tas $
#

# Dependencies:
#    sys-apps/coreutils
#    app-arch/tar
#    app-crypt/gnupg
#    app-arch/par2cmdline

# Fix issues with gpg using agent in GNU Screen
# and other terminal emulators that confuse the
# the TTY device.
export GPG_TTY=`tty`

# Signal all `gpg-agent' processes to discard their passphrase cache.
t_gpg_flush()
{
    kill -1 `pgrep gpg-agent`
}

# create an encrypted tar archive (with datestamp in file name)
# and generate MD5 checksum and PAR-2 integrity codecs
t_gpg_bkup()
{
    prefix="$1"
    shift;

    if [[ -z "$prefix" && -z "$1" ]]; then
	echo "${FUNCNAME[0]} <out_prefix> DIR [...]";
	return 1;
    fi

    DATESTAMP=`date +%Y_%m_%d_%H%M%S`
    o="${prefix}.`hostname -s`.${DATESTAMP}.tar.gpg"
    (
	tar -cO "$@" | \
	    gpg --quiet \
	    --compress-algo bzip2 \
	    --bzip2-compress-level 6 \
	    --cipher-algo AES256 \
	    --symmetric \
	    > "${o}" \
	    || return $?;
    )
    ( 
	b=`basename ${o}`
	d=`dirname ${o}`
	cd ${d}
	md5sum ${b} > ${b}.md5 || return $?;
	par2 create -q -q ${b} || return $?;
    )
}


# encrypt a file and generate MD5 checksum and PAR-2 integrity codecs
t_gpg_file()
{
    if [[ -z "$1" ]]; then
	echo "${FUNCNAME[0]}: FILE [...]";
	return 1;
    fi

    for i in "$@"; do
	o="${i}.gpg"
	cat "${i}" | \
	    gpg --quiet \
	    --compress-algo bzip2 \
	    --bzip2-compress-level 6 \
	    --cipher-algo AES256 \
	    --symmetric \
	    > "${o}" \
	    || return $?;

	(
	    b=`basename ${o}`
	    d=`dirname ${o}`
	    cd ${d}
	    md5sum ${b} > ${b}.md5 || return $?;
	    par2 create -q -q ${b} || return $?;
	)
    done
    return 0
}

t_bkup_mail()
{
    cd $HOME && \
        t_gpg_bkup backups/mail/`id -u -n`_mail Mail/
}

alias shred='shred -u'