freedombone/src/freedombone-encrypt-mail

#!/bin/bash
#  _____               _           _
# |   __|___ ___ ___ _| |___ _____| |_ ___ ___ ___
# |   __|  _| -_| -_| . | . |     | . | . |   | -_|
# |__|  |_| |___|___|___|___|_|_|_|___|___|_|_|___|
#
#                              Freedom in the Cloud
#
# GPG Encrypt a Maildir using gpgit.pl
#
# License
# =======
#
# Copyright (C) 2014-2018 Bob Mottram <bob@freedombone.net>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

USERNAME=$1

PROJECT_NAME='freedombone'
COMPLETION_FILE="$HOME/${PROJECT_NAME}-completed.txt"

UTILS_FILES="/usr/share/${PROJECT_NAME}/utils/${PROJECT_NAME}-utils-*"
for f in $UTILS_FILES
do
  source "$f"
done

ADMIN_USER=$(get_completion_param "Admin user")

if [ ! "$USERNAME" ]; then
    USERNAME=$ADMIN_USER
fi

MAIL_DIR=/home/$USERNAME/Maildir
EMAIL_ADDRESS=$USERNAME@$HOSTNAME

# Does this key exist?
if ! gpg --list-keys "$EMAIL_ADDRESS" > /dev/null 2>&1; then
    echo $"A GPG key for $EMAIL_ADDRESS could not be found!"
    exit 0
fi

# Find all files in the Maildir specified.
echo $"Calling find"
find "$MAIL_DIR" -type f -regex '.*/\(cur\|new\)/.*' "$4"|while read -r line; do
    gpgit.pl --encrypt-mode prefer-inline "$EMAIL_ADDRESS"  "/tmp/msg_$USERNAME"

    # Check to see if there are differences between the existing
    # Maildir file and what was created by gpgit.pl
    diff -qa "$line" "/tmp/msg_$USERNAME" > /dev/null 2>&1;
    # shellcheck disable=SC2181
    if [ $? -gt 0 ]; then
        # Preserve timestamps, set ownership.
        chown "$USERNAME":"$USERNAME" "/tmp/msg_$USERNAME"
        chmod 600   "/tmp/msg_$USERNAME"
        touch   "/tmp/msg_$USERNAME" --reference="$line"

        # Unlink the original Maildir message
        unlink "$line"

        # Strip message sizes, retain experimental flags
        # and status flags, and copy the file over.
        STRIPSIZES=$(/bin/echo "$line"|/bin/sed -e "s/W=[[:digit:]]*//" -e "s/S=[[:digit:]]*//" -e "s/,,//" -e "s/,:2/:2/")
        cp -av "/tmp/msg_$USERNAME" "$STRIPSIZES"

        #Indexes must be rebuilt, weve modified Maildir.
        touch "/tmp/rebuild_index_$USERNAME"
    else
        echo $"Not copying, no differences between /tmp/msg_$USERNAME and $line"
    fi

    # Remove the temporary file
    unlink "/tmp/msg_$USERNAME"
done

# Remove Dovecot index and uids for regeneration.
if [ -f "/tmp/rebuild_index_$USERNAME" ]; then
    echo $"Removing Dovecot indexes and uids"
    find "$MAIL_DIR" -type f -regex '.*\(dovecot-\|dovecot\.\|\.uidvalidity\).*' -delete

    # Remove the temporary file
    unlink "/tmp/rebuild_index_$USERNAME"
else
    echo -n $"No messages found needing GPG encryption, not"
    echo $"removing Dovecot indexes and UIDs."
fi

exit 0