Appends a PDF file to a PGP encrypted PDF file

append_to_encrypted_pdf

#!/bin/bash

# Felix E. Klee <felix.klee@inka.de>

set -e

# Usage info
show_help() {
    cat << EOF
Usage: ${0##*/} PGP_ENCRYPTED_PDF NEW_PDF PGP_ENCRYPTED_RESULT
Appends NEW_PDF to PGP_ENCRYPTED_PDF and saves it to PGP_ENCRYPTED_RESULT.
EOF
}

if [ "$#" -ne 3 ]; then
    show_help >&2
    exit 1
fi

PGP_ENCRYPTED_PDF="$1"
NEW_PDF="$2"
PGP_ENCRYPTED_RESULT="$3"
TEMP_PDF=$(mktemp -t XXXXXXXX.pdf)
gpg --batch --yes -o "$TEMP_PDF" -d "$PGP_ENCRYPTED_PDF"
qpdf "$TEMP_PDF" --replace-input --pages "$TEMP_PDF" "$NEW_PDF" --
gpg -e -r "$EMAIL" "$TEMP_PDF"
mv "$TEMP_PDF.gpg" "$PGP_ENCRYPTED_RESULT"