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Diffstat (limited to '.local/bin/paperbackup')
| -rwxr-xr-x | .local/bin/paperbackup | 165 |
1 files changed, 165 insertions, 0 deletions
diff --git a/.local/bin/paperbackup b/.local/bin/paperbackup new file mode 100755 index 0000000..4300241 --- /dev/null +++ b/.local/bin/paperbackup @@ -0,0 +1,165 @@ +#!/bin/sh -e + +# Copyright (c) 2021, la-ninpre +# +# Permission to use, copy, modify, and/or distribute this software for any +# purpose with or without fee is hereby granted, provided that the above +# copyright notice and this permission notice appear in all copies. +# +# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES +# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF +# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR +# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES +# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN +# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF +# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. +# +# ---------------------------------------------------------------------- # +# +# small script to backup secret gpg keys using paperkey and qrencode. +# +# basic usage: +# +# $ paperbackup -u user@email.com +# +# by default exports minimized public key and paperkeyed secret key +# to qr-encoded images, which then are combined into one image for +# easy printing. +# +# dependencies: +# - gpg (obviously) +# - paperkey +# - qrencode +# - imagemagick (optional, use -n to disable montage) + +usage() { + echo "usage: ${0##*/} [OPTIONS]" + echo + echo "options:" + echo " -u, --uid {UID}" + echo " gpg keyid or uid (this is mandatory)" + echo " -l, --level {L,M,Q,H}" + echo " qrencode correction level" + echo " -t, --term" + echo " output to terminal instead of png image" + echo " -n, --nomontage" + echo " disable composing qrcodes to one image" + echo " -h, --help" + echo " print usage information" + echo +} + +check_uid() { + [ -z "$1" ] && echo "uid could not be empty" && exit 1 + + if ! gpg -K "$1" >/dev/null + then + exit 1 + fi + + PB_UID="$1" +} + +check_corr_lvl() { + case "$1" in + l|L|m|M|q|Q|h|H) + PB_CORR_LVL="$1" + ;; + *) + echo "correction level should be one of L,M,Q,H" + usage + exit 1 + ;; + esac +} + +qr_encode() { + PB_QRENCODE_FLAGS="-8 -l $PB_CORR_LVL -t $PB_TYPE" + + case "$PB_TYPE" in + png) + PB_QRENCODE_FLAGS="$PB_QRENCODE_FLAGS -o $1" + ;; + UTF8) + ;; + *) + exit 1 + ;; + esac + + # i don't know if it is safe to do so, but it's very convenient + # shellcheck disable=SC2086 + qrencode $PB_QRENCODE_FLAGS +} + +get_pubkey() { + [ -n "$1" ] && gpg --export --export-options export-minimal "$1" \ + | qr_encode "$1-pubkey.png" +} + +get_seckey() { + [ -n "$1" ] && gpg --export-secret-key "$1" \ + | paperkey --output-type raw | qr_encode "$1-seckey.png" +} + +montage_keys() { + montage \ + -pointsize 18 \ + -title "\nsecret key backup for $PB_UID\n$PB_DATE" \ + -label pubkey "$PB_UID-pubkey.png" \ + -label seckey "$PB_UID-seckey.png" \ + -mode concatenate \ + "$PB_UID-keys.png" + + rm -f "$PB_UID-pubkey.png" "$PB_UID-seckey.png" +} + +main() { + PB_TYPE="png" + PB_CORR_LVL="H" + PB_DATE=$(date "+%F %T") + PB_MONTAGE=1 + + while [ -n "$1" ] + do + case "$1" in + --uid|-u) + shift + check_uid "$1" + ;; + --level|-l) + shift + check_corr_lvl "$1" + ;; + --term|-t) + PB_TYPE="UTF8" + ;; + --nomontage|-n) + PB_MONTAGE=0 + ;; + --help|-h) + echo "backup secret gpg key using paperkey and qrencode" + echo + usage + exit + ;; + *) + usage + exit 1 + ;; + esac + shift + done + + [ -z "$PB_UID" ] && echo "please specify uid or keyid" && exit 1; + + get_pubkey "$PB_UID" && get_seckey "$PB_UID" + + [ "$PB_TYPE" = "png" ] \ + && [ "$PB_MONTAGE" -eq 1 ] \ + && montage_keys + + exit 0 +} + +main "$@" |