#!/bin/bash
#
#   pacman-key - manages pacman's keyring
#                Based on apt-key, from Debian
#   @configure_input@
#
#   Copyright (c) 2010-2016 Pacman Development Team <pacman-dev@archlinux.org>
#
#   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, see <http://www.gnu.org/licenses/>.
#

# gettext initialization
export TEXTDOMAIN='pacman-scripts'
export TEXTDOMAINDIR='@localedir@'

declare -r myver="@PACKAGE_VERSION@"

# Options
ADD=0
DELETE=0
EDITKEY=0
EXPORT=0
FINGER=0
IMPORT=0
IMPORT_TRUSTDB=0
INIT=0
KEYSERVER=''
LISTKEYS=0
LISTSIGS=0
LSIGNKEY=0
POPULATE=0
RECEIVE=0
REFRESH=0
UPDATEDB=0
USE_COLOR='y'
VERIFY=0

DEFAULT_KEYSERVER='hkp://pool.sks-keyservers.net'

m4_include(library/output_format.sh)

m4_include(library/parseopts.sh)

usage() {
	printf "pacman-key (pacman) %s\n" ${myver}
	echo
	printf -- "$(gettext "Usage: %s [options] operation [targets]")\n" $(basename $0)
	echo
	printf -- "$(gettext "Manage pacman's list of trusted keys")\n"
	echo
	printf -- "$(gettext "Operations:")\n"
	printf -- "$(gettext "  -a, --add                 Add the specified keys (empty for stdin)")\n"
	printf -- "$(gettext "  -d, --delete              Remove the specified keyids")\n"
	printf -- "$(gettext "  -e, --export              Export the specified or all keyids")\n"
	printf -- "$(gettext "  -f, --finger              List fingerprint for specified or all keyids")\n"
	printf -- "$(gettext "  -l, --list-keys           List the specified or all keys")\n"
	printf -- "$(gettext "  -r, --recv-keys           Fetch the specified keyids")\n"
	printf -- "$(gettext "  -u, --updatedb            Update the trustdb of pacman")\n"
	printf -- "$(gettext "  -v, --verify              Verify the file(s) specified by the signature(s)")\n"
	printf -- "$(gettext "  --edit-key                Present a menu for key management task on keyids")\n"
	printf -- "$(gettext "  --import                  Imports pubring.gpg from dir(s)")\n"
	printf -- "$(gettext "  --import-trustdb          Imports ownertrust values from trustdb.gpg in dir(s)")\n"
	printf -- "$(gettext "  --init                    Ensure the keyring is properly initialized")\n"
	printf -- "$(gettext "  --list-sigs               List keys and their signatures")\n"
	printf -- "$(gettext "  --lsign-key               Locally sign the specified keyid")\n"
	printf -- "$(gettext "  --populate                Reload the default keys from the (given) keyrings\n\
                            in '%s'")\n" "@pkgdatadir@/keyrings"
	printf -- "$(gettext "  --refresh-keys            Update specified or all keys from a keyserver")\n"
	echo
	printf -- "$(gettext "Options:")\n"
	printf -- "$(gettext "  --config <file>           Use an alternate config file (instead of\n\
                            '%s')")\n" "@sysconfdir@/pacman.conf"
	printf -- "$(gettext "  --gpgdir <dir>            Set an alternate directory for GnuPG (instead\n\
                            of '%s')")\n" "@sysconfdir@/pacman.d/gnupg"
	printf -- "$(gettext "  --keyserver <server-url>  Specify a keyserver to use if necessary")\n"
	echo
	printf -- "$(gettext "  -h, --help                Show this help message and exit")\n"
	printf -- "$(gettext "  -V, --version             Show program version")\n"
}

version() {
	printf "pacman-key (pacman) %s\n" "${myver}"
	printf -- "$(gettext "\
Copyright (c) 2010-2016 Pacman Development Team <pacman-dev@archlinux.org>.\n\
This is free software; see the source for copying conditions.\n\
There is NO WARRANTY, to the extent permitted by law.\n")"
}

# read the config file "$1" which has key=value pairs, and return the key which
# matches "$2". the equals sign between pairs may be surrounded by any amount
# of whitespace. Optionally, "$3" can be specified which is the default value
# when no key is found.
get_from() {
	while IFS='=' read -r key value; do
		[[ -z $key || ${key:0:1} = '#' ]] && continue

		if [[ ${key%% *} = "$2" && -n ${value##* } ]]; then
			echo "${value##* }"
			return 0
		fi
	done < "$1"
	if [[ -n "$3" ]]; then
		printf '%s\n' "$3"
		return 0
	fi
	return 1
}

key_lookup_from_name() {
	local ids

	mapfile -t ids < \
		<("${GPG_PACMAN[@]}" --search-keys --batch --with-colons "$1" 2>/dev/null |
			awk -F: '$1 == "pub" { print $2 }')

	# only return success on non-ambiguous lookup
	case ${#ids[*]} in
		0)
			error "$(gettext "Failed to lookup key by name:") %s" "$name"
			return 1
			;;
		1)
			printf '%s' "${ids[0]}"
			return 0
			;;
		*)
			error "$(gettext "Key name is ambiguous:") %s" "$name"
			return 1
			;;
	esac
}

generate_master_key() {
	# Generate the master key, which will be in both pubring and secring
	"${GPG_PACMAN[@]}" --gen-key --batch <<EOF
%echo Generating pacman keyring master key...
Key-Type: RSA
Key-Length: 2048
Key-Usage: sign
Name-Real: Pacman Keyring Master Key
Name-Email: pacman@localhost
Expire-Date: 0
%no-protection
%commit
%echo Done
EOF
}

secret_keys_available() {
	"${GPG_PACMAN[@]}" -K --with-colons | wc -l
}

# Adds the given gpg.conf option if it is not present in the file.
# Note that if we find it commented out, we won't add the option.
# args: $1 conffile, $2 option-name, $3 (optional) option-value
add_gpg_conf_option() {
	local conffile=$1; shift
	# looking for the option 'bare', only leading spaces or # chars allowed,
	# followed by at least one space and any other text or the end of line.
	if ! grep -q "^[[:space:]#]*$1\([[:space:]].*\)*$" "$conffile" &>/dev/null; then
		printf '%s\n' "$*" >> "$conffile"
	fi
}

check_keyids_exist() {
	local ret=0
	for key in "$@"; do
		# Verify if the key exists in pacman's keyring
		if ! "${GPG_PACMAN[@]}" --list-keys "$key" &>/dev/null ; then
			error "$(gettext "The key identified by %s could not be found locally.")" "$key"
			ret=1
		fi
	done
	if (( ret )); then
		exit 1
	fi
}

initialize() {
	local conffile keyserv
	# Check for simple existence rather than for a directory as someone
	# may want to use a symlink here
	[[ -e ${PACMAN_KEYRING_DIR} ]] || mkdir -p -m 755 "${PACMAN_KEYRING_DIR}"

	# keyring files
	[[ -f ${PACMAN_KEYRING_DIR}/pubring.gpg ]] || touch ${PACMAN_KEYRING_DIR}/pubring.gpg
	[[ -f ${PACMAN_KEYRING_DIR}/secring.gpg ]] || touch ${PACMAN_KEYRING_DIR}/secring.gpg
	[[ -f ${PACMAN_KEYRING_DIR}/trustdb.gpg ]] || "${GPG_PACMAN[@]}" --update-trustdb
	chmod 644 ${PACMAN_KEYRING_DIR}/{pubring,trustdb}.gpg
	chmod 600 ${PACMAN_KEYRING_DIR}/secring.gpg

	# gpg.conf
	conffile="${PACMAN_KEYRING_DIR}/gpg.conf"
	[[ -f $conffile ]] || touch "$conffile"
	chmod 644 "$conffile"
	add_gpg_conf_option "$conffile" 'no-greeting'
	add_gpg_conf_option "$conffile" 'no-permission-warning'
	add_gpg_conf_option "$conffile" 'lock-never'
	keyserv=${KEYSERVER:-$DEFAULT_KEYSERVER}
	add_gpg_conf_option "$conffile" 'keyserver' "$keyserv"
	add_gpg_conf_option "$conffile" 'keyserver-options' 'timeout=10'

	# set up a private signing key (if none available)
	if [[ $(secret_keys_available) -lt 1 ]]; then
		generate_master_key
		UPDATEDB=1
	fi
}

check_keyring() {
	if [[ ! -r ${PACMAN_KEYRING_DIR}/pubring.gpg || \
			! -r ${PACMAN_KEYRING_DIR}/trustdb.gpg ]]; then
		error "$(gettext "You do not have sufficient permissions to read the %s keyring.")" "pacman"
		msg "$(gettext "Use '%s' to correct the keyring permissions.")" "pacman-key --init"
		exit 1
	fi

	if (( (EXPORT || FINGER || LIST || VERIFY) && EUID != 0 )); then
		if ! grep -q "^[[:space:]]*lock-never[[:space:]]*$" ${PACMAN_KEYRING_DIR}/gpg.conf &>/dev/null; then
			error "$(gettext "You do not have sufficient permissions to run this command.")"
			msg "$(gettext "Use '%s' to correct the keyring permissions.")" "pacman-key --init"
			exit 1
		fi
	fi

	if (( LSIGNKEY )); then
		if [[ $(secret_keys_available) -lt 1 ]]; then
			error "$(gettext "There is no secret key available to sign with.")"
			msg "$(gettext "Use '%s' to generate a default secret key.")" "pacman-key --init"
			exit 1
		fi
	fi
}

populate_keyring() {
	local KEYRING_IMPORT_DIR='@pkgdatadir@/keyrings'

	local keyring KEYRINGIDS=("$@")
	local ret=0
	if (( ${#KEYRINGIDS[*]} == 0 )); then
		# get list of all available keyrings
		shopt -s nullglob
		KEYRINGIDS=("$KEYRING_IMPORT_DIR"/*.gpg)
		shopt -u nullglob
		KEYRINGIDS=("${KEYRINGIDS[@]##*/}")
		KEYRINGIDS=("${KEYRINGIDS[@]%.gpg}")
		if (( ${#KEYRINGIDS[*]} == 0 )); then
			error "$(gettext "No keyring files exist in %s.")" "$KEYRING_IMPORT_DIR"
			ret=1
		fi
	else
		# verify listed keyrings exist
		for keyring in "${KEYRINGIDS[@]}"; do
			if [[ ! -f "$KEYRING_IMPORT_DIR/$keyring.gpg" ]]; then
				error "$(gettext "The keyring file %s does not exist.")" "$KEYRING_IMPORT_DIR/$keyring.gpg"
				ret=1
			fi
		done
	fi

	if (( ret )); then
		exit 1
	fi

	# Variable used for iterating on keyrings
	local keys key_id

	# Add keys from requested keyrings
	for keyring in "${KEYRINGIDS[@]}"; do
		msg "$(gettext "Appending keys from %s.gpg...")" "$keyring"
		"${GPG_PACMAN[@]}" --quiet --import "${KEYRING_IMPORT_DIR}/${keyring}.gpg"
	done

	# Read the trusted key IDs to an array. Because this is an ownertrust
	# file, we know we have the full 40 hex digit fingerprint values.
	# Format of ownertrust dump file:
	#  40CHARFINGERPRINTXXXXXXXXXXXXXXXXXXXXXXX:6:
	#  40CHARFINGERPRINTXXXXXXXXXXXXXXXXXXXXXXX:5:
	local -A trusted_ids
	for keyring in "${KEYRINGIDS[@]}"; do
		if [[ -s "${KEYRING_IMPORT_DIR}/${keyring}-trusted" ]]; then
			while IFS=: read key_id _; do
				# skip blank lines, comments; these are valid in this file
				[[ -z $key_id || ${key_id:0:1} = \# ]] && continue

				# Mark this key to be lsigned
				trusted_ids[$key_id]=$keyring
			done < "${KEYRING_IMPORT_DIR}/${keyring}-trusted"
		fi
	done

	if (( ${#trusted_ids[@]} > 0 )); then
		msg "$(gettext "Locally signing trusted keys in keyring...")"
		lsign_keys "${!trusted_ids[@]}"
		msg "$(gettext "Importing owner trust values...")"
		for keyring in "${KEYRINGIDS[@]}"; do
			if [[ -s "${KEYRING_IMPORT_DIR}/${keyring}-trusted" ]]; then
				"${GPG_PACMAN[@]}" --import-ownertrust "${KEYRING_IMPORT_DIR}/${keyring}-trusted"
			fi
		done
	fi

	local -A revoked_ids
	for keyring in "${KEYRINGIDS[@]}"; do
		if [[ -s $KEYRING_IMPORT_DIR/$keyring-revoked ]]; then
			while read -r key_id; do
				revoked_ids["$key_id"]=1
			done <"$KEYRING_IMPORT_DIR/$keyring-revoked"
		fi
	done

	if (( ${#revoked_ids[@]} > 0 )); then
		msg "$(gettext "Disabling revoked keys in keyring...")"
		for key_id in "${!revoked_ids[@]}"; do
			msg2 "$(gettext "Disabling key %s...")" "${key_id}"
			printf 'disable\nquit\n' | LANG=C "${GPG_PACMAN[@]}" --command-fd 0 --quiet --batch --edit-key "${key_id}" 2>/dev/null
		done
	fi
}

add_keys() {
	if ! "${GPG_PACMAN[@]}" --quiet --batch --import "$@" ; then
		error "$(gettext "A specified keyfile could not be added to the keyring.")"
		exit 1
	fi
}

delete_keys() {
	check_keyids_exist "$@"
	if ! "${GPG_PACMAN[@]}" --quiet --batch --delete-key --yes "$@" ; then
		error "$(gettext "A specified key could not be removed from the keyring.")"
		exit 1
	fi
}

edit_keys() {
	check_keyids_exist "$@"
	local ret=0
	for key in "$@"; do
		if ! "${GPG_PACMAN[@]}" --edit-key "$key" ; then
			error "$(gettext "The key identified by %s could not be edited.")" "$key"
			ret=1
		fi
	done
	if (( ret )); then
		exit 1
	fi
}

export_keys() {
	check_keyids_exist "$@"
	if ! "${GPG_PACMAN[@]}" --armor --export "$@" ; then
		error "$(gettext "A specified key could not be exported from the keyring.")"
		exit 1
	fi
}

finger_keys() {
	check_keyids_exist
	if ! "${GPG_PACMAN[@]}" --batch --fingerprint "$@" ; then
		error "$(gettext "The fingerprint of a specified key could not be determined.")"
		exit 1
	fi
}

import_trustdb() {
	local importdir
	local ret=0
	for importdir in "$@"; do
		if [[ -f "${importdir}/trustdb.gpg" ]]; then
			gpg --homedir "${importdir}" --export-ownertrust | \
				"${GPG_PACMAN[@]}" --import-ownertrust -
			if (( PIPESTATUS )); then
				error "$(gettext "%s could not be imported.")" "${importdir}/trustdb.gpg"
				ret=1
			fi
		else
			error "$(gettext "File %s does not exist and could not be imported.")" "${importdir}/trustdb.gpg"
			ret=1
		fi
	done
	if (( ret )); then
		exit 1
	fi
}

import() {
	local importdir
	local ret=0
	for importdir in "$@"; do
		if [[ -f "${importdir}/pubring.gpg" ]]; then
			if ! "${GPG_PACMAN[@]}" --quiet --batch --import "${importdir}/pubring.gpg" ; then
				error "$(gettext "%s could not be imported.")" "${importdir}/pubring.gpg"
				ret=1
			fi
		else
			error "$(gettext "File %s does not exist and could not be imported.")" "${importdir}/pubring.gpg"
			ret=1
		fi
	done
	if (( ret )); then
		exit 1
	fi
}

list_keys() {
	check_keyids_exist
	if ! "${GPG_PACMAN[@]}" --batch --list-keys "$@" ; then
		error "$(gettext "A specified key could not be listed.")"
		exit 1
	fi
}

list_sigs() {
	check_keyids_exist
	if ! "${GPG_PACMAN[@]}" --batch --list-sigs "$@" ; then
		error "$(gettext "A specified signature could not be listed.")"
		exit 1
	fi
}

lsign_keys() {
	check_keyids_exist

	local ret=0
	for key_id in "$@"; do
		msg2 "$(gettext "Locally signing key %s...")" "${key_id}"
		# we cannot use --yes here as gpg would still ask for confirmation if a key has more than one uid
		printf 'y\ny\n' | LANG=C "${GPG_PACMAN[@]}" --command-fd 0 --quiet --batch --lsign-key "${key_id}" 2>/dev/null
		if (( PIPESTATUS[1] )); then
			error "$(gettext "%s could not be locally signed.")" "${key_id}"
			ret=1
		fi
	done

	if (( ret )); then
		exit 1
	fi
}

receive_keys() {
	local name id keyids

	# if the key is not a hex ID, do a lookup
	for name; do
		if [[ $name = ?(0x)+([0-9a-fA-F]) ]]; then
			keyids+=("$name")
		else
			if id=$(key_lookup_from_name "$name"); then
				keyids+=("$id")
			fi
		fi
	done

	(( ${#keyids[*]} > 0 )) || exit 1

	if ! "${GPG_PACMAN[@]}" --recv-keys "${keyids[@]}" ; then
		error "$(gettext "Remote key not fetched correctly from keyserver.")"
		exit 1
	fi
}

refresh_keys() {
	check_keyids_exist "$@"
	if ! "${GPG_PACMAN[@]}" --refresh-keys "$@" ; then
		error "$(gettext "A specified local key could not be updated from a keyserver.")"
		exit 1
	fi
}

verify_sig() {
	local ret=0
	for sig; do
		msg "Checking %s..." "$sig"
		if grep -q 'BEGIN PGP SIGNATURE' "$sig"; then
			error "$(gettext "Cannot use armored signatures for packages: %s")" "$sig"
			return 1
		fi
		if ! "${GPG_PACMAN[@]}" --status-fd 1 --verify "$sig" | grep -qE '^\[GNUPG:\] TRUST_(FULLY|ULTIMATE).*$'; then
			error "$(gettext "The signature identified by %s could not be verified.")" "$sig"
			ret=1
		fi
	done
	exit $ret
}

updatedb() {
	msg "$(gettext "Updating trust database...")"
	if ! "${GPG_PACMAN[@]}" --batch --check-trustdb ; then
		error "$(gettext "Trust database could not be updated.")"
		exit 1
	fi
}

# PROGRAM START
if ! type gettext &>/dev/null; then
	gettext() {
		echo "$@"
	}
fi

OPT_SHORT="adefhlruvV"
OPT_LONG=('add' 'config:' 'delete' 'edit-key' 'export' 'finger' 'gpgdir:'
          'help' 'import' 'import-trustdb' 'init' 'keyserver:' 'list-keys' 'list-sigs'
          'lsign-key' 'nocolor' 'populate' 'recv-keys' 'refresh-keys' 'updatedb'
          'verify' 'version')
if ! parseopts "$OPT_SHORT" "${OPT_LONG[@]}" -- "$@"; then
	exit 1 # E_INVALID_OPTION;
fi
set -- "${OPTRET[@]}"
unset OPT_SHORT OPT_LONG OPTRET

if [[ $1 == "--" ]]; then
	usage;
	exit 0;
fi

while (( $# )); do
	case $1 in
		-a|--add)         ADD=1 UPDATEDB=1 ;;
		--config)         shift; CONFIG=$1 ;;
		-d|--delete)      DELETE=1 UPDATEDB=1 ;;
		--edit-key)       EDITKEY=1 UPDATEDB=1 ;;
		-e|--export)      EXPORT=1 ;;
		-f|--finger)      FINGER=1 ;;
		--gpgdir)         shift; PACMAN_KEYRING_DIR=$1 ;;
		--import)         IMPORT=1 UPDATEDB=1 ;;
		--import-trustdb) IMPORT_TRUSTDB=1 UPDATEDB=1 ;;
		--init)           INIT=1 ;;
		--keyserver)      shift; KEYSERVER=$1 ;;
		-l|--list-keys)   LISTKEYS=1 ;;
		--list-sigs)      LISTSIGS=1 ;;
		--lsign-key)      LSIGNKEY=1 UPDATEDB=1 ;;
		--nocolor)        USE_COLOR='n';;
		--populate)       POPULATE=1 UPDATEDB=1 ;;
		-r|--recv-keys)   RECEIVE=1 UPDATEDB=1 ;;
		--refresh-keys)   REFRESH=1 ;;
		-u|--updatedb)    UPDATEDB=1 ;;
		-v|--verify)      VERIFY=1 ;;

		-h|--help)        usage; exit 0 ;;
		-V|--version)     version; exit 0 ;;

		--)               shift; break 2 ;;
	esac
	shift
done

m4_include(library/term_colors.sh)

if ! type -p gpg >/dev/null; then
	error "$(gettext "Cannot find the %s binary required for all %s operations.")" "gpg" "pacman-key"
	exit 1
fi

if (( (ADD || DELETE || EDITKEY || IMPORT || IMPORT_TRUSTDB || INIT || LSIGNKEY || POPULATE || RECEIVE || REFRESH || UPDATEDB) && EUID != 0 )); then
	error "$(gettext "%s needs to be run as root for this operation.")" "pacman-key"
	exit 1
fi

CONFIG=${CONFIG:-@sysconfdir@/pacman.conf}
if [[ ! -r "${CONFIG}" ]]; then
	error "$(gettext "%s configuration file '%s' not found.")" "pacman" "$CONFIG"
	exit 1
fi

# if PACMAN_KEYRING_DIR isn't assigned, try to get it from the config
# file, falling back on a hard default
PACMAN_KEYRING_DIR=${PACMAN_KEYRING_DIR:-$(get_from "$CONFIG" "GPGDir" "@sysconfdir@/pacman.d/gnupg")}

GPG_PACMAN=(gpg --homedir "${PACMAN_KEYRING_DIR}" --no-permission-warning)
if [[ -n ${KEYSERVER} ]]; then
	GPG_PACMAN+=(--keyserver "${KEYSERVER}")
fi

# check only a single operation has been given
# don't include UPDATEDB in here as other opts can induce it
numopt=$(( ADD + DELETE + EDITKEY + EXPORT + FINGER + IMPORT + IMPORT_TRUSTDB +
		INIT + LISTKEYS + LISTSIGS + LSIGNKEY + POPULATE + RECEIVE + REFRESH + VERIFY ))

case $numopt in
	0)
		if (( ! UPDATEDB )); then
			error "$(gettext "no operation specified (use -h for help)")"
			exit 1
		fi
		;;
	[!1])
		error "$(gettext "Multiple operations specified.")"
		msg "$(gettext "Please run %s with each operation separately.")" "pacman-key"
		exit 1
		;;
esac

# check for targets where needed
if (( (ADD || DELETE || EDIT || IMPORT || IMPORT_TRUSTDB ||
		LSIGNKEY || RECEIVE || VERIFY) && $# == 0 )); then
	error "$(gettext "No targets specified")"
	exit 1
fi

(( ! INIT )) && check_keyring

(( ADD )) && add_keys "$@"
(( DELETE )) && delete_keys "$@"
(( EDITKEY )) && edit_keys "$@"
(( EXPORT )) && export_keys "$@"
(( FINGER )) && finger_keys "$@"
(( IMPORT )) && import "$@"
(( IMPORT_TRUSTDB)) && import_trustdb "$@"
(( INIT )) && initialize
(( LISTKEYS )) && list_keys "$@"
(( LISTSIGS )) && list_sigs "$@"
(( LSIGNKEY )) && lsign_keys "$@"
(( POPULATE )) && populate_keyring "$@"
(( RECEIVE )) && receive_keys "$@"
(( REFRESH )) && refresh_keys "$@"
(( VERIFY )) && verify_sig "$@"

(( UPDATEDB )) && updatedb

exit 0

# vim: set noet: