From 69556d143544a72f84e9daf25924e3ae5132ce1a Mon Sep 17 00:00:00 2001
From: Sergio Correia <scorreia@redhat.com>
Date: Sat, 30 Nov 2019 14:58:43 -0500
Subject: [PATCH] Add the option to extract luks passphrase used for binding
Usage:
clevis luks pass -d /dev/sda1 -s 1
<passphrase here>
---
src/luks/clevis-luks-pass | 69 +++++++++++++++++++++++++++++
src/luks/clevis-luks-pass.1.adoc | 43 ++++++++++++++++++
src/luks/meson.build | 3 ++
src/luks/tests/meson.build | 11 +++++
src/luks/tests/pass-tang-luks1 | 75 ++++++++++++++++++++++++++++++++
src/luks/tests/pass-tang-luks2 | 75 ++++++++++++++++++++++++++++++++
6 files changed, 276 insertions(+)
create mode 100755 src/luks/clevis-luks-pass
create mode 100644 src/luks/clevis-luks-pass.1.adoc
create mode 100755 src/luks/tests/pass-tang-luks1
create mode 100755 src/luks/tests/pass-tang-luks2
diff --git a/src/luks/clevis-luks-pass b/src/luks/clevis-luks-pass
new file mode 100755
index 0000000..1ce8c4c
--- /dev/null
+++ b/src/luks/clevis-luks-pass
@@ -0,0 +1,69 @@
+#!/bin/bash -e
+# vim: set tabstop=8 shiftwidth=4 softtabstop=4 expandtab smarttab colorcolumn=80:
+#
+# Copyright (c) 2019 Red Hat, Inc.
+# Author: Sergio Correia <scorreia@redhat.com> - LUKS2 support.
+#
+# 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 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 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/>.
+#
+
+. clevis-luks-common-functions
+
+SUMMARY="Returns the LUKS passphrase used for binding a particular slot."
+
+function usage() {
+ echo >&2
+ echo "Usage: clevis luks pass -d DEV -s SLT" >&2
+ echo >&2
+ echo "$SUMMARY": >&2
+ echo >&2
+ echo " -d DEV The LUKS device to extract the LUKS passphrase used for binding" >&2
+ echo >&2
+ echo " -s SLOT The slot number to extract the LUKS passphrase" >&2
+ echo >&2
+ exit 1
+}
+
+if [ ${#} -eq 1 ] && [ "${1}" = "--summary" ]; then
+ echo "${SUMMARY}"
+ exit 0
+fi
+
+while getopts ":d:s:" o; do
+ case "$o" in
+ d) DEV=${OPTARG};;
+ s) SLT=${OPTARG};;
+ *) usage;;
+ esac
+done
+
+if [ -z "${DEV}" ]; then
+ echo "Did not specify a device!" >&2
+ usage
+fi
+
+if [ -z "${SLT}" ]; then
+ echo "Did not specify a slot!" >&2
+ usage
+fi
+
+if ! jwe=$(clevis_luks_read_slot "${DEV}" "${SLT}" 2>/dev/null); then
+ echo "It was not possible to read slot ${SLT} from ${DEV}!" >&2
+ exit 1
+fi
+
+if ! clevis decrypt < <(echo -n "${jwe}"); then
+ echo "It was not possible to decrypt the passphrase associated to slot ${SLT} in {DEV}!" >&2
+ exit 1
+fi
diff --git a/src/luks/clevis-luks-pass.1.adoc b/src/luks/clevis-luks-pass.1.adoc
new file mode 100644
index 0000000..fa9526a
--- /dev/null
+++ b/src/luks/clevis-luks-pass.1.adoc
@@ -0,0 +1,43 @@
+CLEVIS-LUKS-PASS(1)
+===================
+:doctype: manpage
+
+
+== NAME
+
+clevis-luks-pass - Extracts the passphrase used for binding a particular slot in a LUKS device
+
+== SYNOPSIS
+
+*clevis luks pass* -d DEV -s SLT
+
+== OVERVIEW
+
+The *clevis luks pass* command extracts the passphrase used for binding a particular slot in a LUKS device.
+For example:
+
+ clevis luks pass -d /dev/sda1 -s 1
+
+== OPTIONS
+
+* *-d* _DEV_ :
+ The LUKS device on which to extract a passphrase from
+
+* *-s* _SLT_ :
+ The slot to use for extracting the passphrase
+
+== EXAMPLE
+
+ clevis luks pass -d /dev/sda1 -s 1
+ <passphrase here>
+
+Note that the output of *clevis luks pass* might be non-printable, in which case it would be better to redirect its output to a file and use it as a key
+file together with cryptsetup. For instance:
+
+ clevis luks pass -d /dev/sda1 -s 1 > slot1-passphrase
+
+And the file slot1-passphrase will contain the passphrase associated with slot #1 in /dev/sda1.
+
+== SEE ALSO
+
+link:clevis-luks-unlock.1.adoc[*clevis-luks-unlock*(1)],
diff --git a/src/luks/meson.build b/src/luks/meson.build
index 51d82fb..b2dd724 100644
--- a/src/luks/meson.build
+++ b/src/luks/meson.build
@@ -23,6 +23,9 @@ if libcryptsetup.found() and luksmeta.found() and pwmake.found()
bins += join_paths(meson.current_source_dir(), 'clevis-luks-list')
mans += join_paths(meson.current_source_dir(), 'clevis-luks-list.1')
+ bins += join_paths(meson.current_source_dir(), 'clevis-luks-pass')
+ mans += join_paths(meson.current_source_dir(), 'clevis-luks-pass.1')
+
bins += join_paths(meson.current_source_dir(), 'clevis-luks-report')
bins += join_paths(meson.current_source_dir(), 'clevis-luks-report-compare')
bins += join_paths(meson.current_source_dir(), 'clevis-luks-report-decode')
diff --git a/src/luks/tests/meson.build b/src/luks/tests/meson.build
index 6513eaa..248d2ea 100644
--- a/src/luks/tests/meson.build
+++ b/src/luks/tests/meson.build
@@ -1,3 +1,9 @@
+actv = find_program(
+ 'systemd-socket-activate',
+ 'systemd-activate',
+ required: false
+)
+
# We use jq for comparing the pin config in the clevis luks list tests.
jq = find_program('jq', required: false)
@@ -15,8 +21,11 @@ env.prepend('PATH',
join_paths(meson.build_root(), 'src', 'pins', 'sss'),
join_paths(meson.build_root(), 'src', 'pins', 'tang'),
join_paths(meson.build_root(), 'src', 'pins', 'tpm2'),
+ libexecdir,
+ '/usr/libexec',
separator: ':'
)
+env.set('SD_ACTIVATE', actv.path())
if jq.found()
test('list-recursive-luks1', find_program('list-recursive-luks1'), env: env)
@@ -25,6 +34,7 @@ if jq.found()
else
warning('Will not run "clevis luks list" tests due to missing jq dependency')
endif
+test('pass-tang-luks1', find_program('pass-tang-luks1'), env: env)
# LUKS2 tests go here, and they get included if we get support for it, based
# on the cryptsetup version.
@@ -34,3 +44,4 @@ if jq.found()
test('list-tang-luks2', find_program('list-tang-luks2'), env: env, timeout: 60)
test('list-sss-tang-luks2', find_program('list-sss-tang-luks2'), env: env, timeout: 60)
endif
+test('pass-tang-luks2', find_program('pass-tang-luks2'), env: env, timeout: 60)
diff --git a/src/luks/tests/pass-tang-luks1 b/src/luks/tests/pass-tang-luks1
new file mode 100755
index 0000000..05cdb3e
--- /dev/null
+++ b/src/luks/tests/pass-tang-luks1
@@ -0,0 +1,75 @@
+#!/bin/bash -x
+# vim: set tabstop=8 shiftwidth=4 softtabstop=4 expandtab smarttab colorcolumn=80:
+#
+# Copyright (c) 2019 Red Hat, Inc.
+# Author: Sergio Correia <scorreia@redhat.com>
+#
+# 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 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 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/>.
+#
+
+TEST="${0}"
+. tests-common-functions
+
+function on_exit() {
+ if [ "$PID" ]; then kill $PID; wait $PID || true; fi
+ [ -d "$TMP" ] && rm -rf $TMP
+}
+
+trap 'on_exit' EXIT
+trap 'exit' ERR
+
+export TMP=$(mktemp -d)
+mkdir -p "${TMP}/db"
+
+# Generate the server keys
+KEYS="$TMP/db"
+tangd-keygen $TMP/db sig exc
+if which tangd-update; then
+ mkdir -p "${TMP}/cache"
+ tangd-update "${TMP}/db" "${TMP}/cache"
+ KEYS="${TMP}/cache"
+fi
+
+# Start the server.
+port=$(shuf -i 1024-65536 -n 1)
+"${SD_ACTIVATE}" --inetd -l 127.0.0.1:"${port}" -a tangd "${KEYS}" &
+export PID=$!
+sleep 0.25
+
+url="http://localhost:${port}"
+adv="${TMP}/adv"
+curl "${url}/adv" -o "${adv}"
+
+cfg=$(printf '{"url":"%s","adv":"%s"}' "$url" "$adv")
+
+# LUKS1.
+DEV="${TMP}/luks1-device"
+new_device "luks1" "${DEV}"
+
+if ! clevis luks bind -f -d "${DEV}" tang "${cfg}" <<< "${DEFAULT_PASS}"; then
+ error "${TEST}: Bind should have succeeded."
+fi
+
+#Now let's test the passphrase.
+SLT=1
+PASS=$(clevis luks pass -d "${DEV}" -s "${SLT}")
+echo $PASS >&2
+if ! cryptsetup luksOpen --test-passphrase ""${DEV} \
+ --key-file <(clevis luks pass -d "${DEV}" -s "${SLT}"); then
+ error "Passphrase obtained from clevis luks pass failed."
+fi
+
+kill -9 "${PID}"
+! wait "${PID}"
+unset PID
diff --git a/src/luks/tests/pass-tang-luks2 b/src/luks/tests/pass-tang-luks2
new file mode 100755
index 0000000..9123aa0
--- /dev/null
+++ b/src/luks/tests/pass-tang-luks2
@@ -0,0 +1,75 @@
+#!/bin/bash -x
+# vim: set tabstop=8 shiftwidth=4 softtabstop=4 expandtab smarttab colorcolumn=80:
+#
+# Copyright (c) 2019 Red Hat, Inc.
+# Author: Sergio Correia <scorreia@redhat.com>
+#
+# 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 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 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/>.
+#
+
+TEST="${0}"
+. tests-common-functions
+
+function on_exit() {
+ if [ "$PID" ]; then kill $PID; wait $PID || true; fi
+ [ -d "$TMP" ] && rm -rf $TMP
+}
+
+trap 'on_exit' EXIT
+trap 'exit' ERR
+
+export TMP=$(mktemp -d)
+mkdir -p "${TMP}/db"
+
+# Generate the server keys
+KEYS="$TMP/db"
+tangd-keygen $TMP/db sig exc
+if which tangd-update; then
+ mkdir -p "${TMP}/cache"
+ tangd-update "${TMP}/db" "${TMP}/cache"
+ KEYS="${TMP}/cache"
+fi
+
+# Start the server.
+port=$(shuf -i 1024-65536 -n 1)
+"${SD_ACTIVATE}" --inetd -l 127.0.0.1:"${port}" -a tangd "${KEYS}" &
+export PID=$!
+sleep 0.25
+
+url="http://localhost:${port}"
+adv="${TMP}/adv"
+curl "${url}/adv" -o "${adv}"
+
+cfg=$(printf '{"url":"%s","adv":"%s"}' "$url" "$adv")
+
+# LUKS2.
+DEV="${TMP}/luks2-device"
+new_device "luks2" "${DEV}"
+
+if ! clevis luks bind -f -d "${DEV}" tang "${cfg}" <<< "${DEFAULT_PASS}"; then
+ error "${TEST}: Bind should have succeeded."
+fi
+
+#Now let's test the passphrase.
+SLT=1
+PASS=$(clevis luks pass -d "${DEV}" -s "${SLT}")
+echo $PASS >&2
+if ! cryptsetup luksOpen --test-passphrase ""${DEV} \
+ --key-file <(clevis luks pass -d "${DEV}" -s "${SLT}"); then
+ error "Passphrase obtained from clevis luks pass failed."
+fi
+
+kill -9 "${PID}"
+! wait "${PID}"
+unset PID
--
2.18.1