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