From c18dcfaa0b91eb48006232fbfadce9e6a9b4a790 Mon Sep 17 00:00:00 2001

From: Ondrej Kozina <okozina@redhat.com>

Date: Fri, 2 Dec 2022 15:39:36 +0100

Subject: [PATCH 2/2] Abort encryption when header and data devices are same.

If data device reduction is not requsted this led

to data corruption since LUKS metadata was written

over the data device.

---

 src/utils_reencrypt.c          | 42 ++++++++++++++++++++++++++++++----

 tests/luks2-reencryption-test  | 16 +++++++++++++

 tests/reencryption-compat-test | 20 +++++++++++++---

 3 files changed, 70 insertions(+), 8 deletions(-)

diff --git a/src/utils_reencrypt.c b/src/utils_reencrypt.c

index 87ead680..73e0bca8 100644

--- a/src/utils_reencrypt.c

+++ b/src/utils_reencrypt.c

@@ -467,6 +467,26 @@ static int reencrypt_check_active_device_sb_block_size(const char *active_device

 	return reencrypt_check_data_sb_block_size(dm_device, new_sector_size);

 }

+static int reencrypt_is_header_detached(const char *header_device, const char *data_device)

+{

+	int r;

+	struct stat st;

+	struct crypt_device *cd;

+

+	if (!header_device)

+		return 0;

+

+	if (header_device && stat(header_device, &st) < 0 && errno == ENOENT)

+		return 1;

+

+	if ((r = crypt_init_data_device(&cd, header_device, data_device)))

+		return r;

+

+	r = crypt_header_is_detached(cd);

+	crypt_free(cd);

+	return r;

+}

+

 static int encrypt_luks2_init(struct crypt_device **cd, const char *data_device, const char *device_name)

 {

 	int keyslot, r, fd;

@@ -490,9 +510,14 @@ static int encrypt_luks2_init(struct crypt_device **cd, const char *data_device,

 	_set_reencryption_flags(&params.flags);

-	if (!data_shift && !ARG_SET(OPT_HEADER_ID)) {

-		log_err(_("Encryption without detached header (--header) is not possible without data device size reduction (--reduce-device-size)."));

-		return -ENOTSUP;

+	if (!data_shift) {

+		r = reencrypt_is_header_detached(ARG_STR(OPT_HEADER_ID), data_device);

+		if (r < 0)

+			return r;

+		if (!r) {

+			log_err(_("Encryption without detached header (--header) is not possible without data device size reduction (--reduce-device-size)."));

+			return -ENOTSUP;

+		}

 	}

 	if (!ARG_SET(OPT_HEADER_ID) && ARG_UINT64(OPT_OFFSET_ID) &&

@@ -1358,9 +1383,16 @@ static int _encrypt(struct crypt_device *cd, const char *type, enum device_statu

 	if (!type)

 		type = crypt_get_default_type();

-	if (dev_st == DEVICE_LUKS1_UNUSABLE || isLUKS1(type))

+	if (dev_st == DEVICE_LUKS1_UNUSABLE || isLUKS1(type)) {

+		r = reencrypt_is_header_detached(ARG_STR(OPT_HEADER_ID), action_argv[0]);

+		if (r < 0)

+			return r;

+		if (!r && !ARG_SET(OPT_REDUCE_DEVICE_SIZE_ID)) {

+			log_err(_("Encryption without detached header (--header) is not possible without data device size reduction (--reduce-device-size)."));

+			return -ENOTSUP;

+		}

 		return reencrypt_luks1(action_argv[0]);

-	else if (dev_st == DEVICE_NOT_LUKS) {

+	} else if (dev_st == DEVICE_NOT_LUKS) {

 		r = encrypt_luks2_init(&encrypt_cd, action_argv[0], action_argc > 1 ? action_argv[1] : NULL);

 		if (r < 0 || ARG_SET(OPT_INIT_ONLY_ID)) {

 			crypt_free(encrypt_cd);

diff --git a/tests/luks2-reencryption-test b/tests/luks2-reencryption-test

index bab54353..a647a8c2 100755

--- a/tests/luks2-reencryption-test

+++ b/tests/luks2-reencryption-test

@@ -1080,6 +1080,22 @@ $CRYPTSETUP status $DEV_NAME >/dev/null 2>&1 || fail

 $CRYPTSETUP close $DEV_NAME

 echo $PWD1 | $CRYPTSETUP open --header $IMG_HDR $DEV --test-passphrase || fail

+# Encrypt without size reduction must not allow header device same as data device

+wipe_dev_head $DEV 1

+echo $PWD1 | $CRYPTSETUP reencrypt $DEV --type luks2 --encrypt --header $DEV -q $FAST_PBKDF_ARGON 2>/dev/null && fail

+$CRYPTSETUP isLUKS $DEV 2>/dev/null && fail

+ln -s $DEV $DEV_LINK || fail

+echo $PWD1 | $CRYPTSETUP reencrypt $DEV --type luks2 --encrypt --header $DEV_LINK -q $FAST_PBKDF_ARGON 2>/dev/null && fail

+$CRYPTSETUP isLUKS $DEV 2>/dev/null && fail

+rm -f $DEV_LINK || fail

+

+dd if=/dev/zero of=$IMG bs=4k count=1 >/dev/null 2>&1

+echo $PWD1 | $CRYPTSETUP reencrypt $IMG --type luks2 --encrypt --header $IMG -q $FAST_PBKDF_ARGON 2>/dev/null && fail

+$CRYPTSETUP isLUKS $IMG 2>/dev/null && fail

+ln -s $IMG $DEV_LINK || fail

+echo $PWD1 | $CRYPTSETUP reencrypt $IMG --type luks2 --encrypt --header $DEV_LINK -q $FAST_PBKDF_ARGON 2>/dev/null && fail

+$CRYPTSETUP isLUKS $IMG 2>/dev/null && fail

+

 echo "[4] Reencryption with detached header"

 wipe $PWD1 $IMG_HDR

 echo $PWD1 | $CRYPTSETUP reencrypt -c aes-cbc-essiv:sha256 -s 128 --header $IMG_HDR -q $FAST_PBKDF_ARGON $DEV || fail

diff --git a/tests/reencryption-compat-test b/tests/reencryption-compat-test

index f6a84137..453831d1 100755

--- a/tests/reencryption-compat-test

+++ b/tests/reencryption-compat-test

@@ -15,6 +15,7 @@ IMG=reenc-data

 IMG_HDR=$IMG.hdr

 HEADER_LUKS2_PV=blkid-luks2-pv.img

 ORIG_IMG=reenc-data-orig

+DEV_LINK="reenc-test-link"

 KEY1=key1

 PWD1="93R4P4pIqAH8"

 PWD2="1cND4319812f"

@@ -40,7 +41,7 @@ function remove_mapping()

 	[ -b /dev/mapper/$DEV_NAME2 ] && dmsetup remove --retry $DEV_NAME2

 	[ -b /dev/mapper/$DEV_NAME ] && dmsetup remove --retry $DEV_NAME

 	[ ! -z "$LOOPDEV1" ] && losetup -d $LOOPDEV1 >/dev/null 2>&1

-	rm -f $IMG $IMG_HDR $ORIG_IMG $KEY1 $HEADER_LUKS2_PV >/dev/null 2>&1

+	rm -f $IMG $IMG_HDR $ORIG_IMG $KEY1 $HEADER_LUKS2_PV $DEV_LINK >/dev/null 2>&1

 	umount $MNT_DIR > /dev/null 2>&1

 	rmdir $MNT_DIR > /dev/null 2>&1

 	LOOPDEV1=""

@@ -302,12 +303,25 @@ check_slot 0 || fail "Only keyslot 0 expected to be enabled"

 $REENC $LOOPDEV1 -d $KEY1 $FAST_PBKDF -q || fail

 # FIXME echo $PWD1 | $REENC ...

-if [ ! fips_mode ]; then

 echo "[4] Encryption of not yet encrypted device"

+# Encrypt without size reduction must not allow header device same as data device

+wipe_dev $LOOPDEV1

+echo $PWD1 | $REENC $LOOPDEV1 --type luks1 --new --header $LOOPDEV1 -q $FAST_PBKDF_ARGON 2>/dev/null && fail

+$CRYPTSETUP isLUKS $LOOPDEV1 2>/dev/null && fail

+ln -s $LOOPDEV1 $DEV_LINK || fail

+echo $PWD1 | $REENC $LOOPDEV1 --type luks1 --new --header $DEV_LINK -q $FAST_PBKDF_ARGON 2>/dev/null && fail

+$CRYPTSETUP isLUKS $LOOPDEV1 2>/dev/null && fail

+rm -f $DEV_LINK || fail

+echo $PWD1 | $REENC $IMG --type luks1 --new --header $IMG -q $FAST_PBKDF_ARGON 2>/dev/null && fail

+$CRYPTSETUP isLUKS $IMG 2>/dev/null && fail

+ln -s $IMG $DEV_LINK || fail

+echo $PWD1 | $REENC $IMG --type luks1 --new --header $DEV_LINK -q $FAST_PBKDF_ARGON 2>/dev/null && fail

+$CRYPTSETUP isLUKS $IMG 2>/dev/null && fail

+

+if [ ! fips_mode ]; then

 # well, movin' zeroes :-)

 OFFSET=2048

 SIZE=$(blockdev --getsz $LOOPDEV1)

-wipe_dev $LOOPDEV1

 dmsetup create $DEV_NAME2 --table "0 $(($SIZE - $OFFSET)) linear $LOOPDEV1 0" || fail

 check_hash_dev /dev/mapper/$DEV_NAME2 $HASH3

 dmsetup remove --retry $DEV_NAME2 || fail

-- 

2.38.1