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_tools.c b/src/utils_tools.c

--- a/src/utils_tools.c

+++ b/src/utils_tools.c

@@ -624,3 +624,23 @@ int tools_reencrypt_progress(uint64_t si

 	return r;

 }

+

+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_get_metadata_device_name(cd) && crypt_get_device_name(cd) && strcmp(crypt_get_metadata_device_name(cd), crypt_get_device_name(cd));

+	crypt_free(cd);

+	return r;

+}

diff --git a/src/cryptsetup.h b/src/cryptsetup.h

--- a/src/cryptsetup.h

+++ b/src/cryptsetup.h

@@ -103,6 +103,7 @@ void tools_clear_line(void);

 int tools_wipe_progress(uint64_t size, uint64_t offset, void *usrptr);

 int tools_reencrypt_progress(uint64_t size, uint64_t offset, void *usrptr);

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

 int tools_read_mk(const char *file, char **key, int keysize);

 int tools_write_mk(const char *file, const char *key, int keysize);

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

--- a/src/cryptsetup.c

+++ b/src/cryptsetup.c

@@ -2892,6 +2892,16 @@ static int action_encrypt_luks2(struct c

 		return -ENOTSUP;

 	}

+	if (!opt_data_shift) {

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

+	       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 (!opt_header_device && opt_offset && opt_data_shift && (opt_offset > (imaxabs(opt_data_shift) / (2 * SECTOR_SIZE)))) {

 		log_err(_("Requested data offset must be less than or equal to half of --reduce-device-size parameter."));

 		return -EINVAL;

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

--- a/src/cryptsetup_reencrypt.c

+++ b/src/cryptsetup_reencrypt.c

@@ -1553,6 +1553,17 @@ static int run_reencrypt(const char *dev

 		goto out;

 	}

+	if (rc.reencrypt_mode == ENCRYPT) {

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

+		if (r < 0)

+			goto out;

+		if (!r && !opt_reduce_size) {

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

+			r = -ENOTSUP;

+			goto out;

+		}

+	}

+

 	log_dbg("Running reencryption.");

 	if (!rc.in_progress) {

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 +1080,15 @@ $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

+

+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

+

 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

@@ -11,5 +11,6 @@ IMG=reenc-data

 IMG_HDR=$IMG.hdr

 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 >/dev/null 2>&1

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

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

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

 	LOOPDEV1=""

@@ -265,10 +265,16 @@ $REENC $LOOPDEV1 -d $KEY1 $FAST_PBKDF -q

 # FIXME echo $PWD1 | $REENC ...

 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

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

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

+

 # 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