From 6bc1378ddb5bbcc6ba592177c996576b0b3505f9 Mon Sep 17 00:00:00 2001 From: Ondrej Kozina Date: Fri, 22 Oct 2021 13:06:48 +0200 Subject: [PATCH] Remove LUKS2 encryption data size restriction. LUKS2 encryption with data shift required remaining data size (size remaining after substracting --reduce-data-size value) to be at least --reduce-data-size. This was wrong. Remaining data size restriction should be correctly at least single sector (whatever sector size is selected or auto-detected). --- lib/luks2/luks2_reencrypt.c | 31 ++++++++++++----------- tests/api-test-2.c | 6 ++--- tests/luks2-reencryption-test | 46 +++++++++++++++++++++++++++++------ 3 files changed, 57 insertions(+), 26 deletions(-) diff --git a/lib/luks2/luks2_reencrypt.c b/lib/luks2/luks2_reencrypt.c index b45327ad..d0e0dc40 100644 --- a/lib/luks2/luks2_reencrypt.c +++ b/lib/luks2/luks2_reencrypt.c @@ -825,7 +825,7 @@ static int reencrypt_offset_backward_moved(struct luks2_hdr *hdr, json_object *j linear_length += LUKS2_segment_size(hdr, sg, 0); /* all active linear segments length */ - if (linear_length) { + if (linear_length && segs > 1) { if (linear_length < data_shift) return -EINVAL; tmp = linear_length - data_shift; @@ -1745,7 +1745,8 @@ static int reencrypt_set_encrypt_segments(struct crypt_device *cd, struct luks2_ int r; uint64_t first_segment_offset, first_segment_length, second_segment_offset, second_segment_length, - data_offset = LUKS2_get_data_offset(hdr) << SECTOR_SHIFT; + data_offset = LUKS2_get_data_offset(hdr) << SECTOR_SHIFT, + data_size = dev_size - data_shift; json_object *jobj_segment_first = NULL, *jobj_segment_second = NULL, *jobj_segments; if (dev_size < data_shift) @@ -1760,9 +1761,14 @@ static int reencrypt_set_encrypt_segments(struct crypt_device *cd, struct luks2_ * [future LUKS2 header (data shift size)][second data segment][gap (data shift size)][first data segment (data shift size)] */ first_segment_offset = dev_size; - first_segment_length = data_shift; - second_segment_offset = data_shift; - second_segment_length = dev_size - 2 * data_shift; + if (data_size < data_shift) { + first_segment_length = data_size; + second_segment_length = second_segment_offset = 0; + } else { + first_segment_length = data_shift; + second_segment_offset = data_shift; + second_segment_length = data_size - data_shift; + } } else if (data_shift) { first_segment_offset = data_offset; first_segment_length = dev_size; @@ -2163,17 +2169,10 @@ static int reencrypt_move_data(struct crypt_device *cd, int devfd, uint64_t data log_dbg(cd, "Going to move data from head of data device."); - buffer_len = data_shift; - if (!buffer_len) - return -EINVAL; - offset = json_segment_get_offset(LUKS2_get_segment_jobj(hdr, 0), 0); - - /* this is nonsense anyway */ - if (buffer_len != json_segment_get_size(LUKS2_get_segment_jobj(hdr, 0), 0)) { - log_dbg(cd, "buffer_len %" PRIu64", segment size %" PRIu64, buffer_len, json_segment_get_size(LUKS2_get_segment_jobj(hdr, 0), 0)); + buffer_len = json_segment_get_size(LUKS2_get_segment_jobj(hdr, 0), 0); + if (!buffer_len || buffer_len > data_shift) return -EINVAL; - } if (posix_memalign(&buffer, device_alignment(crypt_data_device(cd)), buffer_len)) return -ENOMEM; @@ -2447,7 +2446,7 @@ static int reencrypt_init(struct crypt_device *cd, * encryption initialization (or mount) */ if (move_first_segment) { - if (dev_size < 2 * (params->data_shift << SECTOR_SHIFT)) { + if (dev_size < (params->data_shift << SECTOR_SHIFT)) { log_err(cd, _("Device %s is too small."), device_path(crypt_data_device(cd))); return -EINVAL; } @@ -3484,7 +3483,7 @@ int LUKS2_reencrypt_check_device_size(struct crypt_device *cd, struct luks2_hdr check_size, check_size >> SECTOR_SHIFT, real_size, real_size >> SECTOR_SHIFT, real_size - data_offset, (real_size - data_offset) >> SECTOR_SHIFT); - if (real_size < data_offset || (check_size && (real_size - data_offset) < check_size)) { + if (real_size < data_offset || (check_size && real_size < check_size)) { log_err(cd, _("Device %s is too small."), device_path(crypt_data_device(cd))); return -EINVAL; } diff --git a/tests/api-test-2.c b/tests/api-test-2.c index a01a7a72..05ee8f94 100644 --- a/tests/api-test-2.c +++ b/tests/api-test-2.c @@ -4238,7 +4238,7 @@ static void Luks2Reencryption(void) _cleanup_dmdevices(); OK_(create_dmdevice_over_loop(H_DEVICE, r_header_size)); - OK_(create_dmdevice_over_loop(L_DEVICE_OK, 12*1024*2+1)); + OK_(create_dmdevice_over_loop(L_DEVICE_OK, 8*1024*2+1)); /* encryption with datashift and moved segment (data shift + 1 sector) */ OK_(crypt_init(&cd, DMDIR H_DEVICE)); @@ -4258,11 +4258,11 @@ static void Luks2Reencryption(void) _cleanup_dmdevices(); OK_(create_dmdevice_over_loop(H_DEVICE, r_header_size)); - OK_(create_dmdevice_over_loop(L_DEVICE_OK, 12*1024*2)); + OK_(create_dmdevice_over_loop(L_DEVICE_OK, 2*8200)); OK_(crypt_init(&cd, DMDIR H_DEVICE)); - /* encryption with datashift and moved segment (data shift + data offset > device size) */ + /* encryption with datashift and moved segment (data shift + data offset <= device size) */ memset(&rparams, 0, sizeof(rparams)); params2.sector_size = 512; params2.data_device = DMDIR L_DEVICE_OK; diff --git a/tests/luks2-reencryption-test b/tests/luks2-reencryption-test index 8efb2707..bf711c15 100755 --- a/tests/luks2-reencryption-test +++ b/tests/luks2-reencryption-test @@ -152,14 +152,30 @@ function open_crypt() # $1 pwd, $2 hdr fi } +function wipe_dev_head() # $1 dev, $2 length (in MiBs) +{ + dd if=/dev/zero of=$1 bs=1M count=$2 conv=notrunc >/dev/null 2>&1 +} + function wipe_dev() # $1 dev { if [ -b $1 ] ; then blkdiscard --zeroout $1 2>/dev/null || dd if=/dev/zero of=$1 bs=1M conv=notrunc >/dev/null 2>&1 + if [ $# -gt 2 ]; then + dd if=/dev/urandom of=$1 bs=1M seek=$2 conv=notrunc >/dev/null 2>&1 + fi else local size=$(stat --printf="%s" $1) truncate -s 0 $1 - truncate -s $size $1 + if [ $# -gt 2 ]; then + local diff=$((size-$2*1024*1024)) + echo "size: $size, diff: $diff" + truncate -s $diff $1 + # wipe_dev_head $1 $((diff/(1024*1024))) + dd if=/dev/urandom of=$1 bs=1M seek=$2 size=$((diff/(1024*1024))) conv=notrunc >/dev/null 2>&1 + else + truncate -s $size $1 + fi fi } @@ -214,15 +230,16 @@ function check_hash() # $1 pwd, $2 hash, $3 hdr $CRYPTSETUP remove $DEV_NAME || fail } +function check_hash_dev_head() # $1 dev, $2 len, $3 hash +{ + local hash=$(dd if=$1 bs=512 count=$2 2>/dev/null | sha256sum | cut -d' ' -f1) + [ $hash != "$3" ] && fail "HASH differs (expected: $3) (result $hash)" +} + function check_hash_head() # $1 pwd, $2 len, $3 hash, $4 hdr { open_crypt $1 $4 - if [ -n "$4" ]; then - echo $1 | $CRYPTSETUP resize $DEV_NAME --size $2 --header $4 || fail - else - echo $1 | $CRYPTSETUP resize $DEV_NAME --size $2 || fail - fi - check_hash_dev /dev/mapper/$DEV_NAME $3 + check_hash_dev_head /dev/mapper/$DEV_NAME $2 $3 $CRYPTSETUP remove $DEV_NAME || fail } @@ -865,6 +882,21 @@ $CRYPTSETUP status $DEV_NAME >/dev/null 2>&1 || fail $CRYPTSETUP close $DEV_NAME echo $PWD1 | $CRYPTSETUP open $DEV --test-passphrase || fail +# Small device encryption test +preparebig 65 +# wipe only 1st MiB (final data size after encryption) +wipe_dev $DEV 1 +check_hash_dev_head $DEV 2048 $HASH2 +echo $PWD1 | $CRYPTSETUP reencrypt $DEV --encrypt --reduce-device-size 64M -q $FAST_PBKDF_ARGON || fail +check_hash_head $PWD1 2048 $HASH2 + +wipe_dev_head $DEV 1 +check_hash_dev_head $DEV 2048 $HASH2 +echo $PWD1 | $CRYPTSETUP reencrypt $DEV --encrypt --reduce-device-size 64M --init-only -q $FAST_PBKDF_ARGON $DEV_NAME >/dev/null || fail +check_hash_dev_head /dev/mapper/$DEV_NAME 2048 $HASH2 +echo $PWD1 | $CRYPTSETUP reencrypt $DEV -q || fail +check_hash_dev_head /dev/mapper/$DEV_NAME 2048 $HASH2 + echo "[3] Encryption with detached header" preparebig 256 wipe_dev $DEV -- 2.38.1