Signed-off-by: Maxim Levitsky <mlevi...@redhat.com>
Reviewed-by: Daniel P. Berrangé <berra...@redhat.com>
---
crypto/block-luks.c | 63 ++++++++++++++++++++++++++++-----------------
1 file changed, 40 insertions(+), 23 deletions(-)
diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index c6045da33e..0d155c6614 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -409,6 +409,30 @@ qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm
cipher,
}
}
+/*
+ * Returns number of sectors needed to store the key material
+ * given number of anti forensic stripes
+ */
+static int
+qcrypto_block_luks_splitkeylen_sectors(const QCryptoBlockLUKS *luks,
+ unsigned int header_sectors,
+ unsigned int stripes)
+{
+ /*
+ * This calculation doesn't match that shown in the spec,
+ * but instead follows the cryptsetup implementation.
+ */
+
+ size_t splitkeylen = luks->header.master_key_len * stripes;
+
+ /* First align the key material size to block size*/
+ size_t splitkeylen_sectors =
+ DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE);
+
+ /* Then also align the key material size to the size of the header */
+ return ROUND_UP(splitkeylen_sectors, header_sectors);
+}
+
/*
* Stores the main LUKS header, taking care of endianess
*/
@@ -1124,7 +1148,8 @@ qcrypto_block_luks_create(QCryptoBlock *block,
QCryptoBlockCreateOptionsLUKS luks_opts;
Error *local_err = NULL;
g_autofree uint8_t *masterkey = NULL;
- size_t splitkeylen = 0;
+ size_t header_sectors;
+ size_t split_key_sectors;
size_t i;
g_autofree char *password = NULL;
const char *cipher_alg;
@@ -1343,37 +1368,29 @@ qcrypto_block_luks_create(QCryptoBlock *block,
goto error;
}
+ /* start with the sector that follows the header*/
+ header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
+ QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
+
+ split_key_sectors =
+ qcrypto_block_luks_splitkeylen_sectors(luks,
+ header_sectors,
+ QCRYPTO_BLOCK_LUKS_STRIPES);
- /* Although LUKS has multiple key slots, we're just going
- * to use the first key slot */
- splitkeylen = luks->header.master_key_len * QCRYPTO_BLOCK_LUKS_STRIPES;
for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
- luks->header.key_slots[i].active =
QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
- luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES;
+ QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i];
+ slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
- /* This calculation doesn't match that shown in the spec,
- * but instead follows the cryptsetup implementation.
- */
- luks->header.key_slots[i].key_offset_sector =
- (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
- QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
- (ROUND_UP(DIV_ROUND_UP(splitkeylen,
QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
- (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
- QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i);
+ slot->key_offset_sector = header_sectors + i * split_key_sectors;
+ slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES;
}
-
/* The total size of the LUKS headers is the partition header + key
* slot headers, rounded up to the nearest sector, combined with
* the size of each master key material region, also rounded up
* to the nearest sector */
- luks->header.payload_offset_sector =
- (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
- QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
- (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
- (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
- QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) *
- QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
+ luks->header.payload_offset_sector = header_sectors +
+ QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS * split_key_sectors;
block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
block->payload_offset = luks->header.payload_offset_sector *
--
2.17.2
