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[Qemu-devel] [PATCH 12/12] qcrypto-luks: more rigorous header checking
From: |
Maxim Levitsky |
Subject: |
[Qemu-devel] [PATCH 12/12] qcrypto-luks: more rigorous header checking |
Date: |
Thu, 12 Sep 2019 12:17:10 +0300 |
Check that keyslots don't overlap with the data,
and check that keyslots don't overlap with each other.
(this is done using naive O(n^2) nested loops,
but since there are just 8 keyslots, this doesn't really matter.
Signed-off-by: Maxim Levitsky <address@hidden>
---
crypto/block-luks.c | 52 +++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 52 insertions(+)
diff --git a/crypto/block-luks.c b/crypto/block-luks.c
index 0d155c6614..6c53bdc428 100644
--- a/crypto/block-luks.c
+++ b/crypto/block-luks.c
@@ -530,6 +530,11 @@ qcrypto_block_luks_load_header(QCryptoBlock *block,
static int
qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks, Error **errp)
{
+ size_t i, j;
+
+ unsigned int header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
+ QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
+
if (memcmp(luks->header.magic, qcrypto_block_luks_magic,
QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) {
error_setg(errp, "Volume is not in LUKS format");
@@ -541,6 +546,53 @@ qcrypto_block_luks_check_header(const QCryptoBlockLUKS
*luks, Error **errp)
luks->header.version);
return -1;
}
+
+ /* Check all keyslots for corruption */
+ for (i = 0 ; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; i++) {
+
+ const QCryptoBlockLUKSKeySlot *slot1 = &luks->header.key_slots[i];
+ unsigned int start1 = slot1->key_offset_sector;
+ unsigned int len1 =
+ qcrypto_block_luks_splitkeylen_sectors(luks,
+ header_sectors,
+ slot1->stripes);
+
+ if (slot1->stripes == 0) {
+ error_setg(errp, "Keyslot %zu is corrupted (stripes == 0)", i);
+ return -1;
+ }
+
+ if (slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED &&
+ slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) {
+ error_setg(errp,
+ "Keyslot %zu state (active/disable) is corrupted", i);
+ return -1;
+ }
+
+ if (start1 + len1 > luks->header.payload_offset_sector) {
+ error_setg(errp,
+ "Keyslot %zu is overlapping with the encrypted payload",
+ i);
+ return -1;
+ }
+
+ for (j = i + 1 ; j < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; j++) {
+ const QCryptoBlockLUKSKeySlot *slot2 = &luks->header.key_slots[j];
+ unsigned int start2 = slot2->key_offset_sector;
+ unsigned int len2 =
+ qcrypto_block_luks_splitkeylen_sectors(luks,
+ header_sectors,
+ slot2->stripes);
+
+ if (start1 + len1 > start2 && start2 + len2 > start1) {
+ error_setg(errp,
+ "Keyslots %zu and %zu are overlapping in the
header",
+ i, j);
+ return -1;
+ }
+ }
+
+ }
return 0;
}
--
2.17.2
- [Qemu-devel] [PATCH 06/12] qcrypto-luks: use the parsed encryption settings in QCryptoBlockLUKS, (continued)
- [Qemu-devel] [PATCH 06/12] qcrypto-luks: use the parsed encryption settings in QCryptoBlockLUKS, Maxim Levitsky, 2019/09/12
- [Qemu-devel] [PATCH 07/12] qcrypto-luks: purge unused error codes from open callback, Maxim Levitsky, 2019/09/12
- [Qemu-devel] [PATCH 08/12] qcrypto-luks: extract store and load header, Maxim Levitsky, 2019/09/12
- [Qemu-devel] [PATCH 09/12] qcrypto-luks: extract check and parse header, Maxim Levitsky, 2019/09/12
- [Qemu-devel] [PATCH 10/12] qcrypto-luks: extract store key function, Maxim Levitsky, 2019/09/12
- [Qemu-devel] [PATCH 11/12] qcrypto-luks: simplify the math used for keyslot locations, Maxim Levitsky, 2019/09/12
- [Qemu-devel] [PATCH 12/12] qcrypto-luks: more rigorous header checking,
Maxim Levitsky <=