The option --disable-luks2-reencryption completely disable
LUKS2 reencryption code.
When used, the libcryptsetup library can read metadata with
reencryption code, but all reencryption API calls and cryptsetup
reencrypt commands are disabled.
Devices with online reencryption in progress cannot be activated.
This option can cause some incompatibilities. Please use with care.
Fix possible attacks against data confidentiality through LUKS2 online
reencryption extension crash recovery.
An attacker can modify on-disk metadata to simulate decryption in
progress with crashed (unfinished) reencryption step and persistently
decrypt part of the LUKS device.
This attack requires repeated physical access to the LUKS device but
no knowledge of user passphrases.
The decryption step is performed after a valid user activates
the device with a correct passphrase and modified metadata.
There are no visible warnings for the user that such recovery happened
(except using the luksDump command). The attack can also be reversed
afterward (simulating crashed encryption from a plaintext) with
possible modification of revealed plaintext.
The problem was caused by reusing a mechanism designed for actual
reencryption operation without reassessing the security impact for new
encryption and decryption operations. While the reencryption requires
calculating and verifying both key digests, no digest was needed to
initiate decryption recovery if the destination is plaintext (no
encryption key). Also, some metadata (like encryption cipher) is not
protected, and an attacker could change it. Note that LUKS2 protects
visible metadata only when a random change occurs. It does not protect
against intentional modification but such modification must not cause
a violation of data confidentiality.
The fix introduces additional digest protection of reencryption
metadata. The digest is calculated from known keys and critical
reencryption metadata. Now an attacker cannot create correct metadata
digest without knowledge of a passphrase for used keyslots.
For more details, see LUKS2 On-Disk Format Specification version 1.1.0.
It does not make sense to upload volume keys in
kernel keyring if segment cipher is cipher_null.
The real volume_key is thrown away and replaced
with empty key anyway.
This bug enabled to create LUKS2 keyslots encrypted by
cipher_null when explicitely requested by user. LUKS2
was never meant to allow keyslot encryption with
cipher_null. cipher_null is meant for debug purposes
only as a segment cipher.
These are false positives and gcc internal detection of this
pattern seems to be broken again.
In this path we must avoid memcpy the whole buffer, it can contain
some bytes after null char, so use MIN/strlen here.
The value of h may be NULL. Check it vefore visiting its
memeber to avoid segfault.
Signed-off-by: Lixiaokeng <lixiaokeng@huawei.com>
Signed-off-by: Linfeilong <linfeilong@huawei.com>
Right now, cryptsetup makes an attempt to include the correct
definitions in all of its header files, allowing the headers to
compile regardless of the context in which they are included.
A few files were missed, this change fixes them by adding the minimal
set of #includes needed to get them to compile.
Signed-off-by: Joe Richey <joerichey@google.com>
cipher[31] and cipher_mode[31] buffers were passed to
crypt_parse_name_and_mode() routine where sscanf(s, "%31[^-]-%31s",
cipher, cipher_mode) was called.
In corner case it could cause terminating 0 byte written beyond
respective arrays.
Keep it simple. If there's not enough memory we can't validate
segments. The LUKS2 specification does not recommend to continue
processing LUKS2 metadata if it can not be properly validated.
In case LUKS2 backup segment creates gap in between last regular
segment and backup segment report invalid metadata imediately. We stop
on first error so there's no need to allocate large memory on heap
(we may ran with mlock(MCL_FUTURE) set).
Example:
- total segments count is 3
- regular segments have keys "0" and "1"
- first backup segment has key "42"
Segments are validated in hdr_validate_segments. Gaps in segment keys
are detected when collecting offsets. But if an invalid segment is very
large, larger than count, it could happen that cryptsetup is unable to
allocate enough memory, not giving a clue about what actually is the
problem.
Therefore check for gaps even if not enough memory is available. This
gives much more information with debug output enabled.
Obviously cryptsetup still fails if segments are perfectly fine but not
enough RAM available. But at that stage, the user knows that it's the
fault of the system, not of an invalid segment.
These performance options, introduced in kernel 5.9, configures
dm-crypt to bypass read or write workqueues and run encryption
synchronously.
Also support persistent storage of these flags for LUKS2.
When creating LUKS2 header with specified --offset much larger
then LUKS2 header size we needlessly also wipe (allocate up to
--offset) much larger file than needed.
* TRUE/FALSE are not defined anymore. 1 and 0 are used instead.
* json_object_get_uint64() and json_object_new_uint64() are part
of the upstream API now.
Kernel 5.7 adds support for optional discard/TRIM operation
for dm-integrity (available only for internal hash, not for LUKS2
with integrity).
This patch adds support for the new option.
Some kernels show invalid dm-integrity table if suberblock
contains "recalculate" bit.
We can workaround that by setting recalculate option in table
(kernel uses bits from superblock anyway), so the table displayed
is always correct.
Fixes: #538
LUKS2_hdr_validate() returns positive integer on error. Replace returned
value with negative errno instead so that failed upconversion stops
sooner. It failed anyway but debug messages were misleading.
If LUKS1 payload offset (data offset) is not aligned to
4KiB we create unaligned keyslots area in LUKS2 metadata
during upconversion. Unaligned keyslots area is not valid
from LUKS2 perspective. Fix it by properly aligning future
keyslots area and also check if LUKS1 keyslots area fit
in the new one.
Fixes: #534.
During LUKS2 upconversion we moved binary keyslots area before
validating future LUKS2 header. If later LUKS2 validation failed
for some reason keyslots were already moved to new offsets and
LUKS1 offsets were therefore invalid. Following effort to unlock
such device failed because keyslots were efectively corrupted.
See issue #534.
Original messages could evoke reencryption is currently
in progress. That was inaccurate because code only
detected flag marking such device is in transition state
from metadata pov. We should not imply anything about
running processes. That's detected via reencryption locks.
