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.
If users want to use blake2b/blake2s, the kernel algorithm name
includes dash - like "blake2s-256".
Because we use dash as a separator, this patch adds an exception
for this case.
Fixes: #581.
TrueCrypt/VeraCrypt always use 512-bytes sector for encryption,
but for devices with a larger native sector it stores this value in header.
This patch allows activating of such devices, basically ignoring
the mentioned sector size in header (it only must be multiple
of 512-bytes sector).
Fixes: #580.
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.
We've assumed that first 4 bytes of the decrypted key data is the
size of the key + metadata. Looks like this isn't true and only
first two bytes contain the size and the other two bytes are
unknown data, possibly related to reencryption and/or passphrase
change.
Fixes: #575
The EBOIV initialization vector is intended to be used
internally with BitLocker devices (for CBC mode).
It can be used in some specific cases for other devices.
This patch adds userspace implementation duplicating
the same EBOIV as the dm-crypt kernel.
Fixes: #562
The iv_large_sector option is supported in dm-crypt since introduction
of larger sectors encryption.
It counts Initialization Vector (IV) in larger sector size (if set) instead
of 512 bytes sectors.
This option does not have any performance or security impact, but it can be
used for accessing incompatible existing disk images from other systems.
(It is used internally in BitLocker compatibily code).
This patch allows it to be used for plain type device, so users
can manually map foreign disk images.
Only open action with plain device and sector size > 512 bytes is supported.
