The device_check is done in header write functions,
but these are not recached in normal format path as wipe call
is called earlier.
Call the device check also from wipe function to get better error
description.
This situation happens for example when a block device is too small
(regular file can be enlarged by falloc(); block device cannot).
In LUKS1 there is only one hash algorithm specification,
it cannot happen, that AF hash algorithm is not
available, as it is used immediately before in PBKDF2.
In LUKS2 this can be completely different algorithm, so
it make sense to print a visible warning for user.
For example, Whirlpool and RIPEMD160 is now in OpenSSL legacy
provider which can be unavailable, see #773.)
This patch adds a message only, the code already fails with -EINVAL.
The crypt_keyslot_add_by_keyslot_context & associated
helper functions allow more options when adding new
keyslot. For example there was no simple way of
adding new LUKS2 keyslot when the only active keyslot
could be unlocked by passphrase (KEK) provided by LUKS2 token
(plugin). Now all available options for unlocking keyslots
may also be used when creating new keyslot and it combine
as called needs.
The available methods (keyslot contexts) are:
passphrase, keyfile, key (binary representation) and LUSK2 token.
Following API calls trigerred LUKS2 metadata reload
from storage in case of failure:
crypt_convert
crypt_keyslot_add_by_key
crypt_keyslot_add_by_keyfile_device_offset
crypt_keyslot_add_by_passphrase
crypt_keyslot_change_by_passphrase
crypt_reencrypt_init_by_keyring
crypt_reencrypt_init_by_passphrase
This patch replaces LUKS2 metadata reload with
backup LUKS2 metadata copy kept in memory that is updated on
each sucessfull metadata write and rolled back to it whenever
needed in any of those calls listed above.
The content of LUKS header is not a key material, no need
to lock memory for possibly big header and big memory area locks.
Just ensure we wipe buffer before release of memory.
Do not invalidate LUKS2 format when future online-reencrypt
requirement flag is encountered (by older releases).
But it must stop device from being activated, reencrypted
or modified.
If keyslots are not sorted according to binary area offset,
the calculation of area size is wrong and can overflow
(LUKS1 does not store area size, only offset).
Let's just use function that calculates size from volume key size.
Images where keyslot areas are not aligned to 4k offset
are not supported anyway.
Fixes: #753
Invalid values that overflows in interval check were silently ignored.
Fix this by explictily adding check for interval overflow in keyslots
and segment validation.
Fixes: #748
Adds support for LUKS2 decryption of devices with a
header put in the head of data device. During the initialization
header is exported to a file and first data segment
is moved to head of data device in place of original header.
The feature introduces several new resilience modes (combination
of existing modes datashift and "checksum" or "journal").
Where datashift resilience mode is applied for data moved towards
the first segment and first segment is decrypted in-place.
The mode is not backward compatible with prior LUKS2 reencryption
and therefor interrupted operation in progress can not be resumed
using older cryptsetup releases.
Fixes: #669.
Upper layers always expected 0 on error.
Due to this bug this function could cause
sector_size overflow when segment definition
did not contain 'sector_size' field ('linear').
