To allow resizing integrity devices with detached metadata device, the
check has to be moved from _compare_integrity_devices to
_reload_device_with_integrity.
If the provided key is NULL, we load it from the active device. This is
always available, since keyring keys are not supported in kernel for
integrity devices.
Move code setting data device during format so that
we can properly detect optimal encryption sector size
for data device instead of metadata device (header).
Fixes: #708.
Attribute unused is useless and makes code imcomprehensible
when decorates internal functions not exposed via API.
Let's cleanup internal funtion prototypes whenever possible.
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.
Reverts commit 96d83455ca partially. It is not necessary to
have specific crypt_activate_by_token_type call. Users
may use crypt_activate_by_token_pin with pin argument set to NULL
and achieve same goal as with crypt_activate_by_token_type.
Starting with GCC10 and LTO enabled, current symbols
versioning hack does not work anymore. This patch
reflects on that and should be compatible with older
compilers that does not support __attribute__((symver))
yet.
Inspired by following code:
https://github.com/linux-rdma/rdma-core/blob/master/util/symver.h
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.
To avoid confusion, use just one lib include and specify sub-directories
for format inclusions.
This should also help some analysis tools to find proper includes.
Add API call that can directly print JSON metadata area from LUKS2 device.
For commandline it also adds --dump-json-metadata option for luksDump action.
Note that the binary metadata (UUID, version etc) is not part of this output.
(We reserve flags parameter to be able to add this later.)
Fixes: #511
The code expects that change key is done in-place if there is not
a free space in keyslot area for safe key swap.
This patch makes the code behaves the same as in LUKS1,
luksChangeKey now works the same.
With JSON, we can actually retain the slot number in all cases
(except user intentionally set new slot #).
This patch changes the crypt_keyslot_change_by_passphrase() API
call to retain keyslot number for LUKS2.
Fixes: #464
crypt_header_is_detached checks if initialized LUKS context uses detached header
(LUKS header located on a different device than data.)
This is a runtime attribute, it does not say if a LUKS device requires detached header.
