It allows to get former (old) volume key size
from LUKS2 device in reencryption state when
there's at least one keyslot containing encrypted
volume key.
crypt_activate_by_keyslot_context() returns -EPERM
when key was passed either by CRYPT_KC_TYPE_KEY or
CRYPT_KC_TYPE_VK_KEYRING and does not match the digest
stored in metadata.
Sometimes caller might want to verify if the passed
keyslot contexts matches the effective volume key
or not without the error message. It can be
printed from command line tools when needed.
We do not have to query device-mapper subsystem
twice in order to get volume key description in kernel keyring.
Also there was a bug that wrongly used kernel key type set by function
supposed to set custom user key type used only when linking volume key
in arbitrary kernel keyring on caller demand.
Functions related to uploading/unlinking volume keys in user
requested kernel keyrings are named as follows:
crypt_single_volume_key_load_in_custom_keyring
crypt_volume_key_load_in_custom_keyring
crypt_unlink_key_from_custom_keyring
helpers for unlinking LUKS2 volume keys from thread keyring:
crypt_unlink_key_from_thread_keyring
crypt_unlink_key_by_description_from_thread_keyring
The volume key structure may often be in configuration
where 'key' member does not contain real data. Some
examples:
- volume key acquired by querring device-mapper where key
was originaly passed by kernel keyring reference.
- volume key allocated by crypt_alloc_volume_key(size, NULL)
With this patch access to internal 'uninitialized' data result
in failed assert().
For use cases where key data are not needed (keyring reference wrapper,
key length info only) we do not have to allocate and lock the safe
buffer in memory.
Further improvements might to completely hide the volume key internals
and access only via setter and getter functions.
Switch current code to use following volume key helpers
for accessing internal properties:
crypt_volume_key_length(), crypt_volume_key_get_key(),
crypt_volume_key_description() and crypt_volume_key_kernel_key_type()
Remaining direct access to volume key internals will be dealt with in
later commits since it requires some further changes.
There were two different use cases for weaker keys:
1) empty keys (zero filled buffer)
2) weak 'random' keys not sucking entropy while being generated
Those key types must not be used to encrypt real data. It's used either
to check cipher can be configured sucessfully on the system or as
a fake envelope during metadata repair.
The volume key uploaded attribute is respected only with
regard to volume keys uploaded in the thread keyring in logon key type.
Here the uploaded attribute was set for volume keys uploaded in
custom user keyrings in custome key descriptions.
For now, we used zeroed key for dm-integrity format, as there was not
data area. In future, there can be wrapped key scheme, that will require
to setup real key even in this situation.
This patch modifies the integrity format flow that the real key is used
during format.
Mostly based on code from Ingo Franzki <ifranzki@linux.ibm.com>
This patch add support for setting of integrity key size
for LUKS2 devices.
It adds new (optional) JSON "key_size" attribute in segment.integrity JSON object.
If not set, the code use hash length size (backward compatible).
For LUKS2, we do not allow smaller keys than 128 bits.
Mostly based on code from Ingo Franzki <ifranzki@linux.ibm.com>
This patch implement support for setting specific integrity key size
option in dm-crypt, available since dm-crypt version 1.28.0.
This can be used for setting non-standard HMAC key length.
Mostly based on code from Ingo Franzki <ifranzki@linux.ibm.com>
There is no functional change in this patch except it avoids
strange confusion during some static tests.
The cd->type must be set in this function anyway.
This is only preparation for an extension later, however, the volume
keys should not be unloaded unconditionally from keyring.
Note that all other places dropping keys already check that keys
were uploaded through key ID setting.
(And for suspend unconditional unlink make sense too.)
The key_decripion always contains only a key name,
keyring then contains type of keyring as defned un keyring utils.
For now, only LOGON type is used in commands, it will be extended later.
The luks2_internal.h contains specific JSON implementations while
luks2.h is generic. Code outside of luks2/ dir should not use internals.
Also luks2.h includes functions prototypes that are used from setup.c.
There was a bug in both crypt_token_assign_keyslot and
crypt_token_unsassign_keyslot where CRYPT_ANY_TOKEN
special value could be passed in token parameter.
It would correctly assign/unassign all tokens to/from
the specified keyslot (or from any in case of CRYPT_ANY_SLOT),
but it returned -1 (CRYPT_ANY_TOKEN) which fited error return
values as per API documentation.
We fixed that by not supporting CRYPT_ANY_TOKEN since it does
not make much sense. It can be workarounded by iterating over
all available tokens and calling crypt_token_assign_keyslot or
crypt_token_unassign_keyslot accodingly.
Fixes: #914.
After switching to reencryption by keyslot context,
the digest was not properly verified before crash recovery.
We need to reverify reencryption digest after metadata
reloads unconditionally.
