Move all keyring functions to one place and separate LUKS2 specific
code to generic handling.
Also fix possible mismatch if volume key is in keyring but it is not native
LUKS2 device (libarary cannot process such a device properly).
When loading first dm-crypt table (or action that triggers dm-crypt
module load) we do not know dm-crypt version yet. Let's assume all
kernels before 4.15.0 are flawed and reject VK load via kernel keyring
service.
When dm-crypt is already in kernel, check for correct target version
instead (v1.18.1 or later).
On some systems the requested amount of memory causes OOM killer
to kill the process (instead of returning ENOMEM).
For now, we never try to use more than half of available
physical memory.
This patch adds support for using keyring for volume key
and support for new integrity fields for dm-crypt.
Also helpers for searching disk by id.
To be used later.
Also cache its value in active context, so we run benchmark
only once.
The patch also changes calculated value for LUKS1 key digest
to 125 miliseconds (it means that for full 8 used slots
the additional slow-down is circa 1 second).
Note that there is no need to have too high iteration count
for key digest; if it is too computationally expensive, attacker
will better decrypt of one sector with candidate key anyway.
(Check for a known signature.)
The reason to have some delay for key digest check was
to complicate brute-force search for volume key with LUKS header
only (and if RNG used to generate volumekey was flawed
allowing such a search i reasonable time).
Prepare API for PBKDF that can set three costs
- time (similar to iterations in PBKDF2)
- memory (required memory for memory-hard function)
- threads (required number of threads/CPUs).
This patch also removes wrongly designed API call
crypt_benchmark_kdf and replaces it with the new call
crypt_benchmark_pbkdf.
Two functions for PBKDF per context setting
are introduced: crypt_set_pbkdf_type and crypt_get_pbkdf_type.
The patch should be backward compatible when using
crypt_set_iteration_time function (works only for PBKDF2).
Signed-off-by: Milan Broz <gmazyland@gmail.com>
In some specific situation we do not want to read the devices
before initialization.
Here it is integrity checking that will produce warning, because
the device is not yet initialized.
Used only in wipe function (here we must use direct-io anyway)
and expect the device is capable of direct-io.
It is possible to overflow integers during memory allocation with
insanely large "key bytes" specified in a LUKS header.
Although it could be argued to properly validate LUKS headers while
parsing them, it's still a good idea to fix any form of possible
overflow attacks against cryptsetup in these allocation functions.
Kernel doesn't allow mapping through whle device if some
other partition an the device is used.
So first try to find partition device which match
system encryption (== TCRYPT partition system encryption)
and use that.
- config.h must always be the first file to be included
- Use AM_CFLAGS and AM_LDFLAGS consistently and properly.
(Modified to disable build without largefile support etc
by Milan Broz <gmazyland@gmail.com>)
System encryption hav metadata in space located ouside of
partition itself.
Ideally the check should be automatic but for virtualized systems
(where a partition could be "whole device" for another sustem this
can be dangerous.
Allocate loop device late (only when real block device needed).
Rework underlying device/file access functions.
Move all device (and ioctl) access to utils_device.c.
Allows using file where appropriate without allocation loop device.
