TrueCrypt/VeraCrypt supports backup header, it seems to have
the same format as normal header.
Let's use --header option here, it can be used to unlock data partition
with header backup (open and dump commands).
Fixes: #587.
This patch adds support for Linux kernel (since version 5.11) dm-integrity
fixes that disables integrity recalculation if keyed algorithms (HMAC) is used.
Original dm-integrity superblock version <=4 is recalculation offset
field not protected by HMAC. An attacker can move this pointer and force
the kernel to recalculate the data area, ignoring original HMAC tags.
N.B. dm-integrity was not intended to protect against intentional changes.
Better use authenticated encryption (AEAD) in combination with dm-crypt.
It is designed to protect against random data corruption caused by hardware
or storage medium faults.
Despite that, we try to keep the system secure if keyed algorithms are used.
There are two possible keyed algorithms in dm-integrity - algorithm used
to protect journal and superblock (--journal-integrity) and algorithms
for protecting data (--integrity).
The dm-integrity superblock is guarded by --journal-integrity, so if you want
to protect data with HMAC, you should always also use HMAC for --journal-integrity.
The keys are independent. If HMAC is used for data but not for the journal,
recalculation is disabled by default.
For new kernel dm-integrity, the HMAC option also uses salt in superblock
to avoid an easy way to distinguish that the HMAC key is the same for two devices
(if data are the same).
The new HMAC and superblock are enabled automatically if the kernel supports it
(you can see superblock version 5 and fix_hmac flag in dump command).
If you need to use (insecure) backward compatibility, then two new integritysetup
options are introduced:
Use --integrity-legacy-recalc (instead of --integrity-recalc) to allow recalculation
on legacy devices.
Use --integrity-legacy-hmac in format action to force old insecure version
format (with HMAC).
Libcryptsetup API also introduces flags
CRYPT_COMPAT_LEGACY_INTEGRITY_HMAC and
CRYPT_COMPAT_LEGACY_INTEGRITY_RECALC
to set these through crypt_set_compatibility() call.
* Rename "BASIC COMMANDS" to "BASIC ACTIONS"
* Changed a sentence saying that luksFormat would work on unmapped luks containers, only.
* Insert 6 examples of using cryptsetup for luks containers
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.
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.
Adds option to dump content of LUKS2 unbound keyslot
in to a file:
'cryptsetup luksDump --unbound --master-key-file /file -S 12 /dev/luks2'
or to terminal:
'cryptsetup luksDump --unbound -S 12 /dev/luks2'
Parameters -S (specific keyslot) is mandatory with --unbound.
Fixes: #549
Kernel 5.7 adds support for optional discard/TRIM operation
for dm-integrity (available only for internal hash, not for LUKS2
with integrity).
This patch adds support for the new option.
Optional parameter root hash signature is added that can be added to
veritysetup.
The signature file is opened and the signature is added to the keyring.
The kernel will use the signature to validate the roothash.
Usage: veritysetup open <data_device> name <hash_device> <root_hash> --root-hash-signature=<roothash_p7_sig_file>
Signed-off-by: Jaskaran Khurana <jaskarankhurana@linux.microsoft.com>
Signed-off-by: Luca Boccassi <luca.boccassi@microsoft.com>
[Original patch rewritten by Milan Broz]
It may be useful to activate device right after LUKS2 encryption
is initialized:
device is ready to use immediately even if data encryption runs in
the background for a long time
It simplifies encryption initialization during reboot.
command "man cryptsetup reencrypt" gets redirected to
cryptsetup-reencrypt man page. This may confuse users that LUKS2 online
reencryption is managed by offline utility.
Currently it's used only in LUKS2 reencryption code
for reencrypting initial part of data device only.
It may be used to encrypt/reencrypt only initial part
of data device if user is aware that rest of the device
is empty.
This is very ugly workaround for situation when multiple
devices are being activated in parallel (systemd crypttab)
and system instead of returning ENOMEM use OOM killer
to randomly kill processes.
This flag is intended to be used only in very specific situations.
The JSON structures should not be printed by default to debug log.
This flag introduces new debug level that prints JSON structures
and keeps default debug output separate.
This patch makes available LUKS2 per-keyslot encryption settings to user.
In LUKS2, keyslot can use different encryption that data.
We can use new crypt_keyslot_get_encryption and crypt_keyslot_set_encryption
API calls to set/get this encryption.
For cryptsetup new --keyslot-cipher and --keyslot-key-size options are added.
The default keyslot encryption algorithm (if cannot be derived from data encryption)
is now available as configure options (default is aes-xts-plain64 with 512-bits key).
NOTE: default was increased from 256-bits.
Also print these area sizes in dump command.
NOTE: since now, the metadata area size in dump command contains
mandatory 4k binary section (to be aligned with API definition).
Since the kernel 4.18 there is a possibility to speficy external
data device for dm-integrity that stores all integrity tags.
The new option --data-device in integritysetup uses this feature.
Linux kernel since version 4.18 supports automatic background
recalculation of integrity tags for dm-integrity.
This patch adds new integritysetup --integrity-recalculate options
that uses this option.
