The UUID header for LUKS2 uses a format with dashes, same as for
LUKS(1). But while we strip these dashes for the latter, we don't for
the former. This isn't wrong per se, but it's definitely inconsistent
for users as they need to use the dashed format for LUKS2 and the
non-dashed format for LUKS when e.g. calling "cryptomount -u $UUID".
Fix this inconsistency by stripping dashes off of the LUKS2 UUID.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
While we already set up error messages in both luks2_verify_key() and
luks2_decrypt_key(), we do not ever print them. This makes it really
hard to discover why a given key actually failed to decrypt a disk.
Improve this by including the error message in the user-visible output.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
When decrypting a given keyslot, all error cases except for one set up
an error and return the error code. The only exception is when we try to
read the area key: instead of setting up an error message, we directly
print it via grub_dprintf().
Convert the outlier to use grub_error() to allow more uniform handling
of errors.
Signed-off-by: Patrick Steinhardt <ps@kps.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
The debug message printed when decryption with a keyslot fails is
missing its trailing newline. Add it to avoid mangling it with
subsequent output.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
With cryptsetup 2.0, a new version of LUKS was introduced that breaks
compatibility with the previous version due to various reasons. GRUB
currently lacks any support for LUKS2, making it impossible to decrypt
disks encrypted with that version. This commit implements support for
this new format.
Note that LUKS1 and LUKS2 are quite different data formats. While they
do share the same disk signature in the first few bytes, representation
of encryption parameters is completely different between both versions.
While the former version one relied on a single binary header, only,
LUKS2 uses the binary header only in order to locate the actual metadata
which is encoded in JSON. Furthermore, the new data format is a lot more
complex to allow for more flexible setups, like e.g. having multiple
encrypted segments and other features that weren't previously possible.
Because of this, it was decided that it doesn't make sense to keep both
LUKS1 and LUKS2 support in the same module and instead to implement it
in two different modules luks and luks2.
The proposed support for LUKS2 is able to make use of the metadata to
decrypt such disks. Note though that in the current version, only the
PBKDF2 key derival function is supported. This can mostly attributed to
the fact that the libgcrypt library currently has no support for either
Argon2i or Argon2id, which are the remaining KDFs supported by LUKS2. It
wouldn't have been much of a problem to bundle those algorithms with
GRUB itself, but it was decided against that in order to keep down the
number of patches required for initial LUKS2 support. Adding it in the
future would be trivial, given that the code structure is already in
place.
Signed-off-by: Patrick Steinhardt <ps@pks.im>
Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com>
