android_kernel_motorola_sm6375/include
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Filename Latest commit message Latest commit date
Eric Biggers 66e564c048 fscrypt: add support for IV_INO_LBLK_32 policies
The eMMC inline crypto standard will only specify 32 DUN bits (a.k.a. IV
bits), unlike UFS's 64.  IV_INO_LBLK_64 is therefore not applicable, but
an encryption format which uses one key per policy and permits the
moving of encrypted file contents (as f2fs's garbage collector requires)
is still desirable.

To support such hardware, add a new encryption format IV_INO_LBLK_32
that makes the best use of the 32 bits: the IV is set to
'SipHash-2-4(inode_number) + file_logical_block_number mod 2^32', where
the SipHash key is derived from the fscrypt master key.  We hash only
the inode number and not also the block number, because we need to
maintain contiguity of DUNs to merge bios.

Unlike with IV_INO_LBLK_64, with this format IV reuse is possible; this
is unavoidable given the size of the DUN.  This means this format should
only be used where the requirements of the first paragraph apply.
However, the hash spreads out the IVs in the whole usable range, and the
use of a keyed hash makes it difficult for an attacker to determine
which files use which IVs.

Besides the above differences, this flag works like IV_INO_LBLK_64 in
that on ext4 it is only allowed if the stable_inodes feature has been
enabled to prevent inode numbers and the filesystem UUID from changing.

Link: https://lore.kernel.org/r/20200515204141.251098-1-ebiggers@kernel.org
Reviewed-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Paul Crowley <paulcrowley@google.com>
Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-06-16 14:06:45 -07:00
..
acpi cpufreq: Use per-policy frequency QoS 2019-10-21 02:05:21 +02:00
asm-generic timekeeping/vsyscall: Update VDSO data unconditionally 2019-11-04 23:02:53 +01:00
clocksource
crypto Merge branch 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 2019-09-27 19:37:27 -07:00
drm drm/shmem: Add docbook comments for drm_gem_shmem_object madvise fields 2019-11-06 17:57:42 -06:00
dt-bindings
keys
kvm
linux fscrypt: support test_dummy_encryption=v2 2020-06-16 14:06:41 -07:00
math-emu
media
misc
net net/tls: use sg_next() to walk sg entries 2019-12-04 22:31:02 +01:00
pcmcia
ras
rdma RDMA/uverbs: Prevent potential underflow 2019-10-22 15:05:36 -03:00
scsi SCSI fixes on 20191015 2019-10-15 12:19:08 -07:00
soc
sound ALSA: hda: Modify stream stripe mask only when needed 2019-12-13 08:42:39 +01:00
target
trace f2fs: add compressed/gc data read IO stat 2020-05-18 13:21:19 -07:00
uapi fscrypt: add support for IV_INO_LBLK_32 policies 2020-06-16 14:06:45 -07:00
vdso
video
xen xen: fixes and cleanups for 5.4-rc2 2019-10-04 11:13:09 -07:00
Kbuild