Commit Graph

9 Commits

Author SHA1 Message Date
Ard Biesheuvel
c8bf850e99 crypto: arm/aes-neonbs-ctr - deal with non-multiples of AES block size
Instead of falling back to C code to deal with the final bit of input
that is not a round multiple of the block size, handle this in the asm
code, permitting us to use overlapping loads and stores for performance,
and implement the 16-byte wide XOR using a single NEON instruction.

Since NEON loads and stores have a natural width of 16 bytes, we need to
handle inputs of less than 16 bytes in a special way, but this rarely
occurs in practice so it does not impact performance. All other input
sizes can be consumed directly by the NEON asm code, although it should
be noted that the core AES transform can still only process 128 bytes (8
AES blocks) at a time.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2022-02-05 15:10:51 +11:00
Ard Biesheuvel
be6d699397 crypto: arm/aes-neonbs - avoid loading reorder argument on encryption
Reordering the tweak is never necessary for encryption, so avoid the
argument load on the encryption path.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-09-25 17:48:15 +10:00
Ard Biesheuvel
45a4777e5b crypto: arm/aes-neonbs - avoid hacks to prevent Thumb2 mode switches
Instead of using a homegrown macrofied version of the adr instruction
that sets the Thumb bit in the output value, only to ensure that any
bx instructions consuming that value will not switch out of Thumb mode
when branching, use non-interworking mov (to PC) instructions, which
achieve the same thing.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2020-09-25 17:48:14 +10:00
Ard Biesheuvel
2ed8b79098 crypto: arm/aes-neonbs - implement ciphertext stealing for XTS
Update the AES-XTS implementation based on NEON instructions so that it
can deal with inputs whose size is not a multiple of the cipher block
size. This is part of the original XTS specification, but was never
implemented before in the Linux kernel.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-09-09 17:35:39 +10:00
Ard Biesheuvel
38e73b3d38 crypto: arm/aes-neonbs - replace tweak mask literal with composition
Replace the vector load from memory sequence with a simple instruction
sequence to compose the tweak vector directly.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-09-09 17:35:28 +10:00
Thomas Gleixner
d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
Based on 2 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
Ard Biesheuvel
1a20b96612 crypto: arm/aes - don't use IV buffer to return final keystream block
The ARM bit sliced AES core code uses the IV buffer to pass the final
keystream block back to the glue code if the input is not a multiple of
the block size, so that the asm code does not have to deal with anything
except 16 byte blocks. This is done under the assumption that the outgoing
IV is meaningless anyway in this case, given that chaining is no longer
possible under these circumstances.

However, as it turns out, the CCM driver does expect the IV to retain
a value that is equal to the original IV except for the counter value,
and even interprets byte zero as a length indicator, which may result
in memory corruption if the IV is overwritten with something else.

So use a separate buffer to return the final keystream block.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-02-03 18:16:21 +08:00
Ard Biesheuvel
13954e788d crypto: arm/aes-neonbs - fix issue with v2.22 and older assembler
The GNU assembler for ARM version 2.22 or older fails to infer the
element size from the vmov instructions, and aborts the build in
the following way;

.../aes-neonbs-core.S: Assembler messages:
.../aes-neonbs-core.S:817: Error: bad type for scalar -- `vmov q1h[1],r10'
.../aes-neonbs-core.S:817: Error: bad type for scalar -- `vmov q1h[0],r9'
.../aes-neonbs-core.S:817: Error: bad type for scalar -- `vmov q1l[1],r8'
.../aes-neonbs-core.S:817: Error: bad type for scalar -- `vmov q1l[0],r7'
.../aes-neonbs-core.S:818: Error: bad type for scalar -- `vmov q2h[1],r10'
.../aes-neonbs-core.S:818: Error: bad type for scalar -- `vmov q2h[0],r9'
.../aes-neonbs-core.S:818: Error: bad type for scalar -- `vmov q2l[1],r8'
.../aes-neonbs-core.S:818: Error: bad type for scalar -- `vmov q2l[0],r7'

Fix this by setting the element size explicitly, by replacing vmov with
vmov.32.

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-01-23 22:50:25 +08:00
Ard Biesheuvel
cc477bf645 crypto: arm/aes - replace bit-sliced OpenSSL NEON code
This replaces the unwieldy generated implementation of bit-sliced AES
in CBC/CTR/XTS modes that originated in the OpenSSL project with a
new version that is heavily based on the OpenSSL implementation, but
has a number of advantages over the old version:
- it does not rely on the scalar AES cipher that also originated in the
  OpenSSL project and contains redundant lookup tables and key schedule
  generation routines (which we already have in crypto/aes_generic.)
- it uses the same expanded key schedule for encryption and decryption,
  reducing the size of the per-key data structure by 1696 bytes
- it adds an implementation of AES in ECB mode, which can be wrapped by
  other generic chaining mode implementations
- it moves the handling of corner cases that are non critical to performance
  to the glue layer written in C
- it was written directly in assembler rather than generated from a Perl
  script

Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-01-13 18:27:31 +08:00