Instead of copying the calculated authentication tag to memory and
calling crypto_memneq() to verify it, use vector bytewise compare and
min across vector instructions to decide whether the tag is valid. This
is more efficient, and given that the tag is only transiently held in a
NEON register, it is also safer, given that calculated tags for failed
decryptions should be withheld.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
A couple of functions were missed in the modernisation of assembly macros,
update them too.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
In an effort to clarify and simplify the annotation of assembly functions
in the kernel new macros have been introduced. These replace ENTRY and
ENDPROC and also add a new annotation for static functions which previously
had no ENTRY equivalent. Update the annotations in the crypto code to the
new macros.
There are a small number of files imported from OpenSSL where the assembly
is generated using perl programs, these are not currently annotated at all
and have not been modified.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
To improve performance on cores with deep pipelines such as ThunderX2,
reimplement gcm(aes) using a 4-way interleave rather than the 2-way
interleave we use currently.
This comes down to a complete rewrite of the GCM part of the combined
GCM/GHASH driver, and instead of interleaving two invocations of AES
with the GHASH handling at the instruction level, the new version
uses a more coarse grained approach where each chunk of 64 bytes is
encrypted first and then ghashed (or ghashed and then decrypted in
the converse case).
The core NEON routine is now able to consume inputs of any size,
and tail blocks of less than 64 bytes are handled using overlapping
loads and stores, and processed by the same 4-way encryption and
hashing routines. This gets rid of most of the branches, and avoids
having to return to the C code to handle the tail block using a
stack buffer.
The table below compares the performance of the old driver and the new
one on various micro-architectures and running in various modes.
| AES-128 | AES-192 | AES-256 |
#bytes | 512 | 1500 | 4k | 512 | 1500 | 4k | 512 | 1500 | 4k |
-------+-----+------+-----+-----+------+-----+-----+------+-----+
TX2 | 35% | 23% | 11% | 34% | 20% | 9% | 38% | 25% | 16% |
EMAG | 11% | 6% | 3% | 12% | 4% | 2% | 11% | 4% | 2% |
A72 | 8% | 5% | -4% | 9% | 4% | -5% | 7% | 4% | -5% |
A53 | 11% | 6% | -1% | 10% | 8% | -1% | 10% | 8% | -2% |
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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>
Enhance the GHASH implementation that uses 64-bit polynomial
multiplication by adding support for 4-way aggregation. This
more than doubles the performance, from 2.4 cycles per byte
to 1.1 cpb on Cortex-A53.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Checking the TIF_NEED_RESCHED flag is disproportionately costly on cores
with fast crypto instructions and comparatively slow memory accesses.
On algorithms such as GHASH, which executes at ~1 cycle per byte on
cores that implement support for 64 bit polynomial multiplication,
there is really no need to check the TIF_NEED_RESCHED particularly
often, and so we can remove the NEON yield check from the assembler
routines.
However, unlike the AEAD or skcipher APIs, the shash/ahash APIs take
arbitrary input lengths, and so there needs to be some sanity check
to ensure that we don't hog the CPU for excessive amounts of time.
So let's simply cap the maximum input size that is processed in one go
to 64 KB.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Squeeze out another 5% of performance by minimizing the number
of invocations of kernel_neon_begin()/kernel_neon_end() on the
common path, which also allows some reloads of the key schedule
to be optimized away.
The resulting code runs at 2.3 cycles per byte on a Cortex-A53.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Implement a faster version of the GHASH transform which amortizes
the reduction modulo the characteristic polynomial across two
input blocks at a time.
On a Cortex-A53, the gcm(aes) performance increases 24%, from
3.0 cycles per byte to 2.4 cpb for large input sizes.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Update the core AES/GCM transform and the associated plumbing to operate
on 2 AES/GHASH blocks at a time. By itself, this is not expected to
result in a noticeable speedup, but it paves the way for reimplementing
the GHASH component using 2-way aggregation.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
As it turns out, checking the TIF_NEED_RESCHED flag after each
iteration results in a significant performance regression (~10%)
when running fast algorithms (i.e., ones that use special instructions
and operate in the < 4 cycles per byte range) on in-order cores with
comparatively slow memory accesses such as the Cortex-A53.
Given the speed of these ciphers, and the fact that the page based
nature of the AEAD scatterwalk API guarantees that the core NEON
transform is never invoked with more than a single page's worth of
input, we can estimate the worst case duration of any resulting
scheduling blackout: on a 1 GHz Cortex-A53 running with 64k pages,
processing a page's worth of input at 4 cycles per byte results in
a delay of ~250 us, which is a reasonable upper bound.
So let's remove the yield checks from the fused AES-CCM and AES-GCM
routines entirely.
This reverts commit 7b67ae4d5c and
partially reverts commit 7c50136a8a.
Fixes: 7c50136a8a ("crypto: arm64/aes-ghash - yield NEON after every ...")
Fixes: 7b67ae4d5c ("crypto: arm64/aes-ccm - yield NEON after every ...")
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Avoid excessive scheduling delays under a preemptible kernel by
yielding the NEON after every block of input.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Implement a NEON fallback for systems that do support NEON but have
no support for the optional 64x64->128 polynomial multiplication
instruction that is part of the ARMv8 Crypto Extensions. It is based
on the paper "Fast Software Polynomial Multiplication on ARM Processors
Using the NEON Engine" by Danilo Camara, Conrado Gouvea, Julio Lopez and
Ricardo Dahab (https://hal.inria.fr/hal-01506572), but has been reworked
extensively for the AArch64 ISA.
On a low-end core such as the Cortex-A53 found in the Raspberry Pi3, the
NEON based implementation is 4x faster than the table based one, and
is time invariant as well, making it less vulnerable to timing attacks.
When combined with the bit-sliced NEON implementation of AES-CTR, the
AES-GCM performance increases by 2x (from 58 to 29 cycles per byte).
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Currently, the AES-GCM implementation for arm64 systems that support the
ARMv8 Crypto Extensions is based on the generic GCM module, which combines
the AES-CTR implementation using AES instructions with the PMULL based
GHASH driver. This is suboptimal, given the fact that the input data needs
to be loaded twice, once for the encryption and again for the MAC
calculation.
On Cortex-A57 (r1p2) and other recent cores that implement micro-op fusing
for the AES instructions, AES executes at less than 1 cycle per byte, which
means that any cycles wasted on loading the data twice hurt even more.
So implement a new GCM driver that combines the AES and PMULL instructions
at the block level. This improves performance on Cortex-A57 by ~37% (from
3.5 cpb to 2.6 cpb)
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The GHASH key and digest are both pairs of 64-bit quantities, but the
GHASH code does not always refer to them as such, causing failures when
built for big endian. So replace the 16x1 loads and stores with 2x8 ones.
Fixes: b913a6404c ("arm64/crypto: improve performance of GHASH algorithm")
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This patches modifies the GHASH secure hash implementation to switch to a
faster, polynomial multiplication based reduction instead of one that uses
shifts and rotates.
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This is a port to ARMv8 (Crypto Extensions) of the Intel implementation of the
GHASH Secure Hash (used in the Galois/Counter chaining mode). It relies on the
optional PMULL/PMULL2 instruction (polynomial multiply long, what Intel call
carry-less multiply).
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Herbert Xu <herbert@gondor.apana.org.au>
Ard Biesheuvel