[ Not upstream because this is a minimal fix for a bug where arm32
kernels can use a much slower implementation of AES than is actually
available, potentially forcing vendors to disable encryption on their
devices.]
All the aes-bs (bit-sliced) and aes-ce (cryptographic extensions)
algorithms had a priority of 300. This is undesirable because it means
an aes-bs algorithm may be used when an aes-ce algorithm is available.
The aes-ce algorithms have much better performance (up to 10x faster).
Fix it by decreasing the priority of the aes-bs algorithms to 250.
This was fixed upstream by commit cc477bf645 ("crypto: arm/aes -
replace bit-sliced OpenSSL NEON code"), but it was just a small part of
a complete rewrite. This patch just fixes the priority bug for older
kernels.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Commit 28856a9e52 missed the addition of the crypto/xts.h include file
for different architecture-specific AES implementations.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
The patch centralizes the XTS key check logic into the service function
xts_check_key which is invoked from the different XTS implementations.
With this, the XTS implementations in ARM, ARM64, PPC and S390 have now
a sanity check for the XTS keys similar to the other arches.
In addition, this service function received a check to ensure that the
key != the tweak key which is mandated by FIPS 140-2 IG A.9. As the
check is not present in the standards defining XTS, it is only enforced
in FIPS mode of the kernel.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Flag all NEON bit sliced AES helper ciphers as internal ciphers to
prevent them from being called by normal users.
Signed-off-by: Stephan Mueller <smueller@chronox.de>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Fix the same alignment bug as in arm64 - we need to pass residue
unprocessed bytes as the last argument to blkcipher_walk_done.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # 3.13+
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Bit sliced AES gives around 45% speedup on Cortex-A15 for encryption
and around 25% for decryption. This implementation of the AES algorithm
does not rely on any lookup tables so it is believed to be invulnerable
to cache timing attacks.
This algorithm processes up to 8 blocks in parallel in constant time. This
means that it is not usable by chaining modes that are strictly sequential
in nature, such as CBC encryption. CBC decryption, however, can benefit from
this implementation and runs about 25% faster. The other chaining modes
implemented in this module, XTS and CTR, can execute fully in parallel in
both directions.
The core code has been adopted from the OpenSSL project (in collaboration
with the original author, on cc). For ease of maintenance, this version is
identical to the upstream OpenSSL code, i.e., all modifications that were
required to make it suitable for inclusion into the kernel have been made
upstream. The original can be found here:
http://git.openssl.org/gitweb/?p=openssl.git;a=commit;h=6f6a6130
Note to integrators:
While this implementation is significantly faster than the existing table
based ones (generic or ARM asm), especially in CTR mode, the effects on
power efficiency are unclear as of yet. This code does fundamentally more
work, by calculating values that the table based code obtains by a simple
lookup; only by doing all of that work in a SIMD fashion, it manages to
perform better.
Cc: Andy Polyakov <appro@openssl.org>
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Eric Biggers