* gostdsa-vko.c (gostdsa_vko): Use ecc_mod_mul_canonical to
compute the scalar used for ecc multiplication.

* eddsa-hash.c (_eddsa_hash): Ensure result is canonically
reduced. Two of the three call sites need that.

* ecc-gostdsa-verify.c (ecc_gostdsa_verify): Use ecc_mod_mul_canonical
to compute the scalars used for ecc multiplication.

* ecc-ecdsa-sign.c (ecc_ecdsa_sign): Ensure s output is reduced to
canonical range.

* ecc-ecdsa-verify.c (ecc_ecdsa_verify): Use ecc_mod_mul_canonical
to compute the scalars used for ecc multiplication.
* testsuite/ecdsa-verify-test.c (test_main): Add test case that
triggers an assert on 64-bit platforms, without above fix.
* testsuite/ecdsa-sign-test.c (test_main): Test case generating
the same signature.

* eddsa-verify.c (equal_h): Use ecc_mod_mul_canonical.

* ecc-mod-arith.c (ecc_mod_mul_canonical, ecc_mod_sqr_canonical):
New functions.
* ecc-internal.h: Declare and document new functions.
* curve448-eh-to-x.c (curve448_eh_to_x): Use ecc_mod_sqr_canonical.
* curve25519-eh-to-x.c (curve25519_eh_to_x): Use ecc_mod_mul_canonical.
* ecc-eh-to-a.c (ecc_eh_to_a): Likewise.
* ecc-j-to-a.c (ecc_j_to_a): Likewise.
* ecc-mul-m.c (ecc_mul_m): Likewise.

* configure.ac: Bump package version, to 3.7.1.
(LIBNETTLE_MINOR): Bump minor number, to 8.2.
(LIBHOGWEED_MINOR): Bump minor number, to 6.2.

Michael Weiser authored Dec 25, 2020 and Niels Möller committed Jan 13, 2021

Switch arm neon assembler routines to endianness-agnostic loads and
stores where possible to avoid modifications to the rest of the code.
This involves switching to vld1.32 for loading consecutive 32-bit words
in host endianness as well as vst1.8 for storing back to memory in
little-endian order as required by the caller. Where necessary, r3 is
used to store the precalculated offset into the source vector for the
secondary load operations. vstm is kept for little-endian platforms
because it is faster than vst1 on most ARM implementations.

vst1.x (at least on the Allwinner A20 Cortex-A7 implementation) seems to
interfer with itself on subsequent calls, slowing it down further. So we
reschedule some instructions to do stores as soon as results become
available to have some other calculations or loads before the next
vst1.x. This reliably saves two additional cycles per block on salsa20
and chacha which would otherwise be incurred.

vld1.x does not seem to suffer from this or at least not to a level
where two consecutive vld1.x run slower than an equivalent vldm.
Rescheduling them similarly did not improve performance beyond that of
vldm.

Signed-off-by: Michael Weiser <michael.weiser@gmx.de>

* fat-ppc.c: Don't use __GLIBC_PREREQ in the same preprocessor
conditional as defined(__GLIBC_PREREQ), but move to a nested #if
conditional. Fixes compile error on OpenBSD/powerpc64, reported by
Jasper Lievisse Adriaanse.