Pull in the latest changes from s2n-bignum (2023-08-04)

[aqjune-aws]

Issues:

N/A

Description of changes:

This PR is splitted from #1108 and a successor of (already merged) #1114. This PR is independent from #1135.

This PR pulls in the vectorized versions of functions (which are verified) for montgomery multiplications in Graviton 2 from s2n-bignum. In consequence, this adds the following files from s2n-bignum: arm/fastmul/bignum_emontredc_8n_neon.S, arm/fastmul/bignum_kmul_16_32_neon.S, arm/fastmul/bignum_ksqr_16_32_neon.S, arm/fastmul/bignum_ksqr_16_32_neon.S, arm/fastmul/bignum_ksqr_32_64_neon.S

The commands used:
(The commands in the internal Quip document was used, with PATHS_TO_KEEP added to include the new 5 files)

TODAY=$(date +%Y-%m-%d)

git fetch upstream main  # Fetch the tip of main of AWS-LC 
git checkout -b aws-lc-s2n-bignum-update-${TODAY} upstream/main

git fetch s2n-bignum     # Fetch the tip of main of s2n-bignum
git checkout -b s2n-bignum-${TODAY} s2n-bignum/main

PATHS_TO_KEEP="./arm/p384 ./x86_att/p384 ./arm/p521 ./x86_att/p521 ./x86_att/curve25519/curve25519_x25519.S ./x86_att/curve25519/curve25519_x25519base.S ./x86_att/curve25519/curve25519_x25519_alt.S ./x86_att/curve25519/curve25519_x25519base_alt.S  ./arm/curve25519/curve25519_x25519.S ./arm/curve25519/curve25519_x25519base.S ./arm/curve25519/curve25519_x25519_alt.S ./arm/curve25519/curve25519_x25519base_alt.S ./arm/curve25519/curve25519_x25519_byte.S ./arm/curve25519/curve25519_x25519base_byte.S ./arm/curve25519/curve25519_x25519_byte_alt.S ./arm/curve25519/curve25519_x25519base_byte_alt.S ./arm/fastmul/bignum_emontredc_8n.S ./arm/fastmul/bignum_emontredc_8n_neon.S ./arm/fastmul/bignum_kmul_16_32.S ./arm/fastmul/bignum_kmul_16_32_neon.S ./arm/fastmul/bignum_kmul_32_64.S ./arm/fastmul/bignum_kmul_32_64_neon.S ./arm/fastmul/bignum_ksqr_16_32.S ./arm/fastmul/bignum_ksqr_16_32_neon.S ./arm/fastmul/bignum_ksqr_32_64.S ./arm/fastmul/bignum_ksqr_32_64_neon.S ./arm/generic/bignum_ge.S ./arm/generic/bignum_mul.S ./arm/generic/bignum_optsub.S ./arm/generic/bignum_sqr.S ./include/_internal_s2n_bignum.h"

git filter-branch -f --index-filter "git rm --ignore-unmatch --cached -qr -- . && git reset -q \$GIT_COMMIT -- $PATHS_TO_KEEP" --msg-filter 'cat; echo; echo "s2n-bignum original commit: https://github.com/awslabs/s2n-bignum/commit/$GIT_COMMIT"' --prune-empty -- HEAD

git checkout aws-lc-s2n-bignum-update-${TODAY}
git merge -s subtree -Xsubtree="third_party/s2n-bignum" s2n-bignum-${TODAY} --allow-unrelated-histories

Call-outs:

Point out areas that need special attention or support during the review process. Discuss architecture or design changes.

Testing:

How is this change tested (unit tests, fuzz tests, etc.)? Are there any testing steps to be verified by the reviewer?

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license and the ISC license.