commit b2c312d670b9967cf881419758f0ec286b66a25f
author Adam Langley <agl@google.com> Fri Nov 03 12:03:13 2017 -0700
committer CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org> Fri Nov 03 22:39:31 2017 +0000
tree e0142f6357c84fdf2470172cc3423ec7c787fc4f
parent 5b280a80dfdb70939d725cd22a1a0a902c2fdbef

curve25519: fiat-crypto field arithmetic.

Each operation was translated from fiat-crypto output using fiat-crypto
prettyprint.py. For example fe_mul is synthesized in
https://github.com/mit-plv/fiat-crypto/blob/master/src/Specific/X25519/C32/femul.v,
and shown in the last Coq-compatible form at
https://github.com/mit-plv/fiat-crypto/blob/master/src/Specific/X25519/C32/femulDisplay.log.

Benchmarks on Google Cloud's unidentified Intel Xeon with AVX2:

git checkout $VARIANT && ( cd build && rm -rf * && CC=clang CXX=clang++ cmake -GNinja -DCMAKE_TOOLCHAIN_FILE=../util/32-bit-toolchain.cmake -DCMAKE_BUILD_TYPE=Release .. && ninja && ./tool/bssl speed -filter 25519 )

this branch:

Did 11382 Ed25519 key generation operations in 1053046us (10808.6 ops/sec)
Did 11169 Ed25519 signing operations in 1038080us (10759.3 ops/sec)
Did 2925 Ed25519 verify operations in 1001346us (2921.1 ops/sec)
Did 12000 Curve25519 base-point multiplication operations in 1084851us (11061.4 ops/sec)
Did 3850 Curve25519 arbitrary point multiplication operations in 1085565us (3546.5 ops/sec)

Did 11466 Ed25519 key generation operations in 1049821us (10921.9 ops/sec)
Did 11000 Ed25519 signing operations in 1013317us (10855.4 ops/sec)
Did 3047 Ed25519 verify operations in 1043846us (2919.0 ops/sec)
Did 12000 Curve25519 base-point multiplication operations in 1068924us (11226.2 ops/sec)
Did 3850 Curve25519 arbitrary point multiplication operations in 1090598us (3530.2 ops/sec)

Did 10309 Ed25519 key generation operations in 1003320us (10274.9 ops/sec)
Did 11000 Ed25519 signing operations in 1017862us (10807.0 ops/sec)
Did 3135 Ed25519 verify operations in 1098624us (2853.6 ops/sec)
Did 9000 Curve25519 base-point multiplication operations in 1046608us (8599.2 ops/sec)
Did 3132 Curve25519 arbitrary point multiplication operations in 1038963us (3014.5 ops/sec)

master:

Did 11564 Ed25519 key generation operations in 1068762us (10820.0 ops/sec)
Did 11104 Ed25519 signing operations in 1024278us (10840.8 ops/sec)
Did 3206 Ed25519 verify operations in 1049179us (3055.7 ops/sec)
Did 12000 Curve25519 base-point multiplication operations in 1073619us (11177.1 ops/sec)
Did 3550 Curve25519 arbitrary point multiplication operations in 1000279us (3549.0 ops/sec)
andreser@linux-andreser:~/boringssl$ build/tool/bssl speed -filter 25519
Did 11760 Ed25519 key generation operations in 1072495us (10965.1 ops/sec)
Did 10800 Ed25519 signing operations in 1003486us (10762.5 ops/sec)
Did 3245 Ed25519 verify operations in 1080399us (3003.5 ops/sec)
Did 12000 Curve25519 base-point multiplication operations in 1076021us (11152.2 ops/sec)
Did 3570 Curve25519 arbitrary point multiplication operations in 1005087us (3551.9 ops/sec)
andreser@linux-andreser:~/boringssl$ build/tool/bssl speed -filter 25519
Did 11438 Ed25519 key generation operations in 1041115us (10986.3 ops/sec)
Did 11000 Ed25519 signing operations in 1012589us (10863.2 ops/sec)
Did 3312 Ed25519 verify operations in 1082834us (3058.6 ops/sec)
Did 12000 Curve25519 base-point multiplication operations in 1061318us (11306.7 ops/sec)
Did 3580 Curve25519 arbitrary point multiplication operations in 1004923us (3562.5 ops/sec)

squashed: curve25519: convert field constants to unsigned.

import re, sys, math

def weight(i):
    return 2**int(math.ceil(25.5*i))

def convert(t):
    limbs = [x for x in t.groups() if x.replace('-','').isdigit()]
    v = sum(weight(i)*x for (i,x) in enumerate(map(int, limbs))) % (2**255-19)
    limbs = [(v % weight(i+1)) // weight(i) for i in range(10)]
    assert v == sum(weight(i)*x for (i,x) in enumerate(limbs))

    i = 0
    ret = ''
    for s in t.groups():
        if s.replace('-','').isdigit():
            ret += str(limbs[i])
            i += 1
        else:
            ret += s
    return ret

fe_re = re.compile(r'(\s*,\s*)'.join(r'(-?\d+)' for i in range(10)))
print (re.sub(fe_re, convert, sys.stdin.read()))

Change-Id: Ibd4f7f5c38e5c4d61c9826afb406baebe2be5168
Reviewed-on: https://boringssl-review.googlesource.com/22385
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>