curve25519: replace field implementation with filippo.io/edwards25519

This imports the crypto/ed25519/internal/edwards25519/field package from
CL 276272, and uses it in x/crypto/curve25519.

The ScalarMult code was ported 1:1 from curve25519_generic.go.

                                old code lines     new code lines

Go                              896                463
Assembly (manually written)     1772 (1772)        362 (34)

43% performance loss on amd64, 33% loss on 386, and 45% gain on arm64.
Feels worth it to remove 1700 lines of manually written assembly.

Apple M1

name               old time/op  new time/op  delta
X25519Basepoint-8  85.0µs ± 1%  46.4µs ± 0%  -45.39%  (p=0.000 n=10+9)
X25519-8           84.4µs ± 0%  46.7µs ± 2%  -44.76%  (p=0.000 n=8+9)

Intel(R) Core(TM) i5-7400 CPU @ 3.00GHz

name               old time/op  new time/op  delta
X25519Basepoint-4  42.6µs ± 1%  60.9µs ± 1%  +43.22%  (p=0.000 n=9+10)
X25519-4           42.5µs ± 1%  60.9µs ± 0%  +43.17%  (p=0.000 n=9+9)

Intel(R) Core(TM) i5-7400 CPU @ 3.00GHz [GOARCH=386]

name               old time/op  new time/op  delta
X25519Basepoint-4   530µs ± 1%   703µs ± 1%  +32.81%  (p=0.000 n=10+10)
X25519-4            530µs ± 1%   706µs ± 1%  +33.18%  (p=0.000 n=10+10)

Change-Id: I1dc62a6a3a3e417a1366ff873c475087a0395124
Reviewed-on: https://go-review.googlesource.com/c/crypto/+/315269
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Trust: Filippo Valsorda <filippo@golang.org>
Trust: Katie Hockman <katie@golang.org>
Reviewed-by: Katie Hockman <katie@golang.org>
23 files changed
tree: d854abbf40375cbced0bebe45c52ecbd51b2fa33
  1. acme/
  2. argon2/
  3. bcrypt/
  4. blake2b/
  5. blake2s/
  6. blowfish/
  7. bn256/
  8. cast5/
  9. chacha20/
  10. chacha20poly1305/
  11. cryptobyte/
  12. curve25519/
  13. ed25519/
  14. hkdf/
  15. internal/
  16. md4/
  17. nacl/
  18. ocsp/
  19. openpgp/
  20. otr/
  21. pbkdf2/
  22. pkcs12/
  23. poly1305/
  24. ripemd160/
  25. salsa20/
  26. scrypt/
  27. sha3/
  28. ssh/
  29. tea/
  30. twofish/
  31. xtea/
  32. xts/
  33. .gitattributes
  34. .gitignore
  35. AUTHORS
  36. codereview.cfg
  37. CONTRIBUTING.md
  38. CONTRIBUTORS
  39. go.mod
  40. go.sum
  41. LICENSE
  42. PATENTS
  43. README.md
README.md

Go Cryptography

Go Reference

This repository holds supplementary Go cryptography libraries.

Download/Install

The easiest way to install is to run go get -u golang.org/x/crypto/.... You can also manually git clone the repository to $GOPATH/src/golang.org/x/crypto.

Report Issues / Send Patches

This repository uses Gerrit for code changes. To learn how to submit changes to this repository, see https://golang.org/doc/contribute.html.

The main issue tracker for the crypto repository is located at https://github.com/golang/go/issues. Prefix your issue with “x/crypto:” in the subject line, so it is easy to find.

Note that contributions to the cryptography package receive additional scrutiny due to their sensitive nature. Patches may take longer than normal to receive feedback.