Add a constant-time pshufb-based GHASH implementation.

We currently require clmul instructions for constant-time GHASH
on x86_64. Otherwise, it falls back to a variable-time 4-bit table
implementation. However, a significant proportion of clients lack these
instructions.

Inspired by vpaes, we can use pshufb and a slightly different order of
incorporating the bits to make a constant-time GHASH. This requires
SSSE3, which is very common. Benchmarking old machines we had on hand,
it appears to be a no-op on Sandy Bridge and a small slowdown for
Penryn.

Sandy Bridge (Intel Pentium CPU 987 @ 1.50GHz):
(Note: these numbers are before 16-byte-aligning the table. That was an
improvement on Penryn, so it's possible Sandy Bridge is now better.)
Before:
Did 4244750 AES-128-GCM (16 bytes) seal operations in 4015000us (1057222.9 ops/sec): 16.9 MB/s
Did 442000 AES-128-GCM (1350 bytes) seal operations in 4016000us (110059.8 ops/sec): 148.6 MB/s
Did 84000 AES-128-GCM (8192 bytes) seal operations in 4015000us (20921.5 ops/sec): 171.4 MB/s
Did 3349250 AES-256-GCM (16 bytes) seal operations in 4016000us (833976.6 ops/sec): 13.3 MB/s
Did 343500 AES-256-GCM (1350 bytes) seal operations in 4016000us (85532.9 ops/sec): 115.5 MB/s
Did 65250 AES-256-GCM (8192 bytes) seal operations in 4015000us (16251.6 ops/sec): 133.1 MB/s
After:
Did 4229250 AES-128-GCM (16 bytes) seal operations in 4016000us (1053100.1 ops/sec): 16.8 MB/s [-0.4%]
Did 442250 AES-128-GCM (1350 bytes) seal operations in 4016000us (110122.0 ops/sec): 148.7 MB/s [+0.1%]
Did 83500 AES-128-GCM (8192 bytes) seal operations in 4015000us (20797.0 ops/sec): 170.4 MB/s [-0.6%]
Did 3286500 AES-256-GCM (16 bytes) seal operations in 4016000us (818351.6 ops/sec): 13.1 MB/s [-1.9%]
Did 342750 AES-256-GCM (1350 bytes) seal operations in 4015000us (85367.4 ops/sec): 115.2 MB/s [-0.2%]
Did 65250 AES-256-GCM (8192 bytes) seal operations in 4016000us (16247.5 ops/sec): 133.1 MB/s [-0.0%]

Penryn (Intel Core 2 Duo CPU P8600 @ 2.40GHz):
Before:
Did 1179000 AES-128-GCM (16 bytes) seal operations in 1000139us (1178836.1 ops/sec): 18.9 MB/s
Did 97000 AES-128-GCM (1350 bytes) seal operations in 1006347us (96388.2 ops/sec): 130.1 MB/s
Did 18000 AES-128-GCM (8192 bytes) seal operations in 1028943us (17493.7 ops/sec): 143.3 MB/s
Did 977000 AES-256-GCM (16 bytes) seal operations in 1000197us (976807.6 ops/sec): 15.6 MB/s
Did 82000 AES-256-GCM (1350 bytes) seal operations in 1012434us (80992.9 ops/sec): 109.3 MB/s
Did 15000 AES-256-GCM (8192 bytes) seal operations in 1006528us (14902.7 ops/sec): 122.1 MB/s
After:
Did 1306000 AES-128-GCM (16 bytes) seal operations in 1000153us (1305800.2 ops/sec): 20.9 MB/s [+10.8%]
Did 94000 AES-128-GCM (1350 bytes) seal operations in 1009852us (93082.9 ops/sec): 125.7 MB/s [-3.4%]
Did 17000 AES-128-GCM (8192 bytes) seal operations in 1012096us (16796.8 ops/sec): 137.6 MB/s [-4.0%]
Did 1070000 AES-256-GCM (16 bytes) seal operations in 1000929us (1069006.9 ops/sec): 17.1 MB/s [+9.4%]
Did 79000 AES-256-GCM (1350 bytes) seal operations in 1002209us (78825.9 ops/sec): 106.4 MB/s [-2.7%]
Did 15000 AES-256-GCM (8192 bytes) seal operations in 1061489us (14131.1 ops/sec): 115.8 MB/s [-5.2%]

Change-Id: I1c3760a77af7bee4aee3745d1c648d9e34594afb
Reviewed-on: https://boringssl-review.googlesource.com/c/34267
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
6 files changed
tree: 5120578bec28a56e89b6b252392f05c2411a3faa
  1. .clang-format
  2. .github/
  3. .gitignore
  4. API-CONVENTIONS.md
  5. BREAKING-CHANGES.md
  6. BUILDING.md
  7. CMakeLists.txt
  8. CONTRIBUTING.md
  9. FUZZING.md
  10. INCORPORATING.md
  11. LICENSE
  12. PORTING.md
  13. README.md
  14. STYLE.md
  15. codereview.settings
  16. crypto/
  17. decrepit/
  18. fipstools/
  19. fuzz/
  20. go.mod
  21. include/
  22. infra/
  23. sources.cmake
  24. ssl/
  25. third_party/
  26. tool/
  27. util/
README.md

BoringSSL

BoringSSL is a fork of OpenSSL that is designed to meet Google's needs.

Although BoringSSL is an open source project, it is not intended for general use, as OpenSSL is. We don't recommend that third parties depend upon it. Doing so is likely to be frustrating because there are no guarantees of API or ABI stability.

Programs ship their own copies of BoringSSL when they use it and we update everything as needed when deciding to make API changes. This allows us to mostly avoid compromises in the name of compatibility. It works for us, but it may not work for you.

BoringSSL arose because Google used OpenSSL for many years in various ways and, over time, built up a large number of patches that were maintained while tracking upstream OpenSSL. As Google's product portfolio became more complex, more copies of OpenSSL sprung up and the effort involved in maintaining all these patches in multiple places was growing steadily.

Currently BoringSSL is the SSL library in Chrome/Chromium, Android (but it's not part of the NDK) and a number of other apps/programs.

There are other files in this directory which might be helpful: