Do fewer trial divisions for larger RSA keygens.

Now that Miller-Rabin can reject composites faster, we can do fewer
trial divisions. Halving the table seems to improve things for RSA-3072
and RSA-4096. I left RSA-2048 alone since measurements with it halved
were a bit more of a wash.

(Although now that I've left it alone, it's gotten faster, so these
numbers are generally noisy.)

Did 320 RSA 2048 key-gen operations in 30132984us (10.6 ops/sec)
  min: 27703us, median: 81774us, max: 375687us
Did 84 RSA 3072 key-gen operations in 30166627us (2.8 ops/sec)
  min: 86961us, median: 322184us, max: 1170392us
Did 30 RSA 4096 key-gen operations in 30644802us (1.0 ops/sec)
  min: 260916us, median: 772364us, max: 2743435us

Did 345 RSA 2048 key-gen operations in 30103781us (11.5 ops/sec)
  min: 23359us, median: 75033us, max: 267159us
Did 91 RSA 3072 key-gen operations in 30185495us (3.0 ops/sec)
  min: 72531us, median: 267385us, max: 1119039us
Did 38 RSA 4096 key-gen operations in 30473203us (1.2 ops/sec)
  min: 228529us, median: 720027us, max: 2039681us

Change-Id: I52d431347a70572034ced5b7778a2edac8f15173
Commit-Queue: David Benjamin <>
Reviewed-by: Adam Langley <>
1 file changed
tree: 23163d582cfff54661eee51ab20d3b1b645214ca
  1. .clang-format
  2. .github/
  3. .gitignore
  7. CMakeLists.txt
  15. codereview.settings
  16. crypto/
  17. decrepit/
  18. fuzz/
  19. go.mod
  20. include/
  21. sources.cmake
  22. ssl/
  23. third_party/
  24. tool/
  25. util/


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.

Project links:

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