Check EC_POINT/EC_GROUP compatibility more accurately.

Currently we only check that the underlying EC_METHODs match, which
avoids the points being in different forms, but not that the points are
on the same curves. (We fixed the APIs early on so off-curve EC_POINTs
cannot be created.)

In particular, this comes up with folks implementating Java's crypto
APIs with ECDH_compute_key. These APIs are both unfortunate and should
not be mimicked, as they allow folks to mismatch the groups on the two
multiple EC_POINTs. Instead, ECDH APIs should take the public value as a
byte string.

Thanks also to Java's poor crypto APIs, we must support custom curves,
which makes this particularly gnarly. This CL makes EC_GROUP_cmp work
with custom curves and adds an additional subtle requirement to

Annoyingly, this change is additionally subtle because we now have a
reference cycle to hack around.

Change-Id: I2efbc4bd5cb65fee5f66527bd6ccad6b9d5120b9
Reviewed-by: Adam Langley <>
Commit-Queue: David Benjamin <>
CQ-Verified: CQ bot account: <>
7 files changed
tree: ffc8e63bee532b8c6995b93324bcfb02959bc9fd
  1. .clang-format
  2. .github/
  3. .gitignore
  6. CMakeLists.txt
  14. codereview.settings
  15. crypto/
  16. decrepit/
  17. fipstools/
  18. fuzz/
  19. include/
  20. infra/
  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.

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