Rewrite BN_CTX.

While allocating near INT_MAX BIGNUMs or stack frames would never happen, we
should properly handle overflow here. Rewrite it to just be a STACK_OF(BIGNUM)
plus a stack of indices. Also simplify the error-handling. If we make the
errors truly sticky (rather than just sticky per frame), we don't need to keep
track of err_stack and friends.

Thanks to mlbrown for reporting the integer overflows in the original

Bug: chromium:942269
Change-Id: Ie9c9baea3eeb82d65d88b1cb1388861f5cd84fe5
Commit-Queue: Adam Langley <>
Reviewed-by: Adam Langley <>
1 file changed
tree: 56d10a1040d22b970a34ee420012916b9d1a23f2
  1. .clang-format
  2. .github/
  3. .gitignore
  7. CMakeLists.txt
  15. codereview.settings
  16. crypto/
  17. decrepit/
  18. fipstools/
  19. fuzz/
  20. go.mod
  21. include/
  22. sources.cmake
  23. ssl/
  24. third_party/
  25. tool/
  26. 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: