Fix GRND_NONBLOCK flag when calling getrandom.

I screwed up in 56b6c714c9 and got the direction of this condition
backwards. This doesn't cause a security problem because:
  a) wait_for_entropy will ensure that the pool is initialised.
  b) if GRNG_NONBLOCK is set when not expected, any EAGAIN will
     cause an abort anyway.

However, when coupled with opportunistic entropy collection on platforms
with RDRAND, this could cause an unexpected blocking getrandom call.

This this change, `strace -e getrandom bssl rand 1` shows two getrandom
calls with GRNG_NONBLOCK set, as expected. (The first being the probe to
check whether the kernel supports getrandom, and the second being the
opportunistic entropy gathering to augment RDRAND.)

Change-Id: I98ed1cef90df510f24cf2df1fba9b886fcbf3355
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/38204
Commit-Queue: Adam Langley <agl@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
1 file changed
tree: 8dacf51f70841e5fdb9220ec6b20598c16821218
  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. fuzz/
  19. go.mod
  20. include/
  21. sources.cmake
  22. ssl/
  23. third_party/
  24. tool/
  25. 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.

Project links:

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