Enforce key usage for RSA keys in TLS 1.2.

For now, this is off by default and controlled by SSL_set_enforce_rsa_key_usage.
This may be set as late as certificate verification so we may start by enforcing
it for known roots.

Generalizes ssl_cert_check_digital_signature_key_usage to check any part of the
key_usage, and adds a new error KEY_USAGE_BIT_INCORRECT for the generalized

Bug: chromium:795089
Change-Id: Ifa504c321bec3263a4e74f2dc48513e3b895d3ee
Reviewed-on: https://boringssl-review.googlesource.com/c/34604
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
10 files changed
tree: b11902db8a834b965947f16f2ad83136e93d3f80
  1. .github/
  2. crypto/
  3. decrepit/
  4. fipstools/
  5. fuzz/
  6. include/
  7. ssl/
  8. third_party/
  9. tool/
  10. util/
  11. .clang-format
  12. .gitignore
  15. BUILDING.md
  16. CMakeLists.txt
  17. codereview.settings
  19. FUZZING.md
  20. go.mod
  23. PORTING.md
  24. README.md
  25. sources.cmake
  26. STYLE.md


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: