Run select_certificate_cb multiple times

It's not completely clear to me why select_cetificate_cb behaves the way it
does, however not only is it confusing, but it makes assumptions about the
application using BoringSSL (it's not always possible to implement custom
logic outside of the callbacks provided by libssl), that make this callback
somewhat useless.

Case in point, the callback can be used for changing min/max protocol versions
based on per-site policies, and select_certificate_cb is the only place where
SSL_set_min/max_proto_version() can be used (e.g. you can't call them in
cert_cb because it's too late), but the decision on the specific versions to
use might depend on configuration that needs retrieving asynchronously from
over the network, which requires re-running the callback multiple times.

Change-Id: Ia8e151b163628545373e7fd1f327e9af207478a6
Reviewed-on: https://boringssl-review.googlesource.com/13000
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
3 files changed
tree: eff6641f481843b4e33787792bb93e7512e7b620
  1. .github/
  2. crypto/
  3. decrepit/
  4. fuzz/
  5. include/
  6. infra/
  7. ssl/
  8. third_party/
  9. tool/
  10. util/
  11. .clang-format
  12. .gitignore
  13. API-CONVENTIONS.md
  14. BUILDING.md
  15. CMakeLists.txt
  16. codereview.settings
  17. CONTRIBUTING.md
  18. FUZZING.md
  19. INCORPORATING.md
  20. LICENSE
  21. PORTING.md
  22. README.md
  23. STYLE.md
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.

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