Do not distinguish NULL and empty PSK identity hints.

Plain PSK omits the ServerKeyExchange when there is no hint and includes
it otherwise (it should have always sent it), while other PSK ciphers
like ECDHE_PSK cannot omit the hint. Having different capabilities here
is odd and RFC 4279 5.2 suggests that all PSK ciphers are capable of
"[not] provid[ing] an identity hint".

Interpret this to mean no identity hint and empty identity hint are the
same state. Annoyingly, this gives a plain PSK implementation two
options for spelling an empty hint. The spec isn't clear and this is not
really a battle worth fighting, so I've left both acceptable and added a
test for this case.

See also https://android-review.googlesource.com/c/275217/. This is also
consistent with Android's PskKeyManager API, our only consumer anyway.

https://developer.android.com/reference/android/net/PskKeyManager.html

Change-Id: I8a8e6cc1f7dd1b8b202cdaf3d4f151bebfb4a25b
Reviewed-on: https://boringssl-review.googlesource.com/11087
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
6 files changed
tree: 6613b4f5399048ad0c7038ec5a91768e5ff7c489
  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: