Avoid relying on SSL_get_session's behavior during the handshake.

Mid-renegotiation, there are a lot of sets of TLS parameters flying
around. We need to be clear which one we want for each operation. There
were a few parts of TLS 1.2 which were relying on SSL_get_session to
abstract between the resumption session and a new session.

Implement that separately as ssl_handshake_session, so we're free to
avoid SSL_get_session returning an incomplete session mid-renegotiation.

This doesn't fixed the linked Chromium bug, but it is necessary to do
so. (I'm trying to separate the SSL_get_session change from the
dependencies within the library.)

Update-Note: SSL_generate_key_block will now fail mid-handshake. It is
ambiguous which key block to use and, in some cases, we may not even be
able to compute the right key block.

Bug: chromium:1010748
Change-Id: I30c8a683bb506310e37adbd05a28e3b8de6e6836
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/41865
Reviewed-by: Steven Valdez <svaldez@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
5 files changed
tree: 85956e35da6ea502bc5d03c5ee7c6133504c7496
  1. .clang-format
  2. .github/
  3. .gitignore
  6. BUILDING.md
  7. CMakeLists.txt
  9. FUZZING.md
  12. PORTING.md
  13. README.md
  15. STYLE.md
  16. codereview.settings
  17. crypto/
  18. decrepit/
  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.

Project links:

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