Abstract away BIO_flush calls in the handshake.

This is the first part to removing the buffer BIO. The eventual end
state is the SSL_PROTOCOL_METHOD is responsible for maintaining one
flight's worth of messages. In TLS, it will just be a buffer containing
the flight's ciphertext. In DTLS, it's the existing structure for
retransmit purposes. There will be hooks:

- add_message (synchronous)
- add_change_cipher_spec (synchronous)
- add_warning_alert (synchronous; needed until we lose SSLv3 client auth
  and TLS 1.3 draft 18; draft 19 will switch end_of_early_data to a
  handshake message)
- write_flight (BIO; flush_flight will be renamed to this)

This also preserves the exact return value of BIO_flush. Eventually all
the BIO_write calls will be hidden behind BIO_flush to, to be consistent
with other BIO-based calls, preserve the return value.

BUG=72

Change-Id: I74cd23759a17356aab3bb475a8ea42bd2cd115c9
Reviewed-on: https://boringssl-review.googlesource.com/13222
Reviewed-by: Adam Langley <agl@google.com>
6 files changed
tree: b77d5723b03778a9c54f9ed4a05e84dfb211409a
  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: