Add a more general mechanism for deprecating TLS ciphers

This generalizes the scheme we previously had with
TLS_RSA_WITH_NULL_SHA, in preparation for TLS_RSA_WITH_3DES_EDE_CBC_SHA
(to be deprecated in a later CL) and
TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256 (to regretably be added back in,
but in a deprecated state).

The story is that deprecated ciphers can always be listed by name, but
by default, selectors will not match them when adding ciphers. They will
still match them when removing ciphers. This is so instructions like
"@STRENGTH" or "!RSA" will still sort or disable the deprecated ciphers,
rather than accidentally leaving them at the front or enabled.

Additionally, a selector can mark itself as including deprecated
ciphers. This is specifically for TLS_RSA_WITH_3DES_EDE_CBC_SHA, because
many callers reference it with just "3DES". As an added quirk,
"RSA+3DES" will also match it. (The rule is that, if any selector matches
deprecated ciphers, we'll allow the overall expression to match it. This
is slightly weird, but keeps "RSA+3DES" working.)

Note, in this CL, 3DES is not actually deprecated. This just sets up the
machinery and doesn't do anything with it. But the blockers for
deprecating that should hopefully be resolved soon.

Bug: 599
Change-Id: I7212bdc879b0e49c6742025644f3100026f24228
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/59646
Auto-Submit: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
Commit-Queue: Adam Langley <agl@google.com>
2 files changed
tree: d748b0566c797e9fb6b2ac20c7aa079e4d523711
  1. .github/
  2. cmake/
  3. crypto/
  4. decrepit/
  5. fuzz/
  6. include/
  7. rust/
  8. ssl/
  9. third_party/
  10. tool/
  11. util/
  12. .clang-format
  13. .gitignore
  14. API-CONVENTIONS.md
  15. BREAKING-CHANGES.md
  16. BUILDING.md
  17. CMakeLists.txt
  18. codereview.settings
  19. CONTRIBUTING.md
  20. FUZZING.md
  21. go.mod
  22. go.sum
  23. INCORPORATING.md
  24. LICENSE
  25. PORTING.md
  26. README.md
  27. SANDBOXING.md
  28. sources.cmake
  29. 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.

Project links:

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