Alert on ClientHello with only one of key_share and supported_groups

RFC 8446 section 9.2 states that a ClientHello supporting TLS 1.3 must
always contain both or neither of "key_share" and "supported_groups",
and a violation should result in a "missing extension" alert.

Previously a ClientHello that violated this would fail to negotiate a
group and result in a "handshake failure" alert. This CL aligns with the
spec to send a "missing extension" alert instead.

Update-Note: This CL changes the value of the TLS alert sent by the
server when receiving a TLS 1.3 ClientHello erroneously containing only
one of the key_share and supported_groups extensions. It does not alter
the success or failure of the handshake.

Bug: 500638473
Change-Id: Iebaddc73bdd3a4f2eaf464119fdae8906a6a6964
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/95168
Reviewed-by: David Benjamin <davidben@google.com>
Auto-Submit: Lily Chen <chlily@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Commit-Queue: Lily Chen <chlily@google.com>
3 files changed
tree: f9ac5e51a0a27156e50ca409cc22281e076facf7
  1. .bcr/
  2. .github/
  3. bench/
  4. cmake/
  5. crypto/
  6. decrepit/
  7. docs/
  8. fuzz/
  9. gen/
  10. include/
  11. infra/
  12. pki/
  13. rust/
  14. ssl/
  15. third_party/
  16. tool/
  17. util/
  18. .bazelignore
  19. .bazelrc
  20. .bazelversion
  21. .clang-format
  22. .clang-format-ignore
  23. .clangd
  24. .gitattributes
  25. .gitignore
  26. API-CONVENTIONS.md
  27. AUTHORS
  28. BREAKING-CHANGES.md
  29. BUILD.bazel
  30. build.json
  31. BUILDING.md
  32. CMakeLists.txt
  33. codereview.settings
  34. CONTRIBUTING.md
  35. FUZZING.md
  36. go.mod
  37. go.sum
  38. INCORPORATING.md
  39. LICENSE
  40. MODULE.bazel
  41. MODULE.bazel.lock
  42. PORTING.md
  43. PRESUBMIT.py
  44. PrivacyInfo.xcprivacy
  45. README.md
  46. SANDBOXING.md
  47. SECURITY.md
  48. 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:

To file a security issue, use the Chromium process and mention in the report this is for BoringSSL. You can ignore the parts of the process that are specific to Chromium/Chrome.

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