Deduplicate our three ServerHello parsers.

We do this enough that it's worth extracting a common parser. And this
gives a struct we can pass around. Note this moves the server extensions
block parsing out of ssl_scan_serverhello_tlsext.

I've also consolidated a few error conditions to tighten the code up a
bit: the TLS 1.2 code distinguishes unknown from unadvertised cipher,
while the TLS 1.3 code didn't. And seeing the wrong legacy version
number in TLS 1.3 is really just a syntax error since it's not the
version field anymore. (RFC8446 specifies the value.)

Change-Id: Ia2f44ff9a3899b5a594569f1b258f2b487930496
Commit-Queue: David Benjamin <>
Reviewed-by: Adam Langley <>
5 files changed
tree: 05fc2de883b00ec93c16e8b63991ab0656cbea46
  1. .github/
  2. crypto/
  3. decrepit/
  4. fuzz/
  5. include/
  6. ssl/
  7. third_party/
  8. tool/
  9. util/
  10. .clang-format
  11. .gitignore
  15. CMakeLists.txt
  16. codereview.settings
  19. go.mod
  20. go.sum
  26. sources.cmake


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: