Remove all the logic around custom session IDs and retrying on collisions.

A random 32-byte (so 256-bit) session ID is never going to collide with
an existing one. (And, if it does, SSL_CTX_add_session does account for
this, so the server won't explode. Just attempting to resume some
session will fail.)

That logic didn't completely work anyway as it didn't account for
external session caches or multiple connections picking the same ID in
parallel (generation and insertion happen at different times) or
multiple servers sharing one cache. In theory one could fix this by
passing in a sufficiently clever generate_session_id, but no one does

I found no callers of these functions, so just remove them altogether.

Change-Id: I8500c592cf4676de6d7194d611b99e9e76f150a7
Reviewed-by: Adam Langley <>
6 files changed
tree: 03d0c781ac950bbe440a6b1127f5353ea9174cd2
  1. .clang-format
  2. .gitignore
  4. CMakeLists.txt
  9. codereview.settings
  10. crypto/
  11. decrepit/
  12. include/
  13. ssl/
  14. tool/
  15. 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.

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

  • how to port OpenSSL-using code to BoringSSL.
  • how to build BoringSSL
  • rules and guidelines for coding style.
  • include/openssl: public headers with API documentation in comments. Also available online.