This CL adds an initial implementation of the ECH server, with pieces of
the client in BoGo as necessary for testing. In particular, the server
supports ClientHelloInner compression with ech_outer_extensions. When
ECH decryption fails, it can send retry_configs back to the client.
This server passes the "ech-accept" and "ech-reject" test cases in
tls-interop-runner[0] when tested against both the cloudflare-go and nss
clients. For reproducibility, I started with the main branch at commit
707604c262d8bcf3e944ed1d5a675077304732ce and updated the endpoint's
script to pass the server's ECHConfig and private key to the boringssl
tool.
Follow-up CLs will update HPKE to the latest draft and catch us up to
draft-10.
[0]: https://github.com/xvzcf/tls-interop-runner
Bug: 275
Change-Id: I49be35af46d1fd5dd9c62252f07d0bae179381ab
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/45285
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
Daniel McArdle
Adam Langley