Previously we would extract the KEM ID from the ECHConfig and then parse
the private key using the corresponding KEM type. This CL makes it take
a pre-pared EVP_HPKE_KEY and checks it matches. This does require the
caller pass the key type through externally, which is probably prudent?
(On the other hand we are still inferring config from the rest of the
ECHConfig... maybe we can add an API to extract the EVP_HPKE_KEM from a
serialized ECHConfig if it becomes a problem. I could see runner or tool
wanting that out of convenience.)
The immediate motivation is to add APIs to programmatically construct
ECHConfigs. I'm thinking we can pass a const EVP_HPKE_KEY * to specify
the key, at which point it's weird for SSL_ECH_KEYS_add to look
different.
Bug: 275
Change-Id: I2d424323885103d3fe0a99a9012c160baa8653bd
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/48002
Commit-Queue: David Benjamin <davidben@google.com>
Reviewed-by: Adam Langley <agl@google.com>
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>
David Benjamin
Daniel McArdle
Adam Langley