tree f619efe9f79984ba14c1913c2f2974650504075d
parent ebd8b8965c74ab06bb91f7a00b23822e1f1f26ca
author David Benjamin <davidben@google.com> 1661544169 -0400
committer Boringssl LUCI CQ <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com> 1661549115 +0000

Add an EVP_HPKE_KEM_enc_len API.

OHTTP concatenates enc to the ciphertext without any length prefix
(unlike ECH), so an implementation would want to know the length of enc
for the chosen KEM. Add an accessor to help with that.

While I'm here, fix a couple places where we assumed a specific KEM in
the HPKE implementation (although we still only support the one KEM so
this is all moot).

There's probably something to be said for lifting the length checks out
of the KEM-specific code and into the wrappers, as we're assuming
fixed-width fields anyway. But I've left it alone for now.

Change-Id: I634a053faa5e3b35d846b690140333bdc741f92a
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/54065
Reviewed-by: Adam Langley <agl@google.com>
Auto-Submit: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>