TLS Encrypted Client Hello Draft Specification (F/K/a ESNI)

BoringSSL ticket for ECH implementation: https://bugs.chromium.org/p/boringssl/issues/detail?id=275

Chromium ticket for adding TLS ECH (blocked on above ticket): https://bugs.chromium.org/p/chromium/issues/detail?id=109140...

(FYI good etiquette on these is to avoid piling on with "me too!" or "oh neat!" on such bugs, just click the star if you want to vote for & follow the bugs.)