The hkdf operations done in hpke are not expected to fail given that
we control the inputs. However, propagating the error instead of
doesn't hurt and makes the code more robust to future changes.
Change-Id: I168854593a40f67e2cc275e0dedc3b24b8f1480e
Reviewed-on: https://go-review.googlesource.com/c/go/+/658475 Reviewed-by: Roland Shoemaker <roland@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com> Reviewed-by: David Chase <drchase@google.com>