The current content of the ocsp module is focused on the processing needed to implement an OCSP client: it only implements request generation and response parsing. This change adds response generation and request parsing. Change-Id: Idf6f4e69af504520f2b58340734e45cd92bb3d60 Reviewed-on: https://go-review.googlesource.com/3666 Reviewed-by: Adam Langley <agl@golang.org>