Compatibility changes for wpa_supplicant and OpenSSH.

OpenSSH, especially, does some terrible things that mean that it needs
the EVP_CIPHER structure to be exposed ☹. Damian is open to a better API
to replace this, but only if OpenSSL agree too. Either way, it won't be
happening soon.

Change-Id: I393b7a6af6694d4d2fe9ebcccd40286eff4029bd
Reviewed-on: https://boringssl-review.googlesource.com/4330
Reviewed-by: Adam Langley <agl@google.com>
14 files changed