Return an error if no recipient type matches.

If the key type does not match any CMS recipient type return
an error instead of using a random key (MMA mitigation). This
does not leak any useful information to an attacker.

PR#3348
safety check to ensure we dont send out beyond the users buffer
Unit/regression test for TLS heartbeats.

Regression test against CVE-2014-0160 (Heartbleed).

More info: http://mike-bland.com/tags/heartbleed.html

(based on commit 35cb55988b75573105eefd00d27d0138eebe40b1)