Remove increment of reference count on first certificate added to a new SSL context - the call to SSL_CTX_use_certificate does this internally. When adding extra certificates to the context via calls to SSL_CTX_add_extra_certificate, the explicit increment of the reference count is still required to prevent destruction of the certificates when the SSL context is freed. In OpenSSLContext::setPrivateKey, make sure the EVP_PKEY returned by PEM_read_bio_PrivateKey is tidied up, by wrapping it in a shared_ptr which calls EVP_PKEY_free. Add a new Unit test which creates an SSL context and inserts a multi-element certificate chain and a private key. JIRA: SWIFT-423 Bug: Release-notes: Manual: Change-Id: I82c66139a9dfe7a925eb39f73721200895a689e2 Test-information: Leak testing performed via ASAN-compiled MLink unit tests - now no leaks/errors reported associated with TLS Contexts and Certificates. Swiften unit test runs as expected.