• Returns: {Buffer|undefined} The latest Finished message that has been sent to the socket as part of a SSL/TLS handshake, or undefined if no Finished message has been sent yet.

    As the Finished messages are message digests of the complete handshake (with a total of 192 bits for TLS 1.0 and more for SSL 3.0), they can be used for external authentication procedures when the authentication provided by SSL/TLS is not desired or is not enough.

    Corresponds to the SSL_get_finished routine in OpenSSL and may be used to implement the tls-unique channel binding from [RFC 5929][].