SSL_get_peer_certificate - get the X509 certificate of the peer
X509 *SSL_get_peer_certificate(const SSL *ssl);
Due to the protocol definition, a TLS/SSL server will always send a certificate, if present. A client will only send a certificate when explicitly requested to do so by the server (see SSL_CTX_set_verify(3)). If an anonymous cipher is used, no certificates are sent.
That a certificate is returned does not indicate information about the verification state, use SSL_get_verify_result(3) to check the verification state.
The reference count of the X509 object is incremented by one, so that it
will not be destroyed when the session containing the peer certificate is
freed. The X509 object must be explicitly freed using
The following return values can occur: