SSL_get_version() was an easy one :-)

doc/ssl/SSL_get_version.pod

+=pod
+
+=head1 NAME
+
+SSL_get_version - get the protocol version of a connection.
+
+=head1 SYNOPSIS
+
+ #include <openssl/ssl.h>
+
+ const char *SSL_get_version(SSL *ssl);
+
+=head1 DESCRIPTION
+
+SSL_get_cipher_version() returns the name of the protocol used for the
+connection B<ssl>.
+
+=head1 RETURN VALUES
+
+The following strings can occur:
+
+=over 4
+
+=item SSLv2
+
+The connection uses the SSLv2 protocol.
+
+=item SSLv3
+
+The connection uses the SSLv3 protocol.
+
+=item TLSv1
+
+The connection uses the TLSv1 protocol.
+
+=item unknown
+
+This indicates that no version has been set (no connection established).
+
+=back
+
+=head1 SEE ALSO
+
+L<ssl(3)|ssl(3)>
+
+=cut

doc/ssl/ssl.pod

@@ -681,6 +681,7 @@ L<SSL_get_peer_cert_chain(3)|SSL_get_peer_cert_chain(3)>,
 L<SSL_get_rbio(3)|SSL_get_rbio(3)>,
 L<SSL_get_session(3)|SSL_get_session(3)>,
 L<SSL_get_verify_result(3)|SSL_get_verify_result(3)>,
+L<SSL_get_version(3)|SSL_get_version(3)>,
 L<SSL_library_init(3)|SSL_library_init(3)>,
 L<SSL_load_client_CA_file(3)|SSL_load_client_CA_file(3)>,
 L<SSL_new(3)|SSL_new(3)>,