SSL: the $ssl_client_escaped_cert variable (ticket #857). This variable contains URL-encoded client SSL certificate. In contrast to $ssl_client_cert, it doesn't depend on deprecated header continuation. The NGX_ESCAPE_URI_COMPONENT variant of encoding is used, so the resulting variable can be safely used not only in headers, but also as a request argument. The $ssl_client_cert variable should be considered deprecated now. The $ssl_client_raw_cert variable will be eventually renambed back to $ssl_client_cert.