extern const pcre *regex_STARTTLS; /* For recognizing STARTTLS settings */
extern uschar *tls_advertise_hosts; /* host for which TLS is advertised */
extern uschar *tls_certificate; /* Certificate file */
+extern uschar *tls_channelbinding_b64; /* string of base64 channel binding */
extern uschar *tls_crl; /* CRL File */
extern uschar *tls_dhparam; /* DH param file */
extern BOOL tls_offered; /* Server offered TLS */