anchor.diff:  (defun ssl-ctx-set-options (ctx options)
     "Function version of the openssl macro."
     (ssl-ctx-ctrl ctx +ssl-ctrl-options+ options (cffi:null-pointer)))
  -
  
positive.code: (defconstant +ssl-op-cookie-exchange+ #x00002000)
  ;; Don't use RFC4507 ticket extension
  (defconstant +ssl-op-no-ticket+ #x00004000)
  ;; Use Cisco's "speshul" version of DTLS_BAD_VER (as client) 
  (defconstant +ssl-op-cisco-anyconnect+ #x00008000)
  ;; As server, disallow session resumption on renegotiation
  (defconstant +ssl-op-no-session-resumption-on-renegotiation+ #x00010000)
  
negative.code:   (parg :pointer))
  (cffi:defcfun ("BIO_ctrl_pending" ssl-bio-ctrl-pending) :unsigned-int
    (bio :pointer))
  (cffi:defcfun ("BIO_s_mem" ssl-bio-s-mem) :pointer)
  (cffi:defcfun ("BIO_read" ssl-bio-read) :int
    (bio :pointer)
    (buf :pointer)
  