anchor.diff:  (defvar *fingerprint-length* 5)
   (defvar *fingerprint* #(82 111 98 105 110))
   (defvar *token-length* 128)
  +(defvar *user-tokens-path* #p"/etc/hermes/")
   
   (defun main (&rest args)
     (declare (ignore args))
  
positive.code:     (let ((bytes (make-array *fingerprint-length* :element-type '(unsigned-byte 8))))
        (read-sequence bytes f)
        (every #'= bytes *fingerprint*))))
  
negative.code:         (timing-safe-compare user-token device-token *token-length*)))))
  
  (defun read-user-token (user)
    (read-token (merge-pathnames user *user-tokens-path*)))
  
  (defun read-device-token (device)
    (read-token device 5))
  