anchor.diff:  NIST SP 800-108 specification.
   
   
  -Ciphers
  -~~~~~~~
  -
  -TODO
  +Block Ciphers
  +~~~~~~~~~~~~~
  +
  +WIP
  +
  +
  +Stream Ciphers
  +~~~~~~~~~~~~~~
  +
  +WIP
   
   
   Codecs (binary -> string conversion)
  
positive.code: (require '[ring.util.response :refer (response redirect)])
  
  ;; An unauthorized-handler is executed when `buddy.auth/throw-unauthorized`
  ;; exception is raised and captured by genric authorization middleware:
  ;; `wrap-authorization`. It always receives the current request and metadata
  ;; hash-map that in most cases is empty.
  
  
negative.code:     (response "Permission denied")
      (redirect "/login")))
  ----
  
  .Defining a simple handler that raises unauthorized exception when user is not authenticated
  [source,clojure]
  