gcc/m2/gm2-libs-iso/SimpleCipher.def

   1 (* SimpleCipher.def provides a pegalogical caesar cipher.
   2
   3 Copyright (C) 2008-2021 Free Software Foundation, Inc.
   4 Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
   5
   6 This file is part of GNU Modula-2.
   7
   8 GNU Modula-2 is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GNU Modula-2 is distributed in the hope that it will be useful, but
  14 WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 General Public License for more details.
  17
  18 Under Section 7 of GPL version 3, you are granted additional
  19 permissions described in the GCC Runtime Library Exception, version
  20 3.1, as published by the Free Software Foundation.
  21
  22 You should have received a copy of the GNU General Public License and
  23 a copy of the GCC Runtime Library Exception along with this program;
  24 see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  25 <http://www.gnu.org/licenses/>.  *)
  26
  27 DEFINITION MODULE SimpleCipher ;
  28
  29 (*
  30     Title      : SimpleCipher
  31     Author     : Gaius Mulley
  32     System     : GNU Modula-2
  33     Date       : Mon Sep 29 11:02:56 2008
  34     Revision   : $Version$
  35     Description: provides a simple Caesar cipher layer which
  36                  can be attached to any channel device.  This,
  37                  pedagogical, module is designed to show how
  38                  it is possible to add further layers underneath
  39                  the channel devices.
  40 *)
  41
  42 FROM IOChan IMPORT ChanId ;
  43
  44
  45 (*
  46    InsertCipherLayer - inserts a caesar cipher below channel, cid.
  47                        The encryption, key, is specified.
  48 *)
  49
  50 PROCEDURE InsertCipherLayer (cid: ChanId; key: INTEGER) ;
  51
  52
  53 (*
  54    RemoveCipherLayer - removes a Caesar cipher below channel, cid.
  55 *)
  56
  57 PROCEDURE RemoveCipherLayer (cid: ChanId) ;
  58
  59
  60 END SimpleCipher.