Back to...

   1  --  Zip.CRC_Crypto deals with hash-like functions
   2  --  for data integrity check and encryption
   3  -------------------------------------------------
   4  
   5  --  Legal licensing note:
   6  
   7  --  Copyright (c) 1999 .. 2024 Gautier de Montmollin
   8  --  SWITZERLAND
   9  
  10  --  Permission is hereby granted, free of charge, to any person obtaining a copy
  11  --  of this software and associated documentation files (the "Software"), to deal
  12  --  in the Software without restriction, including without limitation the rights
  13  --  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  --  copies of the Software, and to permit persons to whom the Software is
  15  --  furnished to do so, subject to the following conditions:
  16  
  17  --  The above copyright notice and this permission notice shall be included in
  18  --  all copies or substantial portions of the Software.
  19  
  20  --  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  21  --  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  22  --  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  23  --  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  24  --  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  25  --  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  26  --  THE SOFTWARE.
  27  
  28  --  NB: this is the MIT License, as found on the site
  29  --  http://www.opensource.org/licenses/mit-license.php
  30  
  31  package Zip.CRC_Crypto is
  32  
  33    use Interfaces;
  34  
  35    -------------------------------------------------------------
  36    --  CRC: Cyclic Redundancy Check to verify data integrity  --
  37    -------------------------------------------------------------
  38  
  39    procedure Init (CRC : out Unsigned_32);
  40  
  41    procedure Update (CRC : in out Unsigned_32; InBuf : Zip.Byte_Buffer);
  42    pragma Inline (Update);
  43  
  44    function  Final (CRC : Unsigned_32) return Unsigned_32;
  45    pragma Inline (Final);
  46  
  47    ------------------
  48    --  Encryption  --
  49    ------------------
  50  
  51    type Crypto_pack is private;
  52    --
  53    type Crypto_Mode is (clear, encrypted);
  54    procedure Set_Mode (obj : in out Crypto_pack; new_mode : Crypto_Mode);
  55    function Get_Mode (obj : Crypto_pack) return Crypto_Mode;
  56    --
  57    procedure Init_Keys (obj : in out Crypto_pack; password : String);
  58    --
  59    procedure Encode (obj : in out Crypto_pack; buf : in out Zip.Byte_Buffer);
  60    pragma Inline (Encode);
  61    --
  62    procedure Decode (obj : in out Crypto_pack; b : in out Unsigned_8);
  63    pragma Inline (Decode);
  64  
  65  private
  66    type Decrypt_Keys is array (0 .. 2) of Unsigned_32;
  67    type Crypto_Pack is record
  68      keys         : Decrypt_Keys;
  69      current_mode : Crypto_Mode;
  70    end record;
  71  
  72  end Zip.CRC_Crypto;