1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT LIBRARY COMPONENTS                          --
4--                                                                          --
5--               G N A T . S E C U R E _ H A S H E S . M D 5                --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--         Copyright (C) 2002-2018, Free Software Foundation, Inc.          --
10--                                                                          --
11-- GNAT is free software;  you can  redistribute it  and/or modify it under --
12-- terms of the  GNU General Public License as published  by the Free Soft- --
13-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
14-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
15-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
16-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
17--                                                                          --
18-- As a special exception under Section 7 of GPL version 3, you are granted --
19-- additional permissions described in the GCC Runtime Library Exception,   --
20-- version 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-- GNAT was originally developed  by the GNAT team at  New York University. --
28-- Extensive contributions were provided by Ada Core Technologies Inc.      --
29--                                                                          --
30------------------------------------------------------------------------------
31
32--  This package provides supporting code for implementation of the MD5
33--  Message-Digest Algorithm as described in RFC 1321. The complete text of
34--  RFC 1321 can be found at:
35--          http://www.ietf.org/rfc/rfc1321.txt
36
37--  This is an internal unit and should not be used directly in applications.
38--  Use GNAT.MD5 instead.
39
40with GNAT.Byte_Swapping;
41with Interfaces;
42
43package GNAT.Secure_Hashes.MD5 is
44
45   package Hash_State is
46     new GNAT.Secure_Hashes.Hash_Function_State
47           (Word           => Interfaces.Unsigned_32,
48            Swap           => GNAT.Byte_Swapping.Swap4,
49            Hash_Bit_Order => System.Low_Order_First);
50   --  MD5 operates on 32-bit little endian words
51
52   Block_Words : constant := 16;
53   --  Messages are processed in chunks of 16 words
54
55   procedure Transform
56     (H : in out Hash_State.State;
57      M : in out Message_State);
58   --  Transformation function applied for each block
59
60   Initial_State : constant Hash_State.State;
61   --  Initialization vector
62
63private
64
65   Initial_A : constant := 16#67452301#;
66   Initial_B : constant := 16#EFCDAB89#;
67   Initial_C : constant := 16#98BADCFE#;
68   Initial_D : constant := 16#10325476#;
69
70   Initial_State : constant Hash_State.State :=
71                     (Initial_A, Initial_B, Initial_C, Initial_D);
72   --  Initialization vector from RFC 1321
73
74end GNAT.Secure_Hashes.MD5;
75