1------------------------------------------------------------------------------
2--                                                                          --
3--                         GNAT LIBRARY COMPONENTS                          --
4--                                                                          --
5--              G N A T . S E C U R E _ H A S H E S . S H A 1               --
6--                                                                          --
7--                                 S p e c                                  --
8--                                                                          --
9--         Copyright (C) 2002-2019, 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 SHA-1
33--  secure hash function as described in FIPS PUB 180-3. The complete text
34--  of FIPS PUB 180-3 can be found at:
35--    http://csrc.nist.gov/publications/fips/fips180-3/fips180-3_final.pdf
36
37--  This is an internal unit and should not be used directly in applications.
38--  Use GNAT.SHA1 instead.
39
40with GNAT.Byte_Swapping;
41with Interfaces;
42
43package GNAT.Secure_Hashes.SHA1 is
44
45   package Hash_State is new Hash_Function_State
46     (Word           => Interfaces.Unsigned_32,
47      Swap           => GNAT.Byte_Swapping.Swap4,
48      Hash_Bit_Order => System.High_Order_First);
49   --  SHA-1 operates on 32-bit big endian words
50
51   Block_Words : constant := 16;
52   --  Messages are processed in chunks of 16 words
53
54   procedure Transform
55     (H : in out Hash_State.State;
56      M : in out Message_State);
57   --  Transformation function applied for each block
58
59   Initial_State : constant Hash_State.State;
60   --  Initialization vector
61
62private
63
64   Initial_State : constant Hash_State.State :=
65                     (0 => 16#67452301#,
66                      1 => 16#EFCDAB89#,
67                      2 => 16#98BADCFE#,
68                      3 => 16#10325476#,
69                      4 => 16#C3D2E1F0#);
70   --  Initialization vector from FIPS PUB 180-3
71
72end GNAT.Secure_Hashes.SHA1;
73