gcc/ada/g-sha1.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT LIBRARY COMPONENTS                          --
   4 --                                                                          --
   5 --                            G N A T . S H A 1                             --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --                     Copyright (C) 2002-2006, AdaCore                     --
  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 2,  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.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- As a special exception,  if other files  instantiate  generics from this --
  23 -- unit, or you link  this unit with other files  to produce an executable, --
  24 -- this  unit  does not  by itself cause  the resulting  executable  to  be --
  25 -- covered  by the  GNU  General  Public  License.  This exception does not --
  26 -- however invalidate  any other reasons why  the executable file  might be --
  27 -- covered by the  GNU Public License.                                      --
  28 --                                                                          --
  29 -- GNAT was originally developed  by the GNAT team at  New York University. --
  30 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  31 --                                                                          --
  32 ------------------------------------------------------------------------------
  33
  34 --  This package implements the US Secure Hash Algorithm 1 (SHA1) as described
  35 --  in RFC 3174. The complete text of RFC 3174 can be found at:
  36
  37 --          http://www.ietf.org/rfc/rfc3174.txt
  38
  39 --  Note: the code for this unit is derived from GNAT.MD5
  40
  41 with Ada.Streams;
  42 with Interfaces;
  43
  44 package GNAT.SHA1 is
  45
  46    type Context is private;
  47    --  This type holds the five-word (20 byte) buffer H, as described in
  48    --  RFC 3174 (6.1). Its initial value is Initial_Context below.
  49
  50    Initial_Context : constant Context;
  51    --  Initial value of a Context object. May be used to reinitialize
  52    --  a Context value by simple assignment of this value to the object.
  53
  54    procedure Update
  55      (C     : in out Context;
  56       Input : String);
  57    procedure Wide_Update
  58      (C     : in out Context;
  59       Input : Wide_String);
  60    procedure Update
  61      (C     : in out Context;
  62       Input : Ada.Streams.Stream_Element_Array);
  63    --  Modify the Context C. If C has the initial value Initial_Context,
  64    --  then, after a call to one of these procedures, Digest (C) will return
  65    --  the Message-Digest of Input.
  66    --
  67    --  These procedures may be called successively with the same context and
  68    --  different inputs, and these several successive calls will produce
  69    --  the same final context as a call with the concatenation of the inputs.
  70
  71    subtype Message_Digest is String (1 .. 40);
  72    --  The string type returned by function Digest
  73
  74    function Digest (C : Context) return Message_Digest;
  75    --  Extracts the Message-Digest from a context. This function should be
  76    --  used after one or several calls to Update.
  77
  78    function Digest      (S : String)      return Message_Digest;
  79    function Wide_Digest (W : Wide_String) return Message_Digest;
  80    function Digest
  81      (A : Ada.Streams.Stream_Element_Array) return Message_Digest;
  82    --  These functions are equivalent to the corresponding Update (or
  83    --  Wide_Update) on a default initialized Context, followed by Digest
  84    --  on the resulting Context.
  85
  86 private
  87
  88    --  Magic numbers
  89
  90    Initial_H0 : constant := 16#67452301#;
  91    Initial_H1 : constant := 16#EFCDAB89#;
  92    Initial_H2 : constant := 16#98BADCFE#;
  93    Initial_H3 : constant := 16#10325476#;
  94    Initial_H4 : constant := 16#C3D2E1F0#;
  95
  96    type H_Type is array (0 .. 4) of Interfaces.Unsigned_32;
  97
  98    Initial_H : constant H_Type :=
  99                 (0 => Initial_H0,
 100                  1 => Initial_H1,
 101                  2 => Initial_H2,
 102                  3 => Initial_H3,
 103                  4 => Initial_H4);
 104
 105    type Context is record
 106       H      : H_Type := Initial_H;
 107       Buffer : String (1 .. 64)  := (others => ASCII.NUL);
 108       Last   : Natural := 0;
 109       Length : Natural := 0;
 110    end record;
 111
 112    Initial_Context : constant Context :=
 113      (H => Initial_H,
 114       Buffer => (others => ASCII.NUL), Last => 0, Length => 0);
 115
 116 end GNAT.SHA1;