--  Copyright (C) 2015  Daniel Otte <bg@nerilex.org>
--
--  This program is free software: you can redistribute it and/or modify
--  it under the terms of the GNU General Public License as published by
--  the Free Software Foundation, either version 3 of the License, or
--  (at your option) any later version.
--
--  This program is distributed in the hope that it will be useful,
--  but WITHOUT ANY WARRANTY; without even the implied warranty of
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--  GNU General Public License for more details.
--
--  You should have received a copy of the GNU General Public License
--  along with this program.  If not, see <http://www.gnu.org/licenses/>.

package body SHA2_256 is

   IV : constant u32_Array(1 .. 8) :=
     (
      16#6A09E667#, 16#BB67AE85#, 16#3C6EF372#, 16#A54FF53A#,
      16#510E527F#, 16#9B05688C#, 16#1F83D9AB#, 16#5BE0CD19#
     );

   procedure Initialize(Context : out Context_T) is
   begin
      Context.H := IV;
      Context.Counter := 0;
   end;

   procedure Next_Block(Context : in out Context_T; Block : in Block_512_Bit) is
   begin
      Sha2_Small.Next_Block(Sha2_Small.Context_T(Context), Block);
   end;

   procedure Last_Block(Context : in out Context_T; Block : in u8_Array; Bits : in Integer := -1) is
   begin
      Sha2_Small.Last_Block(Sha2_Small.Context_T(Context), Block, Bits);
   end;

   procedure Get_Digest(Context : in out Context_T; Digest : out Block_256_Bit) is
   begin
      Store_BE(Digest, Context.H);
   end;


   procedure Hash(Data : in u8_Array; Digest : out Block_256_Bit) is
      Context : Context_T;
   begin
      Initialize(Context);
      Last_Block(Context, Data);
      Get_Digest(Context, Digest);
   end;



end SHA2_256;