Subversion Repositories deslxcore

 
-- Copyright (c) 2013 Antonio de la Piedra
 
-- 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/>.
 
library IEEE;
use IEEE.STD_LOGIC_1164.ALL;
 
entity des_loop is
	port(clk :  in std_logic;
		  rst : in std_logic;
		  mode : in std_logic; -- 0 encrypt, 1 decrypt
		  key_in : in std_logic_vector(55 downto 0);
		  key_pre_w_in : in std_logic_vector(63 downto 0);
		  key_pos_w_in : in std_logic_vector(63 downto 0);
		  blk_in : in std_logic_vector(63 downto 0);
		  blk_out : out std_logic_vector(63 downto 0));
end des_loop;
 
architecture Behavioral of des_loop is
 
	signal after_ip_s : std_logic_vector(63 downto 0);
	signal after_ip_minus_one_s : std_logic_vector(63 downto 0);
	signal after_f_s : std_logic_vector(31 downto 0);
	signal final_s : std_logic_vector(63 downto 0);
 
	component des_round is
		port(clk : in std_logic;
			  l_0 : in std_logic_vector(31 downto 0);
		     r_0 : in std_logic_vector(31 downto 0);
		     k_i : in std_logic_vector(47 downto 0);
		     l_1 : out std_logic_vector(31 downto 0);
		     r_1 : out std_logic_vector(31 downto 0));
	end component;
 
	component key_schedule is
		port(clk : in std_logic;
			  rst : in std_logic;
		     mode : in std_logic; -- 0 encrypt, 1 decrypt
	        key : in std_logic_vector(55 downto 0);
		     key_out : out std_logic_vector(47 downto 0));
	end component;
 
	signal key_s : std_logic_vector(47 downto 0);
 
	signal l_0_s : std_logic_vector(31 downto 0);
	signal l_1_s : std_logic_vector(31 downto 0);
	signal r_0_s : std_logic_vector(31 downto 0);
	signal r_1_s : std_logic_vector(31 downto 0);
 
	signal rst_s : std_logic;
 
	signal blk_in_s  : std_logic_vector(63 downto 0);
	signal blk_out_s : std_logic_vector(63 downto 0);
 
begin
 
	pr_rst_delay : process(clk, rst)
	begin
		if rising_edge(clk) then
			rst_s <= rst;
		end if;
	end process;
 
	blk_in_s <= (blk_in xor key_pre_w_in) when mode = '0' else (blk_in xor key_pos_w_in);
 
	pr_seq: process(clk, rst_s, blk_in)
	begin
		if rst_s = '1' then
			l_0_s <= blk_in_s(63 downto 32);
			r_0_s <= blk_in_s(31 downto 0);
		elsif rising_edge(clk) then
			l_0_s <= l_1_s;
			r_0_s <= r_1_s;
		end if;
	end process;
 
	DES_ROUND_0 :  des_round port map (clk, l_0_s, r_0_s, key_s, l_1_s, r_1_s);
 
	blk_out_s <= r_1_s & l_1_s;
 
	blk_out <= (blk_out_s xor key_pre_w_in) when mode = '1' else (blk_out_s xor key_pos_w_in);
 
	KEY_SCHEDULE_0 : key_schedule port map (clk, rst, mode, key_in, key_s);
 
end Behavioral;