cryptography ip-cores in vhdl / verilog
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-- ======================================================================
-- CBC-DES encryption/decryption
-- algorithm according to FIPS 46-3 specification
-- Copyright (C) 2007 Torsten Meissner
-------------------------------------------------------------------------
-- 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 2 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, write to the Free Software
-- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
-- ======================================================================
-- Revision 0.1 2011/09/23
-- Initial release, incomplete and may contain bugs
-- Revision 0.2 2011/10/06
-- corrected some bugs which were found while testing cbc ability
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use work.des_pkg.all;
entity cbcdes is
port (
reset_i : in std_logic; -- low active async reset
clk_i : in std_logic; -- clock
start_i : in std_logic; -- start cbc
mode_i : in std_logic; -- des-modus: 0 = encrypt, 1 = decrypt
key_i : in std_logic_vector(0 TO 63); -- key input
iv_i : in std_logic_vector(0 to 63); -- iv input
data_i : in std_logic_vector(0 TO 63); -- data input
valid_i : in std_logic; -- input key/data valid flag
ready_o : out std_logic; -- ready to encrypt/decrypt
data_o : out std_logic_vector(0 TO 63); -- data output
valid_o : out std_logic -- output data valid flag
);
end entity cbcdes;
architecture rtl of cbcdes is
component des is
port (
clk_i : IN std_logic; -- clock
mode_i : IN std_logic; -- des-modus: 0 = encrypt, 1 = decrypt
key_i : IN std_logic_vector(0 TO 63); -- key input
data_i : IN std_logic_vector(0 TO 63); -- data input
valid_i : IN std_logic; -- input key/data valid flag
data_o : OUT std_logic_vector(0 TO 63); -- data output
valid_o : OUT std_logic -- output data valid flag
);
end component des;
signal s_mode : std_logic;
signal s_des_mode : std_logic;
signal s_start : std_logic;
signal s_key : std_logic_vector(0 to 63);
signal s_des_key : std_logic_vector(0 to 63);
signal s_iv : std_logic_vector(0 to 63);
signal s_datain : std_logic_vector(0 to 63);
signal s_datain_d : std_logic_vector(0 to 63);
signal s_des_datain : std_logic_vector(0 to 63);
signal s_validin : std_logic;
signal s_des_dataout : std_logic_vector(0 to 63);
signal s_dataout : std_logic_vector(0 to 63);
signal s_validout : std_logic;
signal s_ready : std_logic;
signal s_reset : std_logic;
begin
s_des_datain <= iv_i xor data_i when mode_i = '0' and start_i = '1' else
s_dataout xor data_i when s_mode = '0' and start_i = '0' else
data_i;
data_o <= s_iv xor s_des_dataout when s_mode = '1' and s_start = '1' else
s_datain_d xor s_des_dataout when s_mode = '1' and s_start = '0' else
s_des_dataout;
s_des_key <= key_i when start_i = '1' else s_key;
s_des_mode <= mode_i when start_i = '1' else s_mode;
ready_o <= s_ready;
s_validin <= valid_i and s_ready;
valid_o <= s_validout;
inputregister : process(clk_i, reset_i) is
begin
if(reset_i = '0') then
s_reset <= '0';
s_mode <= '0';
s_start <= '0';
s_key <= (others => '0');
s_iv <= (others => '0');
s_datain <= (others => '0');
s_datain_d <= (others => '0');
elsif(rising_edge(clk_i)) then
s_reset <= reset_i;
if(valid_i = '1' and s_ready = '1') then
s_start <= start_i;
s_datain <= data_i;
s_datain_d <= s_datain;
end if;
if(valid_i = '1' and s_ready = '1' and start_i = '1') then
s_mode <= mode_i;
s_key <= key_i;
s_iv <= iv_i;
end if;
end if;
end process inputregister;
outputregister : process(clk_i, reset_i) is
begin
if(reset_i = '0') then
s_ready <= '0';
s_dataout <= (others => '0');
elsif(rising_edge(clk_i)) then
if(valid_i = '1' and s_ready = '1') then
s_ready <= '0';
end if;
if(s_validout = '1' or (reset_i = '1' and s_reset = '0')) then
s_ready <= '1';
s_dataout <= s_des_dataout;
end if;
end if;
end process outputregister;
i_des : des
port map (
clk_i => clk_i,
mode_i => s_des_mode,
key_i => s_des_key,
data_i => s_des_datain,
valid_i => s_validin,
data_o => s_des_dataout,
valid_o => s_validout
);
end architecture rtl;