-- ======================================================================
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-- CBC-MAC-AES
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-- Copyright (C) 2020 Torsten Meissner
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-------------------------------------------------------------------------
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-- This program is free software; you can redistribute it and/or modify
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-- it under the terms of the GNU General Public License as published by
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-- the Free Software Foundation; either version 2 of the License, or
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-- (at your option) any later version.
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-- This program is distributed in the hope that it will be useful,
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-- but WITHOUT ANY WARRANTY; without even the implied warranty of
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-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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-- GNU General Public License for more details.
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-- You should have received a copy of the GNU General Public License
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-- along with this program; if not, write to the Free Software
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-- Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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-- ======================================================================
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library ieee;
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use ieee.std_logic_1164.all;
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use ieee.numeric_std.all;
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use work.aes_pkg.all;
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entity cbcmac_aes is
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port (
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reset_i : in std_logic; -- low active async reset
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clk_i : in std_logic; -- clock
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start_i : in std_logic; -- start cbc
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key_i : in std_logic_vector(0 to 127); -- key input
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data_i : in std_logic_vector(0 to 127); -- data input
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valid_i : in std_logic; -- input key/data valid flag
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accept_o : out std_logic; -- input accept
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data_o : out std_logic_vector(0 tO 127); -- data output
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valid_o : out std_logic; -- output data valid flag
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accept_i : in std_logic -- output accept
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);
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end entity cbcmac_aes;
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architecture rtl of cbcmac_aes is
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-- CBCMAC must have fix IV for security reasons
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constant C_IV : std_logic_vector(0 to 127) := (others => '0');
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signal s_aes_datain : std_logic_vector(0 to 127);
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signal s_aes_dataout : std_logic_vector(0 to 127);
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signal s_aes_dataout_d : std_logic_vector(0 to 127);
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signal s_aes_key : std_logic_vector(0 to 127);
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signal s_key : std_logic_vector(0 to 127);
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signal s_aes_accept : std_logic;
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signal s_aes_validout : std_logic;
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begin
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s_aes_datain <= C_IV xor data_i when start_i = '1' else
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s_aes_dataout_d xor data_i;
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data_o <= s_aes_dataout;
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s_aes_key <= key_i when start_i = '1' else s_key;
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accept_o <= s_aes_accept;
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valid_o <= s_aes_validout;
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inputregister : process (clk_i, reset_i) is
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begin
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if (reset_i = '0') then
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s_key <= (others => '0');
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elsif (rising_edge(clk_i)) then
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if (valid_i = '1' and s_aes_accept = '1' and start_i = '1') then
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s_key <= key_i;
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end if;
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end if;
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end process inputregister;
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outputregister : process (clk_i, reset_i) is
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begin
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if (reset_i = '0') then
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s_aes_dataout_d <= (others => '0');
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elsif (rising_edge(clk_i)) then
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if (s_aes_validout = '1') then
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s_aes_dataout_d <= s_aes_dataout;
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end if;
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end if;
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end process outputregister;
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i_aes : aes_enc
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generic map (
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design_type => "ITER"
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)
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port map (
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reset_i => reset_i,
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clk_i => clk_i,
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key_i => s_aes_key,
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data_i => s_aes_datain,
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valid_i => valid_i,
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accept_o => s_aes_accept,
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data_o => s_aes_dataout,
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valid_o => s_aes_validout,
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accept_i => accept_i
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);
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end architecture rtl;
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