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R10848/aes/src/state_pipeline.vhd
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state_pipeline.vhd
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library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
use std.textio.all;
use work.all;
entity state_pipeline is
port ( SboxIN: out std_logic_vector(7 downto 0);
CT: out std_logic;
MCin0: out std_logic_vector(3 downto 0);
MCin1: out std_logic_vector(3 downto 0);
Clk: in std_logic;
swap_ctrl: in std_logic_vector(2 downto 0);
store_mc: in std_logic;
store_sbox: in std_logic;
init: in std_logic;
newbit: in std_logic;
keybit: in std_logic;
SboxOUT: in std_logic_vector(7 downto 0);
MCout: in std_logic_vector(3 downto 0)
);
end entity state_pipeline;
architecture behav of state_pipeline is
signal st_p, st_n: std_logic_vector(127 downto 0);
signal sbox_in : std_logic;
procedure rotate (
variable s : inout std_logic_vector(127 downto 0);
variable b: in std_logic
) is
begin
s := s(126 downto 0) & b;
end rotate;
procedure swap (
variable a: inout std_logic;
variable b: inout std_logic
) is
variable tmp : std_logic;
begin
tmp := a;
a := b;
b := tmp;
end swap;
begin
SBoxIN <= st_p(6 downto 0) & sbox_in;
process (Clk)
begin
if Clk'event and Clk = '1' then
st_p <= st_n;
end if;
end process;
process (st_p, newbit, keybit, SboxOUT, MCout, store_sbox, swap_ctrl, store_mc, init)
variable s : std_logic_vector(127 downto 0);
variable nextbit: std_logic;
begin
s := st_p;
-- subbyte (expect the last bit)
if store_sbox = '1' then
s(6 downto 0) := SboxOUT(7 downto 1);
end if;
if swap_ctrl(0) = '1' then
swap(s(127 - 80), s(127 - 112));
end if;
if swap_ctrl(1) = '1' then
swap(s(127 - 56), s(127 - 120));
end if;
if swap_ctrl(2) = '1' then
swap(s(127-121), s(127 - 25));
end if;
-- mixColumn
MCin0 <= s(127) & s(119) & s(111) & s(103);
MCin1 <= s(126) & s(118) & s(110) & s(102);
if store_mc = '1' then
s(127) := MCout(3);
s(127 - 8) := MCout(2);
s(127 - 16) := MCout(1);
s(127 - 24) := MCout(0);
end if;
sbox_in <= s(127) xor keybit;
if init = '1' then
sbox_in <= newbit xor keybit;
nextbit := newbit xor keybit;
if store_sbox = '1' then
nextbit := SboxOUT(0);
end if;
else
if store_sbox = '0' then
nextbit := s(127) xor keybit;
else
sbox_in <= s(127) xor keybit;
nextbit := SboxOUT(0);
end if;
end if;
CT <= s(127) xor keybit;
rotate(s, nextbit);
st_n <= s;
end process;
end architecture behav;
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