Line 1... |
Line 1... |
|
--------------------------------------------------------------------------------
|
|
-- This file is part of the project avs_aes
|
|
-- see: http://opencores.org/project,avs_aes
|
|
--
|
|
-- description:
|
|
-- Mix the columns of the AES Block (decryption version)
|
|
-- Invert what was computed in mixcol_fwd.vhd
|
|
-- For decrytion the inverse matrix is needed:
|
|
--
|
|
-- | E B D 9 | a(n,0)
|
|
-- | 9 E B D | x a(n,1)
|
|
-- | D 9 E B | a(n,2)
|
|
-- | B D 9 E | a(n,3)
|
|
--
|
|
-------------------------------------------------------------------------------
|
|
--
|
|
-- Author(s):
|
|
-- Thomas Ruschival -- ruschi@opencores.org (www.ruschival.de)
|
|
--
|
|
--------------------------------------------------------------------------------
|
|
-- Copyright (c) 2009, Authors and opencores.org
|
|
-- All rights reserved.
|
|
--
|
|
-- Redistribution and use in source and binary forms, with or without modification,
|
|
-- are permitted provided that the following conditions are met:
|
|
-- * Redistributions of source code must retain the above copyright notice,
|
|
-- this list of conditions and the following disclaimer.
|
|
-- * Redistributions in binary form must reproduce the above copyright notice,
|
|
-- this list of conditions and the following disclaimer in the documentation
|
|
-- and/or other materials provided with the distribution.
|
|
-- * Neither the name of the organization nor the names of its contributors
|
|
-- may be used to endorse or promote products derived from this software without
|
|
-- specific prior written permission.
|
|
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
|
|
-- AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
|
|
-- IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
|
|
-- ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
|
|
-- LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY,
|
|
-- OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
|
-- SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
|
-- INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
|
-- CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
|
-- ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
|
|
-- THE POSSIBILITY OF SUCH DAMAGE
|
|
-------------------------------------------------------------------------------
|
|
-- version management:
|
|
-- $Author$
|
|
-- $Date$
|
|
-- $Revision$
|
|
-------------------------------------------------------------------------------
|
|
|
|
|
|
library IEEE;
|
|
use IEEE.std_logic_1164.all;
|
|
use ieee.numeric_std.all;
|
|
|
|
library avs_aes_lib;
|
|
use avs_aes_lib.avs_aes_pkg.all;
|
|
|
|
|
|
architecture inv of mixcol
|
|
is
|
|
signal byte0 : BYTE;
|
|
signal byte1 : BYTE;
|
|
signal byte2 : BYTE;
|
|
signal byte3 : BYTE;
|
|
begin -- architecture ARCH1
|
|
|
|
-- Easier handling of the single cells of the column
|
|
byte0 <= col_in(31 downto 24);
|
|
byte1 <= col_in(23 downto 16);
|
|
byte2 <= col_in(15 downto 8);
|
|
byte3 <= col_in(7 downto 0);
|
|
|
|
-- purpose: multiplies the column of the input block with the matrix
|
|
-- type : combinational
|
|
-- inputs : direction,byte0,byte1,byte2,byte3
|
|
-- outputs: col_out
|
|
matrix_mult : process ( byte0, byte1, byte2, byte3) is
|
|
-- temporary results for the row-col multiplication have to be 9 Bits
|
|
-- long because the input is shifted left
|
|
variable tmp_res0 : STD_LOGIC_VECTOR(10 downto 0); -- result of row1*col
|
|
variable tmp_res1 : STD_LOGIC_VECTOR(10 downto 0); -- result of row2*col
|
|
variable tmp_res2 : STD_LOGIC_VECTOR(10 downto 0); -- result of row3*col
|
|
variable tmp_res3 : STD_LOGIC_VECTOR(10 downto 0); -- result of row4*col
|
|
begin -- process matrix_mult
|
|
-- Multiply by 1st row of the inverse matrix ( E B D 9 )
|
|
tmp_res0 := byte0 & "000" xor '0' & byte0 & "00" xor "00" & byte0 & '0' xor -- byte0*8+byte0*4+byte0*2 +
|
|
byte1 & "000" xor "00" & byte1 & '0' xor "000" & byte1 xor -- byte1*8 + byte1*2 + byte1
|
|
byte2 & "000" xor "0" & byte2 & "00" xor "000" & byte2 xor -- byte2*8 + byte2*4 + byte2
|
|
byte3 & "000" xor "000" & byte3; -- byte3*8 + byte3*1
|
|
|
|
-- check if bits>7 = 1 and XOR with magic numbers to make it 8 BIT
|
|
if tmp_res0(10) = '1' then
|
|
tmp_res0 := tmp_res0 xor "10001101100";
|
|
end if;
|
|
if tmp_res0(9) = '1' then
|
|
tmp_res0 := tmp_res0 xor "01000110110";
|
|
end if;
|
|
if tmp_res0(8) = '1' then
|
|
tmp_res0 := tmp_res0 xor "00100011011";
|
|
end if;
|
|
|
|
-- Multiply by 2nd row of the inverse matrix ( 9 E B D )
|
|
tmp_res1 := byte0 & "000" xor "000" & byte0 xor
|
|
byte1 & "000" xor "0" & byte1 & "00" xor "00" & byte1 & '0' xor
|
|
byte2 & "000" xor "00" & byte2 & '0' xor "000" & byte2 xor
|
|
byte3 & "000" xor '0' & byte3 & "00" xor "000" & byte3;
|
|
|
|
-- check if bits>7 = 1 and XOR with magic numbers to make it 8 BIT
|
|
if tmp_res1(10) = '1' then
|
|
tmp_res1 := tmp_res1 xor "10001101100";
|
|
end if;
|
|
if tmp_res1(9) = '1' then
|
|
tmp_res1 := tmp_res1 xor "01000110110";
|
|
end if;
|
|
if tmp_res1(8) = '1' then
|
|
tmp_res1 := tmp_res1 xor "00100011011";
|
|
end if;
|
|
|
|
-- Multiply by 3rd row of the inverse matrix (D 9 E B)
|
|
tmp_res2 := byte0 & "000" xor "0" & byte0 & "00" xor "000" & byte0 xor -- byte0*8 + byte0*4 + byte0
|
|
byte1 & "000" xor "000" & byte1 xor -- byte1*8 + byte1
|
|
byte2 & "000" xor "0" & byte2 & "00" xor "00" & byte2 &'0' xor -- byte2*8 + byte2*4 + byte2*2
|
|
byte3 & "000" xor "00" & byte3 & '0' xor "000" & byte3; -- byte3*8 + byte3*2 + byte3
|
|
-- check if bits>7 = 1 and XOR with magic numbers to make it 8 BIT
|
|
if tmp_res2(10) = '1' then
|
|
tmp_res2 := tmp_res2 xor "10001101100";
|
|
end if;
|
|
if tmp_res2(9) = '1' then
|
|
tmp_res2 := tmp_res2 xor "01000110110";
|
|
end if;
|
|
if tmp_res2(8) = '1' then
|
|
tmp_res2 := tmp_res2 xor "00100011011";
|
|
end if;
|
|
|
|
-- Multiply by 4th row of the inverse matrix (B D 9 E)
|
|
tmp_res3 := byte0 & "000" xor "00" & byte0 & '0' xor "000" & byte0 xor -- byte0*8 + byte0*2 + byte0*1
|
|
byte1 & "000" xor '0' & byte1 &"00" xor "000" & byte1 xor -- byte1*8 + byte1*4 + byte1
|
|
byte2 & "000" xor "000" & byte2 xor -- byte2*8 + byte2
|
|
byte3 & "000" xor "0" & byte3 & "00" xor "00" & byte3 &'0'; -- byte3*8 + byte3*4 + byte3*2
|
|
|
|
-- check if bits>7 = 1 and XOR with magic numbers to make it 8 BIT
|
|
if tmp_res3(10) = '1' then
|
|
tmp_res3 := tmp_res3 xor "10001101100";
|
|
end if;
|
|
if tmp_res3(9) = '1' then
|
|
tmp_res3 := tmp_res3 xor "01000110110";
|
|
end if;
|
|
if tmp_res3(8) = '1' then
|
|
tmp_res3 := tmp_res3 xor "00100011011";
|
|
end if;
|
|
|
|
-- build output signal (BYTE_RANGE =7 downto 0 see util_pkg.vhd)
|
|
col_out(31 downto 24) <= tmp_res0(BYTE_RANGE);
|
|
col_out(23 downto 16) <= tmp_res1(BYTE_RANGE);
|
|
col_out(15 downto 8) <= tmp_res2(BYTE_RANGE);
|
|
col_out(7 downto 0) <= tmp_res3(BYTE_RANGE);
|
|
end process matrix_mult;
|
|
|
|
end architecture inv;
|
|
|
|
|
No newline at end of file
|
No newline at end of file
|