| 1 |
4 |
gajos |
-----------------------------------------------------------------------
|
| 2 |
|
|
---- ----
|
| 3 |
|
|
---- Present - a lightweight block cipher project ----
|
| 4 |
|
|
---- ----
|
| 5 |
|
|
---- This file is part of the Present - a lightweight block ----
|
| 6 |
|
|
---- cipher project ----
|
| 7 |
|
|
---- http://www.http://opencores.org/project,present ----
|
| 8 |
|
|
---- ----
|
| 9 |
|
|
---- Description: ----
|
| 10 |
|
|
---- Inverse Key update module for present cipher decoding ----
|
| 11 |
|
|
---- it is 'signal mixing' made by rotation right by 61 bits, ----
|
| 12 |
|
|
---- using one s-box, and output of the counter. Note, that order ----
|
| 13 |
|
|
---- of this operatins must be inverse in comparison with key_upd. ----
|
| 14 |
|
|
---- For more information see ----
|
| 15 |
|
|
---- http://homes.esat.kuleuven.be/~abogdano/papers/ ----
|
| 16 |
|
|
---- present_ches07.pdf ----
|
| 17 |
|
|
---- To Do: ----
|
| 18 |
|
|
---- ----
|
| 19 |
|
|
---- Author(s): ----
|
| 20 |
|
|
---- - Krzysztof Gajewski, gajos@opencores.org ----
|
| 21 |
|
|
---- k.gajewski@gmail.com ----
|
| 22 |
|
|
---- ----
|
| 23 |
|
|
-----------------------------------------------------------------------
|
| 24 |
|
|
---- ----
|
| 25 |
|
|
---- Copyright (C) 2013 Authors and OPENCORES.ORG ----
|
| 26 |
|
|
---- ----
|
| 27 |
|
|
---- This source file may be used and distributed without ----
|
| 28 |
|
|
---- restriction provided that this copyright statement is not ----
|
| 29 |
|
|
---- removed from the file and that any derivative work contains ----
|
| 30 |
|
|
---- the original copyright notice and the associated disclaimer. ----
|
| 31 |
|
|
---- ----
|
| 32 |
|
|
---- This source file is free software; you can redistribute it ----
|
| 33 |
|
|
---- and-or modify it under the terms of the GNU Lesser General ----
|
| 34 |
|
|
---- Public License as published by the Free Software Foundation; ----
|
| 35 |
|
|
---- either version 2.1 of the License, or (at your option) any ----
|
| 36 |
|
|
---- later version. ----
|
| 37 |
|
|
---- ----
|
| 38 |
|
|
---- This source is distributed in the hope that it will be ----
|
| 39 |
|
|
---- useful, but WITHOUT ANY WARRANTY; without even the implied ----
|
| 40 |
|
|
---- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR ----
|
| 41 |
|
|
---- PURPOSE. See the GNU Lesser General Public License for more ----
|
| 42 |
|
|
---- details. ----
|
| 43 |
|
|
---- ----
|
| 44 |
|
|
---- You should have received a copy of the GNU Lesser General ----
|
| 45 |
|
|
---- Public License along with this source; if not, download it ----
|
| 46 |
|
|
---- from http://www.opencores.org/lgpl.shtml ----
|
| 47 |
|
|
---- ----
|
| 48 |
|
|
-----------------------------------------------------------------------
|
| 49 |
3 |
gajos |
library IEEE;
|
| 50 |
|
|
use IEEE.STD_LOGIC_1164.ALL;
|
| 51 |
|
|
use IEEE.STD_LOGIC_ARITH.ALL;
|
| 52 |
|
|
use IEEE.STD_LOGIC_UNSIGNED.ALL;
|
| 53 |
|
|
|
| 54 |
|
|
entity keyupd_inv is
|
| 55 |
|
|
generic(
|
| 56 |
|
|
w_80: integer := 80;
|
| 57 |
|
|
w_5 : integer := 5;
|
| 58 |
|
|
w_4 : integer := 4);
|
| 59 |
|
|
port(
|
| 60 |
|
|
key : in std_logic_vector(w_80-1 downto 0);
|
| 61 |
|
|
num : in std_logic_vector(w_5-1 downto 0);
|
| 62 |
|
|
keyout : out std_logic_vector(w_80-1 downto 0)
|
| 63 |
|
|
);
|
| 64 |
|
|
end keyupd_inv;
|
| 65 |
|
|
|
| 66 |
|
|
architecture Behavioral of keyupd_inv is
|
| 67 |
|
|
|
| 68 |
|
|
component slayer_inv is
|
| 69 |
|
|
generic(w_4: integer := 4);
|
| 70 |
|
|
port(
|
| 71 |
|
|
input : in std_logic_vector(w_4-1 downto 0);
|
| 72 |
|
|
output : out std_logic_vector(w_4-1 downto 0)
|
| 73 |
|
|
);
|
| 74 |
|
|
end component;
|
| 75 |
|
|
|
| 76 |
|
|
signal changed : std_logic_vector(w_4-1 downto 0);
|
| 77 |
|
|
signal changin : std_logic_vector(w_4-1 downto 0);
|
| 78 |
|
|
signal keytemp : std_logic_vector(w_80-1 downto 0);
|
| 79 |
|
|
|
| 80 |
|
|
begin
|
| 81 |
|
|
s1: slayer_inv port map(input => changin, output => changed);
|
| 82 |
|
|
changin <= key(79 downto 76);
|
| 83 |
|
|
keytemp(79 downto 76)<= changed;
|
| 84 |
|
|
keytemp(75 downto 20) <= key(75 downto 20);
|
| 85 |
|
|
keytemp(19 downto 15)<= key(19 downto 15) xor num;
|
| 86 |
|
|
keytemp(14 downto 0) <= key(14 downto 0);
|
| 87 |
|
|
keyout <= keytemp(60 downto 0) & keytemp(79 downto 61);
|
| 88 |
|
|
end Behavioral;
|
