//////////////////////////////////////////////////////////////////
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//////////////////////////////////////////////////////////////////
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////
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////
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////
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////
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//// AES CORE BLOCK
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//// AES CORE BLOCK
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////
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////
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////
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////
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////
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////
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//// This file is part of the APB to I2C project
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//// This file is part of the APB to AES128 project
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////
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////
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//// http://www.opencores.org/cores/apbi2c/
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//// http://www.opencores.org/cores/apbtoaes128/
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////
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////
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////
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////
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////
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////
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//// Description
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//// Description
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////
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////
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//// Implementation of APB IP core according to
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//// Implementation of APB IP core according to
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////
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////
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//// aes128_spec IP core specification document.
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//// aes128_spec IP core specification document.
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////
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////
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////
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////
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////
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////
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//// To Do: Things are right here but always all block can suffer changes
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//// To Do: Things are right here but always all block can suffer changes
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////
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////
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////
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////
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////
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////
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////
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////
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////
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////
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//// Author(s): - Felipe Fernandes Da Costa, fefe2560@gmail.com
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//// Author(s): - Felipe Fernandes Da Costa, fefe2560@gmail.com
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//// Julio Cesar
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//// Julio Cesar
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////
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////
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/////////////////////////////////////////////////////////////////
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/////////////////////////////////////////////////////////////////
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////
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////
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////
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////
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//// Copyright (C) 2009 Authors and OPENCORES.ORG
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//// Copyright (C) 2009 Authors and OPENCORES.ORG
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////
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////
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////
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////
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////
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////
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//// This source file may be used and distributed without
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//// This source file may be used and distributed without
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////
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////
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//// restriction provided that this copyright statement is not
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//// restriction provided that this copyright statement is not
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////
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////
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//// removed from the file and that any derivative work contains
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//// removed from the file and that any derivative work contains
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//// the original copyright notice and the associated disclaimer.
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//// the original copyright notice and the associated disclaimer.
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////
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////
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////
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////
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//// This source file is free software; you can redistribute it
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//// This source file is free software; you can redistribute it
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////
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////
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//// and/or modify it under the terms of the GNU Lesser General
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//// and/or modify it under the terms of the GNU Lesser General
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////
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////
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//// Public License as published by the Free Software Foundation;
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//// Public License as published by the Free Software Foundation;
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//// either version 2.1 of the License, or (at your option) any
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//// either version 2.1 of the License, or (at your option) any
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////
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////
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//// later version.
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//// later version.
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////
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////
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////
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////
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////
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////
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//// This source is distributed in the hope that it will be
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//// This source is distributed in the hope that it will be
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////
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////
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//// useful, but WITHOUT ANY WARRANTY; without even the implied
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//// useful, but WITHOUT ANY WARRANTY; without even the implied
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////
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////
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//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
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//// warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
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////
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////
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//// PURPOSE. See the GNU Lesser General Public License for more
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//// PURPOSE. See the GNU Lesser General Public License for more
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//// details.
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//// details.
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////
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////
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////
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////
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////
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////
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//// You should have received a copy of the GNU Lesser General
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//// You should have received a copy of the GNU Lesser General
|
////
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////
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//// Public License along with this source; if not, download it
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//// Public License along with this source; if not, download it
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////
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////
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//// from http://www.opencores.org/lgpl.shtml
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//// from http://www.opencores.org/lgpl.shtml
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////
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////
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////
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////
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///////////////////////////////////////////////////////////////////
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///////////////////////////////////////////////////////////////////
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module key_expander
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module key_expander
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(
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(
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// OUTPUTS
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// OUTPUTS
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output [127:0] key_out,
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output [127:0] key_out,
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output [ 31:0] g_in,
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output [ 31:0] g_in,
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// INPUTS
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// INPUTS
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input [ 31:0] g_out,
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input [ 31:0] g_out,
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input [127:0] key_in,
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input [127:0] key_in,
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input [ 3:0] round,
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input [ 3:0] round,
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input add_w_out,
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input add_w_out,
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input enc_dec
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input enc_dec
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);
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);
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localparam KEY_WIDTH = 32;
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localparam KEY_WIDTH = 32;
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localparam KEY_NUM = 4;
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localparam KEY_NUM = 4;
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localparam WORD = 8;
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localparam WORD = 8;
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localparam ROUNDS = 10;
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localparam ROUNDS = 10;
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wire [KEY_WIDTH - 1 : 0] key [0 : KEY_NUM - 1];
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wire [KEY_WIDTH - 1 : 0] key [0 : KEY_NUM - 1];
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wire [ WORD - 1 : 0] rot_in[0 : KEY_NUM - 1];
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wire [ WORD - 1 : 0] rot_in[0 : KEY_NUM - 1];
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wire [KEY_WIDTH - 1 : 0] g_func;
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wire [KEY_WIDTH - 1 : 0] g_func;
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reg [ WORD - 1 : 0] rc_dir, rc_inv;
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reg [ WORD - 1 : 0] rc_dir, rc_inv;
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wire [ WORD - 1 : 0] rc;
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wire [ WORD - 1 : 0] rc;
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//=====================================================================================
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//=====================================================================================
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// Key Generation
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// Key Generation
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//=====================================================================================
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//=====================================================================================
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generate
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generate
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genvar i;
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genvar i;
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for(i = 0; i < KEY_NUM; i = i + 1)
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for(i = 0; i < KEY_NUM; i = i + 1)
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begin
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begin
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assign key[KEY_NUM - 1 - i] = key_in[KEY_WIDTH*(i + 1) - 1 : KEY_WIDTH*i];
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assign key[KEY_NUM - 1 - i] = key_in[KEY_WIDTH*(i + 1) - 1 : KEY_WIDTH*i];
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end
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end
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endgenerate
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endgenerate
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//=====================================================================================
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//=====================================================================================
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// Key Out Generation
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// Key Out Generation
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//=====================================================================================
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//=====================================================================================
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generate
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generate
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genvar j;
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genvar j;
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for(j = 0; j < KEY_NUM; j = j + 1)
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for(j = 0; j < KEY_NUM; j = j + 1)
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begin
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begin
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if(j == 0)
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if(j == 0)
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assign key_out[KEY_WIDTH*(KEY_NUM - j) - 1 : KEY_WIDTH*(KEY_NUM - j - 1)] = key[j] ^ g_func;
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assign key_out[KEY_WIDTH*(KEY_NUM - j) - 1 : KEY_WIDTH*(KEY_NUM - j - 1)] = key[j] ^ g_func;
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else
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else
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if(j == 1)
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if(j == 1)
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assign key_out[KEY_WIDTH*(KEY_NUM - j) - 1 : KEY_WIDTH*(KEY_NUM - j - 1)] = (add_w_out) ? key[j] ^ key[j - 1] ^ g_func : key[j] ^ key[j - 1];
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assign key_out[KEY_WIDTH*(KEY_NUM - j) - 1 : KEY_WIDTH*(KEY_NUM - j - 1)] = (add_w_out) ? key[j] ^ key[j - 1] ^ g_func : key[j] ^ key[j - 1];
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else
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else
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assign key_out[KEY_WIDTH*(KEY_NUM - j) - 1 : KEY_WIDTH*(KEY_NUM - j - 1)] = key[j] ^ key[j - 1];
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assign key_out[KEY_WIDTH*(KEY_NUM - j) - 1 : KEY_WIDTH*(KEY_NUM - j - 1)] = key[j] ^ key[j - 1];
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end
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end
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endgenerate
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endgenerate
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//=====================================================================================
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//=====================================================================================
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// G Function Input Generation
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// G Function Input Generation
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//=====================================================================================
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//=====================================================================================
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generate
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generate
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genvar k;
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genvar k;
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for(k = 0; k < KEY_NUM; k = k + 1)
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for(k = 0; k < KEY_NUM; k = k + 1)
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assign rot_in[k] = (enc_dec) ? key[KEY_NUM - 1][WORD*(k + 1) - 1 : WORD*k] : key[KEY_NUM - 1][WORD*(k + 1) - 1 : WORD*k] ^ key[KEY_NUM - 2][WORD*(k + 1) - 1 : WORD*k];
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assign rot_in[k] = (enc_dec) ? key[KEY_NUM - 1][WORD*(k + 1) - 1 : WORD*k] : key[KEY_NUM - 1][WORD*(k + 1) - 1 : WORD*k] ^ key[KEY_NUM - 2][WORD*(k + 1) - 1 : WORD*k];
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endgenerate
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endgenerate
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generate
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generate
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genvar l;
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genvar l;
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for(l = 0; l < KEY_NUM; l = l + 1)
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for(l = 0; l < KEY_NUM; l = l + 1)
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assign g_in[WORD*(l + 1) - 1 : WORD*l] = rot_in[(KEY_NUM + l - 1)%KEY_NUM];
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assign g_in[WORD*(l + 1) - 1 : WORD*l] = rot_in[(KEY_NUM + l - 1)%KEY_NUM];
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endgenerate
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endgenerate
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//=====================================================================================
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//=====================================================================================
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// G Functin Output Processsing
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// G Functin Output Processsing
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//=====================================================================================
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//=====================================================================================
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assign g_func = {g_out[KEY_WIDTH - 1 : KEY_WIDTH - WORD] ^ rc, g_out[KEY_WIDTH - WORD - 1 : 0]};
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assign g_func = {g_out[KEY_WIDTH - 1 : KEY_WIDTH - WORD] ^ rc, g_out[KEY_WIDTH - WORD - 1 : 0]};
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assign rc = (enc_dec) ? rc_dir : rc_inv;
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assign rc = (enc_dec) ? rc_dir : rc_inv;
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always @(*)
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always @(*)
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begin: RC_DIR
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begin: RC_DIR
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integer i;
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integer i;
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for(i = 0; i < ROUNDS; i = i + 1)
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for(i = 0; i < ROUNDS; i = i + 1)
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if(round == 8)
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if(round == 8)
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rc_dir = 8'h1b;
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rc_dir = 8'h1b;
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else
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else
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if(round == 9)
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if(round == 9)
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rc_dir = 8'h36;
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rc_dir = 8'h36;
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else
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else
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rc_dir = 8'h01 << round;
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rc_dir = 8'h01 << round;
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end
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end
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always @(*)
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always @(*)
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begin: RC_INV
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begin: RC_INV
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integer i;
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integer i;
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for(i = 0; i < ROUNDS; i = i + 1)
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for(i = 0; i < ROUNDS; i = i + 1)
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if(round == 1)
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if(round == 1)
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rc_inv = 8'h1b;
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rc_inv = 8'h1b;
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else
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else
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if(round == 0)
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if(round == 0)
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rc_inv = 8'h36;
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rc_inv = 8'h36;
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else
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else
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rc_inv = 8'h80 >> (round - 2);
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rc_inv = 8'h80 >> (round - 2);
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end
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end
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endmodule
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endmodule
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