Subversion Repositories gcm-aes

/////////////////////////////////////////////////////////////////////

////                                                             ////

////  AES Key Expand Block (for 128 bit keys)                    ////

////                                                             ////

////                                                             ////

////  Author: Rudolf Usselmann                                   ////

////          rudi@asics.ws                                      ////

////                                                             ////

////                                                             ////

////  Downloaded from: http://www.opencores.org/cores/aes_core/  ////

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//// Copyright (C) 2000-2002 Rudolf Usselmann                    ////

////                         www.asics.ws                        ////

////                         rudi@asics.ws                       ////

////                                                             ////

//// This source file may be used and distributed without        ////

//// restriction provided that this copyright statement is not   ////

//// removed from the file and that any derivative work contains ////

//// the original copyright notice and the associated disclaimer.////

////                                                             ////

////     THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY     ////

//// EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED   ////

//// TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS   ////

//// FOR A PARTICULAR PURPOSE. IN NO EVENT SHALL THE AUTHOR      ////

//// 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.                                 ////

////                                                             ////

/////////////////////////////////////////////////////////////////////

//  CVS Log

//

//  $Id: aes_key_expand_128.v,v 1.1.1.1 2002-11-09 11:22:38 rudi Exp $

//

//  $Date: 2002-11-09 11:22:38 $

//  $Revision: 1.1.1.1 $

//  $Author: rudi $

//  $Locker:  $

//  $State: Exp $

//

// Change History:

//               $Log: not supported by cvs2svn $

//

//

//

//

//

`timescale 1 ns/1 ps

module aes_key_expand_128(clk, kld, key, wo_0, wo_1, wo_2, wo_3);

input           clk;

input           kld;

input   [127:0]  key;

output  [31:0]   wo_0, wo_1, wo_2, wo_3;                 //output

reg     [31:0]   w[7:0];

wire    [31:0]   tmp_w;

wire    [31:0]   subword;

wire    [31:0]   rcon;                   //round constant

assign wo_0 = w[0];

assign wo_1 = w[1];

assign wo_2 = w[2];

assign wo_3 = w[3];

assign w1_0 = w[4];

assign w1_1 = w[5];

assign w1_2 = w[6];

assign w1_3 = w[7];

always @(posedge clk)

                begin

                                                                w[0] <=  kld ? key[127:096] : w[0]^subword^{rcon[31:24],24'b0};

                                                                w[1] <=  kld ? key[095:064] : w[0]^w[1]^subword^{rcon[31:24],24'b0};

                                                                w[2] <=  kld ? key[063:032] : w[0]^w[2]^w[1]^subword^{rcon[31:24],24'b0};

                                                                w[3] <=  kld ? key[031:000] : w[0]^w[3]^w[2]^w[1]^subword^{rcon[31:24],24'b0};

                end

assign tmp_w = w[3];

/*

assign subword[31:24]     = aes_sbox(tmp_w[23:16]);

assign subword[23:16]     = aes_sbox(tmp_w[15:08]);

assign subword[15:08]     = aes_sbox(tmp_w[07:00]);

assign subword[07:00]     = aes_sbox(tmp_w[31:24]);

*/

aes_sbox u0(    .a(tmp_w[23:16]), .d(subword[31:24]));

aes_sbox u1(    .a(tmp_w[15:08]), .d(subword[23:16]));

aes_sbox u2(    .a(tmp_w[07:00]), .d(subword[15:08]));

aes_sbox u3(    .a(tmp_w[31:24]), .d(subword[07:00]));

aes_rcon r0(    .clk(clk), .kld(kld), .out(rcon[31:24]));

endmodule