// ======================================================================
|
|
// DES encryption/decryption
|
|
// algorithm according:FIPS 46-3 specification
|
|
// Copyright (C) 2012 Torsten Meissner
|
|
//-----------------------------------------------------------------------
|
|
// This program is free software; you can redistribute it and/or modify
|
|
// it under the terms of the GNU General Public License as published by
|
|
// the Free Software Foundation; either version 2 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// This program is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU General Public License
|
|
// along with this program; if not, write:the Free Software
|
|
// Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
|
|
// ======================================================================
|
|
|
|
|
|
|
|
module des
|
|
(
|
|
input reset_i, // async reset
|
|
input clk_i, // clock
|
|
input mode_i, // des-mode: 0 = encrypt, 1 = decrypt
|
|
input [0:63] key_i, // key input
|
|
input [0:63] data_i, // data input
|
|
input valid_i, // input key/data valid flag
|
|
output reg [0:63] data_o, // data output
|
|
output valid_o // output data valid flag
|
|
);
|
|
|
|
|
|
`include "../../rtl/verilog/des_pkg.v"
|
|
|
|
// valid, mode register
|
|
reg [0:17] valid;
|
|
reg [0:16] mode;
|
|
|
|
// algorithm pipeline register
|
|
// key calculation register
|
|
reg [0:27] c0;
|
|
reg [0:27] c1;
|
|
reg [0:27] c2;
|
|
reg [0:27] c3;
|
|
reg [0:27] c4;
|
|
reg [0:27] c5;
|
|
reg [0:27] c6;
|
|
reg [0:27] c7;
|
|
reg [0:27] c8;
|
|
reg [0:27] c9;
|
|
reg [0:27] c10;
|
|
reg [0:27] c11;
|
|
reg [0:27] c12;
|
|
reg [0:27] c13;
|
|
reg [0:27] c14;
|
|
reg [0:27] c15;
|
|
reg [0:27] c16;
|
|
reg [0:27] d0;
|
|
reg [0:27] d1;
|
|
reg [0:27] d2;
|
|
reg [0:27] d3;
|
|
reg [0:27] d4;
|
|
reg [0:27] d5;
|
|
reg [0:27] d6;
|
|
reg [0:27] d7;
|
|
reg [0:27] d8;
|
|
reg [0:27] d9;
|
|
reg [0:27] d10;
|
|
reg [0:27] d11;
|
|
reg [0:27] d12;
|
|
reg [0:27] d13;
|
|
reg [0:27] d14;
|
|
reg [0:27] d15;
|
|
reg [0:27] d16;
|
|
// key register
|
|
reg [0:47] key1;
|
|
reg [0:47] key2;
|
|
reg [0:47] key3;
|
|
reg [0:47] key4;
|
|
reg [0:47] key5;
|
|
reg [0:47] key6;
|
|
reg [0:47] key7;
|
|
reg [0:47] key8;
|
|
reg [0:47] key9;
|
|
reg [0:47] key10;
|
|
reg [0:47] key11;
|
|
reg [0:47] key12;
|
|
reg [0:47] key13;
|
|
reg [0:47] key14;
|
|
reg [0:47] key15;
|
|
reg [0:47] key16;
|
|
// register for left, right data blocks
|
|
reg [0:31] l0;
|
|
reg [0:31] l1;
|
|
reg [0:31] l2;
|
|
reg [0:31] l3;
|
|
reg [0:31] l4;
|
|
reg [0:31] l5;
|
|
reg [0:31] l6;
|
|
reg [0:31] l7;
|
|
reg [0:31] l8;
|
|
reg [0:31] l9;
|
|
reg [0:31] l10;
|
|
reg [0:31] l11;
|
|
reg [0:31] l12;
|
|
reg [0:31] l13;
|
|
reg [0:31] l14;
|
|
reg [0:31] l15;
|
|
reg [0:31] l16;
|
|
reg [0:31] r0;
|
|
reg [0:31] r1;
|
|
reg [0:31] r2;
|
|
reg [0:31] r3;
|
|
reg [0:31] r4;
|
|
reg [0:31] r5;
|
|
reg [0:31] r6;
|
|
reg [0:31] r7;
|
|
reg [0:31] r8;
|
|
reg [0:31] r9;
|
|
reg [0:31] r10;
|
|
reg [0:31] r11;
|
|
reg [0:31] r12;
|
|
reg [0:31] r13;
|
|
reg [0:31] r14;
|
|
reg [0:31] r15;
|
|
reg [0:31] r16;
|
|
|
|
wire valid_o = valid[17];
|
|
|
|
// valid, mode register
|
|
always @(posedge clk_i, negedge reset_i) begin
|
|
if(~reset_i) begin
|
|
valid <= 0;
|
|
end
|
|
else begin
|
|
// shift registers
|
|
valid[1:17] <= valid[0:16];
|
|
valid[0] <= valid_i;
|
|
mode[1:16] <= mode[0:15];
|
|
mode[0] <= mode_i;
|
|
end
|
|
end
|
|
|
|
// des algorithm pipeline
|
|
always @(posedge clk_i, negedge reset_i) begin
|
|
if(~reset_i) begin
|
|
c0 <= 0;
|
|
c1 <= 0;
|
|
c2 <= 0;
|
|
c3 <= 0;
|
|
c4 <= 0;
|
|
c5 <= 0;
|
|
c6 <= 0;
|
|
c7 <= 0;
|
|
c8 <= 0;
|
|
c9 <= 0;
|
|
c10 <= 0;
|
|
c11 <= 0;
|
|
c12 <= 0;
|
|
c13 <= 0;
|
|
c14 <= 0;
|
|
c15 <= 0;
|
|
c16 <= 0;
|
|
d0 <= 0;
|
|
d1 <= 0;
|
|
d2 <= 0;
|
|
d3 <= 0;
|
|
d4 <= 0;
|
|
d5 <= 0;
|
|
d6 <= 0;
|
|
d7 <= 0;
|
|
d8 <= 0;
|
|
d9 <= 0;
|
|
d10 <= 0;
|
|
d11 <= 0;
|
|
d12 <= 0;
|
|
d13 <= 0;
|
|
d14 <= 0;
|
|
d15 <= 0;
|
|
d16 <= 0;
|
|
key1 <= 0;
|
|
key2 <= 0;
|
|
key3 <= 0;
|
|
key4 <= 0;
|
|
key5 <= 0;
|
|
key6 <= 0;
|
|
key7 <= 0;
|
|
key8 <= 0;
|
|
key9 <= 0;
|
|
key10 <= 0;
|
|
key11 <= 0;
|
|
key12 <= 0;
|
|
key13 <= 0;
|
|
key14 <= 0;
|
|
key15 <= 0;
|
|
key16 <= 0;
|
|
l0 <= 0;
|
|
l1 <= 0;
|
|
l2 <= 0;
|
|
l3 <= 0;
|
|
l4 <= 0;
|
|
l5 <= 0;
|
|
l6 <= 0;
|
|
l7 <= 0;
|
|
l8 <= 0;
|
|
l9 <= 0;
|
|
l10 <= 0;
|
|
l11 <= 0;
|
|
l12 <= 0;
|
|
l13 <= 0;
|
|
l14 <= 0;
|
|
l15 <= 0;
|
|
l16 <= 0;
|
|
r0 <= 0;
|
|
r1 <= 0;
|
|
r2 <= 0;
|
|
r3 <= 0;
|
|
r4 <= 0;
|
|
r5 <= 0;
|
|
r6 <= 0;
|
|
r7 <= 0;
|
|
r8 <= 0;
|
|
r9 <= 0;
|
|
r10 <= 0;
|
|
r11 <= 0;
|
|
r12 <= 0;
|
|
r13 <= 0;
|
|
r14 <= 0;
|
|
r15 <= 0;
|
|
r16 <= 0;
|
|
data_o <= 0;
|
|
end
|
|
else begin
|
|
// output stage
|
|
data_o = ipn({r16, l16});
|
|
// 16. stage
|
|
if (mode[16] == 1'b0) begin
|
|
c16 = {c15[1:27], c15[0]};
|
|
d16 = {d15[1:27], d15[0]};
|
|
end
|
|
else begin
|
|
c16 = {c15[27], c15[0:26]};
|
|
d16 = {d15[27], d15[0:26]};
|
|
end
|
|
key16 = pc2({c16, d16});
|
|
l16 = r15;
|
|
r16 = l15 ^ (f(r15, key16));
|
|
// 15. stage
|
|
if (mode[15] == 1'b0) begin
|
|
c15 = {c14[2:27], c14[0:1]};
|
|
d15 = {d14[2:27], d14[0:1]};
|
|
end
|
|
else begin
|
|
c15 = {c14[26:27], c14[0:25]};
|
|
d15 = {d14[26:27], d14[0:25]};
|
|
end
|
|
key15 = pc2({c15, d15});
|
|
l15 = r14;
|
|
r15 = l14 ^ (f(r14, key15));
|
|
// 14. stage
|
|
if (mode[14] == 1'b0) begin
|
|
c14 = {c13[2:27], c13[0:1]};
|
|
d14 = {d13[2:27], d13[0:1]};
|
|
end
|
|
else begin
|
|
c14 = {c13[26:27], c13[0:25]};
|
|
d14 = {d13[26:27], d13[0:25]};
|
|
end
|
|
key14 = pc2({c14, d14});
|
|
l14 = r13;
|
|
r14 = l13 ^ (f(r13, key14));
|
|
// 13. stage
|
|
if (mode[13] == 1'b0) begin
|
|
c13 = {c12[2:27], c12[0:1]};
|
|
d13 = {d12[2:27], d12[0:1]};
|
|
end
|
|
else begin
|
|
c13 = {c12[26:27], c12[0:25]};
|
|
d13 = {d12[26:27], d12[0:25]};
|
|
end
|
|
key13 = pc2({c13, d13});
|
|
l13 = r12;
|
|
r13 = l12 ^ (f(r12, key13));
|
|
// 12. stage
|
|
if (mode[12] == 1'b0) begin
|
|
c12 = {c11[2:27], c11[0:1]};
|
|
d12 = {d11[2:27], d11[0:1]};
|
|
end
|
|
else begin
|
|
c12 = {c11[26:27], c11[0:25]};
|
|
d12 = {d11[26:27], d11[0:25]};
|
|
end
|
|
key12 = pc2({c12, d12});
|
|
l12 = r11;
|
|
r12 = l11 ^ (f(r11, key12));
|
|
// 11. stage
|
|
if (mode[11] == 1'b0) begin
|
|
c11 = {c10[2:27], c10[0:1]};
|
|
d11 = {d10[2:27], d10[0:1]};
|
|
end
|
|
else begin
|
|
c11 = {c10[26:27], c10[0:25]};
|
|
d11 = {d10[26:27], d10[0:25]};
|
|
end
|
|
key11 = pc2({c11, d11});
|
|
l11 = r10;
|
|
r11 = l10 ^ (f(r10, key11));
|
|
// 10. stage
|
|
if (mode[10] == 1'b0) begin
|
|
c10 = {c9[2:27], c9[0:1]};
|
|
d10 = {d9[2:27], d9[0:1]};
|
|
end
|
|
else begin
|
|
c10 = {c9[26:27], c9[0:25]};
|
|
d10 = {d9[26:27], d9[0:25]};
|
|
end
|
|
key10 = pc2({c10, d10});
|
|
l10 = r9;
|
|
r10 = l9 ^ (f(r9, key10));
|
|
// 9. stage
|
|
if (mode[9] == 1'b0) begin
|
|
c9 = {c8[1:27], c8[0]};
|
|
d9 = {d8[1:27], d8[0]};
|
|
end
|
|
else begin
|
|
c9 = {c8[27], c8[0:26]};
|
|
d9 = {d8[27], d8[0:26]};
|
|
end
|
|
key9 = pc2({c9, d9});
|
|
l9 = r8;
|
|
r9 = l8 ^ (f(r8, key9));
|
|
// 8. stage
|
|
if (mode[8] == 1'b0) begin
|
|
c8 = {c7[2:27], c7[0:1]};
|
|
d8 = {d7[2:27], d7[0:1]};
|
|
end
|
|
else begin
|
|
c8 = {c7[26:27], c7[0:25]};
|
|
d8 = {d7[26:27], d7[0:25]};
|
|
end
|
|
key8 = pc2({c8, d8});
|
|
l8 = r7;
|
|
r8 = l7 ^ (f(r7, key8));
|
|
// 7. stage
|
|
if (mode[7] == 1'b0) begin
|
|
c7 = {c6[2:27], c6[0:1]};
|
|
d7 = {d6[2:27], d6[0:1]};
|
|
end
|
|
else begin
|
|
c7 = {c6[26:27], c6[0:25]};
|
|
d7 = {d6[26:27], d6[0:25]};
|
|
end
|
|
key7 = pc2({c7, d7});
|
|
l7 = r6;
|
|
r7 = l6 ^ (f(r6, key7));
|
|
// 6. stage
|
|
if (mode[6] == 1'b0) begin
|
|
c6 = {c5[2:27], c5[0:1]};
|
|
d6 = {d5[2:27], d5[0:1]};
|
|
end
|
|
else begin
|
|
c6 = {c5[26:27], c5[0:25]};
|
|
d6 = {d5[26:27], d5[0:25]};
|
|
end
|
|
key6 = pc2({c6, d6});
|
|
l6 = r5;
|
|
r6 = l5 ^ (f(r5, key6));
|
|
// 5. stage
|
|
if (mode[5] == 1'b0) begin
|
|
c5 = {c4[2:27], c4[0:1]};
|
|
d5 = {d4[2:27], d4[0:1]};
|
|
end
|
|
else begin
|
|
c5 = {c4[26:27], c4[0:25]};
|
|
d5 = {d4[26:27], d4[0:25]};
|
|
end
|
|
key5 = pc2({c5, d5});
|
|
l5 = r4;
|
|
r5 = l4 ^ (f(r4, key5));
|
|
// 4. stage
|
|
if (mode[4] == 1'b0) begin
|
|
c4 = {c3[2:27], c3[0:1]};
|
|
d4 = {d3[2:27], d3[0:1]};
|
|
end
|
|
else begin
|
|
c4 = {c3[26:27], c3[0:25]};
|
|
d4 = {d3[26:27], d3[0:25]};
|
|
end
|
|
key4 = pc2({c4, d4});
|
|
l4 = r3;
|
|
r4 = l3 ^ (f(r3, key4));
|
|
// 3. stage
|
|
if (mode[3] == 1'b0) begin
|
|
c3 = {c2[2:27], c2[0:1]};
|
|
d3 = {d2[2:27], d2[0:1]};
|
|
end
|
|
else begin
|
|
c3 = {c2[26:27], c2[0:25]};
|
|
d3 = {d2[26:27], d2[0:25]};
|
|
end
|
|
key3 = pc2({c3, d3});
|
|
l3 = r2;
|
|
r3 = l2 ^ (f(r2, key3));
|
|
// 2. stage
|
|
if (mode[2] == 1'b0) begin
|
|
c2 = {c1[1:27], c1[0]};
|
|
d2 = {d1[1:27], d1[0]};
|
|
end
|
|
else begin
|
|
c2 = {c1[27], c1[0:26]};
|
|
d2 = {d1[27], d1[0:26]};
|
|
end
|
|
key2 = pc2({c2, d2});
|
|
l2 = r1;
|
|
r2 = l1 ^ (f(r1, key2));
|
|
// 1. stage
|
|
if (mode[1] == 1'b0) begin
|
|
c1 = {c0[1:27], c0[0]};
|
|
d1 = {d0[1:27], d0[0]};
|
|
end
|
|
else begin
|
|
c1 = c0;
|
|
d1 = d0;
|
|
end
|
|
key1 = pc2({c1, d1});
|
|
l1 = r0;
|
|
r1 = l0 ^ (f(r0, key1));
|
|
// input stage
|
|
l0 = ip0(data_i);
|
|
r0 = ip0(data_i);
|
|
c0 = pc1_c(key_i);
|
|
d0 = pc1_d(key_i);
|
|
end
|
|
end
|
|
|
|
|
|
endmodule
|
|
|
|
|
|
|
|
|