//======================================================================
//
// tb_aes.v
// --------
// Testbench for the aes top level wrapper.
//
//
// Author: Joachim Strombergson
// Copyright (c) 2014, NORDUnet A/S
// 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 NORDUnet 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.
//
//======================================================================
//------------------------------------------------------------------
// Test module.
//------------------------------------------------------------------
module tb_aes();
//----------------------------------------------------------------
// Internal constant and parameter definitions.
//----------------------------------------------------------------
parameter DEBUG = 0;
parameter CLK_HALF_PERIOD = 1;
parameter CLK_PERIOD = 2 * CLK_HALF_PERIOD;
// The DUT address map.
parameter ADDR_NAME0 = 8'h00;
parameter ADDR_NAME1 = 8'h01;
parameter ADDR_VERSION = 8'h02;
parameter ADDR_CTRL = 8'h08;
parameter CTRL_INIT_BIT = 0;
parameter CTRL_NEXT_BIT = 1;
parameter CTRL_ENCDEC_BIT = 2;
parameter CTRL_KEYLEN_BIT = 3;
parameter ADDR_STATUS = 8'h09;
parameter STATUS_READY_BIT = 0;
parameter STATUS_VALID_BIT = 1;
parameter ADDR_CONFIG = 8'h0a;
parameter ADDR_KEY0 = 8'h10;
parameter ADDR_KEY1 = 8'h11;
parameter ADDR_KEY2 = 8'h12;
parameter ADDR_KEY3 = 8'h13;
parameter ADDR_KEY4 = 8'h14;
parameter ADDR_KEY5 = 8'h15;
parameter ADDR_KEY6 = 8'h16;
parameter ADDR_KEY7 = 8'h17;
parameter ADDR_BLOCK0 = 8'h20;
parameter ADDR_BLOCK1 = 8'h21;
parameter ADDR_BLOCK2 = 8'h22;
parameter ADDR_BLOCK3 = 8'h23;
parameter ADDR_RESULT0 = 8'h30;
parameter ADDR_RESULT1 = 8'h31;
parameter ADDR_RESULT2 = 8'h32;
parameter ADDR_RESULT3 = 8'h33;
parameter AES_128_BIT_KEY = 0;
parameter AES_256_BIT_KEY = 1;
parameter AES_DECIPHER = 1'b0;
parameter AES_ENCIPHER = 1'b1;
//----------------------------------------------------------------
// Register and Wire declarations.
//----------------------------------------------------------------
reg [31 : 0] cycle_ctr;
reg [31 : 0] error_ctr;
reg [31 : 0] tc_ctr;
reg [31 : 0] read_data;
reg [127 : 0] result_data;
reg tb_clk;
reg tb_reset_n;
reg tb_cs;
reg tb_we;
reg [7 : 0] tb_address;
reg [31 : 0] tb_write_data;
wire [31 : 0] tb_read_data;
wire tb_error;
//----------------------------------------------------------------
// Device Under Test.
//----------------------------------------------------------------
aes dut(
.clk(tb_clk),
.reset_n(tb_reset_n),
.cs(tb_cs),
.we(tb_we),
.address(tb_address),
.write_data(tb_write_data),
.read_data(tb_read_data),
.error(tb_error)
);
//----------------------------------------------------------------
// clk_gen
//
// Always running clock generator process.
//----------------------------------------------------------------
always
begin : clk_gen
#CLK_HALF_PERIOD;
tb_clk = !tb_clk;
end // clk_gen
//----------------------------------------------------------------
// sys_monitor()
//
// An always running process that creates a cycle counter and
// conditionally displays information about the DUT.
//----------------------------------------------------------------
always
begin : sys_monitor
cycle_ctr = cycle_ctr + 1;
#(CLK_PERIOD);
if (DEBUG)
begin
dump_dut_state();
end
end
//----------------------------------------------------------------
// dump_dut_state()
//
// Dump the state of the dump when needed.
//----------------------------------------------------------------
task dump_dut_state;
begin
$display("cycle: 0x%016x", cycle_ctr);
$display("State of DUT");
$display("------------");
$display("ctrl_reg: init = 0x%01x, next = 0x%01x", dut.init_reg, dut.next_reg);
$display("config_reg: encdec = 0x%01x, length = 0x%01x ", dut.encdec_reg, dut.keylen_reg);
$display("");
$display("block: 0x%08x, 0x%08x, 0x%08x, 0x%08x",
dut.block_reg[0], dut.block_reg[1], dut.block_reg[2], dut.block_reg[3]);
$display("");
end
endtask // dump_dut_state
//----------------------------------------------------------------
// reset_dut()
//
// Toggle reset to put the DUT into a well known state.
//----------------------------------------------------------------
task reset_dut;
begin
$display("*** Toggle reset.");
tb_reset_n = 0;
#(2 * CLK_PERIOD);
tb_reset_n = 1;
$display("");
end
endtask // reset_dut
//----------------------------------------------------------------
// display_test_results()
//
// Display the accumulated test results.
//----------------------------------------------------------------
task display_test_results;
begin
if (error_ctr == 0)
begin
$display("*** All %02d test cases completed successfully", tc_ctr);
end
else
begin
$display("*** %02d tests completed - %02d test cases did not complete successfully.",
tc_ctr, error_ctr);
end
end
endtask // display_test_results
//----------------------------------------------------------------
// init_sim()
//
// Initialize all counters and testbed functionality as well
// as setting the DUT inputs to defined values.
//----------------------------------------------------------------
task init_sim;
begin
cycle_ctr = 0;
error_ctr = 0;
tc_ctr = 0;
tb_clk = 0;
tb_reset_n = 1;
tb_cs = 0;
tb_we = 0;
tb_address = 8'h0;
tb_write_data = 32'h0;
end
endtask // init_sim
//----------------------------------------------------------------
// write_word()
//
// Write the given word to the DUT using the DUT interface.
//----------------------------------------------------------------
task write_word(input [11 : 0] address,
input [31 : 0] word);
begin
if (DEBUG)
begin
$display("*** Writing 0x%08x to 0x%02x.", word, address);
$display("");
end
tb_address = address;
tb_write_data = word;
tb_cs = 1;
tb_we = 1;
#(2 * CLK_PERIOD);
tb_cs = 0;
tb_we = 0;
end
endtask // write_word
//----------------------------------------------------------------
// write_block()
//
// Write the given block to the dut.
//----------------------------------------------------------------
task write_block(input [127 : 0] block);
begin
write_word(ADDR_BLOCK0, block[127 : 96]);
write_word(ADDR_BLOCK1, block[95 : 64]);
write_word(ADDR_BLOCK2, block[63 : 32]);
write_word(ADDR_BLOCK3, block[31 : 0]);
end
endtask // write_block
//----------------------------------------------------------------
// read_word()
//
// Read a data word from the given address in the DUT.
// the word read will be available in the global variable
// read_data.
//----------------------------------------------------------------
task read_word(input [11 : 0] address);
begin
tb_address = address;
tb_cs = 1;
tb_we = 0;
#(CLK_PERIOD);
read_data = tb_read_data;
tb_cs = 0;
if (DEBUG)
begin
$display("*** Reading 0x%08x from 0x%02x.", read_data, address);
$display("");
end
end
endtask // read_word
//----------------------------------------------------------------
// wait_ready
//
// Wait for the DUT to signal that the result is ready
//----------------------------------------------------------------
task wait_ready;
begin : wait_ready
reg rdy;
rdy = 1'b0;
while (rdy != 1'b1)
begin
read_word(ADDR_STATUS);
rdy = tb_read_data[STATUS_READY_BIT];
end
end
endtask // wait_ready
//----------------------------------------------------------------
// read_result()
//
// Read the result block in the dut.
//----------------------------------------------------------------
task read_result;
begin
read_word(ADDR_RESULT0);
result_data[127 : 096] = read_data;
read_word(ADDR_RESULT1);
result_data[095 : 064] = read_data;
read_word(ADDR_RESULT2);
result_data[063 : 032] = read_data;
read_word(ADDR_RESULT3);
result_data[031 : 000] = read_data;
end
endtask // read_result
//----------------------------------------------------------------
// init_key()
//
// init the key in the dut by writing the given key and
// key length and then trigger init processing.
//----------------------------------------------------------------
task init_key(input [255 : 0] key, input key_length);
begin
if (DEBUG)
begin
$display("key length: 0x%01x", key_length);
$display("Initializing key expansion for key: 0x%016x", key);
end
write_word(ADDR_KEY0, key[255 : 224]);
write_word(ADDR_KEY1, key[223 : 192]);
write_word(ADDR_KEY2, key[191 : 160]);
write_word(ADDR_KEY3, key[159 : 128]);
write_word(ADDR_KEY4, key[127 : 96]);
write_word(ADDR_KEY5, key[95 : 64]);
write_word(ADDR_KEY6, key[63 : 32]);
write_word(ADDR_KEY7, key[31 : 0]);
if (key_length)
begin
write_word(ADDR_CONFIG, 8'h02);
end
else
begin
write_word(ADDR_CONFIG, 8'h00);
end
write_word(ADDR_CTRL, 8'h01);
#(100 * CLK_PERIOD);
end
endtask // init_key
//----------------------------------------------------------------
// ecb_mode_single_block_test()
//
// Perform ECB mode encryption or decryption single block test.
//----------------------------------------------------------------
task ecb_mode_single_block_test(input [7 : 0] tc_number,
input encdec,
input [255 : 0] key,
input key_length,
input [127 : 0] block,
input [127 : 0] expected);
begin
$display("*** TC %0d ECB mode test started.", tc_number);
tc_ctr = tc_ctr + 1;
init_key(key, key_length);
write_block(block);
dump_dut_state();
write_word(ADDR_CONFIG, (8'h00 + (key_length << 1)+ encdec));
write_word(ADDR_CTRL, 8'h02);
wait_ready();
$display("*** Ready has been set!");
dump_dut_state();
read_result();
if (result_data == expected)
begin
$display("*** TC %0d successful.", tc_number);
$display("");
end
else
begin
$display("*** ERROR: TC %0d NOT successful.", tc_number);
$display("Expected: 0x%032x", expected);
$display("Got: 0x%032x", result_data);
$display("");
error_ctr = error_ctr + 1;
end
end
endtask // ecb_mode_single_block_test
//----------------------------------------------------------------
// single_block_mangle_test()
//
// Perform single block test, but try to mangle the operation
// by changing from encryption to decryption mid-processing.
// This should cause errors unless changes to config during
// processing.
//----------------------------------------------------------------
task single_block_mangle_test(input [7 : 0] tc_number,
input [255 : 0] key,
input [127 : 0] block,
input [127 : 0] expected);
begin
$display("*** TC %0d mangle test started.", tc_number);
tc_ctr = tc_ctr + 1;
init_key(key, AES_128_BIT_KEY);
write_block(block);
dump_dut_state();
// Set that we want to encipher and start processing.
$display("*** Staring encipher operation");
write_word(ADDR_CONFIG, (8'h00 + (AES_128_BIT_KEY << 1) + AES_ENCIPHER));
write_word(ADDR_CTRL, 8'h02);
// Wait a number of cycles and then switch from encipher to decipher.
#(10 * CLK_PERIOD);
$display("*** Switching to decipher operation");
write_word(ADDR_CONFIG, (8'h00 + (AES_128_BIT_KEY << 1) + AES_DECIPHER));
wait_ready();
$display("*** Ready has been set!");
dump_dut_state();
read_result();
if (result_data == expected)
begin
$display("*** TC %0d successful.", tc_number);
$display("");
end
else
begin
$display("*** ERROR: TC %0d NOT successful.", tc_number);
$display("Expected: 0x%032x", expected);
$display("Got: 0x%032x", result_data);
$display("");
error_ctr = error_ctr + 1;
end
end
endtask // ecb_mode_single_block_test
//----------------------------------------------------------------
// aes_test()
//
// Main test task will perform complete NIST test of AES.
//----------------------------------------------------------------
task aes_test;
reg [255 : 0] nist_aes128_key;
reg [255 : 0] nist_aes256_key;
reg [127 : 0] nist_plaintext0;
reg [127 : 0] nist_plaintext1;
reg [127 : 0] nist_plaintext2;
reg [127 : 0] nist_plaintext3;
reg [127 : 0] nist_ecb_128_enc_expected0;
reg [127 : 0] nist_ecb_128_enc_expected1;
reg [127 : 0] nist_ecb_128_enc_expected2;
reg [127 : 0] nist_ecb_128_enc_expected3;
reg [127 : 0] nist_ecb_256_enc_expected0;
reg [127 : 0] nist_ecb_256_enc_expected1;
reg [127 : 0] nist_ecb_256_enc_expected2;
reg [127 : 0] nist_ecb_256_enc_expected3;
begin
nist_aes128_key = 256'h2b7e151628aed2a6abf7158809cf4f3c00000000000000000000000000000000;
nist_aes256_key = 256'h603deb1015ca71be2b73aef0857d77811f352c073b6108d72d9810a30914dff4;
nist_plaintext0 = 128'h6bc1bee22e409f96e93d7e117393172a;
nist_plaintext1 = 128'hae2d8a571e03ac9c9eb76fac45af8e51;
nist_plaintext2 = 128'h30c81c46a35ce411e5fbc1191a0a52ef;
nist_plaintext3 = 128'hf69f2445df4f9b17ad2b417be66c3710;
nist_ecb_128_enc_expected0 = 128'h3ad77bb40d7a3660a89ecaf32466ef97;
nist_ecb_128_enc_expected1 = 128'hf5d3d58503b9699de785895a96fdbaaf;
nist_ecb_128_enc_expected2 = 128'h43b1cd7f598ece23881b00e3ed030688;
nist_ecb_128_enc_expected3 = 128'h7b0c785e27e8ad3f8223207104725dd4;
nist_ecb_256_enc_expected0 = 128'hf3eed1bdb5d2a03c064b5a7e3db181f8;
nist_ecb_256_enc_expected1 = 128'h591ccb10d410ed26dc5ba74a31362870;
nist_ecb_256_enc_expected2 = 128'hb6ed21b99ca6f4f9f153e7b1beafed1d;
nist_ecb_256_enc_expected3 = 128'h23304b7a39f9f3ff067d8d8f9e24ecc7;
$display("ECB 128 bit key tests");
$display("---------------------");
ecb_mode_single_block_test(8'h01, AES_ENCIPHER, nist_aes128_key, AES_128_BIT_KEY,
nist_plaintext0, nist_ecb_128_enc_expected0);
ecb_mode_single_block_test(8'h02, AES_ENCIPHER, nist_aes128_key, AES_128_BIT_KEY,
nist_plaintext1, nist_ecb_128_enc_expected1);
ecb_mode_single_block_test(8'h03, AES_ENCIPHER, nist_aes128_key, AES_128_BIT_KEY,
nist_plaintext2, nist_ecb_128_enc_expected2);
ecb_mode_single_block_test(8'h04, AES_ENCIPHER, nist_aes128_key, AES_128_BIT_KEY,
nist_plaintext3, nist_ecb_128_enc_expected3);
ecb_mode_single_block_test(8'h05, AES_DECIPHER, nist_aes128_key, AES_128_BIT_KEY,
nist_ecb_128_enc_expected0, nist_plaintext0);
ecb_mode_single_block_test(8'h06, AES_DECIPHER, nist_aes128_key, AES_128_BIT_KEY,
nist_ecb_128_enc_expected1, nist_plaintext1);
ecb_mode_single_block_test(8'h07, AES_DECIPHER, nist_aes128_key, AES_128_BIT_KEY,
nist_ecb_128_enc_expected2, nist_plaintext2);
ecb_mode_single_block_test(8'h08, AES_DECIPHER, nist_aes128_key, AES_128_BIT_KEY,
nist_ecb_128_enc_expected3, nist_plaintext3);
$display("");
$display("ECB 256 bit key tests");
$display("---------------------");
ecb_mode_single_block_test(8'h10, AES_ENCIPHER, nist_aes256_key, AES_256_BIT_KEY,
nist_plaintext0, nist_ecb_256_enc_expected0);
ecb_mode_single_block_test(8'h11, AES_ENCIPHER, nist_aes256_key, AES_256_BIT_KEY,
nist_plaintext1, nist_ecb_256_enc_expected1);
ecb_mode_single_block_test(8'h12, AES_ENCIPHER, nist_aes256_key, AES_256_BIT_KEY,
nist_plaintext2, nist_ecb_256_enc_expected2);
ecb_mode_single_block_test(8'h13, AES_ENCIPHER, nist_aes256_key, AES_256_BIT_KEY,
nist_plaintext3, nist_ecb_256_enc_expected3);
ecb_mode_single_block_test(8'h14, AES_DECIPHER, nist_aes256_key, AES_256_BIT_KEY,
nist_ecb_256_enc_expected0, nist_plaintext0);
ecb_mode_single_block_test(8'h15, AES_DECIPHER, nist_aes256_key, AES_256_BIT_KEY,
nist_ecb_256_enc_expected1, nist_plaintext1);
ecb_mode_single_block_test(8'h16, AES_DECIPHER, nist_aes256_key, AES_256_BIT_KEY,
nist_ecb_256_enc_expected2, nist_plaintext2);
ecb_mode_single_block_test(8'h17, AES_DECIPHER, nist_aes256_key, AES_256_BIT_KEY,
nist_ecb_256_enc_expected3, nist_plaintext3);
$display("Block processing mangling test");
$display("------------------------------");
single_block_mangle_test(8'h18, nist_aes128_key, nist_plaintext0,
nist_ecb_128_enc_expected0);
end
endtask // aes_test
//----------------------------------------------------------------
// main
//
// The main test functionality.
//----------------------------------------------------------------
initial
begin : main
$display(" -= Testbench for AES started =-");
$display(" ==============================");
$display("");
init_sim();
dump_dut_state();
reset_dut();
dump_dut_state();
aes_test();
display_test_results();
$display("");
$display("*** AES simulation done. ***");
$finish;
end // main
endmodule // tb_aes
//======================================================================
// EOF tb_aes.v
//======================================================================
