aes128_fast.vhd

Consecutive AES core Description of project.. Features - AES encoder - 128/192/256 bit -

    
    s_02(0) <= sbox_val(s2_buf(0));
    s_02(1) <= sbox_val(s2_buf(1));
    s_02(2) <= sbox_val(s2_buf(2));
    s_02(3) <= sbox_val(s2_buf(3));
    
    s_03(0) <= sbox_val(s3_buf(0));
    s_03(1) <= sbox_val(s3_buf(1));
    s_03(2) <= sbox_val(s3_buf(2));
    s_03(3) <= sbox_val(s3_buf(3));
  else
    s_00(0) <= inv_sbox_val(s0_buf(0));
    s_00(1) <= inv_sbox_val(s0_buf(1));
    s_00(2) <= inv_sbox_val(s0_buf(2));
    s_00(3) <= inv_sbox_val(s0_buf(3));
    
    s_01(0) <= inv_sbox_val(s1_buf(0));
    s_01(1) <= inv_sbox_val(s1_buf(1));
    s_01(2) <= inv_sbox_val(s1_buf(2));
    s_01(3) <= inv_sbox_val(s1_buf(3));
    
    s_02(0) <= inv_sbox_val(s2_buf(0));
    s_02(1) <= inv_sbox_val(s2_buf(1));
    s_02(2) <= inv_sbox_val(s2_buf(2));
    s_02(3) <= inv_sbox_val(s2_buf(3));
    
    s_03(0) <= inv_sbox_val(s3_buf(0));
    s_03(1) <= inv_sbox_val(s3_buf(1));
    s_03(2) <= inv_sbox_val(s3_buf(2));
    s_03(3) <= inv_sbox_val(s3_buf(3));
  end if;
end process;  

-----------SHIFT ROWS TRANSFORMATION--------------------------------------
process(s_00,s_01,s_02,s_03,mode)
begin
  if(mode = '1') then
    r_00 <= (s_00(0),s_01(1),s_02(2),s_03(3));
    r_01 <= (s_01(0),s_02(1),s_03(2),s_00(3));
    r_02 <= (s_02(0),s_03(1),s_00(2),s_01(3));
    r_03 <= (s_03(0),s_00(1),s_01(2),s_02(3));
  else
    r_00 <= (s_00(0),s_03(1),s_02(2),s_01(3)); 
    r_01 <= (s_01(0),s_00(1),s_03(2),s_02(3)); 
    r_02 <= (s_02(0),s_01(1),s_00(2),s_03(3)); 
    r_03 <= (s_03(0),s_02(1),s_01(2),s_00(3)); 
  end if;
end process;  
-----------MIX COLUMNS TRANSFORMATION--------------------------------------        

mix_col_array <= mix_cols_routine(r_00,r_01,r_02,r_03,mode);
mixcol_0 <= (mix_col_array(0 to 7),mix_col_array(8 to 15),mix_col_array(16 to 23),mix_col_array(24 to 31));
mixcol_1 <= (mix_col_array(32 to 39),mix_col_array(40 to 47),mix_col_array(48 to 55),mix_col_array(56 to 63));
mixcol_2 <= (mix_col_array(64 to 71),mix_col_array(72 to 79),mix_col_array(80 to 87),mix_col_array(88 to 95));
mixcol_3 <= (mix_col_array(96 to 103),mix_col_array(104 to 111),mix_col_array(112 to 119),mix_col_array(120 to 127));

mixcol_key_array <= mix_cols_routine(new_key0_d1,new_key1_d1,new_key2_d1,new_key3_d1,mode);
mixcol_key_0 <= (mixcol_key_array(0 to 7),mixcol_key_array(8 to 15),mixcol_key_array(16 to 23),mixcol_key_array(24 to 31));
mixcol_key_1 <= (mixcol_key_array(32 to 39),mixcol_key_array(40 to 47),mixcol_key_array(48 to 55),mixcol_key_array(56 to 63));
mixcol_key_2 <= (mixcol_key_array(64 to 71),mixcol_key_array(72 to 79),mixcol_key_array(80 to 87),mixcol_key_array(88 to 95));
mixcol_key_3 <= (mixcol_key_array(96 to 103),mixcol_key_array(104 to 111),mixcol_key_array(112 to 119),mixcol_key_array(120 to 127));

---------ADD ROUND KEY STEP-------------------------------------------------
expand_key:  key_expander 
             port map(
                          clk       => clk,
                          reset     => reset,
                          key_in_c0 => key_reg0,
                          key_in_c1 => key_reg1,
                          key_in_c2 => key_reg2,
                          key_in_c3 => key_reg3,
                          count     => round_cnt,
                          mode      => mode,
                          keyout_c0 => new_key0,
                          keyout_c1 => new_key1,
                          keyout_c2 => new_key2,
                          keyout_c3 => new_key3
                       );

process(clk,reset)  ---- registered to increase speed
begin
  if(reset = '1') then
    new_key0_d1 <= (others =>(others => '0'));
    new_key1_d1 <= (others =>(others => '0'));
    new_key2_d1 <= (others =>(others => '0'));
    new_key3_d1 <= (others =>(others => '0'));
  elsif rising_edge(clk) then  
    new_key0_d1 <= new_key0;
    new_key1_d1 <= new_key1;
    new_key2_d1 <= new_key2;
    new_key3_d1 <= new_key3;
  end if;
end process;

-- Previous round output as input to next round
next_round_data_0 <= (pr_data_0(0) xor key_select_0(0),pr_data_0(1) xor key_select_0(1),pr_data_0(2) xor key_select_0(2),pr_data_0(3) xor key_select_0(3)); 
next_round_data_1 <= (pr_data_1(0) xor key_select_1(0),pr_data_1(1) xor key_select_1(1),pr_data_1(2) xor key_select_1(2),pr_data_1(3) xor key_select_1(3));  
next_round_data_2 <= (pr_data_2(0) xor key_select_2(0),pr_data_2(1) xor key_select_2(1),pr_data_2(2) xor key_select_2(2),pr_data_2(3) xor key_select_2(3));  
next_round_data_3 <= (pr_data_3(0) xor key_select_3(0),pr_data_3(1) xor key_select_3(1),pr_data_3(2) xor key_select_3(2),pr_data_3(3) xor key_select_3(3));  

-- Muxing for choosing data for the last round
pr_data_0 <= r_00 when round_cnt=11 else
             mixcol_0;
pr_data_1 <= r_01 when round_cnt=11 else
             mixcol_1;
pr_data_2 <= r_02 when round_cnt=11 else
             mixcol_2;
pr_data_3 <= r_03 when round_cnt=11 else
             mixcol_3;
             
key_select_0 <= new_key0_d1 when (mode = '1') else
                mixcol_key_0 when(mode = '0' and round_cnt < 11) else
                new_key0_d1;
key_select_1 <= new_key1_d1 when (mode = '1') else
                mixcol_key_1 when(mode = '0' and round_cnt < 11) else
                new_key1_d1;
key_select_2 <= new_key2_d1 when (mode = '1') else
                mixcol_key_2 when(mode = '0' and round_cnt < 11) else
                new_key2_d1;
key_select_3 <= new_key3_d1 when (mode = '1') else
                mixcol_key_3 when(mode = '0' and round_cnt < 11) else
                new_key3_d1;
done <= done_d2;             

-- Registering start and load             
process(clk,reset)
begin
  if(reset = '1') then
    load_d1  <= '0';
    start_d1 <= '0';
    start_d2 <= '0';
  elsif rising_edge(clk) then
    load_d1  <= load;
    start_d1 <= start;
    start_d2 <= start_d1;
  end if;
end process;  

-- Register outputs at end of each round
process(clk,reset)
begin
  if(reset = '1') then
    s0_buf <= (others =>(others => '0'));
    s1_buf <= (others =>(others => '0'));
    s2_buf <= (others =>(others => '0'));
    s3_buf <= (others =>(others => '0'));
  elsif rising_edge(clk) then
    if(round_cnt = 0 or round_cnt = 1) then
      s0_buf <= s0;
      s1_buf <= s1;
      s2_buf <= s2;
      s3_buf <= s3;
    else
      s0_buf <= next_round_data_0;
      s1_buf <= next_round_data_1;
      s2_buf <= next_round_data_2;
      s3_buf <= next_round_data_3;
    end if;
  end if;  
end process;  

-- Initiator process
process(clk,reset)
begin
  if(reset = '1') then
    round_cnt <= 0;
    flag_cnt <= '0';
  elsif rising_edge(clk) then
    if((start_d2 = '1' and start_d1 = '0') or flag_cnt = '1') then
      if(round_cnt < 11) then
        round_cnt <= round_cnt + 1;
        flag_cnt <= '1';
      else  
        round_cnt <= 0;
        flag_cnt <= '0';
      end if;  
    end if;
  end if;  
end process;  

-- Completion signalling process
process(clk,reset)
begin
  if(reset = '1') then
    done_d1 <= '0';
    done_d2 <= '0';
  elsif rising_edge(clk) then
    if(start_d2 = '1' and start_d1 = '0') then
      done_d1 <= '0';
      done_d2 <= '0';
    elsif(round_cnt = 10) then
      done_d1 <= '1';
    end if;  
    done_d2 <= done_d1;
  end if;
end process;  

-- Output assignment process        
process(clk,reset)
begin
  if(reset= '1') then
    data_out <= (others => '0');
  elsif rising_edge(clk) then  
    if(done_d1 = '1' and done_d2 = '0') then
        data_out <= (next_round_data_0(0) & next_round_data_0(1) & next_round_data_0(2) & next_round_data_0(3) &
                     next_round_data_1(0) & next_round_data_1(1) & next_round_data_1(2) & next_round_data_1(3) &
                     next_round_data_2(0) & next_round_data_2(1) & next_round_data_2(2) & next_round_data_2(3) &
                     next_round_data_3(0) & next_round_data_3(1) & next_round_data_3(2) & next_round_data_3(3));
    end if;
  end if;
end process;

end mapping;