From a689dccc34edcc6b955c9b522bb141e32c871add Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Joachim=20Stro=CC=88mbergson?= Date: Tue, 22 May 2018 11:18:35 +0200 Subject: Combined all AES round operations into a single operation for a round. --- src/rtl/aes_decipher_block.v | 102 +++++++++++-------------------------------- 1 file changed, 25 insertions(+), 77 deletions(-) (limited to 'src/rtl/aes_decipher_block.v') diff --git a/src/rtl/aes_decipher_block.v b/src/rtl/aes_decipher_block.v index c2304d6..ce34cc8 100644 --- a/src/rtl/aes_decipher_block.v +++ b/src/rtl/aes_decipher_block.v @@ -72,9 +72,8 @@ module aes_decipher_block( localparam CTRL_IDLE = 3'h0; localparam CTRL_INIT = 3'h1; - localparam CTRL_SBOX = 3'h2; - localparam CTRL_MAIN = 3'h3; - localparam CTRL_FINAL = 3'h4; + localparam CTRL_MAIN = 3'h2; + localparam CTRL_FINAL = 3'h3; //---------------------------------------------------------------- @@ -192,22 +191,16 @@ module aes_decipher_block( //---------------------------------------------------------------- // Registers including update variables and write enable. //---------------------------------------------------------------- + reg [127 : 0] block_reg; + reg [127 : 0] block_new; + reg block_we; + reg [3 : 0] round_ctr_reg; reg [3 : 0] round_ctr_new; reg round_ctr_we; reg round_ctr_set; reg round_ctr_dec; - reg [127 : 0] block_new; - reg [31 : 0] block_w0_reg; - reg [31 : 0] block_w1_reg; - reg [31 : 0] block_w2_reg; - reg [31 : 0] block_w3_reg; - reg block_w0_we; - reg block_w1_we; - reg block_w2_we; - reg block_w3_we; - reg ready_reg; reg ready_new; reg ready_we; @@ -243,8 +236,8 @@ module aes_decipher_block( //---------------------------------------------------------------- // Concurrent connectivity for ports etc. //---------------------------------------------------------------- + assign new_block = block_reg; assign round = round_ctr_reg; - assign new_block = {block_w0_reg, block_w1_reg, block_w2_reg, block_w3_reg}; assign ready = ready_reg; @@ -259,27 +252,15 @@ module aes_decipher_block( begin: reg_update if (!reset_n) begin - block_w0_reg <= 32'h0; - block_w1_reg <= 32'h0; - block_w2_reg <= 32'h0; - block_w3_reg <= 32'h0; + block_reg <= 128'h0; round_ctr_reg <= 4'h0; ready_reg <= 1'b1; dec_ctrl_reg <= CTRL_IDLE; end else begin - if (block_w0_we) - block_w0_reg <= block_new[127 : 096]; - - if (block_w1_we) - block_w1_reg <= block_new[095 : 064]; - - if (block_w2_we) - block_w2_reg <= block_new[063 : 032]; - - if (block_w3_we) - block_w3_reg <= block_new[031 : 000]; + if (block_we) + block_reg <= block_new; if (round_ctr_we) round_ctr_reg <= round_ctr_new; @@ -300,68 +281,43 @@ module aes_decipher_block( //---------------------------------------------------------------- always @* begin : round_logic - reg [127 : 0] old_block, inv_shiftrows_block, inv_mixcolumns_block; + reg [127 : 0] subbytes_block, inv_shiftrows_block, inv_mixcolumns_block; reg [127 : 0] addkey_block; inv_shiftrows_block = 128'h0; inv_mixcolumns_block = 128'h0; addkey_block = 128'h0; block_new = 128'h0; - block_w0_we = 1'b0; - block_w1_we = 1'b0; - block_w2_we = 1'b0; - block_w3_we = 1'b0; + block_we = 1'b0; - sboxw0 = block_w0_reg; - sboxw1 = block_w1_reg; - sboxw2 = block_w2_reg; - sboxw3 = block_w3_reg; + sboxw0 = block_reg[127 : 96]; + sboxw1 = block_reg[95 : 64]; + sboxw2 = block_reg[63 : 32]; + sboxw3 = block_reg[31 : 0]; + subbytes_block = {new_sboxw0, new_sboxw1, new_sboxw2, new_sboxw3}; - old_block = {block_w0_reg, block_w1_reg, block_w2_reg, block_w3_reg}; - - // Update based on update type. case (update_type) - // InitRound INIT_UPDATE: begin - old_block = block; - addkey_block = addroundkey(old_block, round_key); + addkey_block = addroundkey(block, round_key); inv_shiftrows_block = inv_shiftrows(addkey_block); block_new = inv_shiftrows_block; - block_w0_we = 1'b1; - block_w1_we = 1'b1; - block_w2_we = 1'b1; - block_w3_we = 1'b1; - end - - SBOX_UPDATE: - begin - block_new = {new_sboxw0, new_sboxw1, new_sboxw2, new_sboxw3}; - block_w0_we = 1'b1; - block_w1_we = 1'b1; - block_w2_we = 1'b1; - block_w3_we = 1'b1; + block_we = 1'b1; end MAIN_UPDATE: begin - addkey_block = addroundkey(old_block, round_key); + addkey_block = addroundkey(subbytes_block, round_key); inv_mixcolumns_block = inv_mixcolumns(addkey_block); inv_shiftrows_block = inv_shiftrows(inv_mixcolumns_block); block_new = inv_shiftrows_block; - block_w0_we = 1'b1; - block_w1_we = 1'b1; - block_w2_we = 1'b1; - block_w3_we = 1'b1; + block_we = 1'b1; end FINAL_UPDATE: begin - block_new = addroundkey(old_block, round_key); - block_w0_we = 1'b1; - block_w1_we = 1'b1; - block_w2_we = 1'b1; - block_w3_we = 1'b1; + block_new = addroundkey(subbytes_block, round_key); + block_we = 1'b1; end default: @@ -431,15 +387,8 @@ module aes_decipher_block( CTRL_INIT: begin - update_type = INIT_UPDATE; - dec_ctrl_new = CTRL_SBOX; - dec_ctrl_we = 1'b1; - end - - CTRL_SBOX: - begin - update_type = SBOX_UPDATE; round_ctr_dec = 1'b1; + update_type = INIT_UPDATE; dec_ctrl_new = CTRL_MAIN; dec_ctrl_we = 1'b1; end @@ -448,9 +397,8 @@ module aes_decipher_block( begin if (round_ctr_reg > 0) begin + round_ctr_dec = 1'b1; update_type = MAIN_UPDATE; - dec_ctrl_new = CTRL_SBOX; - dec_ctrl_we = 1'b1; end else begin -- cgit v1.2.3