From 732478fb1672a3ee16f10602ae443db7d0e9fd59 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Joachim=20Stro=CC=88mbergson?= Date: Thu, 5 Jul 2018 15:29:45 +0200 Subject: Updated keywrap logic to support unwrap. Split state to handle next start in both wrap and unwrap cases. --- src/rtl/keywrap_core.v | 86 +++++++++++++++++++++++++++++++++----------------- 1 file changed, 57 insertions(+), 29 deletions(-) diff --git a/src/rtl/keywrap_core.v b/src/rtl/keywrap_core.v index 91e5161..99736f2 100644 --- a/src/rtl/keywrap_core.v +++ b/src/rtl/keywrap_core.v @@ -73,13 +73,15 @@ module keywrap_core ( localparam CTRL_IDLE = 4'h0; localparam CTRL_INIT_WAIT = 4'h1; - localparam CTRL_NEXT_LOOP = 4'h2; - localparam CTRL_NEXT_WAIT0 = 4'h3; - localparam CTRL_NEXT_WAIT = 4'h4; - localparam CTRL_NEXT_UPDATE = 4'h5; - localparam CTRL_NEXT_WRAP = 4'h6; - localparam CTRL_NEXT_UNWRAP = 4'h7; - localparam CTRL_NEXT_FINALIZE = 4'h8; + localparam CTRL_NEXT_WSTART = 4'h2; + localparam CTRL_NEXT_USTART = 4'h3; + localparam CTRL_NEXT_LOOP = 4'h4; + localparam CTRL_NEXT_WAIT0 = 4'h5; + localparam CTRL_NEXT_WAIT = 4'h6; + localparam CTRL_NEXT_UPDATE = 4'h7; + localparam CTRL_NEXT_WCHECK = 4'h8; + localparam CTRL_NEXT_UCHECK = 4'h9; + localparam CTRL_NEXT_FINALIZE = 4'ha; //---------------------------------------------------------------- @@ -221,23 +223,28 @@ module keywrap_core ( //---------------------------------------------------------------- - // keywrap_dp + // keywrap_logic // // Main logic for the key wrap functionality. //---------------------------------------------------------------- always @* - begin : keywrap_dp + begin : keywrap_logic reg [63 : 0] xor_val; a_new = 64'h0; a_we = 1'h0; core_addr = block_ctr_reg - 1'h1; - core_we = 1'h0; + core_we = 1'h0; - aes_block = {a_reg, core_rd_data}; - core_wr_data = aes_result[63 : 0]; xor_val = (rlen * iteration_ctr_reg) + {51'h0, block_ctr_reg}; + if (encdec) + aes_block = {a_reg, core_rd_data}; + else + aes_block = {(a_reg ^ xor_val), core_rd_data}; + + core_wr_data = aes_result[63 : 0]; + if (init_a) begin a_new = a_init; @@ -246,9 +253,13 @@ module keywrap_core ( if (update_state) begin - a_new = aes_result[127 : 64] ^ xor_val; - a_we = 1'h1; core_we = 1'h1; + + if (encdec) + a_new = aes_result[127 : 64] ^ xor_val; + else + a_new = aes_result[127 : 64]; + a_we = 1'h1; end end @@ -258,7 +269,7 @@ module keywrap_core ( //---------------------------------------------------------------- always @* begin : block_ctr - block_ctr_new = 13'h1; + block_ctr_new = 13'h0; block_ctr_we = 1'h0; if (block_ctr_rst) @@ -363,18 +374,21 @@ module keywrap_core ( if (next) begin - block_ctr_rst = 1'h1; - iteration_ctr_rst = 1'h1; ready_new = 1'h0; ready_we = 1'h1; valid_new = 1'h0; valid_we = 1'h1; init_a = 1'h1; - keywrap_core_ctrl_new = CTRL_NEXT_LOOP; + + if (encdec) + keywrap_core_ctrl_new = CTRL_NEXT_WSTART; + else + keywrap_core_ctrl_new = CTRL_NEXT_USTART; keywrap_core_ctrl_we = 1'h1; end end + CTRL_INIT_WAIT: begin if (aes_ready) @@ -387,6 +401,24 @@ module keywrap_core ( end + CTRL_NEXT_WSTART: + begin + block_ctr_rst = 1'h1; + iteration_ctr_rst = 1'h1; + keywrap_core_ctrl_new = CTRL_NEXT_LOOP; + keywrap_core_ctrl_we = 1'h1; + end + + + CTRL_NEXT_USTART: + begin + block_ctr_set = 1'h1; + iteration_ctr_set = 1'h1; + keywrap_core_ctrl_new = CTRL_NEXT_LOOP; + keywrap_core_ctrl_we = 1'h1; + end + + CTRL_NEXT_LOOP: begin aes_next = 1'h1; @@ -414,21 +446,17 @@ module keywrap_core ( CTRL_NEXT_UPDATE: begin - update_state = 1'h1; + update_state = 1'h1; + if (encdec) - begin - keywrap_core_ctrl_new = CTRL_NEXT_WRAP; - keywrap_core_ctrl_we = 1'h1; - end + keywrap_core_ctrl_new = CTRL_NEXT_WCHECK; else - begin - keywrap_core_ctrl_new = CTRL_NEXT_UNWRAP; - keywrap_core_ctrl_we = 1'h1; - end + keywrap_core_ctrl_new = CTRL_NEXT_UCHECK; + keywrap_core_ctrl_we = 1'h1; end - CTRL_NEXT_WRAP: + CTRL_NEXT_WCHECK: begin if (block_ctr_reg < rlen) begin @@ -453,7 +481,7 @@ module keywrap_core ( end - CTRL_NEXT_UNWRAP: + CTRL_NEXT_UCHECK: begin if (block_ctr_reg > 0) begin -- cgit v1.2.3