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authorJoachim StroĢˆmbergson <joachim@secworks.se>2014-09-03 15:49:00 +0200
committerJoachim StroĢˆmbergson <joachim@secworks.se>2014-09-03 15:49:00 +0200
commit9e7c659fb59877c00f8f3761e57b1e8918ddec0a (patch)
tree3969639c9fdd2add83d8b2fb4827bef0b6c222e9 /src/rtl
parentabf962fccb4c44b8a71180aa770bea5f9f653ac0 (diff)
Adding RTL code for the ChaCha stream cipher.
Diffstat (limited to 'src/rtl')
-rw-r--r--src/rtl/chacha.v896
-rw-r--r--src/rtl/chacha_core.v1308
-rw-r--r--src/rtl/chacha_qr.v119
3 files changed, 2323 insertions, 0 deletions
diff --git a/src/rtl/chacha.v b/src/rtl/chacha.v
new file mode 100644
index 0000000..c83710d
--- /dev/null
+++ b/src/rtl/chacha.v
@@ -0,0 +1,896 @@
+//======================================================================
+//
+// chacha.v
+// --------
+// Top level wrapper for the ChaCha stream, cipher core providing
+// a simple memory like interface with 32 bit data access.
+//
+//
+// Author: Joachim Strombergson
+// Copyright (c) 2011, 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.
+//
+//======================================================================
+
+module chacha(
+ // Clock and reset.
+ input wire clk,
+ input wire reset_n,
+
+ // Control.
+ input wire cs,
+ input wire we,
+
+ // Data ports.
+ input wire [7 : 0] address,
+ input wire [31 : 0] write_data,
+ output wire [31 : 0] read_data,
+ output wire error
+ );
+
+ //----------------------------------------------------------------
+ // Internal constant and parameter definitions.
+ //----------------------------------------------------------------
+ parameter ADDR_CTRL = 8'h00;
+ parameter CTRL_INIT_BIT = 0;
+ parameter CTRL_NEXT_BIT = 1;
+
+ parameter ADDR_STATUS = 8'h01;
+ parameter STATUS_READY_BIT = 0;
+
+ parameter ADDR_KEYLEN = 8'h08;
+ parameter KEYLEN_BIT = 0;
+ parameter ADDR_ROUNDS = 8'h09;
+ parameter ROUNDS_HIGH_BIT = 4;
+ parameter ROUNDS_LOW_BIT = 0;
+
+ 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_IV0 = 8'h20;
+ parameter ADDR_IV1 = 8'h21;
+
+ parameter ADDR_DATA_IN0 = 8'h40;
+ parameter ADDR_DATA_IN1 = 8'h41;
+ parameter ADDR_DATA_IN2 = 8'h42;
+ parameter ADDR_DATA_IN3 = 8'h43;
+ parameter ADDR_DATA_IN4 = 8'h44;
+ parameter ADDR_DATA_IN5 = 8'h45;
+ parameter ADDR_DATA_IN6 = 8'h46;
+ parameter ADDR_DATA_IN7 = 8'h47;
+ parameter ADDR_DATA_IN8 = 8'h48;
+ parameter ADDR_DATA_IN9 = 8'h49;
+ parameter ADDR_DATA_IN10 = 8'h4a;
+ parameter ADDR_DATA_IN11 = 8'h4b;
+ parameter ADDR_DATA_IN12 = 8'h4c;
+ parameter ADDR_DATA_IN13 = 8'h4d;
+ parameter ADDR_DATA_IN14 = 8'h4e;
+ parameter ADDR_DATA_IN15 = 8'h4f;
+
+ parameter ADDR_DATA_OUT0 = 8'h80;
+ parameter ADDR_DATA_OUT1 = 8'h81;
+ parameter ADDR_DATA_OUT2 = 8'h82;
+ parameter ADDR_DATA_OUT3 = 8'h83;
+ parameter ADDR_DATA_OUT4 = 8'h84;
+ parameter ADDR_DATA_OUT5 = 8'h85;
+ parameter ADDR_DATA_OUT6 = 8'h86;
+ parameter ADDR_DATA_OUT7 = 8'h87;
+ parameter ADDR_DATA_OUT8 = 8'h88;
+ parameter ADDR_DATA_OUT9 = 8'h89;
+ parameter ADDR_DATA_OUT10 = 8'h8a;
+ parameter ADDR_DATA_OUT11 = 8'h8b;
+ parameter ADDR_DATA_OUT12 = 8'h8c;
+ parameter ADDR_DATA_OUT13 = 8'h8d;
+ parameter ADDR_DATA_OUT14 = 8'h8e;
+ parameter ADDR_DATA_OUT15 = 8'h8f;
+
+ parameter DEFAULT_CTR_INIT = 64'h0000000000000000;
+
+
+ //----------------------------------------------------------------
+ // Registers including update variables and write enable.
+ //----------------------------------------------------------------
+ reg init_reg;
+ reg next_reg;
+ reg ctrl_we;
+
+ reg ready_reg;
+
+ reg keylen_reg;
+ reg keylen_we;
+
+ reg [4 : 0] rounds_reg;
+ reg rounds_we;
+
+ reg data_out_valid_reg;
+
+ reg [31 : 0] key0_reg;
+ reg key0_we;
+ reg [31 : 0] key1_reg;
+ reg key1_we;
+ reg [31 : 0] key2_reg;
+ reg key2_we;
+ reg [31 : 0] key3_reg;
+ reg key3_we;
+ reg [31 : 0] key4_reg;
+ reg key4_we;
+ reg [31 : 0] key5_reg;
+ reg key5_we;
+ reg [31 : 0] key6_reg;
+ reg key6_we;
+ reg [31 : 0] key7_reg;
+ reg key7_we;
+
+ reg [31 : 0] iv0_reg;
+ reg iv0_we;
+ reg [31 : 0] iv1_reg;
+ reg iv1_we;
+
+ reg [31 : 0] data_in0_reg;
+ reg data_in0_we;
+ reg [31 : 0] data_in1_reg;
+ reg data_in1_we;
+ reg [31 : 0] data_in2_reg;
+ reg data_in2_we;
+ reg [31 : 0] data_in3_reg;
+ reg data_in3_we;
+ reg [31 : 0] data_in4_reg;
+ reg data_in4_we;
+ reg [31 : 0] data_in5_reg;
+ reg data_in5_we;
+ reg [31 : 0] data_in6_reg;
+ reg data_in6_we;
+ reg [31 : 0] data_in7_reg;
+ reg data_in7_we;
+ reg [31 : 0] data_in8_reg;
+ reg data_in8_we;
+ reg [31 : 0] data_in9_reg;
+ reg data_in9_we;
+ reg [31 : 0] data_in10_reg;
+ reg data_in10_we;
+ reg [31 : 0] data_in11_reg;
+ reg data_in11_we;
+ reg [31 : 0] data_in12_reg;
+ reg data_in12_we;
+ reg [31 : 0] data_in13_reg;
+ reg data_in13_we;
+ reg [31 : 0] data_in14_reg;
+ reg data_in14_we;
+ reg [31 : 0] data_in15_reg;
+ reg data_in15_we;
+
+ reg [31 : 0] data_out0_reg;
+ reg [31 : 0] data_out0_new;
+ reg [31 : 0] data_out1_reg;
+ reg [31 : 0] data_out1_new;
+ reg [31 : 0] data_out2_reg;
+ reg [31 : 0] data_out2_new;
+ reg [31 : 0] data_out3_reg;
+ reg [31 : 0] data_out3_new;
+ reg [31 : 0] data_out4_reg;
+ reg [31 : 0] data_out4_new;
+ reg [31 : 0] data_out5_reg;
+ reg [31 : 0] data_out5_new;
+ reg [31 : 0] data_out6_reg;
+ reg [31 : 0] data_out6_new;
+ reg [31 : 0] data_out7_reg;
+ reg [31 : 0] data_out7_new;
+ reg [31 : 0] data_out8_reg;
+ reg [31 : 0] data_out8_new;
+ reg [31 : 0] data_out9_reg;
+ reg [31 : 0] data_out9_new;
+ reg [31 : 0] data_out10_reg;
+ reg [31 : 0] data_out10_new;
+ reg [31 : 0] data_out11_reg;
+ reg [31 : 0] data_out11_new;
+ reg [31 : 0] data_out12_reg;
+ reg [31 : 0] data_out12_new;
+ reg [31 : 0] data_out13_reg;
+ reg [31 : 0] data_out13_new;
+ reg [31 : 0] data_out14_reg;
+ reg [31 : 0] data_out14_new;
+ reg [31 : 0] data_out15_reg;
+ reg [31 : 0] data_out15_new;
+
+
+ //----------------------------------------------------------------
+ // Wires.
+ //----------------------------------------------------------------
+ wire core_init;
+ wire core_next;
+ wire [255 : 0] core_key;
+ wire core_keylen;
+ wire [4 : 0] core_rounds;
+ wire [63 : 0] core_iv;
+ wire core_ready;
+ wire [511 : 0] core_data_in;
+ wire [511 : 0] core_data_out;
+ wire core_data_out_valid;
+
+ reg [31 : 0] tmp_read_data;
+ reg tmp_error;
+
+
+ //----------------------------------------------------------------
+ // Concurrent connectivity for ports etc.
+ //----------------------------------------------------------------
+ assign core_init = init_reg;
+
+ assign core_next = next_reg;
+
+ assign core_keylen = keylen_reg;
+
+ assign core_rounds = rounds_reg;
+
+ assign core_key = {key0_reg, key1_reg, key2_reg, key3_reg,
+ key4_reg, key5_reg, key6_reg, key7_reg};
+
+ assign core_iv = {iv0_reg, iv1_reg};
+
+ assign core_data_in = {data_in0_reg, data_in1_reg, data_in2_reg, data_in3_reg,
+ data_in4_reg, data_in5_reg, data_in6_reg, data_in7_reg,
+ data_in8_reg, data_in9_reg, data_in10_reg, data_in11_reg,
+ data_in12_reg, data_in13_reg, data_in14_reg, data_in15_reg};
+
+ assign read_data = tmp_read_data;
+ assign error = tmp_error;
+
+
+ //----------------------------------------------------------------
+ // core instantiation.
+ //----------------------------------------------------------------
+ chacha_core core (
+ .clk(clk),
+ .reset_n(reset_n),
+
+ .init(core_init),
+ .next(core_next),
+
+ .key(core_key),
+ .keylen(core_keylen),
+ .iv(core_iv),
+ .ctr(DEFAULT_CTR_INIT),
+ .rounds(core_rounds),
+
+ .data_in(core_data_in),
+
+ .ready(core_ready),
+
+ .data_out(core_data_out),
+ .data_out_valid(core_data_out_valid)
+ );
+
+
+ //----------------------------------------------------------------
+ // reg_update
+ // Update functionality for all registers in the core.
+ // All registers are positive edge triggered with synchronous
+ // active low reset. All registers have write enable.
+ //----------------------------------------------------------------
+ always @ (posedge clk)
+ begin
+ if (!reset_n)
+ begin
+ init_reg <= 0;
+ next_reg <= 0;
+ ready_reg <= 0;
+ keylen_reg <= 0;
+ rounds_reg <= 5'b00000;
+ data_out_valid_reg <= 0;
+
+ key0_reg <= 32'h00000000;
+ key1_reg <= 32'h00000000;
+ key2_reg <= 32'h00000000;
+ key3_reg <= 32'h00000000;
+ key4_reg <= 32'h00000000;
+ key5_reg <= 32'h00000000;
+ key6_reg <= 32'h00000000;
+ key7_reg <= 32'h00000000;
+
+ iv0_reg <= 32'h00000000;
+ iv1_reg <= 32'h00000000;
+
+ data_in0_reg <= 32'h00000000;
+ data_in1_reg <= 32'h00000000;
+ data_in2_reg <= 32'h00000000;
+ data_in3_reg <= 32'h00000000;
+ data_in4_reg <= 32'h00000000;
+ data_in5_reg <= 32'h00000000;
+ data_in6_reg <= 32'h00000000;
+ data_in7_reg <= 32'h00000000;
+ data_in8_reg <= 32'h00000000;
+ data_in9_reg <= 32'h00000000;
+ data_in10_reg <= 32'h00000000;
+ data_in11_reg <= 32'h00000000;
+ data_in12_reg <= 32'h00000000;
+ data_in13_reg <= 32'h00000000;
+ data_in14_reg <= 32'h00000000;
+ data_in15_reg <= 32'h00000000;
+
+ data_out0_reg <= 32'h00000000;
+ data_out1_reg <= 32'h00000000;
+ data_out2_reg <= 32'h00000000;
+ data_out3_reg <= 32'h00000000;
+ data_out4_reg <= 32'h00000000;
+ data_out5_reg <= 32'h00000000;
+ data_out6_reg <= 32'h00000000;
+ data_out7_reg <= 32'h00000000;
+ data_out8_reg <= 32'h00000000;
+ data_out9_reg <= 32'h00000000;
+ data_out10_reg <= 32'h00000000;
+ data_out11_reg <= 32'h00000000;
+ data_out12_reg <= 32'h00000000;
+ data_out13_reg <= 32'h00000000;
+ data_out14_reg <= 32'h00000000;
+ data_out15_reg <= 32'h00000000;
+ end
+ else
+ begin
+ ready_reg <= core_ready;
+ data_out_valid_reg <= core_data_out_valid;
+
+ if (ctrl_we)
+ begin
+ init_reg <= write_data[CTRL_INIT_BIT];
+ next_reg <= write_data[CTRL_NEXT_BIT];
+ end
+
+ if (keylen_we)
+ begin
+ keylen_reg <= write_data[KEYLEN_BIT];
+ end
+
+ if (rounds_we)
+ begin
+ rounds_reg <= write_data[ROUNDS_HIGH_BIT : ROUNDS_LOW_BIT];
+ end
+
+ if (key0_we)
+ begin
+ key0_reg <= write_data;
+ end
+
+ if (key1_we)
+ begin
+ key1_reg <= write_data;
+ end
+
+ if (key2_we)
+ begin
+ key2_reg <= write_data;
+ end
+
+ if (key3_we)
+ begin
+ key3_reg <= write_data;
+ end
+
+ if (key4_we)
+ begin
+ key4_reg <= write_data;
+ end
+
+ if (key5_we)
+ begin
+ key5_reg <= write_data;
+ end
+
+ if (key6_we)
+ begin
+ key6_reg <= write_data;
+ end
+
+ if (key7_we)
+ begin
+ key7_reg <= write_data;
+ end
+
+ if (iv0_we)
+ begin
+ iv0_reg <= write_data;
+ end
+
+ if (iv1_we)
+ begin
+ iv1_reg <= write_data;
+ end
+
+ if (data_in0_we)
+ begin
+ data_in0_reg <= write_data;
+ end
+
+ if (data_in1_we)
+ begin
+ data_in1_reg <= write_data;
+ end
+
+ if (data_in2_we)
+ begin
+ data_in2_reg <= write_data;
+ end
+
+ if (data_in3_we)
+ begin
+ data_in3_reg <= write_data;
+ end
+
+ if (data_in4_we)
+ begin
+ data_in4_reg <= write_data;
+ end
+
+ if (data_in5_we)
+ begin
+ data_in5_reg <= write_data;
+ end
+
+ if (data_in6_we)
+ begin
+ data_in6_reg <= write_data;
+ end
+
+ if (data_in7_we)
+ begin
+ data_in7_reg <= write_data;
+ end
+
+ if (data_in8_we)
+ begin
+ data_in8_reg <= write_data;
+ end
+
+ if (data_in9_we)
+ begin
+ data_in9_reg <= write_data;
+ end
+
+ if (data_in10_we)
+ begin
+ data_in10_reg <= write_data;
+ end
+
+ if (data_in11_we)
+ begin
+ data_in11_reg <= write_data;
+ end
+
+ if (data_in12_we)
+ begin
+ data_in12_reg <= write_data;
+ end
+
+ if (data_in13_we)
+ begin
+ data_in13_reg <= write_data;
+ end
+
+ if (data_in14_we)
+ begin
+ data_in14_reg <= write_data;
+ end
+
+ if (data_in15_we)
+ begin
+ data_in15_reg <= write_data;
+ end
+
+ if (core_data_out_valid)
+ begin
+ data_out0_reg <= core_data_out[511 : 480];
+ data_out1_reg <= core_data_out[479 : 448];
+ data_out2_reg <= core_data_out[447 : 416];
+ data_out3_reg <= core_data_out[415 : 384];
+ data_out4_reg <= core_data_out[383 : 352];
+ data_out5_reg <= core_data_out[351 : 320];
+ data_out6_reg <= core_data_out[319 : 288];
+ data_out7_reg <= core_data_out[287 : 256];
+ data_out8_reg <= core_data_out[255 : 224];
+ data_out9_reg <= core_data_out[223 : 192];
+ data_out10_reg <= core_data_out[191 : 160];
+ data_out11_reg <= core_data_out[159 : 128];
+ data_out12_reg <= core_data_out[127 : 96];
+ data_out13_reg <= core_data_out[95 : 64];
+ data_out14_reg <= core_data_out[63 : 32];
+ data_out15_reg <= core_data_out[31 : 0];
+ end
+ end
+ end // reg_update
+
+
+ //----------------------------------------------------------------
+ // Address decoder logic.
+ //----------------------------------------------------------------
+ always @*
+ begin : addr_decoder
+ ctrl_we = 0;
+ keylen_we = 0;
+ rounds_we = 0;
+
+ key0_we = 0;
+ key1_we = 0;
+ key2_we = 0;
+ key3_we = 0;
+ key4_we = 0;
+ key5_we = 0;
+ key6_we = 0;
+ key7_we = 0;
+
+ iv0_we = 0;
+ iv1_we = 0;
+
+ data_in0_we = 0;
+ data_in1_we = 0;
+ data_in2_we = 0;
+ data_in3_we = 0;
+ data_in4_we = 0;
+ data_in5_we = 0;
+ data_in6_we = 0;
+ data_in7_we = 0;
+ data_in8_we = 0;
+ data_in9_we = 0;
+ data_in10_we = 0;
+ data_in11_we = 0;
+ data_in12_we = 0;
+ data_in13_we = 0;
+ data_in14_we = 0;
+ data_in15_we = 0;
+
+ tmp_read_data = 32'h00000000;
+ tmp_error = 0;
+
+ if (cs)
+ begin
+ if (we)
+ begin
+ case (address)
+ ADDR_CTRL:
+ begin
+ ctrl_we = 1;
+ end
+
+ ADDR_KEYLEN:
+ begin
+ keylen_we = 1;
+ end
+
+ ADDR_ROUNDS:
+ begin
+ rounds_we = 1;
+ end
+
+ ADDR_KEY0:
+ begin
+ key0_we = 1;
+ end
+
+ ADDR_KEY1:
+ begin
+ key1_we = 1;
+ end
+
+ ADDR_KEY2:
+ begin
+ key2_we = 1;
+ end
+
+ ADDR_KEY3:
+ begin
+ key3_we = 1;
+ end
+
+ ADDR_KEY4:
+ begin
+ key4_we = 1;
+ end
+
+ ADDR_KEY5:
+ begin
+ key5_we = 1;
+ end
+
+ ADDR_KEY6:
+ begin
+ key6_we = 1;
+ end
+
+ ADDR_KEY7:
+ begin
+ key7_we = 1;
+ end
+
+ ADDR_IV0:
+ begin
+ iv0_we = 1;
+ end
+
+ ADDR_IV1:
+ begin
+ iv1_we = 1;
+ end
+
+ ADDR_DATA_IN0:
+ begin
+ data_in0_we = 1;
+ end
+
+ ADDR_DATA_IN1:
+ begin
+ data_in1_we = 1;
+ end
+
+ ADDR_DATA_IN2:
+ begin
+ data_in2_we = 1;
+ end
+
+ ADDR_DATA_IN3:
+ begin
+ data_in3_we = 1;
+ end
+
+ ADDR_DATA_IN4:
+ begin
+ data_in4_we = 1;
+ end
+
+ ADDR_DATA_IN5:
+ begin
+ data_in5_we = 1;
+ end
+
+ ADDR_DATA_IN6:
+ begin
+ data_in6_we = 1;
+ end
+
+ ADDR_DATA_IN7:
+ begin
+ data_in7_we = 1;
+ end
+
+ ADDR_DATA_IN8:
+ begin
+ data_in8_we = 1;
+ end
+
+ ADDR_DATA_IN9:
+ begin
+ data_in9_we = 1;
+ end
+
+ ADDR_DATA_IN10:
+ begin
+ data_in10_we = 1;
+ end
+
+ ADDR_DATA_IN11:
+ begin
+ data_in11_we = 1;
+ end
+
+ ADDR_DATA_IN12:
+ begin
+ data_in12_we = 1;
+ end
+
+ ADDR_DATA_IN13:
+ begin
+ data_in13_we = 1;
+ end
+
+ ADDR_DATA_IN14:
+ begin
+ data_in14_we = 1;
+ end
+
+ ADDR_DATA_IN15:
+ begin
+ data_in15_we = 1;
+ end
+
+ default:
+ begin
+ tmp_error = 1;
+ end
+ endcase // case (address)
+ end // if (we)
+
+ else
+ begin
+ case (address)
+ ADDR_CTRL:
+ begin
+ tmp_read_data = {28'h0000000, 2'b00, next_reg, init_reg};
+ end
+
+ ADDR_STATUS:
+ begin
+ tmp_read_data = {28'h0000000, 2'b00,
+ {data_out_valid_reg, ready_reg}};
+ end
+
+ ADDR_KEYLEN:
+ begin
+ tmp_read_data = {28'h0000000, 3'b000, keylen_reg};
+ end
+
+ ADDR_ROUNDS:
+ begin
+ tmp_read_data = {24'h000000, 3'b000, rounds_reg};
+ end
+
+ ADDR_KEY0:
+ begin
+ tmp_read_data = key0_reg;
+ end
+
+ ADDR_KEY1:
+ begin
+ tmp_read_data = key1_reg;
+ end
+
+ ADDR_KEY2:
+ begin
+ tmp_read_data = key2_reg;
+ end
+
+ ADDR_KEY3:
+ begin
+ tmp_read_data = key3_reg;
+ end
+
+ ADDR_KEY4:
+ begin
+ tmp_read_data = key4_reg;
+ end
+
+ ADDR_KEY5:
+ begin
+ tmp_read_data = key5_reg;
+ end
+
+ ADDR_KEY6:
+ begin
+ tmp_read_data = key6_reg;
+ end
+
+ ADDR_KEY7:
+ begin
+ tmp_read_data = key7_reg;
+ end
+
+ ADDR_IV0:
+ begin
+ tmp_read_data = iv0_reg;
+ end
+
+ ADDR_IV1:
+ begin
+ tmp_read_data = iv1_reg;
+ end
+
+ ADDR_DATA_OUT0:
+ begin
+ tmp_read_data = data_out0_reg;
+ end
+
+ ADDR_DATA_OUT1:
+ begin
+ tmp_read_data = data_out1_reg;
+ end
+
+ ADDR_DATA_OUT2:
+ begin
+ tmp_read_data = data_out2_reg;
+ end
+
+ ADDR_DATA_OUT3:
+ begin
+ tmp_read_data = data_out3_reg;
+ end
+
+ ADDR_DATA_OUT4:
+ begin
+ tmp_read_data = data_out4_reg;
+ end
+
+ ADDR_DATA_OUT5:
+ begin
+ tmp_read_data = data_out5_reg;
+ end
+
+ ADDR_DATA_OUT6:
+ begin
+ tmp_read_data = data_out6_reg;
+ end
+
+ ADDR_DATA_OUT7:
+ begin
+ tmp_read_data = data_out7_reg;
+ end
+
+ ADDR_DATA_OUT8:
+ begin
+ tmp_read_data = data_out8_reg;
+ end
+
+ ADDR_DATA_OUT9:
+ begin
+ tmp_read_data = data_out9_reg;
+ end
+
+ ADDR_DATA_OUT10:
+ begin
+ tmp_read_data = data_out10_reg;
+ end
+
+ ADDR_DATA_OUT11:
+ begin
+ tmp_read_data = data_out11_reg;
+ end
+
+ ADDR_DATA_OUT12:
+ begin
+ tmp_read_data = data_out12_reg;
+ end
+
+ ADDR_DATA_OUT13:
+ begin
+ tmp_read_data = data_out13_reg;
+ end
+
+ ADDR_DATA_OUT14:
+ begin
+ tmp_read_data = data_out14_reg;
+ end
+
+ ADDR_DATA_OUT15:
+ begin
+ tmp_read_data = data_out15_reg;
+ end
+
+ default:
+ begin
+ tmp_error = 1;
+ end
+ endcase // case (address)
+ end
+ end
+ end // addr_decoder
+endmodule // chacha
+
+//======================================================================
+// EOF chacha.v
+//======================================================================
diff --git a/src/rtl/chacha_core.v b/src/rtl/chacha_core.v
new file mode 100644
index 0000000..891ee55
--- /dev/null
+++ b/src/rtl/chacha_core.v
@@ -0,0 +1,1308 @@
+//======================================================================
+//
+// chacha_core.v
+// --------------
+// Verilog 2001 implementation of the stream cipher ChaCha.
+// This is the internal core with wide interfaces.
+//
+//
+// Author: Joachim Strombergson
+// Copyright (c) 2011, 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.
+//
+//======================================================================
+
+module chacha_core(
+ input wire clk,
+ input wire reset_n,
+
+ input wire init,
+ input wire next,
+
+ input wire [255 : 0] key,
+ input wire keylen,
+ input wire [63 : 0] iv,
+ input wire [63 : 0] ctr,
+ input wire [4 : 0] rounds,
+
+ input wire [511 : 0] data_in,
+
+ output wire ready,
+
+ output wire [511 : 0] data_out,
+ output wire data_out_valid
+ );
+
+
+ //----------------------------------------------------------------
+ // Internal constant and parameter definitions.
+ //----------------------------------------------------------------
+ // Datapath quartterround states names.
+ parameter QR0 = 1'b0;
+ parameter QR1 = 1'b1;
+
+ parameter NUM_ROUNDS = 4'h8;
+
+ parameter TAU0 = 32'h61707865;
+ parameter TAU1 = 32'h3120646e;
+ parameter TAU2 = 32'h79622d36;
+ parameter TAU3 = 32'h6b206574;
+
+ parameter SIGMA0 = 32'h61707865;
+ parameter SIGMA1 = 32'h3320646e;
+ parameter SIGMA2 = 32'h79622d32;
+ parameter SIGMA3 = 32'h6b206574;
+
+ parameter CTRL_IDLE = 3'h0;
+ parameter CTRL_INIT = 3'h1;
+ parameter CTRL_ROUNDS = 3'h2;
+ parameter CTRL_FINALIZE = 3'h3;
+ parameter CTRL_DONE = 3'h4;
+
+
+ //----------------------------------------------------------------
+ // Registers including update variables and write enable.
+ //----------------------------------------------------------------
+ reg [31 : 0] key0_reg;
+ reg [31 : 0] key0_new;
+ reg [31 : 0] key1_reg;
+ reg [31 : 0] key1_new;
+ reg [31 : 0] key2_reg;
+ reg [31 : 0] key2_new;
+ reg [31 : 0] key3_reg;
+ reg [31 : 0] key3_new;
+ reg [31 : 0] key4_reg;
+ reg [31 : 0] key4_new;
+ reg [31 : 0] key5_reg;
+ reg [31 : 0] key5_new;
+ reg [31 : 0] key6_reg;
+ reg [31 : 0] key6_new;
+ reg [31 : 0] key7_reg;
+ reg [31 : 0] key7_new;
+
+ reg keylen_reg;
+ reg keylen_new;
+
+ reg [31 : 0] iv0_reg;
+ reg [31 : 0] iv0_new;
+ reg [31 : 0] iv1_reg;
+ reg [31 : 0] iv1_new;
+
+ reg [31 : 0] state0_reg;
+ reg [31 : 0] state0_new;
+ reg [31 : 0] state1_reg;
+ reg [31 : 0] state1_new;
+ reg [31 : 0] state2_reg;
+ reg [31 : 0] state2_new;
+ reg [31 : 0] state3_reg;
+ reg [31 : 0] state3_new;
+ reg [31 : 0] state4_reg;
+ reg [31 : 0] state4_new;
+ reg [31 : 0] state5_reg;
+ reg [31 : 0] state5_new;
+ reg [31 : 0] state6_reg;
+ reg [31 : 0] state6_new;
+ reg [31 : 0] state7_reg;
+ reg [31 : 0] state7_new;
+ reg [31 : 0] state8_reg;
+ reg [31 : 0] state8_new;
+ reg [31 : 0] state9_reg;
+ reg [31 : 0] state9_new;
+ reg [31 : 0] state10_reg;
+ reg [31 : 0] state10_new;
+ reg [31 : 0] state11_reg;
+ reg [31 : 0] state11_new;
+ reg [31 : 0] state12_reg;
+ reg [31 : 0] state12_new;
+ reg [31 : 0] state13_reg;
+ reg [31 : 0] state13_new;
+ reg [31 : 0] state14_reg;
+ reg [31 : 0] state14_new;
+ reg [31 : 0] state15_reg;
+ reg [31 : 0] state15_new;
+ reg state_we;
+
+ reg [31 : 0] x0_reg;
+ reg [31 : 0] x0_new;
+ reg x0_we;
+
+ reg [31 : 0] x1_reg;
+ reg [31 : 0] x1_new;
+ reg x1_we;
+
+ reg [31 : 0] x2_reg;
+ reg [31 : 0] x2_new;
+ reg x2_we;
+
+ reg [31 : 0] x3_reg;
+ reg [31 : 0] x3_new;
+ reg x3_we;
+
+ reg [31 : 0] x4_reg;
+ reg [31 : 0] x4_new;
+ reg x4_we;
+
+ reg [31 : 0] x5_reg;
+ reg [31 : 0] x5_new;
+ reg x5_we;
+
+ reg [31 : 0] x6_reg;
+ reg [31 : 0] x6_new;
+ reg x6_we;
+
+ reg [31 : 0] x7_reg;
+ reg [31 : 0] x7_new;
+ reg x7_we;
+
+ reg [31 : 0] x8_reg;
+ reg [31 : 0] x8_new;
+ reg x8_we;
+
+ reg [31 : 0] x9_reg;
+ reg [31 : 0] x9_new;
+ reg x9_we;
+
+ reg [31 : 0] x10_reg;
+ reg [31 : 0] x10_new;
+ reg x10_we;
+
+ reg [31 : 0] x11_reg;
+ reg [31 : 0] x11_new;
+ reg x11_we;
+
+ reg [31 : 0] x12_reg;
+ reg [31 : 0] x12_new;
+ reg x12_we;
+
+ reg [31 : 0] x13_reg;
+ reg [31 : 0] x13_new;
+ reg x13_we;
+
+ reg [31 : 0] x14_reg;
+ reg [31 : 0] x14_new;
+ reg x14_we;
+
+ reg [31 : 0] x15_reg;
+ reg [31 : 0] x15_new;
+ reg x15_we;
+
+ reg [3 : 0] rounds_reg;
+ reg [3 : 0] rounds_new;
+
+ reg [511 : 0] data_in_reg;
+ reg data_in_we;
+
+ reg [511 : 0] data_out_reg;
+ reg [511 : 0] data_out_new;
+ reg data_out_we;
+
+ reg data_out_valid_reg;
+ reg data_out_valid_new;
+ reg data_out_valid_we;
+
+ reg qr_ctr_reg;
+ reg qr_ctr_new;
+ reg qr_ctr_we;
+ reg qr_ctr_inc;
+ reg qr_ctr_rst;
+
+ reg [3 : 0] dr_ctr_reg;
+ reg [3 : 0] dr_ctr_new;
+ reg dr_ctr_we;
+ reg dr_ctr_inc;
+ reg dr_ctr_rst;
+
+ reg [31 : 0] block0_ctr_reg;
+ reg [31 : 0] block0_ctr_new;
+ reg block0_ctr_we;
+ reg [31 : 0] block1_ctr_reg;
+ reg [31 : 0] block1_ctr_new;
+ reg block1_ctr_we;
+ reg block_ctr_inc;
+ reg block_ctr_rst;
+
+ reg [2 : 0] chacha_ctrl_reg;
+ reg [2 : 0] chacha_ctrl_new;
+ reg chacha_ctrl_we;
+
+
+ //----------------------------------------------------------------
+ // Wires.
+ //----------------------------------------------------------------
+ reg sample_params;
+ reg init_state;
+ reg update_state;
+ reg update_output;
+
+ reg [31 : 0] qr0_a;
+ reg [31 : 0] qr0_b;
+ reg [31 : 0] qr0_c;
+ reg [31 : 0] qr0_d;
+ wire [31 : 0] qr0_a_prim;
+ wire [31 : 0] qr0_b_prim;
+ wire [31 : 0] qr0_c_prim;
+ wire [31 : 0] qr0_d_prim;
+
+ reg [31 : 0] qr1_a;
+ reg [31 : 0] qr1_b;
+ reg [31 : 0] qr1_c;
+ reg [31 : 0] qr1_d;
+ wire [31 : 0] qr1_a_prim;
+ wire [31 : 0] qr1_b_prim;
+ wire [31 : 0] qr1_c_prim;
+ wire [31 : 0] qr1_d_prim;
+
+ reg [31 : 0] qr2_a;
+ reg [31 : 0] qr2_b;
+ reg [31 : 0] qr2_c;
+ reg [31 : 0] qr2_d;
+ wire [31 : 0] qr2_a_prim;
+ wire [31 : 0] qr2_b_prim;
+ wire [31 : 0] qr2_c_prim;
+ wire [31 : 0] qr2_d_prim;
+
+ reg [31 : 0] qr3_a;
+ reg [31 : 0] qr3_b;
+ reg [31 : 0] qr3_c;
+ reg [31 : 0] qr3_d;
+ wire [31 : 0] qr3_a_prim;
+ wire [31 : 0] qr3_b_prim;
+ wire [31 : 0] qr3_c_prim;
+ wire [31 : 0] qr3_d_prim;
+
+ reg ready_wire;
+
+
+ //----------------------------------------------------------------
+ // Instantiation of the qr modules.
+ //----------------------------------------------------------------
+ chacha_qr qr0(
+ .a(qr0_a),
+ .b(qr0_b),
+ .c(qr0_c),
+ .d(qr0_d),
+
+ .a_prim(qr0_a_prim),
+ .b_prim(qr0_b_prim),
+ .c_prim(qr0_c_prim),
+ .d_prim(qr0_d_prim)
+ );
+
+ chacha_qr qr1(
+ .a(qr1_a),
+ .b(qr1_b),
+ .c(qr1_c),
+ .d(qr1_d),
+
+ .a_prim(qr1_a_prim),
+ .b_prim(qr1_b_prim),
+ .c_prim(qr1_c_prim),
+ .d_prim(qr1_d_prim)
+ );
+
+ chacha_qr qr2(
+ .a(qr2_a),
+ .b(qr2_b),
+ .c(qr2_c),
+ .d(qr2_d),
+
+ .a_prim(qr2_a_prim),
+ .b_prim(qr2_b_prim),
+ .c_prim(qr2_c_prim),
+ .d_prim(qr2_d_prim)
+ );
+
+ chacha_qr qr3(
+ .a(qr3_a),
+ .b(qr3_b),
+ .c(qr3_c),
+ .d(qr3_d),
+
+ .a_prim(qr3_a_prim),
+ .b_prim(qr3_b_prim),
+ .c_prim(qr3_c_prim),
+ .d_prim(qr3_d_prim)
+ );
+
+
+ //----------------------------------------------------------------
+ // Concurrent connectivity for ports etc.
+ //----------------------------------------------------------------
+ assign data_out = data_out_reg;
+
+ assign data_out_valid = data_out_valid_reg;
+
+ assign ready = ready_wire;
+
+
+
+ //----------------------------------------------------------------
+ // reg_update
+ // Update functionality for all registers in the core.
+ // All registers are positive edge triggered with synchronous
+ // active low reset. All registers have write enable.
+ //----------------------------------------------------------------
+ always @ (posedge clk)
+ begin : reg_update
+ if (!reset_n)
+ begin
+ key0_reg <= 32'h00000000;
+ key1_reg <= 32'h00000000;
+ key2_reg <= 32'h00000000;
+ key3_reg <= 32'h00000000;
+ key4_reg <= 32'h00000000;
+ key5_reg <= 32'h00000000;
+ key6_reg <= 32'h00000000;
+ key7_reg <= 32'h00000000;
+ iv0_reg <= 32'h00000000;
+ iv1_reg <= 32'h00000000;
+ state0_reg <= 32'h00000000;
+ state1_reg <= 32'h00000000;
+ state2_reg <= 32'h00000000;
+ state3_reg <= 32'h00000000;
+ state4_reg <= 32'h00000000;
+ state5_reg <= 32'h00000000;
+ state6_reg <= 32'h00000000;
+ state7_reg <= 32'h00000000;
+ state8_reg <= 32'h00000000;
+ state9_reg <= 32'h00000000;
+ state10_reg <= 32'h00000000;
+ state11_reg <= 32'h00000000;
+ state12_reg <= 32'h00000000;
+ state13_reg <= 32'h00000000;
+ state14_reg <= 32'h00000000;
+ state15_reg <= 32'h00000000;
+ x0_reg <= 32'h00000000;
+ x1_reg <= 32'h00000000;
+ x2_reg <= 32'h00000000;
+ x3_reg <= 32'h00000000;
+ x4_reg <= 32'h00000000;
+ x5_reg <= 32'h00000000;
+ x6_reg <= 32'h00000000;
+ x7_reg <= 32'h00000000;
+ x8_reg <= 32'h00000000;
+ x9_reg <= 32'h00000000;
+ x10_reg <= 32'h00000000;
+ x11_reg <= 32'h00000000;
+ x12_reg <= 32'h00000000;
+ x13_reg <= 32'h00000000;
+ x14_reg <= 32'h00000000;
+ x15_reg <= 32'h00000000;
+ data_in_reg <= 512'h00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000;
+ data_out_reg <= 512'h00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000;
+ rounds_reg <= 4'h0;
+ data_out_valid_reg <= 0;
+ qr_ctr_reg <= QR0;
+ dr_ctr_reg <= 0;
+ block0_ctr_reg <= 32'h00000000;
+ block1_ctr_reg <= 32'h00000000;
+ chacha_ctrl_reg <= CTRL_IDLE;
+ end
+ else
+ begin
+ if (sample_params)
+ begin
+ key0_reg <= key0_new;
+ key1_reg <= key1_new;
+ key2_reg <= key2_new;
+ key3_reg <= key3_new;
+ key4_reg <= key4_new;
+ key5_reg <= key5_new;
+ key6_reg <= key6_new;
+ key7_reg <= key7_new;
+ iv0_reg <= iv0_new;
+ iv1_reg <= iv1_new;
+ rounds_reg <= rounds_new;
+ keylen_reg <= keylen_new;
+ end
+
+ if (data_in_we)
+ begin
+ data_in_reg <= data_in;
+ end
+
+ if (state_we)
+ begin
+ state0_reg <= state0_new;
+ state1_reg <= state1_new;
+ state2_reg <= state2_new;
+ state3_reg <= state3_new;
+ state4_reg <= state4_new;
+ state5_reg <= state5_new;
+ state6_reg <= state6_new;
+ state7_reg <= state7_new;
+ state8_reg <= state8_new;
+ state9_reg <= state9_new;
+ state10_reg <= state10_new;
+ state11_reg <= state11_new;
+ state12_reg <= state12_new;
+ state13_reg <= state13_new;
+ state14_reg <= state14_new;
+ state15_reg <= state15_new;
+ end
+
+ if (x0_we)
+ begin
+ x0_reg <= x0_new;
+ end
+
+ if (x1_we)
+ begin
+ x1_reg <= x1_new;
+ end
+
+ if (x2_we)
+ begin
+ x2_reg <= x2_new;
+ end
+
+ if (x3_we)
+ begin
+ x3_reg <= x3_new;
+ end
+
+ if (x4_we)
+ begin
+ x4_reg <= x4_new;
+ end
+
+ if (x5_we)
+ begin
+ x5_reg <= x5_new;
+ end
+
+ if (x6_we)
+ begin
+ x6_reg <= x6_new;
+ end
+
+ if (x7_we)
+ begin
+ x7_reg <= x7_new;
+ end
+
+ if (x8_we)
+ begin
+ x8_reg <= x8_new;
+ end
+
+ if (x9_we)
+ begin
+ x9_reg <= x9_new;
+ end
+
+ if (x10_we)
+ begin
+ x10_reg <= x10_new;
+ end
+
+ if (x11_we)
+ begin
+ x11_reg <= x11_new;
+ end
+
+ if (x12_we)
+ begin
+ x12_reg <= x12_new;
+ end
+
+ if (x13_we)
+ begin
+ x13_reg <= x13_new;
+ end
+
+ if (x14_we)
+ begin
+ x14_reg <= x14_new;
+ end
+
+ if (x15_we)
+ begin
+ x15_reg <= x15_new;
+ end
+
+ if (data_out_we)
+ begin
+ data_out_reg <= data_out_new;
+ end
+
+ if (data_out_valid_we)
+ begin
+ data_out_valid_reg <= data_out_valid_new;
+ end
+
+ if (qr_ctr_we)
+ begin
+ qr_ctr_reg <= qr_ctr_new;
+ end
+
+ if (dr_ctr_we)
+ begin
+ dr_ctr_reg <= dr_ctr_new;
+ end
+
+ if (block0_ctr_we)
+ begin
+ block0_ctr_reg <= block0_ctr_new;
+ end
+
+ if (block1_ctr_we)
+ begin
+ block1_ctr_reg <= block1_ctr_new;
+ end
+
+ if (chacha_ctrl_we)
+ begin
+ chacha_ctrl_reg <= chacha_ctrl_new;
+ end
+ end
+ end // reg_update
+
+
+ //----------------------------------------------------------------
+ // data_out_logic
+ // Final output logic that combines the result from procceing
+ // with the input word. This adds a final layer of XOR gates.
+ //
+ // Note that we also remap all the words into LSB format.
+ //----------------------------------------------------------------
+ always @*
+ begin : data_out_logic
+ reg [31 : 0] msb_block_state0;
+ reg [31 : 0] msb_block_state1;
+ reg [31 : 0] msb_block_state2;
+ reg [31 : 0] msb_block_state3;
+ reg [31 : 0] msb_block_state4;
+ reg [31 : 0] msb_block_state5;
+ reg [31 : 0] msb_block_state6;
+ reg [31 : 0] msb_block_state7;
+ reg [31 : 0] msb_block_state8;
+ reg [31 : 0] msb_block_state9;
+ reg [31 : 0] msb_block_state10;
+ reg [31 : 0] msb_block_state11;
+ reg [31 : 0] msb_block_state12;
+ reg [31 : 0] msb_block_state13;
+ reg [31 : 0] msb_block_state14;
+ reg [31 : 0] msb_block_state15;
+
+ reg [31 : 0] lsb_block_state0;
+ reg [31 : 0] lsb_block_state1;
+ reg [31 : 0] lsb_block_state2;
+ reg [31 : 0] lsb_block_state3;
+ reg [31 : 0] lsb_block_state4;
+ reg [31 : 0] lsb_block_state5;
+ reg [31 : 0] lsb_block_state6;
+ reg [31 : 0] lsb_block_state7;
+ reg [31 : 0] lsb_block_state8;
+ reg [31 : 0] lsb_block_state9;
+ reg [31 : 0] lsb_block_state10;
+ reg [31 : 0] lsb_block_state11;
+ reg [31 : 0] lsb_block_state12;
+ reg [31 : 0] lsb_block_state13;
+ reg [31 : 0] lsb_block_state14;
+ reg [31 : 0] lsb_block_state15;
+
+ reg [511 : 0] lsb_block_state;
+
+ lsb_block_state = 512'h00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000;
+
+ data_out_new = 512'h00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000;
+ data_out_we = 0;
+
+ if (update_output)
+ begin
+ msb_block_state0 = state0_reg + x0_reg;
+ msb_block_state1 = state1_reg + x1_reg;
+ msb_block_state2 = state2_reg + x2_reg;
+ msb_block_state3 = state3_reg + x3_reg;
+ msb_block_state4 = state4_reg + x4_reg;
+ msb_block_state5 = state5_reg + x5_reg;
+ msb_block_state6 = state6_reg + x6_reg;
+ msb_block_state7 = state7_reg + x7_reg;
+ msb_block_state8 = state8_reg + x8_reg;
+ msb_block_state9 = state9_reg + x9_reg;
+ msb_block_state10 = state10_reg + x10_reg;
+ msb_block_state11 = state11_reg + x11_reg;
+ msb_block_state12 = state12_reg + x12_reg;
+ msb_block_state13 = state13_reg + x13_reg;
+ msb_block_state14 = state14_reg + x14_reg;
+ msb_block_state15 = state15_reg + x15_reg;
+
+ lsb_block_state0 = {msb_block_state0[7 : 0],
+ msb_block_state0[15 : 8],
+ msb_block_state0[23 : 16],
+ msb_block_state0[31 : 24]};
+
+ lsb_block_state1 = {msb_block_state1[7 : 0],
+ msb_block_state1[15 : 8],
+ msb_block_state1[23 : 16],
+ msb_block_state1[31 : 24]};
+
+ lsb_block_state2 = {msb_block_state2[7 : 0],
+ msb_block_state2[15 : 8],
+ msb_block_state2[23 : 16],
+ msb_block_state2[31 : 24]};
+
+ lsb_block_state3 = {msb_block_state3[7 : 0],
+ msb_block_state3[15 : 8],
+ msb_block_state3[23 : 16],
+ msb_block_state3[31 : 24]};
+
+ lsb_block_state4 = {msb_block_state4[7 : 0],
+ msb_block_state4[15 : 8],
+ msb_block_state4[23 : 16],
+ msb_block_state4[31 : 24]};
+
+ lsb_block_state5 = {msb_block_state5[7 : 0],
+ msb_block_state5[15 : 8],
+ msb_block_state5[23 : 16],
+ msb_block_state5[31 : 24]};
+
+ lsb_block_state6 = {msb_block_state6[7 : 0],
+ msb_block_state6[15 : 8],
+ msb_block_state6[23 : 16],
+ msb_block_state6[31 : 24]};
+
+ lsb_block_state7 = {msb_block_state7[7 : 0],
+ msb_block_state7[15 : 8],
+ msb_block_state7[23 : 16],
+ msb_block_state7[31 : 24]};
+
+ lsb_block_state8 = {msb_block_state8[7 : 0],
+ msb_block_state8[15 : 8],
+ msb_block_state8[23 : 16],
+ msb_block_state8[31 : 24]};
+
+ lsb_block_state9 = {msb_block_state9[7 : 0],
+ msb_block_state9[15 : 8],
+ msb_block_state9[23 : 16],
+ msb_block_state9[31 : 24]};
+
+ lsb_block_state10 = {msb_block_state10[7 : 0],
+ msb_block_state10[15 : 8],
+ msb_block_state10[23 : 16],
+ msb_block_state10[31 : 24]};
+
+ lsb_block_state11 = {msb_block_state11[7 : 0],
+ msb_block_state11[15 : 8],
+ msb_block_state11[23 : 16],
+ msb_block_state11[31 : 24]};
+
+ lsb_block_state12 = {msb_block_state12[7 : 0],
+ msb_block_state12[15 : 8],
+ msb_block_state12[23 : 16],
+ msb_block_state12[31 : 24]};
+
+ lsb_block_state13 = {msb_block_state13[7 : 0],
+ msb_block_state13[15 : 8],
+ msb_block_state13[23 : 16],
+ msb_block_state13[31 : 24]};
+
+ lsb_block_state14 = {msb_block_state14[7 : 0],
+ msb_block_state14[15 : 8],
+ msb_block_state14[23 : 16],
+ msb_block_state14[31 : 24]};
+
+ lsb_block_state15 = {msb_block_state15[7 : 0],
+ msb_block_state15[15 : 8],
+ msb_block_state15[23 : 16],
+ msb_block_state15[31 : 24]};
+
+ lsb_block_state = {lsb_block_state0, lsb_block_state1,
+ lsb_block_state2, lsb_block_state3,
+ lsb_block_state4, lsb_block_state5,
+ lsb_block_state6, lsb_block_state7,
+ lsb_block_state8, lsb_block_state9,
+ lsb_block_state10, lsb_block_state11,
+ lsb_block_state12, lsb_block_state13,
+ lsb_block_state14, lsb_block_state15};
+
+ data_out_new = data_in_reg ^ lsb_block_state;
+ data_out_we = 1;
+ end // if (update_output)
+ end // data_out_logic
+
+
+ //----------------------------------------------------------------
+ // sample_parameters
+ // Logic (wires) that convert parameter input to appropriate
+ // format for processing.
+ //----------------------------------------------------------------
+ always @*
+ begin : sample_parameters
+ key0_new = 32'h00000000;
+ key1_new = 32'h00000000;
+ key2_new = 32'h00000000;
+ key3_new = 32'h00000000;
+ key4_new = 32'h00000000;
+ key5_new = 32'h00000000;
+ key6_new = 32'h00000000;
+ key7_new = 32'h00000000;
+ iv0_new = 32'h00000000;
+ iv1_new = 32'h00000000;
+ rounds_new = 4'h0;
+ keylen_new = 1'b0;
+
+ if (sample_params)
+ begin
+ key0_new = {key[231 : 224], key[239 : 232],
+ key[247 : 240], key[255 : 248]};
+ key1_new = {key[199 : 192], key[207 : 200],
+ key[215 : 208], key[223 : 216]};
+ key2_new = {key[167 : 160], key[175 : 168],
+ key[183 : 176], key[191 : 184]};
+ key3_new = {key[135 : 128], key[143 : 136],
+ key[151 : 144], key[159 : 152]};
+ key4_new = {key[103 : 96], key[111 : 104],
+ key[119 : 112], key[127 : 120]};
+ key5_new = {key[71 : 64], key[79 : 72],
+ key[87 : 80], key[95 : 88]};
+ key6_new = {key[39 : 32], key[47 : 40],
+ key[55 : 48], key[63 : 56]};
+ key7_new = {key[7 : 0], key[15 : 8],
+ key[23 : 16], key[31 : 24]};
+
+ iv0_new = {iv[39 : 32], iv[47 : 40],
+ iv[55 : 48], iv[63 : 56]};
+ iv1_new = {iv[7 : 0], iv[15 : 8],
+ iv[23 : 16], iv[31 : 24]};
+
+ // Div by two since we count double rounds.
+ rounds_new = rounds[4 : 1];
+
+ keylen_new = keylen;
+ end
+ end
+
+
+ //----------------------------------------------------------------
+ // state_logic
+ // Logic to init and update the internal state.
+ //----------------------------------------------------------------
+ always @*
+ begin : state_logic
+ reg [31 : 0] new_state_word0;
+ reg [31 : 0] new_state_word1;
+ reg [31 : 0] new_state_word2;
+ reg [31 : 0] new_state_word3;
+ reg [31 : 0] new_state_word4;
+ reg [31 : 0] new_state_word5;
+ reg [31 : 0] new_state_word6;
+ reg [31 : 0] new_state_word7;
+ reg [31 : 0] new_state_word8;
+ reg [31 : 0] new_state_word9;
+ reg [31 : 0] new_state_word10;
+ reg [31 : 0] new_state_word11;
+ reg [31 : 0] new_state_word12;
+ reg [31 : 0] new_state_word13;
+ reg [31 : 0] new_state_word14;
+ reg [31 : 0] new_state_word15;
+
+ new_state_word0 = 32'h00000000;
+ new_state_word1 = 32'h00000000;
+ new_state_word2 = 32'h00000000;
+ new_state_word3 = 32'h00000000;
+ new_state_word4 = 32'h00000000;
+ new_state_word5 = 32'h00000000;
+ new_state_word6 = 32'h00000000;
+ new_state_word7 = 32'h00000000;
+ new_state_word8 = 32'h00000000;
+ new_state_word9 = 32'h00000000;
+ new_state_word10 = 32'h00000000;
+ new_state_word11 = 32'h00000000;
+ new_state_word12 = 32'h00000000;
+ new_state_word13 = 32'h00000000;
+ new_state_word14 = 32'h00000000;
+ new_state_word15 = 32'h00000000;
+
+ x0_new = 32'h00000000;
+ x1_new = 32'h00000000;
+ x2_new = 32'h00000000;
+ x3_new = 32'h00000000;
+ x4_new = 32'h00000000;
+ x5_new = 32'h00000000;
+ x6_new = 32'h00000000;
+ x7_new = 32'h00000000;
+ x8_new = 32'h00000000;
+ x9_new = 32'h00000000;
+ x10_new = 32'h00000000;
+ x11_new = 32'h00000000;
+ x12_new = 32'h00000000;
+ x13_new = 32'h00000000;
+ x14_new = 32'h00000000;
+ x15_new = 32'h00000000;
+ x0_we = 0;
+ x1_we = 0;
+ x2_we = 0;
+ x3_we = 0;
+ x4_we = 0;
+ x5_we = 0;
+ x6_we = 0;
+ x7_we = 0;
+ x8_we = 0;
+ x9_we = 0;
+ x10_we = 0;
+ x11_we = 0;
+ x12_we = 0;
+ x13_we = 0;
+ x14_we = 0;
+ x15_we = 0;
+
+ state0_new = 32'h00000000;
+ state1_new = 32'h00000000;
+ state2_new = 32'h00000000;
+ state3_new = 32'h00000000;
+ state4_new = 32'h00000000;
+ state5_new = 32'h00000000;
+ state6_new = 32'h00000000;
+ state7_new = 32'h00000000;
+ state8_new = 32'h00000000;
+ state9_new = 32'h00000000;
+ state10_new = 32'h00000000;
+ state11_new = 32'h00000000;
+ state12_new = 32'h00000000;
+ state13_new = 32'h00000000;
+ state14_new = 32'h00000000;
+ state15_new = 32'h00000000;
+ state_we = 0;
+
+ if (init_state)
+ begin
+ new_state_word4 = key0_reg;
+ new_state_word5 = key1_reg;
+ new_state_word6 = key2_reg;
+ new_state_word7 = key3_reg;
+
+ new_state_word12 = block0_ctr_reg;
+ new_state_word13 = block1_ctr_reg;
+
+ new_state_word14 = iv0_reg;
+ new_state_word15 = iv1_reg;
+
+ if (keylen_reg)
+ begin
+ // 256 bit key.
+ new_state_word0 = SIGMA0;
+ new_state_word1 = SIGMA1;
+ new_state_word2 = SIGMA2;
+ new_state_word3 = SIGMA3;
+ new_state_word8 = key4_reg;
+ new_state_word9 = key5_reg;
+ new_state_word10 = key6_reg;
+ new_state_word11 = key7_reg;
+ end
+ else
+ begin
+ // 128 bit key.
+ new_state_word0 = TAU0;
+ new_state_word1 = TAU1;
+ new_state_word2 = TAU2;
+ new_state_word3 = TAU3;
+ new_state_word8 = key0_reg;
+ new_state_word9 = key1_reg;
+ new_state_word10 = key2_reg;
+ new_state_word11 = key3_reg;
+ end
+
+ x0_new = new_state_word0;
+ x1_new = new_state_word1;
+ x2_new = new_state_word2;
+ x3_new = new_state_word3;
+ x4_new = new_state_word4;
+ x5_new = new_state_word5;
+ x6_new = new_state_word6;
+ x7_new = new_state_word7;
+ x8_new = new_state_word8;
+ x9_new = new_state_word9;
+ x10_new = new_state_word10;
+ x11_new = new_state_word11;
+ x12_new = new_state_word12;
+ x13_new = new_state_word13;
+ x14_new = new_state_word14;
+ x15_new = new_state_word15;
+ x0_we = 1;
+ x1_we = 1;
+ x2_we = 1;
+ x3_we = 1;
+ x4_we = 1;
+ x5_we = 1;
+ x6_we = 1;
+ x7_we = 1;
+ x8_we = 1;
+ x9_we = 1;
+ x10_we = 1;
+ x11_we = 1;
+ x12_we = 1;
+ x13_we = 1;
+ x14_we = 1;
+ x15_we = 1;
+
+ state0_new = new_state_word0;
+ state1_new = new_state_word1;
+ state2_new = new_state_word2;
+ state3_new = new_state_word3;
+ state4_new = new_state_word4;
+ state5_new = new_state_word5;
+ state6_new = new_state_word6;
+ state7_new = new_state_word7;
+ state8_new = new_state_word8;
+ state9_new = new_state_word9;
+ state10_new = new_state_word10;
+ state11_new = new_state_word11;
+ state12_new = new_state_word12;
+ state13_new = new_state_word13;
+ state14_new = new_state_word14;
+ state15_new = new_state_word15;
+ state_we = 1;
+ end // if (init_state)
+
+ else if (update_state)
+ begin
+ case (qr_ctr_reg)
+ QR0:
+ begin
+ x0_new = qr0_a_prim;
+ x4_new = qr0_b_prim;
+ x8_new = qr0_c_prim;
+ x12_new = qr0_d_prim;
+ x0_we = 1;
+ x4_we = 1;
+ x8_we = 1;
+ x12_we = 1;
+
+ x1_new = qr1_a_prim;
+ x5_new = qr1_b_prim;
+ x9_new = qr1_c_prim;
+ x13_new = qr1_d_prim;
+ x1_we = 1;
+ x5_we = 1;
+ x9_we = 1;
+ x13_we = 1;
+
+ x2_new = qr2_a_prim;
+ x6_new = qr2_b_prim;
+ x10_new = qr2_c_prim;
+ x14_new = qr2_d_prim;
+ x2_we = 1;
+ x6_we = 1;
+ x10_we = 1;
+ x14_we = 1;
+
+ x3_new = qr3_a_prim;
+ x7_new = qr3_b_prim;
+ x11_new = qr3_c_prim;
+ x15_new = qr3_d_prim;
+ x3_we = 1;
+ x7_we = 1;
+ x11_we = 1;
+ x15_we = 1;
+ end
+
+ QR1:
+ begin
+ x0_new = qr0_a_prim;
+ x5_new = qr0_b_prim;
+ x10_new = qr0_c_prim;
+ x15_new = qr0_d_prim;
+ x0_we = 1;
+ x5_we = 1;
+ x10_we = 1;
+ x15_we = 1;
+
+ x1_new = qr1_a_prim;
+ x6_new = qr1_b_prim;
+ x11_new = qr1_c_prim;
+ x12_new = qr1_d_prim;
+ x1_we = 1;
+ x6_we = 1;
+ x11_we = 1;
+ x12_we = 1;
+
+ x2_new = qr2_a_prim;
+ x7_new = qr2_b_prim;
+ x8_new = qr2_c_prim;
+ x13_new = qr2_d_prim;
+ x2_we = 1;
+ x7_we = 1;
+ x8_we = 1;
+ x13_we = 1;
+
+ x3_new = qr3_a_prim;
+ x4_new = qr3_b_prim;
+ x9_new = qr3_c_prim;
+ x14_new = qr3_d_prim;
+ x3_we = 1;
+ x4_we = 1;
+ x9_we = 1;
+ x14_we = 1;
+ end
+ endcase // case (quarterround_select)
+ end // if (update_state)
+ end // state_logic
+
+
+ //----------------------------------------------------------------
+ // quarterround_mux
+ // Quarterround muxes that selects operands for quarterrounds.
+ //----------------------------------------------------------------
+ always @*
+ begin : quarterround_mux
+ case (qr_ctr_reg)
+ QR0:
+ begin
+ qr0_a = x0_reg;
+ qr0_b = x4_reg;
+ qr0_c = x8_reg;
+ qr0_d = x12_reg;
+
+ qr1_a = x1_reg;
+ qr1_b = x5_reg;
+ qr1_c = x9_reg;
+ qr1_d = x13_reg;
+
+ qr2_a = x2_reg;
+ qr2_b = x6_reg;
+ qr2_c = x10_reg;
+ qr2_d = x14_reg;
+
+ qr3_a = x3_reg;
+ qr3_b = x7_reg;
+ qr3_c = x11_reg;
+ qr3_d = x15_reg;
+ end
+
+ QR1:
+ begin
+ qr0_a = x0_reg;
+ qr0_b = x5_reg;
+ qr0_c = x10_reg;
+ qr0_d = x15_reg;
+
+ qr1_a = x1_reg;
+ qr1_b = x6_reg;
+ qr1_c = x11_reg;
+ qr1_d = x12_reg;
+
+ qr2_a = x2_reg;
+ qr2_b = x7_reg;
+ qr2_c = x8_reg;
+ qr2_d = x13_reg;
+
+ qr3_a = x3_reg;
+ qr3_b = x4_reg;
+ qr3_c = x9_reg;
+ qr3_d = x14_reg;
+ end
+ endcase // case (quarterround_select)
+ end // quarterround_mux
+
+
+ //----------------------------------------------------------------
+ // qr_ctr
+ // Update logic for the quarterround counter, a monotonically
+ // increasing counter with reset.
+ //----------------------------------------------------------------
+ always @*
+ begin : qr_ctr
+ qr_ctr_new = 0;
+ qr_ctr_we = 0;
+
+ if (qr_ctr_rst)
+ begin
+ qr_ctr_new = 0;
+ qr_ctr_we = 1;
+ end
+
+ if (qr_ctr_inc)
+ begin
+ qr_ctr_new = qr_ctr_reg + 1'b1;
+ qr_ctr_we = 1;
+ end
+ end // qr_ctr
+
+
+ //----------------------------------------------------------------
+ // dr_ctr
+ // Update logic for the round counter, a monotonically
+ // increasing counter with reset.
+ //----------------------------------------------------------------
+ always @*
+ begin : dr_ctr
+ dr_ctr_new = 0;
+ dr_ctr_we = 0;
+
+ if (dr_ctr_rst)
+ begin
+ dr_ctr_new = 0;
+ dr_ctr_we = 1;
+ end
+
+ if (dr_ctr_inc)
+ begin
+ dr_ctr_new = dr_ctr_reg + 1'b1;
+ dr_ctr_we = 1;
+ end
+ end // dr_ctr
+
+
+ //----------------------------------------------------------------
+ // block_ctr
+ // Update logic for the 64-bit block counter, a monotonically
+ // increasing counter with reset.
+ //----------------------------------------------------------------
+ always @*
+ begin : block_ctr
+ // Defult assignments
+ block0_ctr_new = 32'h00000000;
+ block1_ctr_new = 32'h00000000;
+ block0_ctr_we = 0;
+ block1_ctr_we = 0;
+
+ if (block_ctr_rst)
+ begin
+ block0_ctr_new = ctr[31 : 00];
+ block1_ctr_new = ctr[63 : 32];
+ block0_ctr_we = 1;
+ block1_ctr_we = 1;
+ end
+
+ if (block_ctr_inc)
+ begin
+ block0_ctr_new = block0_ctr_reg + 1;
+ block0_ctr_we = 1;
+
+ // Avoid chaining the 32-bit adders.
+ if (block0_ctr_reg == 32'hffffffff)
+ begin
+ block1_ctr_new = block1_ctr_reg + 1;
+ block1_ctr_we = 1;
+ end
+ end
+ end // block_ctr
+
+
+ //----------------------------------------------------------------
+ // chacha_ctrl_fsm
+ // Logic for the state machine controlling the core behaviour.
+ //----------------------------------------------------------------
+ always @*
+ begin : chacha_ctrl_fsm
+ init_state = 0;
+ update_state = 0;
+ sample_params = 0;
+ update_output = 0;
+ qr_ctr_inc = 0;
+ qr_ctr_rst = 0;
+ dr_ctr_inc = 0;
+ dr_ctr_rst = 0;
+ block_ctr_inc = 0;
+ block_ctr_rst = 0;
+ data_in_we = 0;
+ ready_wire = 0;
+ data_out_valid_new = 0;
+ data_out_valid_we = 0;
+ chacha_ctrl_new = CTRL_IDLE;
+ chacha_ctrl_we = 0;
+
+ case (chacha_ctrl_reg)
+ CTRL_IDLE:
+ begin
+ ready_wire = 1;
+ if (init)
+ begin
+ data_in_we = 1;
+ sample_params = 1;
+ block_ctr_rst = 1;
+ chacha_ctrl_new = CTRL_INIT;
+ chacha_ctrl_we = 1;
+ end
+ end
+
+ CTRL_INIT:
+ begin
+ init_state = 1;
+ qr_ctr_rst = 1;
+ dr_ctr_rst = 1;
+ chacha_ctrl_new = CTRL_ROUNDS;
+ chacha_ctrl_we = 1;
+ end
+
+ CTRL_ROUNDS:
+ begin
+ update_state = 1;
+ qr_ctr_inc = 1;
+ if (qr_ctr_reg == QR1)
+ begin
+ dr_ctr_inc = 1;
+ if (dr_ctr_reg == (rounds_reg - 1))
+ begin
+ chacha_ctrl_new = CTRL_FINALIZE;
+ chacha_ctrl_we = 1;
+ end
+ end
+ end
+
+ CTRL_FINALIZE:
+ begin
+ update_output = 1;
+ data_out_valid_new = 1;
+ data_out_valid_we = 1;
+ chacha_ctrl_new = CTRL_DONE;
+ chacha_ctrl_we = 1;
+ end
+
+ CTRL_DONE:
+ begin
+ ready_wire = 1;
+ if (init)
+ begin
+ data_out_valid_new = 0;
+ data_out_valid_we = 1;
+ data_in_we = 1;
+ sample_params = 1;
+ block_ctr_rst = 1;
+ chacha_ctrl_new = CTRL_INIT;
+ chacha_ctrl_we = 1;
+ end
+ else if (next)
+ begin
+ data_out_valid_new = 0;
+ data_out_valid_we = 1;
+ data_in_we = 1;
+ block_ctr_inc = 1;
+ chacha_ctrl_new = CTRL_INIT;
+ chacha_ctrl_we = 1;
+ end
+ end
+ endcase // case (chacha_ctrl_reg)
+ end // chacha_ctrl_fsm
+endmodule // chacha_core
+
+//======================================================================
+// EOF chacha_core.v
+//======================================================================
diff --git a/src/rtl/chacha_qr.v b/src/rtl/chacha_qr.v
new file mode 100644
index 0000000..1909a1c
--- /dev/null
+++ b/src/rtl/chacha_qr.v
@@ -0,0 +1,119 @@
+//======================================================================
+//
+// chacha_qr.v
+// -----------
+// Verilog 2001 implementation of the stream cipher ChaCha.
+// This is the combinational QR logic as a separade module to allow
+// us to build versions of the cipher with 1, 2, 4 and even 8
+// parallel qr functions.
+//
+//
+// Author: Joachim Strombergson
+// Copyright (c) 2011, 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.
+//
+//======================================================================
+
+module chacha_qr(
+ input wire [31 : 0] a,
+ input wire [31 : 0] b,
+ input wire [31 : 0] c,
+ input wire [31 : 0] d,
+
+ output wire [31 : 0] a_prim,
+ output wire [31 : 0] b_prim,
+ output wire [31 : 0] c_prim,
+ output wire [31 : 0] d_prim
+ );
+
+ //----------------------------------------------------------------
+ // Wires.
+ //----------------------------------------------------------------
+ reg [31 : 0] internal_a_prim;
+ reg [31 : 0] internal_b_prim;
+ reg [31 : 0] internal_c_prim;
+ reg [31 : 0] internal_d_prim;
+
+
+ //----------------------------------------------------------------
+ // Concurrent connectivity for ports.
+ //----------------------------------------------------------------
+ assign a_prim = internal_a_prim;
+ assign b_prim = internal_b_prim;
+ assign c_prim = internal_c_prim;
+ assign d_prim = internal_d_prim;
+
+
+ //----------------------------------------------------------------
+ // qr
+ //
+ // The actual quarterround function.
+ //----------------------------------------------------------------
+ always @*
+ begin : qr
+ reg [31 : 0] a0;
+ reg [31 : 0] a1;
+
+ reg [31 : 0] b0;
+ reg [31 : 0] b1;
+ reg [31 : 0] b2;
+ reg [31 : 0] b3;
+
+ reg [31 : 0] c0;
+ reg [31 : 0] c1;
+ reg [31 : 0] c2;
+ reg [31 : 0] c3;
+
+ reg [31 : 0] d0;
+ reg [31 : 0] d1;
+ reg [31 : 0] d2;
+ reg [31 : 0] d3;
+
+ a0 = a + b;
+ d0 = d ^ a0;
+ d1 = {d0[15 : 0], d0[31 : 16]};
+ c0 = c + d1;
+ b0 = b ^ c0;
+ b1 = {b0[19 : 0], b0[31 : 20]};
+ a1 = a0 + b1;
+ d2 = d1 ^ a1;
+ d3 = {d2[23 : 0], d2[31 : 24]};
+ c1 = c0 + d3;
+ b2 = b1 ^ c1;
+ b3 = {b2[24 : 0], b2[31 : 25]};
+
+ internal_a_prim = a1;
+ internal_b_prim = b3;
+ internal_c_prim = c1;
+ internal_d_prim = d3;
+ end // qr
+endmodule // chacha_qr
+
+//======================================================================
+// EOF chacha_qr.v
+//======================================================================