Estoy tratando de implementar una tubería MD5 de 3 etapas según este enlace . En particular, los algoritmos en la página 31. También hay otro documento que describe el reenvío de datos. Esto se hace en un FPGA (Terasic DE2-115). No hay esquemas en este proyecto, solo código VHDL.
library ieee;
use ieee.std_logic_1164.all;
use ieee.numeric_std.all;
entity md5core is
port (
CLOCK_50 : in std_logic;
SW : in std_logic_vector(17 downto 17)
);
end entity md5core;
architecture md5core_rtl of md5core is
type r_array is array(0 to 64) of std_logic_vector(7 downto 0);
constant R : r_array := ( x"07", x"0c", x"11", x"16", x"07", x"0c", x"11", x"16", x"07", x"0c", x"11", x"16", x"07", x"0c", x"11",
x"16", x"05", x"09", x"0e", x"14", x"05", x"09", x"0e", x"14", x"05", x"09", x"0e", x"14", x"05", x"09",
x"0e", x"14", x"04", x"0b", x"10", x"17", x"04", x"0b", x"10", x"17", x"04", x"0b", x"10", x"17", x"04",
x"0b", x"10", x"17", x"06", x"0a", x"0f", x"15", x"06", x"0a", x"0f", x"15", x"06", x"0a", x"0f", x"15",
x"06", x"0a", x"0f", x"15", others => x"00");
type k_array is array(0 to 66) of std_logic_vector(31 downto 0);
constant K : k_array := (x"d76aa478", x"e8c7b756", x"242070db", x"c1bdceee",
x"f57c0faf", x"4787c62a", x"a8304613", x"fd469501",
x"698098d8", x"8b44f7af", x"ffff5bb1", x"895cd7be",
x"6b901122", x"fd987193", x"a679438e", x"49b40821",
x"f61e2562", x"c040b340", x"265e5a51", x"e9b6c7aa",
x"d62f105d", x"02441453", x"d8a1e681", x"e7d3fbc8",
x"21e1cde6", x"c33707d6", x"f4d50d87", x"455a14ed",
x"a9e3e905", x"fcefa3f8", x"676f02d9", x"8d2a4c8a",
x"fffa3942", x"8771f681", x"6d9d6122", x"fde5380c",
x"a4beea44", x"4bdecfa9", x"f6bb4b60", x"bebfbc70",
x"289b7ec6", x"eaa127fa", x"d4ef3085", x"04881d05",
x"d9d4d039", x"e6db99e5", x"1fa27cf8", x"c4ac5665",
x"f4292244", x"432aff97", x"ab9423a7", x"fc93a039",
x"655b59c3", x"8f0ccc92", x"ffeff47d", x"85845dd1",
x"6fa87e4f", x"fe2ce6e0", x"a3014314", x"4e0811a1",
x"f7537e82", x"bd3af235", x"2ad7d2bb", x"eb86d391", others => x"00000000");
type g_array is array(0 to 64) of integer range 0 to 15;
constant g_arr : g_array := (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,
1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12,
5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2,
0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9, 0);
type w_array is array(0 to 15) of std_logic_vector(31 downto 0);
signal W : w_array;
constant AA : std_logic_vector(31 downto 0) := x"67452301";
constant BB : std_logic_vector(31 downto 0) := x"EFCDAB89";
constant CC : std_logic_vector(31 downto 0) := x"98BADCFE";
constant DD : std_logic_vector(31 downto 0) := x"10325476";
signal res_A : std_logic_vector(31 downto 0) := x"00000000";
signal res_B : std_logic_vector(31 downto 0) := x"00000000";
signal res_C : std_logic_vector(31 downto 0) := x"00000000";
signal res_D : std_logic_vector(31 downto 0) := x"00000000";
type in_str_t is array(0 to 5) of std_logic_vector(7 downto 0);
constant in_str : in_str_t := (x"68", x"65", x"6c", x"6c", x"6f", x"6f");
type pad_str_t is array(0 to 63) of std_logic_vector(7 downto 0);
signal pad_str : pad_str_t;
type state_t is (start, padding, init_w, state_1, state_2, state_3, state_4, done);
signal state : state_t;
signal a, b, c, d, f : std_logic_vector(31 downto 0) := x"00000000";
signal i : integer range 0 to 64 := 0;
signal g : integer range 0 to 15 := 0;
--signal tmp_b : std_logic_vector(31 downto 0);
signal akw : std_logic_vector(31 downto 0);
signal ak : std_logic_vector(31 downto 0);
signal b_tmp : std_logic_vector(31 downto 0);
begin
--tmp_b <= std_logic_vector(unsigned(b) + rotate_left(unsigned(a) + unsigned(f) + unsigned(K(i)) + unsigned(W(g)), to_integer(unsigned(R(i)))));
pipe_p : process(CLOCK_50, SW, a, b, c, d, i)
begin
if SW(17) = '0' then
-- ak <= std_logic_vector(unsigned(K(2)) + unsigned(BB));
-- akw <= std_logic_vector(unsigned(W(0)) + 1 + unsigned(K(2)) + unsigned(BB));
b_tmp <= BB;
elsif rising_edge(CLOCK_50) and state = state_1 then
if i = 0 then
ak <= std_logic_vector(unsigned(K(0)) + unsigned(a));
elsif i = 1 then
ak <= std_logic_vector(unsigned(K(1)) + unsigned(a));
akw <= std_logic_vector(unsigned(W(0)) + unsigned(ak));
elsif i = 2 then
ak <= std_logic_vector(unsigned(K(2)) + unsigned(a));
akw <= std_logic_vector(unsigned(W(1)) + unsigned(ak));
b_tmp <= std_logic_vector(unsigned(b) + (rotate_left(unsigned(akw) + unsigned(f), to_integer(unsigned(R(0))))));
else
ak <= std_logic_vector(unsigned(K(i)) + unsigned(a));
akw <= std_logic_vector(unsigned(W(g_arr(i-1))) + unsigned(ak));
b_tmp <= std_logic_vector(unsigned(b) + (rotate_left(unsigned(akw) + unsigned(f), to_integer(unsigned(R(i-2))))));
end if;
end if;
end process pipe_p;
md5_f_p : process(state, a, b, c, d, i)
begin
case state is
when state_1 =>
if i = 0 or i > 4 then
f <= (b and c) or ((not b) and d);
g <= g_arr(i);
end if;
when state_2 =>
f <= (d and b) or ((not d) and c);
g <= g_arr(i);
when state_3 =>
f <= b xor c xor d;
g <= g_arr(i);
when state_4 =>
f <= c xor (b or (not d));
g <= g_arr(i);
when others =>
f <= x"00000000";
g <= 0;
end case;
end process md5_f_p;
md5_p : process(CLOCK_50, SW, a, b, c, d, f, g)
begin
if SW(17) = '0' then
state <= start;
i <= 0;
a <= AA;
b <= BB;
c <= CC;
d <= DD;
W <= (others => x"00000000");
pad_str <= (others => x"00");
--tmp_b := BB;
elsif rising_edge(CLOCK_50) then
case state is
when start =>
pad_str(0) <= in_str(0);
pad_str(1) <= in_str(1);
pad_str(2) <= in_str(2);
pad_str(3) <= in_str(3);
pad_str(4) <= in_str(4);
pad_str(5) <= in_str(5);
state <= padding;
when padding =>
pad_str(6) <= "10000000";
pad_str(56) <= std_logic_vector(to_unsigned(in_str'length*8, 8));
state <= init_w;
when init_w =>
W(0) <= pad_str(3) & pad_str(2) & pad_str(1) & pad_str(0);
W(1) <= pad_str(7) & pad_str(6) & pad_str(5) & pad_str(4);
W(14) <= pad_str(59) & pad_str(58) & pad_str(57) & pad_str(56);
state <= state_1;
when state_1 =>
if i = 16 then
state <= state_2;
else
if i > 2 then
--tmp_b := b;
a <= d;
c <= b;
d <= c;
b <= b_tmp;
-- d <= c;
-- b <= b_tmp;
-- c <= b;
-- a <= d;
end if;
i <= i + 1;
end if;
when state_2 =>
if i = 32 then
state <= state_3;
else
d <= c;
b <= b_tmp;
c <= b;
a <= d;
i <= i + 1;
end if;
when state_3 =>
if i = 48 then
state <= state_4;
else
d <= c;
b <= b_tmp;
c <= b;
a <= d;
i <= i + 1;
end if;
when state_4 =>
if i = 64 then
res_A <= std_logic_vector(unsigned(AA) + unsigned(a));
res_B <= std_logic_vector(unsigned(BB) + unsigned(b));
res_C <= std_logic_vector(unsigned(CC) + unsigned(c));
res_D <= std_logic_vector(unsigned(DD) + unsigned(d));
state <= done;
else
d <= c;
c <= b;
b <= b_tmp;
a <= d;
i <= i + 1;
end if;
when done =>
state <= done;
when others =>
state <= done;
end case;
end if;
end process md5_p;
end architecture md5core_rtl;
Al usar este código, obtengo los valores correctos para b en la primera etapa de la ronda 0, pero a partir de entonces nada parece encajar. Como se ve en esta simulación, la primera etapa en la ronda 0 es correcta, pero luego no. Esto es cuando se usa a en esta expresión:
ak <= std_logic_vector(unsigned(K(0)) + unsigned(a)); -- using a
Pero ... Si entiendo el segundo documento correctamente, debería usar c en lugar de a (reenvío de datos), pero la primera etapa en la ronda 0 tampoco funciona. Es decir, cuando hago esto, la primera etapa en la ronda 0 también tiene los números equivocados.
ak <= std_logic_vector(unsigned(K(0)) + unsigned(c)); -- changed to c
Para la cadena en particular en el código ( helloo ) los siguientes valores son correctos (primeras 3 etapas de la ronda 0).
i:0 => a:271733878, b:3679623978, c:4023233417, d:2562383102, f:2562383102, g:0
i:1 => a:2562383102, b:268703616, c:3679623978, d:4023233417, f:3421032412, g:1
i:2 => a:4023233417, b:566857930, c:268703616, d:3679623978, f:4291410697, g:2
Por cierto, AKM en el documento es akw en el código.
Cualquier consejo o sugerencia para traerme en la dirección correcta sería muy apreciado. El código sería ideal. Si algo no está claro, editaré la pregunta e intentaré rectificarla.