I'm trying to write a sha256 implementation in pure pascal like sha1 and
md5 units.
With negative results.
Someone can helpme with this?
--
H. Gabriel Máculus
http://twitter.com/gabrielix - https://prism-break.org/
<http://github.com/gabrielix/>
program sha256_test;
{$mode objfpc}{$h+}
Type
TSHA256Digest = array[0..32] Of Byte;
TSHA256Context = record
State : array[0..7] of Cardinal;
data : array[0..63] of Byte;
datalen : cardinal;
bitlen : qword;
end;
const
HexTable: array[0..15] of char='0123456789abcdef';
h0 : cardinal = $6a09e667;
h1 : cardinal = $bb67ae85;
h2 : cardinal = $3c6ef372;
h3 : cardinal = $a54ff53a;
h4 : cardinal = $510e527f;
h5 : cardinal = $9b05688c;
h6 : cardinal = $1f83d9ab;
h7 : cardinal = $5be0cd19;
k :array[0..63] Of cardinal = (
$428a2f98, $71374491, $b5c0fbcf, $e9b5dba5, $3956c25b, $59f111f1,
$923f82a4, $ab1c5ed5,
$d807aa98, $12835b01, $243185be, $550c7dc3, $72be5d74, $80deb1fe,
$9bdc06a7, $c19bf174,
$e49b69c1, $efbe4786, $0fc19dc6, $240ca1cc, $2de92c6f, $4a7484aa,
$5cb0a9dc, $76f988da,
$983e5152, $a831c66d, $b00327c8, $bf597fc7, $c6e00bf3, $d5a79147,
$06ca6351, $14292967,
$27b70a85, $2e1b2138, $4d2c6dfc, $53380d13, $650a7354, $766a0abb,
$81c2c92e, $92722c85,
$a2bfe8a1, $a81a664b, $c24b8b70, $c76c51a3, $d192e819, $d6990624,
$f40e3585, $106aa070,
$19a4c116, $1e376c08, $2748774c, $34b0bcb5, $391c0cb3, $4ed8aa4a,
$5b9cca4f, $682e6ff3,
$748f82ee, $78a5636f, $84c87814, $8cc70208, $90befffa, $a4506ceb,
$bef9a3f7, $c67178f2);
function rotl(a : cardinal; n : byte) : cardinal;
begin
rotl := (a shl n) or (a shr (32 - n));
end;
function rotr(a : cardinal; n : byte) : cardinal;
begin
rotr := (a shr n) or (a shl (32 - n));
end;
function ch(x, y, z : cardinal) : cardinal;
begin
ch := (( (x) and (y) ) xor ( not (x) and (z)));
end;
function maj(x, y, z : cardinal) : cardinal;
begin
maj := (((x) and (y)) xor ((x) and (z)) xor ((y) and (z)));
end;
function ep0(x : cardinal) : cardinal;
begin
ep0 := (rotr(x,2) xor rotr(x,13) xor rotr(x,22));
end;
function ep1(x : cardinal) : cardinal;
begin
ep1 := (rotr(x,6) xor rotr(x,11) xor rotr(x,25));
end;
function sig0(x : cardinal) : cardinal;
begin
sig0 := (rotr(x,7) xor rotr(x,18) xor (x shr 3));
end;
function sig1(x : cardinal) : cardinal;
begin
sig1 := (rotr(x,17) xor rotr(x,19) xor (x shr 10));
end;
procedure sha256_transform(var ctx : TSHA256Context; var data : array of byte);
var
a, b, c, d, e, f, g, h, i, j, t1, t2 : cardinal;
m : array[0..63] of byte;
begin
j := 0;
for i := 0 to 15 do
begin
m[i] := (data[j] shl 24) or (data[j + 1] shl 16) or (data[j + 2] shl 8) or (data[j + 3]);
inc(j, 4);
end;
j := 0;
for i:= 0 to 15 do
begin
m[i] := (data[j] shl 24) or (data[j + 1] shl 16) or (data[j + 2] shl 8) or (data[j + 3]);
end;
for i:=16 to 63 do
begin
m[i] := sig1(m[i - 2]) + m[i - 7] + sig0(m[i - 15]) + m[i - 16];
end;
a := ctx.state[0];
b := ctx.state[1];
c := ctx.state[2];
d := ctx.state[3];
e := ctx.state[4];
f := ctx.state[5];
g := ctx.state[6];
h := ctx.state[7];
for i := 0 to 63 do
begin
t1 := h + ep1(e) + ch(e, f, g) + k[i] + m[i];
t2 := ep0(a) + maj(a,b,c);
h := g;
g := f;
f := e;
e := d + t1;
d := c;
c := b;
b := a;
a := t1 + t2;
end;
ctx.state[0] := ctx.state[0] + a;
ctx.state[1] := ctx.state[1] + b;
ctx.state[2] := ctx.state[2] + c;
ctx.state[3] := ctx.state[3] + d;
ctx.state[4] := ctx.state[4] + e;
ctx.state[5] := ctx.state[5] + f;
ctx.state[6] := ctx.state[6] + g;
ctx.state[7] := ctx.state[7] + h;
end;
procedure sha256_init(var ctx : TSHA256Context);
begin
ctx.datalen := 0;
ctx.bitlen := 0;
ctx.state[0] := $6a09e667;
ctx.state[1] := $bb67ae85;
ctx.state[2] := $3c6ef372;
ctx.state[3] := $a54ff53a;
ctx.state[4] := $510e527f;
ctx.state[5] := $9b05688c;
ctx.state[6] := $1f83d9ab;
ctx.state[7] := $5be0cd19;
end;
procedure sha256_update(var ctx : TSHA256Context; var data : array of byte; len : cardinal);
var
i :cardinal;
begin
for i:=0 to (len-1) do
begin
ctx.data[ctx.datalen] := data[i];
inc(ctx.datalen);
if ctx.datalen = 64 then
begin
sha256_transform(ctx, ctx.data);
inc(ctx.bitlen, 512);
ctx.datalen := 0;
end;
end;
end;
procedure sha256_final(var ctx : TSHA256Context; var hash : array of byte);
var
i : cardinal;
begin
i := ctx.datalen;
// Pad whatever data is left in the buffer.
if ctx.datalen < 56 then
begin
ctx.data[i] := $80;
inc(i);
while i < 56 do
begin
ctx.data[i] := $00;
inc(i);
end;
end
else
begin
ctx.data[i] := $80;
inc(i);
while i < 64 do
begin
ctx.data[i] := $00;
inc(i);
end;
sha256_transform(ctx, ctx.data);
fillbyte(ctx.data, 56, 0);
end;
ctx.bitlen := ctx.bitlen + (ctx.datalen * 8);
ctx.data[63] := ctx.bitlen;
ctx.data[62] := ctx.bitlen shr 8;
ctx.data[61] := ctx.bitlen shr 16;
ctx.data[60] := ctx.bitlen shr 24;
ctx.data[59] := ctx.bitlen shr 32;
ctx.data[58] := ctx.bitlen shr 40;
ctx.data[57] := ctx.bitlen shr 48;
ctx.data[56] := ctx.bitlen shr 56;
sha256_transform(ctx, ctx.data);
for i := 0 to 3 do
begin
hash[i] := (ctx.state[0] shr (24 - i * 8)) and $000000ff;
hash[i + 4] := (ctx.state[1] shr (24 - i * 8)) and $000000ff;
hash[i + 8] := (ctx.state[2] shr (24 - i * 8)) and $000000ff;
hash[i + 12] := (ctx.state[3] shr (24 - i * 8)) and $000000ff;
hash[i + 16] := (ctx.state[4] shr (24 - i * 8)) and $000000ff;
hash[i + 20] := (ctx.state[5] shr (24 - i * 8)) and $000000ff;
hash[i + 24] := (ctx.state[6] shr (24 - i * 8)) and $000000ff;
hash[i + 28] := (ctx.state[7] shr (24 - i * 8)) and $000000ff;
end;
end;
var
myctx : TSHA256Context;
datos : array[0..1] of byte = (ord('b'), ord('a'));
salida : array[0..31] of byte;
i : integer;
compose : char;
p : pchar;
begin
sha256_init(myctx);
sha256_update(myctx, datos, 2);
sha256_final(myctx, salida);
i :=0;
repeat
write(hextable[(salida[i] shr 4) and 15],
hextable[salida[i] and 15]
);
inc(i);
until i = 32;
writeln;
end.
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