Курсовая работа: Защита информации от несанкционированного доступа

CodingTools;

function coding_GOST(Buf: Pointer; Size: LongWord; Param: TCodingParameters):Integer;

function coding_GOSTSE(Buf: Pointer; Size: LongWord; Param: TCodingParameters):Integer;

implementation

var

Key: array [0..7] of LongWord;

const

ExchTable: array [0..7,0..15] of byte =

((2,5,3,7,12,1,15,14,9,4,6,8,10,0,11,13),

(8,3,1,9,10,15,2,14,13,5,11,7,0,12,4,3),

(15,1,14,2,13,3,12,4,11,5,10,0,6,9,7,8),

(1,3,5,7,9,2,4,6,8,10,11,13,15,12,14,0),

(1,4,7,10,13,2,5,8,11,0,14,3,6,9,12,15),

(1,5,9,13,2,6,10,0,14,3,7,11,15,4,8,12),

(1,6,11,2,7,12,0,3,8,13,4,9,14,5,10,15),

(1,7,0,13,2,8,14,3,9,15,4,10,5,11,6,12));

C1 = $1010101;

C2 = $1010104;

procedure BaseStep(var N:word64; X: longword);

var

i:integer;

s:word64;

begin

s.v32[0]:=(N.v32[0] + X) mod $100000000;

fori:=0 to 3 do

begin

//Замена по таблице младшие или старшие 4 бита

s.v8[i]:=(ExchTable[i*2,(s.v8[i] and $0F)]) or (ExchTable[i*2+1,((s.v8[i] shr 4) and $0F)] shl 4);

end;