📄 des.pas
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unit Des;
interface
uses SysUtils;
type
TKeyByte = array[0..5] of Byte;
TDesMode = (dmEncry, dmDecry);
function EncryStr(Str, Key: String): String;
function DecryStr(Str, Key: String): String;
function EncryStrHex(Str, Key: String): String;
function DecryStrHex(StrHex, Key: String): String;
const
BitIP: array[0..63] of Byte =
(57, 49, 41, 33, 25, 17, 9, 1,
59, 51, 43, 35, 27, 19, 11, 3,
61, 53, 45, 37, 29, 21, 13, 5,
63, 55, 47, 39, 31, 23, 15, 7,
56, 48, 40, 32, 24, 16, 8, 0,
58, 50, 42, 34, 26, 18, 10, 2,
60, 52, 44, 36, 28, 20, 12, 4,
62, 54, 46, 38, 30, 22, 14, 6 );
BitCP: array[0..63] of Byte =
( 39, 7, 47, 15, 55, 23, 63, 31,
38, 6, 46, 14, 54, 22, 62, 30,
37, 5, 45, 13, 53, 21, 61, 29,
36, 4, 44, 12, 52, 20, 60, 28,
35, 3, 43, 11, 51, 19, 59, 27,
34, 2, 42, 10, 50, 18, 58, 26,
33, 1, 41, 9, 49, 17, 57, 25,
32, 0, 40, 8, 48, 16, 56, 24 );
BitExp: array[0..47] of Integer =
( 31, 0, 1, 2, 3, 4, 3, 4, 5, 6, 7, 8, 7, 8, 9,10,
11,12,11,12,13,14,15,16,15,16,17,18,19,20,19,20,
21,22,23,24,23,24,25,26,27,28,27,28,29,30,31,0 );
BitPM: array[0..31] of Byte =
( 15, 6,19,20,28,11,27,16, 0,14,22,25, 4,17,30, 9,
1, 7,23,13,31,26, 2, 8,18,12,29, 5,21,10, 3,24 );
sBox: array[0..7] of array[0..63] of Byte =
( ( 14, 4, 13, 1, 2, 15, 11, 8, 3, 10, 6, 12, 5, 9, 0, 7,
0, 15, 7, 4, 14, 2, 13, 1, 10, 6, 12, 11, 9, 5, 3, 8,
4, 1, 14, 8, 13, 6, 2, 11, 15, 12, 9, 7, 3, 10, 5, 0,
15, 12, 8, 2, 4, 9, 1, 7, 5, 11, 3, 14, 10, 0, 6, 13 ),
( 15, 1, 8, 14, 6, 11, 3, 4, 9, 7, 2, 13, 12, 0, 5, 10,
3, 13, 4, 7, 15, 2, 8, 14, 12, 0, 1, 10, 6, 9, 11, 5,
0, 14, 7, 11, 10, 4, 13, 1, 5, 8, 12, 6, 9, 3, 2, 15,
13, 8, 10, 1, 3, 15, 4, 2, 11, 6, 7, 12, 0, 5, 14, 9 ),
( 10, 0, 9, 14, 6, 3, 15, 5, 1, 13, 12, 7, 11, 4, 2, 8,
13, 7, 0, 9, 3, 4, 6, 10, 2, 8, 5, 14, 12, 11, 15, 1,
13, 6, 4, 9, 8, 15, 3, 0, 11, 1, 2, 12, 5, 10, 14, 7,
1, 10, 13, 0, 6, 9, 8, 7, 4, 15, 14, 3, 11, 5, 2, 12 ),
( 7, 13, 14, 3, 0, 6, 9, 10, 1, 2, 8, 5, 11, 12, 4, 15,
13, 8, 11, 5, 6, 15, 0, 3, 4, 7, 2, 12, 1, 10, 14, 9,
10, 6, 9, 0, 12, 11, 7, 13, 15, 1, 3, 14, 5, 2, 8, 4,
3, 15, 0, 6, 10, 1, 13, 8, 9, 4, 5, 11, 12, 7, 2, 14 ),
( 2, 12, 4, 1, 7, 10, 11, 6, 8, 5, 3, 15, 13, 0, 14, 9,
14, 11, 2, 12, 4, 7, 13, 1, 5, 0, 15, 10, 3, 9, 8, 6,
4, 2, 1, 11, 10, 13, 7, 8, 15, 9, 12, 5, 6, 3, 0, 14,
11, 8, 12, 7, 1, 14, 2, 13, 6, 15, 0, 9, 10, 4, 5, 3 ),
( 12, 1, 10, 15, 9, 2, 6, 8, 0, 13, 3, 4, 14, 7, 5, 11,
10, 15, 4, 2, 7, 12, 9, 5, 6, 1, 13, 14, 0, 11, 3, 8,
9, 14, 15, 5, 2, 8, 12, 3, 7, 0, 4, 10, 1, 13, 11, 6,
4, 3, 2, 12, 9, 5, 15, 10, 11, 14, 1, 7, 6, 0, 8, 13 ),
( 4, 11, 2, 14, 15, 0, 8, 13, 3, 12, 9, 7, 5, 10, 6, 1,
13, 0, 11, 7, 4, 9, 1, 10, 14, 3, 5, 12, 2, 15, 8, 6,
1, 4, 11, 13, 12, 3, 7, 14, 10, 15, 6, 8, 0, 5, 9, 2,
6, 11, 13, 8, 1, 4, 10, 7, 9, 5, 0, 15, 14, 2, 3, 12 ),
( 13, 2, 8, 4, 6, 15, 11, 1, 10, 9, 3, 14, 5, 0, 12, 7,
1, 15, 13, 8, 10, 3, 7, 4, 12, 5, 6, 11, 0, 14, 9, 2,
7, 11, 4, 1, 9, 12, 14, 2, 0, 6, 10, 13, 15, 3, 5, 8,
2, 1, 14, 7, 4, 10, 8, 13, 15, 12, 9, 0, 3, 5, 6, 11 ) );
BitPMC1: array[0..55] of Byte =
( 56, 48, 40, 32, 24, 16, 8,
0, 57, 49, 41, 33, 25, 17,
9, 1, 58, 50, 42, 34, 26,
18, 10, 2, 59, 51, 43, 35,
62, 54, 46, 38, 30, 22, 14,
6, 61, 53, 45, 37, 29, 21,
13, 5, 60, 52, 44, 36, 28,
20, 12, 4, 27, 19, 11, 3 );
BitPMC2: array[0..47] of Byte =
( 13, 16, 10, 23, 0, 4,
2, 27, 14, 5, 20, 9,
22, 18, 11, 3, 25, 7,
15, 6, 26, 19, 12, 1,
40, 51, 30, 36, 46, 54,
29, 39, 50, 44, 32, 47,
43, 48, 38, 55, 33, 52,
45, 41, 49, 35, 28, 31 );
var
subKey: array[0..15] of TKeyByte;
implementation
procedure initPermutation(var inData: array of Byte);
var
newData: array[0..7] of Byte;
i: Integer;
begin
FillChar(newData, 8, 0);
for i := 0 to 63 do
if (inData[BitIP[i] shr 3] and (1 shl (7- (BitIP[i] and $07)))) < > 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7-(i and $07)));
for i := 0 to 7 do inData[i] := newData[i];
end;
procedure conversePermutation(var inData: array of Byte);
var
newData: array[0..7] of Byte;
i: Integer;
begin
FillChar(newData, 8, 0);
for i := 0 to 63 do
if (inData[BitCP[i] shr 3] and (1 shl (7-(BitCP[i] and $07)))) < > 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7-(i and $07)));
for i := 0 to 7 do inData[i] := newData[i];
end;
procedure expand(inData: array of Byte; var outData: array of Byte);
var
i: Integer;
begin
FillChar(outData, 6, 0);
for i := 0 to 47 do
if (inData[BitExp[i] shr 3] and (1 shl (7-(BitExp[i] and $07)))) < > 0 then
outData[i shr 3] := outData[i shr 3] or (1 shl (7-(i and $07)));
end;
procedure permutation(var inData: array of Byte);
var
newData: array[0..3] of Byte;
i: Integer;
begin
FillChar(newData, 4, 0);
for i := 0 to 31 do
if (inData[BitPM[i] shr 3] and (1 shl (7-(BitPM[i] and $07)))) < > 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7-(i and $07)));
for i := 0 to 3 do inData[i] := newData[i];
end;
function si(s,inByte: Byte): Byte;
var
c: Byte;
begin
c := (inByte and $20) or ((inByte and $1e) shr 1) or
((inByte and $01) shl 4);
Result := (sBox[s][c] and $0f);
end;
procedure permutationChoose1(inData: array of Byte;
var outData: array of Byte);
var
i: Integer;
begin
FillChar(outData, 7, 0);
for i := 0 to 55 do
if (inData[BitPMC1[i] shr 3] and (1 shl (7-(BitPMC1[i] and $07)))) < > 0 then
outData[i shr 3] := outData[i shr 3] or (1 shl (7-(i and $07)));
end;
procedure permutationChoose2(inData: array of Byte;
var outData: array of Byte);
var
i: Integer;
begin
FillChar(outData, 6, 0);
for i := 0 to 47 do
if (inData[BitPMC2[i] shr 3] and (1 shl (7-(BitPMC2[i] and $07)))) < > 0 then
outData[i shr 3] := outData[i shr 3] or (1 shl (7-(i and $07)));
end;
procedure cycleMove(var inData: array of Byte; bitMove: Byte);
var
i: Integer;
begin
for i := 0 to bitMove - 1 do
begin
inData[0] := (inData[0] shl 1) or (inData[1] shr 7);
inData[1] := (inData[1] shl 1) or (inData[2] shr 7);
inData[2] := (inData[2] shl 1) or (inData[3] shr 7);
inData[3] := (inData[3] shl 1) or ((inData[0] and $10) shr 4);
inData[0] := (inData[0] and $0f);
end;
end;
procedure makeKey(inKey: array of Byte; var outKey: array of TKeyByte);
const
bitDisplace: array[0..15] of Byte =
( 1,1,2,2, 2,2,2,2, 1,2,2,2, 2,2,2,1 );
var
outData56: array[0..6] of Byte;
key28l: array[0..3] of Byte;
key28r: array[0..3] of Byte;
key56o: array[0..6] of Byte;
i: Integer;
begin
permutationChoose1(inKey, outData56);
key28l[0] := outData56[0] shr 4;
key28l[1] := (outData56[0] shl 4) or (outData56[1] shr 4);
key28l[2] := (outData56[1] shl 4) or (outData56[2] shr 4);
key28l[3] := (outData56[2] shl 4) or (outData56[3] shr 4);
key28r[0] := outData56[3] and $0f;
key28r[1] := outData56[4];
key28r[2] := outData56[5];
key28r[3] := outData56[6];
for i := 0 to 15 do
begin
cycleMove(key28l, bitDisplace[i]);
cycleMove(key28r, bitDisplace[i]);
key56o[0] := (key28l[0] shl 4) or (key28l[1] shr 4);
key56o[1] := (key28l[1] shl 4) or (key28l[2] shr 4);
key56o[2] := (key28l[2] shl 4) or (key28l[3] shr 4);
key56o[3] := (key28l[3] shl 4) or (key28r[0]);
key56o[4] := key28r[1];
key56o[5] := key28r[2];
key56o[6] := key28r[3];
permutationChoose2(key56o, outKey[i]);
end;
end;
procedure initPermutation(var inData: array of Byte);
var
newData: array[0..7] of Byte;
i: Integer;
begin
FillChar(newData, 8, 0);
for i := 0 to 63 do
if (inData[BitIP[i] shr 3] and (1 shl (7- (BitIP[i] and $07)))) < > 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7-(i and $07)));
for i := 0 to 7 do inData[i] := newData[i];
end;
procedure conversePermutation(var inData: array of Byte);
var
newData: array[0..7] of Byte;
i: Integer;
begin
FillChar(newData, 8, 0);
for i := 0 to 63 do
if (inData[BitCP[i] shr 3] and (1 shl (7-(BitCP[i] and $07)))) < > 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7-(i and $07)));
for i := 0 to 7 do inData[i] := newData[i];
end;
procedure expand(inData: array of Byte; var outData: array of Byte);
var
i: Integer;
begin
FillChar(outData, 6, 0);
for i := 0 to 47 do
if (inData[BitExp[i] shr 3] and (1 shl (7-(BitExp[i] and $07)))) < > 0 then
outData[i shr 3] := outData[i shr 3] or (1 shl (7-(i and $07)));
end;
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