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;
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);
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 encry(inData, subKey: array of Byte;
var outData: array of Byte);
var
outBuf: array[0..5] of Byte;
buf: array[0..7] of Byte;
i: Integer;
begin
expand(inData, outBuf);
for i := 0 to 5 do outBuf[i] := outBuf[i] xor subKey[i];
// outBuf xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx xxxxxxxx
buf[0] := outBuf[0] shr 2; //xxxxxx -> 2
buf[1] := ((outBuf[0] and $03) shl 4) or (outBuf[1] shr 4); // 4 <- xx xxxx -> 4
buf[2] := ((outBuf[1] and $0f) shl 2) or (outBuf[2] shr 6); // 2 <- xxxx xx -> 6
buf[3] := outBuf[2] and $3f; // xxxxxx
buf[4] := outBuf[3] shr 2; // xxxxxx
buf[5] := ((outBuf[3] and $03) shl 4) or (outBuf[4] shr 4); // xx xxxx
buf[6] := ((outBuf[4] and $0f) shl 2) or (outBuf[5] shr 6); // xxxx xx
buf[7] := outBuf[5] and $3f; // xxxxxx
for i := 0 to 7 do buf[i] := si(i, buf[i]);
for i := 0 to 3 do outBuf[i] := (buf[i*2] shl 4) or buf[i*2+1];
permutation(outBuf);
for i := 0 to 3 do outData[i] := outBuf[i];
end;
procedure desData(desMode: TDesMode;
inData: array of Byte; var outData: array of Byte);
// inData, outData 都为8Bytes，否则出错
var
i, j: Integer;
temp, buf: array[0..3] of Byte;
begin
for i := 0 to 7 do outData[i] := inData[i];
initPermutation(outData);
if desMode = dmEncry then
begin
for i := 0 to 15 do
begin
for j := 0 to 3 do temp[j] := outData[j]; //temp = Ln
for j := 0 to 3 do outData[j] := outData[j + 4]; //Ln+1 = Rn
encry(outData, subKey[i], buf); //Rn ==Kn==> buf
for j := 0 to 3 do outData[j + 4] := temp[j] xor buf[j]; //Rn+1 = Ln^buf
end;
for j := 0 to 3 do temp[j] := outData[j + 4];
for j := 0 to 3 do outData[j + 4] := outData[j];
for j := 0 to 3 do outData[j] := temp[j];
end
else if desMode = dmDecry then
begin
for i := 15 downto 0 do
begin
for j := 0 to 3 do temp[j] := outData[j];
for j := 0 to 3 do outData[j] := outData[j + 4];
encry(outData, subKey[i], buf);
for j := 0 to 3 do outData[j + 4] := temp[j] xor buf[j];
end;
for j := 0 to 3 do temp[j] := outData[j + 4];
for j := 0 to 3 do outData[j + 4] := outData[j];
for j := 0 to 3 do outData[j] := temp[j];
end;
conversePermutation(outData);
end;
function EncryStr(Str, Key: String): String;
var
StrByte, OutByte, KeyByte: array[0..7] of Byte;
StrResult: String;
I, J: Integer;
begin
if (Length(Str) > 0) and (Ord(Str[Length(Str)]) = 0) then
raise Exception.Create('Error: the last char is NULL char.');
if Length(Key) < 8 then
while Length(Key) < 8 do Key := Key + Chr(0);
while Length(Str) mod 8 <> 0 do Str := Str + Chr(0);
for J := 0 to 7 do KeyByte[J] := Ord(Key[J + 1]);
makeKey(keyByte, subKey);
StrResult := '';
for I := 0 to Length(Str) div 8 - 1 do
begin
for J := 0 to 7 do
StrByte[J] := Ord(Str[I * 8 + J + 1]);
desData(dmEncry, StrByte, OutByte);
for J := 0 to 7 do
StrResult := StrResult + Chr(OutByte[J]);
end;
Result := StrResult;
end;
function DecryStr(Str, Key: String): String;
var
StrByte, OutByte, KeyByte: array[0..7] of Byte;
StrResult: String;
I, J: Integer;
begin
if Length(Key) < 8 then
while Length(Key) < 8 do Key := Key + Chr(0);
for J := 0 to 7 do KeyByte[J] := Ord(Key[J + 1]);
makeKey(keyByte, subKey);
StrResult := '';
for I := 0 to Length(Str) div 8 - 1 do
begin
for J := 0 to 7 do StrByte[J] := Ord(Str[I * 8 + J + 1]);
desData(dmDecry, StrByte, OutByte);
for J := 0 to 7 do
StrResult := StrResult + Chr(OutByte[J]);
end;
while (Length(StrResult) > 0) and
(Ord(StrResult[Length(StrResult)]) = 0) do
Delete(StrResult, Length(StrResult), 1);
Result := StrResult;
end;
function EncryStrHex(Str, Key: String): String;
var
StrResult, TempResult, Temp: String;
I: Integer;
begin
TempResult := EncryStr(Str, Key);
StrResult := '';
for I := 0 to Length(TempResult) - 1 do
begin
Temp := Format('%x', [Ord(TempResult[I + 1])]);
if Length(Temp) = 1 then Temp := '0' + Temp;
StrResult := StrResult + Temp;
end;
Result := StrResult;
end;
function DecryStrHex(StrHex, Key: String): String;
function HexToInt(Hex: String): Integer;
var
I, Res: Integer;
ch: Char;
begin
Res := 0;
for I := 0 to Length(Hex) - 1 do
begin
ch := Hex[I + 1];
if (ch >= '0') and (ch <= '9') then
Res := Res * 16 + Ord(ch) - Ord('0')
else if (ch >= 'A') and (ch <= 'F') then
Res := Res * 16 + Ord(ch) - Ord('A') + 10
else if (ch >= 'a') and (ch <= 'f') then
Res := Res * 16 + Ord(ch) - Ord('a') + 10
else raise Exception.Create('Error: not a Hex String');
end;
Result := Res;
end;
var
Str, Temp: String;
I: Integer;
begin
Str := '';
for I := 0 to Length(StrHex) div 2 - 1 do
begin
Temp := Copy(StrHex, I * 2 + 1, 2);
Str := Str + Chr(HexToInt(Temp));
end;
Result := DecryStr(Str, Key);
end;
end.
