软件加密系列问题2：加密算法(150分)

请教不可逆的，多层加密位算法。

http://www.efg2.com/Lab/Library/Delphi/MathFunctions/Cryptography.htm

DES，AES。
最新的AES资料可以从官方网站上获得。

MY GOD!
E文的网站，对不起，看不懂呀！
有中文的吗？谢谢！

外国人发明的算法当然是E文，而且比较新，中文资料很少。想看中文的先找本密码学的
书看看DES的基本原理，我感觉原理都差不多，只是加密的位数长短不太一样。
不过我也没有实践过，我同学下过AES的资料，光源程序就几十页，所以如果只是做一般系统，
找些加密控件就行了，如果是搞研究，就非要了解原理并实践。

同意jinmen的看法

加密控件？

unit WNDES;
interface
uses
Windows, Messages, ShlObj, WinSock, IniFiles, ActiveX, SysUtils,
Classes, Graphics, Controls, Forms, Dialogs;
type
TKeyByte = array[0..5] of Byte;
TDesMode = (dmEncry, dmDESry);
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);
//////////////////DES加密算法////////////////////////////
function EncryStr(Str, Key: string): string;
//加密
function EncryStrHex(Str, Key: string): string;
//以十六进制加密(有些时侯加密的密文含有特殊字符文本框不能显示、数据库文本字段也不能存储。以十六进制形式表示可保证绝对不会出现该种情况)
function DESryStr(Str, Key: string): string;
//解密
function DESryStrHex(StrHex, Key: string): string;
//解密十六进制加密的密文
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 63do
if (inData[BitIP shr 3] and (1 shl (7 - (BitIP and $07)))) <> 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7 - (i and $07)));
for i := 0 to 7do
inData := newData;
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 63do
if (inData[BitCP shr 3] and (1 shl (7 - (BitCP and $07)))) <> 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7 - (i and $07)));
for i := 0 to 7do
inData := newData;
end;

procedure expand(inData: array of Byte;
var outData: array of Byte);
var
i: Integer;
begin
FillChar(outData, 6, 0);
for i := 0 to 47do
if (inData[BitExp shr 3] and (1 shl (7 - (BitExp 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 31do
if (inData[BitPM shr 3] and (1 shl (7 - (BitPM and $07)))) <> 0 then
newData[i shr 3] := newData[i shr 3] or (1 shl (7 - (i and $07)));
for i := 0 to 3do
inData := newData;
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[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 55do
if (inData[BitPMC1 shr 3] and (1 shl (7 - (BitPMC1 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 47do
if (inData[BitPMC2 shr 3] and (1 shl (7 - (BitPMC2 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 - 1do
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 15do
begin
cycleMove(key28l, bitDisplace);
cycleMove(key28r, bitDisplace);
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);
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 5do
outBuf := outBuf xor subKey;
// 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 7do
buf := si(i, buf);
for i := 0 to 3do
outBuf := (buf[i * 2] shl 4) or buf[i * 2 + 1];
permutation(outBuf);
for i := 0 to 3do
outData := outBuf;
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 7do
outData := inData;
initPermutation(outData);
if desMode = dmEncry then
begin
for i := 0 to 15do
begin
for j := 0 to 3do
temp[j] := outData[j];
//temp = Ln
for j := 0 to 3do
outData[j] := outData[j + 4];
//Ln+1 = Rn
encry(outData, subKey, buf);
//Rn ==Kn==> buf
for j := 0 to 3do
outData[j + 4] := temp[j] xor buf[j];
//Rn+1 = Ln^buf
end;

for j := 0 to 3do
temp[j] := outData[j + 4];
for j := 0 to 3do
outData[j + 4] := outData[j];
for j := 0 to 3do
outData[j] := temp[j];
end
else
if desMode = dmDESry then
begin
for i := 15do
wnto 0do
begin
for j := 0 to 3do
temp[j] := outData[j];
for j := 0 to 3do
outData[j] := outData[j + 4];
encry(outData, subKey, buf);
for j := 0 to 3do
outData[j + 4] := temp[j] xor buf[j];
end;
for j := 0 to 3do
temp[j] := outData[j + 4];
for j := 0 to 3do
outData[j + 4] := outData[j];
for j := 0 to 3do
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) < 8do
Key := Key + Chr(0);
while Length(Str) mod 8 <> 0do
Str := Str + Chr(0);
for J := 0 to 7do
KeyByte[J] := Ord(Key[J + 1]);
makeKey(keyByte, subKey);
StrResult := '';
for I := 0 to Length(Str) div 8 - 1do
begin
for J := 0 to 7do
StrByte[J] := Ord(Str[I * 8 + J + 1]);
desData(dmEncry, StrByte, OutByte);
for J := 0 to 7do
StrResult := StrResult + Chr(OutByte[J]);
end;

Result := StrResult;
end;

function DESryStr(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) < 8do
Key := Key + Chr(0);
for J := 0 to 7do
KeyByte[J] := Ord(Key[J + 1]);
makeKey(keyByte, subKey);
StrResult := '';
for I := 0 to Length(Str) div 8 - 1do
begin
for J := 0 to 7do
StrByte[J] := Ord(Str[I * 8 + J + 1]);
desData(dmDESry, StrByte, OutByte);
for J := 0 to 7do
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) - 1do
begin
Temp := Format('%x', [Ord(TempResult[I + 1])]);
if Length(Temp) = 1 then
Temp := '0' + Temp;
StrResult := StrResult + Temp;
end;
Result := StrResult;
end;

function DESryStrHex(StrHex, Key: string): string;
function HexToInt(Hex: string): Integer;
var
I, Res: Integer;
ch: Char;
begin
Res := 0;
for I := 0 to Length(Hex) - 1do
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 - 1do
begin
Temp := Copy(StrHex, I * 2 + 1, 2);
Str := Str + Chr(HexToInt(Temp));
end;
Result := DESryStr(Str, Key);
end;

end.

多人接受答案了。