前两天学到对称密码DES算法，然后就自己亲手写了个实现程序出来，好多地方用得着呐。这里是用ASP实现，当然也就是可以移到VB啦。懂得怎样写后写成什么语言都行啦，只要懂得那门语言。如果有朋友想知道具体DES算法过程是怎样的，可以到网上查找。
（这两天又把它改进了一下，加密字符串并且使用十六进制，这样加密后的字符串会短些~~~ —— 2007年5月2日）
<%
Class Cls_DES
Private IPRule, CPRule, EPRule, PRule, SBox(7), PCRule(1), MvRule
Private K(16), L(16), R(16)
Private FillCode, DesStatus
Private Sub Class_Initialize()
DesStatus = -1
FillCode = "0001101"
IPRule = "58,50,42,34,26,18,10,2," &_
"60,52,44,36,28,20,12,4," &_
"62,54,46,38,30,22,14,6," &_
"64,56,48,40,32,24,16,8," &_
"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,"
CPRule = "40, 8,48,16,56,24,64,32," &_
"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,"
EPRule = "32, 1, 2, 3, 4, 5," &_
" 4, 5, 6, 7, 8, 9," &_
" 8, 9,10,11,12,13," &_
"12,13,14,15,16,17," &_
"16,17,18,19,20,21," &_
"20,21,22,23,24,25," &_
"24,25,26,27,28,29," &_
"28,29,30,31,32, 1,"
PRule = "16, 7,20,21,29,12,28,17," &_
" 1,15,23,26, 5,18,31,10," &_
" 2, 8,24,14,32,27, 3, 9," &_
"19,13,30, 6,22,11, 4,25,"
SBox(0) = "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,"
SBox(1) = "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,"
SBox(2) = "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,"
SBox(3) = " 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,"
SBox(4) = " 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,"
SBox(5) = "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,"
SBox(6) = " 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,"
SBox(7) = "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,"
PCRule(0) = "57,49,41,33,25,17, 9," &_
" 1,58,50,42,34,26,18," &_
"10, 2,59,51,43,35,27," &_
"19,11, 3,60,52,44,36," &_
"63,55,47,39,31,23,15," &_
" 7,62,54,46,38,30,22," &_
"14, 6,61,53,45,37,29," &_
"21,13, 5,28,20,12, 4,"
PCRule(1) = "14,17,11,24, 1, 5, 3,28," &_
"15, 6,21,10,23,19,12, 4," &_
"26, 8,16, 7,27,20,13, 2," &_
"41,52,31,37,47,55,30,40," &_
"51,45,33,48,44,49,39,56," &_
"34,53,46,42,50,36,29,32,"
MvRule = "1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1"
End Sub
Private Function Permute(ByVal Rule, ByVal Text)
Dim P_Rule, Num, PText
PText = ""
P_Rule = Split(Rule, ",")
For Each Num In P_Rule
Num = Trim(Num) & ""
If Num <> "" Then
Num = CLng(Num)
PText = PText & Mid(Text, Num, 1)
End If
Next
Erase P_Rule
Permute = PText
End Function
Private Function CreateKey()
Dim IPKey, C(16), D(16), i, Mv_Rule, MvLen
IPKey = Permute(PCRule(0), K(0))
C(0) = Left(IPKey, 28)
D(0) = Right(IPKey, 28)
Mv_Rule = Split(MvRule, ",")
For i = 1 To 16
MvLen = CLng(Trim(Mv_Rule(i - 1)))
C(i) = Right(C(i -1), Len(C(i -1)) - MvLen) & Left(C(i -1), MvLen)
D(i) = Right(D(i -1), Len(D(i -1)) - MvLen) & Left(D(i -1), MvLen)
K(i) = Permute(PCRule(1), C(i) & D(i))
Next
End Function
Private Function IP(ByVal Text)
Dim IPText
IPText = Permute(IPRule, Text)
L(0) = Left(IPText, 32)
R(0) = Right(IPText, 32)
IP = IPText
End Function
Private Function IterativeLR()
Dim i
For i = 1 To 16
L(i) = R(i - 1)
R(i) = B_XOR(L(i - 1), F(R(i - 1), K(i)))
Next
End Function
Private Function F(ByVal RText, ByVal Keys)
Dim EPText, XORText, Result, SKey(7), i, x, y
Result = ""
EPText = Permute(EPRule, RText)
XORText = B_XOR(EPText, Keys)
For i = 1 To Len(XORText) \ 6
SKey(i - 1) = Mid(XORText, (i - 1) * 6 + 1, 6)
x = BinaryToDecimal(Left(SKey(i - 1), 1) & Right(SKey(i - 1), 1))
y = BinaryToDecimal(Mid(SKey(i - 1), 2, 4))
SKey(i - 1) = DecimalToBinary(Trim(Split(SBox(i -1), ",")(x * 16 + y)))
If Len(SKey(i - 1)) < 4 Then
Select Case (4 - Len(SKey(i - 1)))
Case 1
SKey(i - 1) = "0" & SKey(i - 1)
Case 2
SKey(i - 1) = "00" & SKey(i - 1)
Case 3
SKey(i - 1) = "000" & SKey(i - 1)
End Select
End If
Result = Result & SKey(i - 1)
Next
Result = Permute(PRule, Result)
F = Result
End Function
Private Function B_XOR(ByVal Expression1, ByVal Expression2)
Dim E, K, i, XORText
XORText = ""
E = Trim(Expression1) & ""
K = Trim(Expression2) & ""
For i = 1 To Len(K)
XORText = XORText & CStr(CInt(Mid(E, i, 1)) Xor CInt(Mid(K, i, 1)))
Next
B_XOR = XORText
End Function
Private Function BinaryToDecimal(ByVal binNum)
Dim Binary, Decimal, i, Length
Decimal = 0
Binary = Trim(binNum) & ""
If Binary <> "" Then
While Left(Binary, 1) = "0"
Binary = Right(Binary, Len(Binary) - 1)
Wend
Length = Len(Binary)
For i = 1 To Length
Decimal = Decimal + CInt(Mid(Binary, i, 1)) * 2^(Length - i)
Next
End If
BinaryToDecimal = Decimal
End Function
Private Function DecimalToBinary(ByVal decNum)
Dim Decimal, Binary, division
Binary = ""
Decimal = Trim(decNum) & ""
If Decimal <> "" Then
Decimal = CLng(Decimal)
While Decimal > 1
Binary = Binary & CStr(Decimal Mod 2)
Decimal = Decimal \ 2
Wend
Binary = StrReverse(Binary & Decimal)
End If
DecimalToBinary = Binary
End Function
Private Function StrToBinary(ByVal Str)
Dim Data, Binary, Text, TextLen, i
Text = ""
Data = Str
For i = 1 To Len(Data)
Binary = CStr(DecimalToBinary(Asc(Mid(Data, i, 1))))
If Len(Binary) < 7 Then
Select Case (7 - Len(Binary))
Case 1
Binary = "0" & Binary
Case 2
Binary = "00" & Binary
Case 3
Binary = "000" & Binary
Case 4
Binary = "0000" & Binary
Case 5
Binary = "00000" & Binary
Case 6
Binary = "000000" & Binary
End Select
End If
Text = Text & Binary
Next
TextLen = Len(Text)
If TextLen >= 63 Then
If (TextLen Mod 63) <> 0 Then
For i = 1 To ((TextLen - TextLen Mod 63) \ 7)
Text = Text & FillCode
Next
End If
Else
For i = 1 To ((63 - TextLen) \ 7)
Text = Text & FillCode
Next
End If
Binary = Text
Text = ""
For i = 0 To (Len(Binary) \ 63 - 1)
Text = Text & Mid(Binary, i * 63 + 1, 63) & "0"
Next
StrToBinary = Text
End Function
Private Function BinaryToStr(ByVal binNum)
Dim Text, binText, Length, Group, i, j
Text = ""
binText = Trim(binNum) & ""
If binText <> "" Then
Length = Len(binText) \ 64 - 1
ReDim Group(Length)
For i = 0 To Length
Group(i) = Left(Mid(binText, i * 64 + 1, 64), 63)
Next
While Right(Group(Length), 7) = FillCode
Group(Length) = Left(Group(Length), Len(Group(Length)) - 7)
Wend
For i = 0 To Length
For j = 1 To Len(Group(i)) \ 7
Text = Text & Chr(BinaryToDecimal(Mid(Group(i), (j - 1) * 7 + 1, 7)))
Next
Next
Erase Group
End If
BinaryToStr = Text
End Function
Private Function BinaryToHex(ByVal binNum)
Dim binText, Text, Length, FillLen, Temp, i
Text = ""
binText = Trim(binNum) & ""
If binText <> "" Then
Length = Len(binText)
If Length >= 4 Then
FillLen = Length Mod 4
Else
FillLen = 4 - Length
End If
Select Case FillLen
Case 1
binText = "0" & binText
Case 2
binText = "00" & binText
Case 3
binText = "000" & binText
End Select
For i = 0 To (Len(binText) \ 4 - 1)
Temp = Mid(binText, i * 4 + 1, 4)
Select Case Temp
Case "0000"
Text = Text & "0"
Case "0001"
Text = Text & "1"
Case "0010"
Text = Text & "2"
Case "0011"
Text = Text & "3"
Case "0100"
Text = Text & "4"
Case "0101"
Text = Text & "5"
Case "0110"
Text = Text & "6"
Case "0111"
Text = Text & "7"
Case "1000"
Text = Text & "8"
Case "1001"
Text = Text & "9"
Case "1010"
Text = Text & "A"
Case "1011"
Text = Text & "B"
Case "1100"
Text = Text & "C"
Case "1101"
Text = Text & "D"
Case "1110"
Text = Text & "E"
Case "1111"
Text = Text & "F"
End Select
Next
End If
BinaryToHex = Text
End Function
Private Function HexToBinary(ByVal hexNum)
Dim hexText, Text, Temp, i
Text = ""
hexText = Trim(hexNum) & ""
For i = 1 To Len(hexText)
Temp = UCase(Mid(hexText, i, 1))
Select Case Temp
Case "0"
Text = Text & "0000"
Case "1"
Text = Text & "0001"
Case "2"
Text = Text & "0010"
Case "3"
Text = Text & "0011"
Case "4"
Text = Text & "0100"
Case "5"
Text = Text & "0101"
Case "6"
Text = Text & "0110"
Case "7"
Text = Text & "0111"
Case "8"
Text = Text & "1000"
Case "9"
Text = Text & "1001"
Case "A"
Text = Text & "1010"
Case "B"
Text = Text & "1011"
Case "C"
Text = Text & "1100"
Case "D"
Text = Text & "1101"
Case "E"
Text = Text & "1110"
Case "F"
Text = Text & "1111"
End Select
Next
HexToBinary = Text
End Function
Private Function KeyReverse()
Dim Temp, i
For i = 1 To 8
Temp = K(i)
K(i) = K(16 - i + 1)
K(16 - i + 1) = Temp
Next
End Function
Public Function DES(ByVal Data, ByVal Keys, ByVal Work)
Dim Text, i, Group, GroupLen
Text = Data
K(0) = HexToBinary(Keys)
If Work = 0 Then
Text = StrToBinary(Text)
Else
Text = HexToBinary(Text)
End If
GroupLen = Len(Text) \ 64 - 1
ReDim Group(GroupLen)
For i = 0 To GroupLen
Group(i) = Mid(Text, i * 64 + 1, 64)
Next
Text = ""
CreateKey()
For i = 0 To GroupLen
IP(Group(i))
If Work <> 0 And DesStatus <> 1 Then
KeyReverse()
DesStatus = 1
ElseIf Work = 0 And DesStatus = 1 Then
KeyReverse()
DesStatus = 0
End If
IterativeLR()
Text = Text & Permute(CPRule, R(16) & L(16))
Next
Erase Group
If Work = 0 Then
Text = BinaryToHex(Text)
Else
Text = BinaryToStr(Text)
End If
DES = Text
End Function
End Class
%>
使用说明：
本程序只对ASCII码在000—127范围的字符加密，如果不是这个范围的，加密会出错或者不正确。即在正常在键盘上输入的字符都可以加密（非中文）。因为程序中我使用了ASCII码为013的字符（回车符）作为分组填充字符，所以要加密的字符串记得末尾不能有回车符（回车符和换行符是不同的字符）。
密钥和加密后的字符串都用十六进制数，需要加密的字符串就是原明文字符串。密钥是14位十六进制数（0—9,A,B,C,D,E,F）。下面是加密解密例子：
加密：
key = "F7F741E99D0137"
data = "Qiuyi Studio,OK!"
Set DesCrypt = New Cls_DES
Response.Write(DesCrypt.DES(data,key,0))
Set DesCrypt = Nothing
结果：9E9E1DC1CF117A936DCA399A26C47946
解密：
key = "F7F741E99D0137"
data = "9E9E1DC1CF117A936DCA399A26C47946"
Set DesCrypt = New Cls_DES
Response.Write(DesCrypt.DES(data,key,1))
Set DesCrypt = Nothing
结果：Qiuyi Studio,OK!
（2007-4-29）
（这两天又把它改进了一下，加密字符串并且使用十六进制，这样加密后的字符串会短些~~~ —— 2007年5月2日）
<%
Class Cls_DES
Private IPRule, CPRule, EPRule, PRule, SBox(7), PCRule(1), MvRule
Private K(16), L(16), R(16)
Private FillCode, DesStatus
Private Sub Class_Initialize()
DesStatus = -1
FillCode = "0001101"
IPRule = "58,50,42,34,26,18,10,2," &_
"60,52,44,36,28,20,12,4," &_
"62,54,46,38,30,22,14,6," &_
"64,56,48,40,32,24,16,8," &_
"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,"
CPRule = "40, 8,48,16,56,24,64,32," &_
"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,"
EPRule = "32, 1, 2, 3, 4, 5," &_
" 4, 5, 6, 7, 8, 9," &_
" 8, 9,10,11,12,13," &_
"12,13,14,15,16,17," &_
"16,17,18,19,20,21," &_
"20,21,22,23,24,25," &_
"24,25,26,27,28,29," &_
"28,29,30,31,32, 1,"
PRule = "16, 7,20,21,29,12,28,17," &_
" 1,15,23,26, 5,18,31,10," &_
" 2, 8,24,14,32,27, 3, 9," &_
"19,13,30, 6,22,11, 4,25,"
SBox(0) = "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,"
SBox(1) = "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,"
SBox(2) = "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,"
SBox(3) = " 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,"
SBox(4) = " 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,"
SBox(5) = "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,"
SBox(6) = " 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,"
SBox(7) = "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,"
PCRule(0) = "57,49,41,33,25,17, 9," &_
" 1,58,50,42,34,26,18," &_
"10, 2,59,51,43,35,27," &_
"19,11, 3,60,52,44,36," &_
"63,55,47,39,31,23,15," &_
" 7,62,54,46,38,30,22," &_
"14, 6,61,53,45,37,29," &_
"21,13, 5,28,20,12, 4,"
PCRule(1) = "14,17,11,24, 1, 5, 3,28," &_
"15, 6,21,10,23,19,12, 4," &_
"26, 8,16, 7,27,20,13, 2," &_
"41,52,31,37,47,55,30,40," &_
"51,45,33,48,44,49,39,56," &_
"34,53,46,42,50,36,29,32,"
MvRule = "1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1"
End Sub
Private Function Permute(ByVal Rule, ByVal Text)
Dim P_Rule, Num, PText
PText = ""
P_Rule = Split(Rule, ",")
For Each Num In P_Rule
Num = Trim(Num) & ""
If Num <> "" Then
Num = CLng(Num)
PText = PText & Mid(Text, Num, 1)
End If
Next
Erase P_Rule
Permute = PText
End Function
Private Function CreateKey()
Dim IPKey, C(16), D(16), i, Mv_Rule, MvLen
IPKey = Permute(PCRule(0), K(0))
C(0) = Left(IPKey, 28)
D(0) = Right(IPKey, 28)
Mv_Rule = Split(MvRule, ",")
For i = 1 To 16
MvLen = CLng(Trim(Mv_Rule(i - 1)))
C(i) = Right(C(i -1), Len(C(i -1)) - MvLen) & Left(C(i -1), MvLen)
D(i) = Right(D(i -1), Len(D(i -1)) - MvLen) & Left(D(i -1), MvLen)
K(i) = Permute(PCRule(1), C(i) & D(i))
Next
End Function
Private Function IP(ByVal Text)
Dim IPText
IPText = Permute(IPRule, Text)
L(0) = Left(IPText, 32)
R(0) = Right(IPText, 32)
IP = IPText
End Function
Private Function IterativeLR()
Dim i
For i = 1 To 16
L(i) = R(i - 1)
R(i) = B_XOR(L(i - 1), F(R(i - 1), K(i)))
Next
End Function
Private Function F(ByVal RText, ByVal Keys)
Dim EPText, XORText, Result, SKey(7), i, x, y
Result = ""
EPText = Permute(EPRule, RText)
XORText = B_XOR(EPText, Keys)
For i = 1 To Len(XORText) \ 6
SKey(i - 1) = Mid(XORText, (i - 1) * 6 + 1, 6)
x = BinaryToDecimal(Left(SKey(i - 1), 1) & Right(SKey(i - 1), 1))
y = BinaryToDecimal(Mid(SKey(i - 1), 2, 4))
SKey(i - 1) = DecimalToBinary(Trim(Split(SBox(i -1), ",")(x * 16 + y)))
If Len(SKey(i - 1)) < 4 Then
Select Case (4 - Len(SKey(i - 1)))
Case 1
SKey(i - 1) = "0" & SKey(i - 1)
Case 2
SKey(i - 1) = "00" & SKey(i - 1)
Case 3
SKey(i - 1) = "000" & SKey(i - 1)
End Select
End If
Result = Result & SKey(i - 1)
Next
Result = Permute(PRule, Result)
F = Result
End Function
Private Function B_XOR(ByVal Expression1, ByVal Expression2)
Dim E, K, i, XORText
XORText = ""
E = Trim(Expression1) & ""
K = Trim(Expression2) & ""
For i = 1 To Len(K)
XORText = XORText & CStr(CInt(Mid(E, i, 1)) Xor CInt(Mid(K, i, 1)))
Next
B_XOR = XORText
End Function
Private Function BinaryToDecimal(ByVal binNum)
Dim Binary, Decimal, i, Length
Decimal = 0
Binary = Trim(binNum) & ""
If Binary <> "" Then
While Left(Binary, 1) = "0"
Binary = Right(Binary, Len(Binary) - 1)
Wend
Length = Len(Binary)
For i = 1 To Length
Decimal = Decimal + CInt(Mid(Binary, i, 1)) * 2^(Length - i)
Next
End If
BinaryToDecimal = Decimal
End Function
Private Function DecimalToBinary(ByVal decNum)
Dim Decimal, Binary, division
Binary = ""
Decimal = Trim(decNum) & ""
If Decimal <> "" Then
Decimal = CLng(Decimal)
While Decimal > 1
Binary = Binary & CStr(Decimal Mod 2)
Decimal = Decimal \ 2
Wend
Binary = StrReverse(Binary & Decimal)
End If
DecimalToBinary = Binary
End Function
Private Function StrToBinary(ByVal Str)
Dim Data, Binary, Text, TextLen, i
Text = ""
Data = Str
For i = 1 To Len(Data)
Binary = CStr(DecimalToBinary(Asc(Mid(Data, i, 1))))
If Len(Binary) < 7 Then
Select Case (7 - Len(Binary))
Case 1
Binary = "0" & Binary
Case 2
Binary = "00" & Binary
Case 3
Binary = "000" & Binary
Case 4
Binary = "0000" & Binary
Case 5
Binary = "00000" & Binary
Case 6
Binary = "000000" & Binary
End Select
End If
Text = Text & Binary
Next
TextLen = Len(Text)
If TextLen >= 63 Then
If (TextLen Mod 63) <> 0 Then
For i = 1 To ((TextLen - TextLen Mod 63) \ 7)
Text = Text & FillCode
Next
End If
Else
For i = 1 To ((63 - TextLen) \ 7)
Text = Text & FillCode
Next
End If
Binary = Text
Text = ""
For i = 0 To (Len(Binary) \ 63 - 1)
Text = Text & Mid(Binary, i * 63 + 1, 63) & "0"
Next
StrToBinary = Text
End Function
Private Function BinaryToStr(ByVal binNum)
Dim Text, binText, Length, Group, i, j
Text = ""
binText = Trim(binNum) & ""
If binText <> "" Then
Length = Len(binText) \ 64 - 1
ReDim Group(Length)
For i = 0 To Length
Group(i) = Left(Mid(binText, i * 64 + 1, 64), 63)
Next
While Right(Group(Length), 7) = FillCode
Group(Length) = Left(Group(Length), Len(Group(Length)) - 7)
Wend
For i = 0 To Length
For j = 1 To Len(Group(i)) \ 7
Text = Text & Chr(BinaryToDecimal(Mid(Group(i), (j - 1) * 7 + 1, 7)))
Next
Next
Erase Group
End If
BinaryToStr = Text
End Function
Private Function BinaryToHex(ByVal binNum)
Dim binText, Text, Length, FillLen, Temp, i
Text = ""
binText = Trim(binNum) & ""
If binText <> "" Then
Length = Len(binText)
If Length >= 4 Then
FillLen = Length Mod 4
Else
FillLen = 4 - Length
End If
Select Case FillLen
Case 1
binText = "0" & binText
Case 2
binText = "00" & binText
Case 3
binText = "000" & binText
End Select
For i = 0 To (Len(binText) \ 4 - 1)
Temp = Mid(binText, i * 4 + 1, 4)
Select Case Temp
Case "0000"
Text = Text & "0"
Case "0001"
Text = Text & "1"
Case "0010"
Text = Text & "2"
Case "0011"
Text = Text & "3"
Case "0100"
Text = Text & "4"
Case "0101"
Text = Text & "5"
Case "0110"
Text = Text & "6"
Case "0111"
Text = Text & "7"
Case "1000"
Text = Text & "8"
Case "1001"
Text = Text & "9"
Case "1010"
Text = Text & "A"
Case "1011"
Text = Text & "B"
Case "1100"
Text = Text & "C"
Case "1101"
Text = Text & "D"
Case "1110"
Text = Text & "E"
Case "1111"
Text = Text & "F"
End Select
Next
End If
BinaryToHex = Text
End Function
Private Function HexToBinary(ByVal hexNum)
Dim hexText, Text, Temp, i
Text = ""
hexText = Trim(hexNum) & ""
For i = 1 To Len(hexText)
Temp = UCase(Mid(hexText, i, 1))
Select Case Temp
Case "0"
Text = Text & "0000"
Case "1"
Text = Text & "0001"
Case "2"
Text = Text & "0010"
Case "3"
Text = Text & "0011"
Case "4"
Text = Text & "0100"
Case "5"
Text = Text & "0101"
Case "6"
Text = Text & "0110"
Case "7"
Text = Text & "0111"
Case "8"
Text = Text & "1000"
Case "9"
Text = Text & "1001"
Case "A"
Text = Text & "1010"
Case "B"
Text = Text & "1011"
Case "C"
Text = Text & "1100"
Case "D"
Text = Text & "1101"
Case "E"
Text = Text & "1110"
Case "F"
Text = Text & "1111"
End Select
Next
HexToBinary = Text
End Function
Private Function KeyReverse()
Dim Temp, i
For i = 1 To 8
Temp = K(i)
K(i) = K(16 - i + 1)
K(16 - i + 1) = Temp
Next
End Function
Public Function DES(ByVal Data, ByVal Keys, ByVal Work)
Dim Text, i, Group, GroupLen
Text = Data
K(0) = HexToBinary(Keys)
If Work = 0 Then
Text = StrToBinary(Text)
Else
Text = HexToBinary(Text)
End If
GroupLen = Len(Text) \ 64 - 1
ReDim Group(GroupLen)
For i = 0 To GroupLen
Group(i) = Mid(Text, i * 64 + 1, 64)
Next
Text = ""
CreateKey()
For i = 0 To GroupLen
IP(Group(i))
If Work <> 0 And DesStatus <> 1 Then
KeyReverse()
DesStatus = 1
ElseIf Work = 0 And DesStatus = 1 Then
KeyReverse()
DesStatus = 0
End If
IterativeLR()
Text = Text & Permute(CPRule, R(16) & L(16))
Next
Erase Group
If Work = 0 Then
Text = BinaryToHex(Text)
Else
Text = BinaryToStr(Text)
End If
DES = Text
End Function
End Class
%>
使用说明：
本程序只对ASCII码在000—127范围的字符加密，如果不是这个范围的，加密会出错或者不正确。即在正常在键盘上输入的字符都可以加密（非中文）。因为程序中我使用了ASCII码为013的字符（回车符）作为分组填充字符，所以要加密的字符串记得末尾不能有回车符（回车符和换行符是不同的字符）。
密钥和加密后的字符串都用十六进制数，需要加密的字符串就是原明文字符串。密钥是14位十六进制数（0—9,A,B,C,D,E,F）。下面是加密解密例子：
加密：
key = "F7F741E99D0137"
data = "Qiuyi Studio,OK!"
Set DesCrypt = New Cls_DES
Response.Write(DesCrypt.DES(data,key,0))
Set DesCrypt = Nothing
结果：9E9E1DC1CF117A936DCA399A26C47946
解密：
key = "F7F741E99D0137"
data = "9E9E1DC1CF117A936DCA399A26C47946"
Set DesCrypt = New Cls_DES
Response.Write(DesCrypt.DES(data,key,1))
Set DesCrypt = Nothing
结果：Qiuyi Studio,OK!
（2007-4-29）
