VB6.0简单编写DB5加密

写惯了VC代码，偶尔看看VB代码也是件好事，VB加密其实很多，这是其中一种，希望对你有所帮助。

1、新建一个窗体，创建一个文本框和命令按钮，加入下面代码：Option ExplicitPrivate Sub Command1_Click()Dim c1 As New Class1MsgBox c1.DigestStrToHexStr(Text1.Text)End Sub2、添加一个类模块，加入下面代码：Option ExplicitPrivate Const OFFSET_4 = 4294967296#Private Const MAXINT_4 = 2147483647Private Const S11 = 7Private Const S12 = 12Private Const S13 = 17Private Const S14 = 22Private Const S21 = 5Private Const S22 = 9Private Const S23 = 14Private Const S24 = 20Private Const S31 = 4Private Const S32 = 11Private Const S33 = 16Private Const S34 = 23Private Const S41 = 6Private Const S42 = 10Private Const S43 = 15Private Const S44 = 21'='= Class Variables'=Private State(4) As LongPrivate ByteCounter As LongPrivate ByteBuffer(63) As Byte'='= Class Properties'=Property Get RegisterA() As String RegisterA = State(1)End PropertyProperty Get RegisterB() As String RegisterB = State(2)End PropertyProperty Get RegisterC() As String RegisterC = State(3)End PropertyProperty Get RegisterD() As String RegisterD = State(4)End Property'='= Class Functions'='' Function to quickly digest a file into a hex string'Public Function DigestFileToHexStr(FileName As String) As String Open FileName For Binary Access Read As #1 MD5Init Do While Not EOF(1) Get #1,ByteBuffer If Loc(1) < LOF(1) Then ByteCounter = ByteCounter + 64 MD5Transform ByteBuffer End If Loop ByteCounter = ByteCounter + (LOF(1) Mod 64) Close #1 MD5Final DigestFileToHexStr = GetValuesEnd Function'' Function to digest a text string and output the result as a string' of hexadecimal characters.'Public Function DigestStrToHexStr(SourceString As String) As String MD5Init MD5Update Len(SourceString),StringToArray(SourceString) MD5Final DigestStrToHexStr = GetValuesEnd Function'' A utility function which converts a string into an array of' bytes.'Private Function StringToArray(InString As String) As Byte() Dim I As Integer Dim bytBuffer() As Byte ReDim bytBuffer(Len(InString)) For I = 0 To Len(InString) - 1 bytBuffer(I) = Asc(Mid(InString,I + 1,1)) Next I StringToArray = bytBufferEnd Function'' Concatenate the four state vaules into one string'Public Function GetValues() As String GetValues = LongToString(State(1)) & LongToString(State(2)) & LongToString(State(3)) & LongToString(State(4))End Function'' Convert a Long to a Hex string'Private Function LongToString(Num As Long) As String Dim a As Byte Dim b As Byte Dim c As Byte Dim d As Byte a = Num And &HFF& If a < 16 Then LongToString = "0" & Hex(a) Else LongToString = Hex(a) End If b = (Num And &HFF00&) / 256 If b < 16 Then LongToString = LongToString & "0" & Hex(b) Else LongToString = LongToString & Hex(b) End If c = (Num And &HFF0000) / 65536 If c < 16 Then LongToString = LongToString & "0" & Hex(c) Else LongToString = LongToString & Hex(c) End If If Num < 0 Then d = ((Num And &H7F000000) / 16777216) Or &H80& Else d = (Num And &HFF000000) / 16777216 End If If d < 16 Then LongToString = LongToString & "0" & Hex(d) Else LongToString = LongToString & Hex(d) End If End Function'' Initialize the class' This must be called before a digest calculation is started'Public Sub MD5Init() ByteCounter = 0 State(1) = UnsignedToLong(1732584193#) State(2) = UnsignedToLong(4023233417#) State(3) = UnsignedToLong(2562383102#) State(4) = UnsignedToLong(271733878#)End Sub'' MD5 Final'Public Sub MD5Final() Dim dblBits As Double Dim padding(72) As Byte Dim lngBytesBuffered As Long padding(0) = &H80 dblBits = ByteCounter * 8 ' Pad out lngBytesBuffered = ByteCounter Mod 64 If lngBytesBuffered <= 56 Then MD5Update 56 - lngBytesBuffered,padding Else MD5Update 120 - ByteCounter,padding End If padding(0) = UnsignedToLong(dblBits) And &HFF& padding(1) = UnsignedToLong(dblBits) / 256 And &HFF& padding(2) = UnsignedToLong(dblBits) / 65536 And &HFF& padding(3) = UnsignedToLong(dblBits) / 16777216 And &HFF& padding(4) = 0 padding(5) = 0 padding(6) = 0 padding(7) = 0 MD5Update 8,paddingEnd Sub'' Break up input stream into 64 byte chunks'Public Sub MD5Update(InputLen As Long,InputBuffer() As Byte) Dim II As Integer Dim I As Integer Dim J As Integer Dim K As Integer Dim lngBufferedBytes As Long Dim lngBufferRemaining As Long Dim lngRem As Long lngBufferedBytes = ByteCounter Mod 64 lngBufferRemaining = 64 - lngBufferedBytes ByteCounter = ByteCounter + InputLen ' Use up old buffer results first If InputLen >= lngBufferRemaining Then For II = 0 To lngBufferRemaining - 1 ByteBuffer(lngBufferedBytes + II) = InputBuffer(II) Next II MD5Transform ByteBuffer lngRem = (InputLen) Mod 64 ' The transfer is a multiple of 64 lets do some transformations For I = lngBufferRemaining To InputLen - II - lngRem Step 64 For J = 0 To 63 ByteBuffer(J) = InputBuffer(I + J) Next J MD5Transform ByteBuffer Next I lngBufferedBytes = 0 Else I = 0 End If ' Buffer any remaining input For K = 0 To InputLen - I - 1 ByteBuffer(lngBufferedBytes + K) = InputBuffer(I + K) Next K End Sub'' MD5 Transform'Private Sub MD5Transform(Buffer() As Byte) Dim x(16) As Long Dim a As Long Dim b As Long Dim c As Long Dim d As Long a = State(1) b = State(2) c = State(3) d = State(4) Decode 64,x,Buffer ' Round 1 FF a,b,c,d,x(0),S11,-680876936 FF d,a,x(1),S12,-389564586 FF c,x(2),S13,606105819 FF b,x(3),S14,-1044525330 FF a,x(4),-176418897 FF d,x(5),1200080426 FF c,x(6),-1473231341 FF b,x(7),-45705983 FF a,x(8),1770035416 FF d,x(9),-1958414417 FF c,x(10),-42063 FF b,x(11),-1990404162 FF a,x(12),1804603682 FF d,x(13),-40341101 FF c,x(14),-1502002290 FF b,x(15),1236535329 ' Round 2 GG a,S21,-165796510 GG d,S22,-1069501632 GG c,S23,643717713 GG b,S24,-373897302 GG a,-701558691 GG d,38016083 GG c,-660478335 GG b,-405537848 GG a,568446438 GG d,-1019803690 GG c,-187363961 GG b,1163531501 GG a,-1444681467 GG d,-51403784 GG c,1735328473 GG b,-1926607734 ' Round 3 HH a,S31,-378558 HH d,S32,-2022574463 HH c,S33,1839030562 HH b,S34,-35309556 HH a,-1530992060 HH d,1272893353 HH c,-155497632 HH b,-1094730640 HH a,681279174 HH d,-358537222 HH c,-722521979 HH b,76029189 HH a,-640364487 HH d,-421815835 HH c,530742520 HH b,-995338651 ' Round 4 II a,S41,-198630844 II d,S42,1126891415 II c,S43,-1416354905 II b,S44,-57434055 II a,1700485571 II d,-1894986606 II c,-1051523 II b,-2054922799 II a,1873313359 II d,-30611744 II c,-1560198380 II b,1309151649 II a,-145523070 II d,-1120210379 II c,718787259 II b,-343485551 State(1) = LongOverflowAdd(State(1),a) State(2) = LongOverflowAdd(State(2),b) State(3) = LongOverflowAdd(State(3),c) State(4) = LongOverflowAdd(State(4),d)' /* Zeroize sensitive information.'*/' MD5_memset ((POINTER)x,sizeof (x)); End SubPrivate Sub Decode(Length As Integer,OutputBuffer() As Long,InputBuffer() As Byte) Dim intDblIndex As Integer Dim intByteIndex As Integer Dim dblSum As Double intDblIndex = 0 For intByteIndex = 0 To Length - 1 Step 4 dblSum = InputBuffer(intByteIndex) + _ InputBuffer(intByteIndex + 1) * 256# + _ InputBuffer(intByteIndex + 2) * 65536# + _ InputBuffer(intByteIndex + 3) * 16777216# OutputBuffer(intDblIndex) = UnsignedToLong(dblSum) intDblIndex = intDblIndex + 1 Next intByteIndexEnd Sub'' FF,GG,HH,and II transformations for rounds 1,2,3,and 4.' Rotation is separate from addition to prevent recomputation.'Private Function FF(a As Long,_ b As Long,_ c As Long,_ d As Long,_ x As Long,_ s As Long,_ ac As Long) As Long a = LongOverflowAdd4(a,(b And c) Or (Not (b) And d),ac) a = LongLeftRotate(a,s) a = LongOverflowAdd(a,b)End FunctionPrivate Function GG(a As Long,(b And d) Or (c And Not (d)),b)End FunctionPrivate Function HH(a As Long,b Xor c Xor d,b)End FunctionPrivate Function II(a As Long,c Xor (b Or Not (d)),b)End Function'' Rotate a long to the right'Function LongLeftRotate(value As Long,bits As Long) As Long Dim lngSign As Long Dim lngI As Long bits = bits Mod 32 If bits = 0 Then LongLeftRotate = value: Exit Function For lngI = 1 To bits lngSign = value And &HC0000000 value = (value And &H3FFFFFFF) * 2 value = value Or ((lngSign < 0) And 1) Or (CBool(lngSign And _ &H40000000) And &H80000000) Next LongLeftRotate = valueEnd Function'' Function to add two unsigned numbers together as in C.' Overflows are ignored!'Private Function LongOverflowAdd(Val1 As Long,Val2 As Long) As Long Dim lngHighWord As Long Dim lngLowWord As Long Dim lngOverflow As Long lngLowWord = (Val1 And &HFFFF&) + (Val2 And &HFFFF&) lngOverflow = lngLowWord / 65536 lngHighWord = (((Val1 And &HFFFF0000) / 65536) + ((Val2 And &HFFFF0000) / 65536) + lngOverflow) And &HFFFF& LongOverflowAdd = UnsignedToLong((lngHighWord * 65536#) + (lngLowWord And &HFFFF&))End Function'' Function to add two unsigned numbers together as in C.' Overflows are ignored!'Private Function LongOverflowAdd4(Val1 As Long,Val2 As Long,val3 As Long,val4 As Long) As Long Dim lngHighWord As Long Dim lngLowWord As Long Dim lngOverflow As Long lngLowWord = (Val1 And &HFFFF&) + (Val2 And &HFFFF&) + (val3 And &HFFFF&) + (val4 And &HFFFF&) lngOverflow = lngLowWord / 65536 lngHighWord = (((Val1 And &HFFFF0000) / 65536) + _ ((Val2 And &HFFFF0000) / 65536) + _ ((val3 And &HFFFF0000) / 65536) + _ ((val4 And &HFFFF0000) / 65536) + _ lngOverflow) And &HFFFF& LongOverflowAdd4 = UnsignedToLong((lngHighWord * 65536#) + (lngLowWord And &HFFFF&))End Function'' Convert an unsigned double into a long'Private Function UnsignedToLong(value As Double) As Long If value < 0 Or value >= OFFSET_4 Then Error 6 ' Overflow If value <= MAXINT_4 Then UnsignedToLong = value Else UnsignedToLong = value - OFFSET_4 End If End Function'' Convert a long to an unsigned Double'Private Function LongToUnsigned(value As Long) As Double If value < 0 Then LongToUnsigned = value + OFFSET_4 Else LongToUnsigned = value End IfEnd Function

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