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Шифрование паролей

Ранее упоминалась достаточно глобальная проблема шифрования и ее самое разумное решение — md5. И был предложен алгоритм для шифровки данным алгоритмом на языке PHP. Сегодня мы поговорим о реализации этого на Visual Basic.

Шифрование паролей MD5 реализует следующий код:

Option Explicit
Private Const OFFSET_4 = 4294967296#
Private Const MAXINT_4 = 2147483647
Private Const S11 = 7
Private Const S12 = 12
Private Const S13 = 17
Private Const S14 = 22
Private Const S21 = 5
Private Const S22 = 9
Private Const S23 = 14
Private Const S24 = 20
Private Const S31 = 4
Private Const S32 = 11
Private Const S33 = 16
Private Const S34 = 23
Private Const S41 = 6
Private Const S42 = 10
Private Const S43 = 15
Private Const S44 = 21
Private State(4) As Long
Private ByteCounter As Long
Private ByteBuffer(63) As Byte
Property Get RegisterA() As String
RegisterA = State(1)
End Property
Property Get RegisterB() As String
RegisterB = State(2)
End Property
Property Get RegisterC() As String
RegisterC = State(3)
End Property
Property Get RegisterD() As String
RegisterD = State(4)
End Property
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 = GetValues
End Function
Public Function DigestStrToHexStr(SourceString As String) As String
MD5Init
MD5Update Len(SourceString), StringToArray(SourceString)
MD5Final
DigestStrToHexStr = GetValues
End Function
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 = bytBuffer
End Function
Public Function GetValues() As String
GetValues = LongToString(State(1)) & LongToString(State(2)) & LongToString(State(3)) & LongToString(State(4))
End Function
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
Public Sub MD5Init()
ByteCounter = 0
State(1) = UnsignedToLong(1732584193#)
State(2) = UnsignedToLong(4023233417#)
State(3) = UnsignedToLong(2562383102#)
State(4) = UnsignedToLong(271733878#)
End Sub
Public Sub MD5Final()
Dim dblBits As Double
Dim padding(72) As Byte
Dim lngBytesBuffered As Long
padding(0) = &H80
dblBits = ByteCounter * 8
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, padding
End Sub
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
If InputLen >= lngBufferRemaining Then
For II = 0 To lngBufferRemaining - 1
ByteBuffer(lngBufferedBytes + II) = InputBuffer(II)
Next II
MD5Transform ByteBuffer

lngRem = (InputLen) Mod 64
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

For K = 0 To InputLen - I - 1
ByteBuffer(lngBufferedBytes + K) = InputBuffer(I + K)
Next K
End Sub
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
FF a, b, c, d, x(0), S11, -680876936
FF d, a, b, c, x(1), S12, -389564586
FF c, d, a, b, x(2), S13, 606105819
FF b, c, d, a, x(3), S14, -1044525330
FF a, b, c, d, x(4), S11, -176418897
FF d, a, b, c, x(5), S12, 1200080426
FF c, d, a, b, x(6), S13, -1473231341
FF b, c, d, a, x(7), S14, -45705983
FF a, b, c, d, x(8), S11, 1770035416
FF d, a, b, c, x(9), S12, -1958414417
FF c, d, a, b, x(10), S13, -42063
FF b, c, d, a, x(11), S14, -1990404162
FF a, b, c, d, x(12), S11, 1804603682
FF d, a, b, c, x(13), S12, -40341101
FF c, d, a, b, x(14), S13, -1502002290
FF b, c, d, a, x(15), S14, 1236535329
GG a, b, c, d, x(1), S21, -165796510
GG d, a, b, c, x(6), S22, -1069501632
GG c, d, a, b, x(11), S23, 643717713
GG b, c, d, a, x(0), S24, -373897302
GG a, b, c, d, x(5), S21, -701558691
GG d, a, b, c, x(10), S22, 38016083
GG c, d, a, b, x(15), S23, -660478335
GG b, c, d, a, x(4), S24, -405537848
GG a, b, c, d, x(9), S21, 568446438
GG d, a, b, c, x(14), S22, -1019803690
GG c, d, a, b, x(3), S23, -187363961
GG b, c, d, a, x(8), S24, 1163531501
GG a, b, c, d, x(13), S21, -1444681467
GG d, a, b, c, x(2), S22, -51403784
GG c, d, a, b, x(7), S23, 1735328473
GG b, c, d, a, x(12), S24, -1926607734
HH a, b, c, d, x(5), S31, -378558
HH d, a, b, c, x(8), S32, -2022574463
HH c, d, a, b, x(11), S33, 1839030562
HH b, c, d, a, x(14), S34, -35309556
HH a, b, c, d, x(1), S31, -1530992060
HH d, a, b, c, x(4), S32, 1272893353
HH c, d, a, b, x(7), S33, -155497632
HH b, c, d, a, x(10), S34, -1094730640
HH a, b, c, d, x(13), S31, 681279174
HH d, a, b, c, x(0), S32, -358537222
HH c, d, a, b, x(3), S33, -722521979
HH b, c, d, a, x(6), S34, 76029189
HH a, b, c, d, x(9), S31, -640364487
HH d, a, b, c, x(12), S32, -421815835
HH c, d, a, b, x(15), S33, 530742520
HH b, c, d, a, x(2), S34, -995338651
II a, b, c, d, x(0), S41, -198630844
II d, a, b, c, x(7), S42, 1126891415
II c, d, a, b, x(14), S43, -1416354905
II b, c, d, a, x(5), S44, -57434055
II a, b, c, d, x(12), S41, 1700485571
II d, a, b, c, x(3), S42, -1894986606
II c, d, a, b, x(10), S43, -1051523
II b, c, d, a, x(1), S44, -2054922799
II a, b, c, d, x(8), S41, 1873313359
II d, a, b, c, x(15), S42, -30611744
II c, d, a, b, x(6), S43, -1560198380
II b, c, d, a, x(13), S44, 1309151649
II a, b, c, d, x(4), S41, -145523070
II d, a, b, c, x(11), S42, -1120210379
II c, d, a, b, x(2), S43, 718787259
II b, c, d, a, x(9), S44, -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)
End Sub

Private 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 intByteIndex
End Sub
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), x, ac)
a = LongLeftRotate(a, s)
a = LongOverflowAdd(a, b)
End Function
Private Function GG(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 d) Or (c And Not (d)), x, ac)
a = LongLeftRotate(a, s)
a = LongOverflowAdd(a, b)
End Function
Private Function HH(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 Xor c Xor d, x, ac)
a = LongLeftRotate(a, s)
a = LongOverflowAdd(a, b)
End Function
Private Function II(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, c Xor (b Or Not (d)), x, ac)
a = LongLeftRotate(a, s)
a = LongOverflowAdd(a, b)
End Function
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 = value
End Function
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
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
Private Function UnsignedToLong(value As Double) As Long
If value < 0 Or value >= OFFSET_4 Then Error 6
If value <= MAXINT_4 Then
UnsignedToLong = value
Else
UnsignedToLong = value - OFFSET_4
End If
End Function
Private Function LongToUnsigned(value As Long) As Double
If value < 0 Then
LongToUnsigned = value + OFFSET_4
Else
LongToUnsigned = value
End If
End Function
Готовая библиотека для шифрования паролей методом md5 на visual basic:

  md5.cls (18,4 KiB, 812 hits)

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