MD5 er ikke kryptering, men blot en algoritme til message digest generering, som sikrer en rimelig spredning af bitmønsteret som kommer ud.
På samme måde som crc heller ikke er kryptering, men blot en signatur (eller message digest om du vil) af nogle data.
Nogle kalder det for en en-vejs kryptering, og det er fordi du ikke kan kalde data frem igen, men blot behandle rå data og sammen ligne det nye message digest med gamle message digest.
Men det er ikke kryptering, for kryptering indbærer ikke tab af data.
Derimod er det smart hvis man vil være fri for at gemme f.eks. adgangskoden i rå tekst, så kan man blot gemme en digest af den (som jo ikke kan laves tilbage til tekst), og så behandle login forøg med md5 og sammen ligne digests.
Og det er hvad du har lavet i PHP.
Og jeg tror godt du kan bruge md5 i VB men det er en anden historie som jeg skal undlade at gøre mig klog på.
okay ja jeg har så altid kaldt det envejs kryptering men sådan er det jo og tak for rettelsen 
Du kan prøve at lede, men jeg brugte meget tid på at finde et modul der virkede, jeg kan poste modullet her når jeg kopmmer hje.
-Thomas
-------------------------------------------------------
Visual Basic noget for dig?
tjek Visual Basic-Gruppen
http://www.udvikleren.dk/groups/?gid=41
okay det ville være dejligt
<pre>
'libMD5_R5:
'Option Public
'Option Declare
Private Const OFFSET_4 = 4294967296#
Private Const MAXINT_4 = 2147483647
Private State(4) As Long
Private ByteCounter As Long
' [mw]: Byte is not allowed
Private ByteBuffer(63) As Integer
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
'%REM
' Standard MD5 implementation optimised for the Lotus Notes environment.
' Conforms to all standards and can be used in digital signature or password
' protection related schemes. (-->
http://www.faqs.org/rfcs/rfc1321.html )
'This version uses 'Integer' instead of 'Byte' type, so it runs on R5.
'(Current source:
http://wwWendt.de/tech/md5) 'Based on the Visual Basic MD5 Implementation by Robert Hubley and David Midkiff
'Martin Wendt (martin@wwWendt.de)
'--------------------------------------------------------------------------------
'Usage:
' Get hash value for a string:
Public Function CalculateMD5(strIn As String) As String
hash = DigestStrToHexStr(strIn)
'Incremental Update:
Dim aByte() As Integer, chunk As String
Call MD5Init
'[...]
'Loop
' chunk = ...
Call md5StringToArray(chunk, aByte)
Call MD5Update(Len(chunk), aByte)
' end loop
Call MD5Final
'hash = MD5GetValues()
CalculateMD5 = LCase$(hash)
End Function
'%END REM
Private Property Get RegisterA() As String
RegisterA = State(1)
End Property
Private Property Get RegisterB() As String
RegisterB = State(2)
End Property
Private Property Get RegisterC() As String
RegisterC = State(3)
End Property
Private Property Get RegisterD() As String
RegisterD = State(4)
End Property
Private Function LongToString(Num As Long) As String
Dim A As Integer, B As Integer, C As Integer, D As Integer
A = Num And &HFF&
If A < 16 Then LongToString = "0" & Hex(A) Else LongToString = Hex(A)
B = (Num And &HFF00&) \\ 256
If B < 16 Then LongToString = LongToString & "0" & Hex(B) Else LongToString = LongToString & Hex(B)
C = (Num And &HFF0000) \\ 65536
If C < 16 Then LongToString = LongToString & "0" & Hex(C) Else LongToString = LongToString & Hex(C)
If Num < 0 Then D = ((Num And &H7F000000) \\ 16777216) Or &H80& Else D = (Num And &HFF000000) \\ 16777216
If D < 16 Then LongToString = LongToString & "0" & Hex(D) Else LongToString = LongToString & Hex(D)
End Function
Private Sub MD5Transform(Buffer() As Integer)
Dim X(16) As Long, A As Long, B As Long, C As Long, 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 Integer)
Dim intDblIndex As Integer, intByteIndex As Integer, dblSum As Double
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
Private Function LongLeftRotate(value As Long, Bits As Long) As Long
Dim lngSign As Long, 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)
value = value Or ((lngSign < 0) And 1) Or (False <> (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, lngLowWord As Long, 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, lngLowWord As Long, 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 Function
Private Function LongToUnsigned(value As Long) As Double
If value < 0 Then LongToUnsigned = value + OFFSET_4 Else LongToUnsigned = value
End Function
Sub md5StringToArray(InString As String, aByte() As Integer)
Dim I As Integer
ReDim aByte(Len(InString))
For I = 0 To Len(InString) - 1
aByte(I) = Asc(Mid$(InString, I + 1, 1))
Next I
End Sub
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 MD5Update(InputLen As Long, InputBuffer() As Integer)
Dim II As Integer, I As Integer, J As Integer, K As Integer
Dim lngBufferedBytes As Long, lngBufferRemaining As Long, 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
Public Sub MD5Final()
Dim dblBits As Double, padding(72) As Integer, 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
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 Function DigestStrToHexStr(SourceString As String) As String
MD5Init
Dim aByte() As Integer
Call md5StringToArray(SourceString, aByte)
MD5Update Len(SourceString), aByte
MD5Final
DigestStrToHexStr = MD5GetValues
End Function
Public Function MD5GetValues() As String
MD5GetValues = LongToString(State(1)) & LongToString(State(2)) _
& LongToString(State(3)) & LongToString(State(4))
End Function
'Private Function md5Test0(strIn As String, strHash As String, bDump As Integer) As Integer
' Dim res As String, msg As String
' res = DigestStrToHexStr(strIn)
' msg = "MD5('" & strIn & "') = '" & res & "'"
'If Strcompare(res, strHash, 1) = 0 Then
' msg = msg & " [ok]"
' md5Test0 = True
'Else
' msg = msg & " --> ERROR! Should be '" & strHash & "'"
' md5Test0 = False
'End If
'If bDump Then Print msg
'End Function
Function md5Test(bDump As Integer) As Integer
' MD5 test suite (
http://www.faqs.org/rfcs/rfc1321.html)' Print "CBool:" & Clng(true=Cbool (1))
Dim bRes As Integer
bRes = True
'bRes = bRes And md5Test0("", "d41d8cd98f00b204e9800998ecf8427e", bDump)
'bRes = bRes And md5Test0("a", "0cc175b9c0f1b6a831c399e269772661", bDump)
'bRes = bRes And md5Test0("abc", "900150983cd24fb0d6963f7d28e17f72", bDump)
'bRes = bRes And md5Test0("message digest", "f96b697d7cb7938d525a2f31aaf161d0", bDump)
'bRes = bRes And md5Test0("abcdefghijklmnopqrstuvwxyz", "c3fcd3d76192e4007dfb496cca67e13b", bDump)
'bRes = bRes And md5Test0("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789", "d174ab98d277d9f5a5611c2c9f419d9f", bDump)
'bRes = bRes And md5Test0("12345678901234567890123456789012345678901234567890123456789012345678901234567890", "57edf4a22be3c955ac49da2e2107b67a", bDump)
md5Test = bRes
If bRes Then
'Print "Test Passed!"
Else
MsgBox "Test FAILED!"
End If
End Function
</pre>
du kalder bare
<pre>
VarHash=CalculateMD5("din tekst her")
</pre>
Som lovet er module her.
mvh.
Thomas Christensen
-------------------------------------------------------
Visual Basic noget for dig?
tjek Visual Basic-Gruppen
http://www.udvikleren.dk/groups/?gid=41