'
' 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 = GetValues
End 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 = bytBuffer
End 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, padding
End 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, 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,

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