VB中實現(xiàn)MD5加密

'  /* Zeroize sensitive information.
'*/
'  MD5_memset ((POINTER)x, 0, sizeof (x));
   
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

'
' 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), 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