MD5 加密算法 VB 实现代码

虽然现在MD5 加密算法严格来讲已经不算安全，但一般小功能或公司内部使用应该足够了 
Attribute VB_Name = "modMd5"
' MODULE:       CMD5
'*******************************************************************************
Option Explicit
Public Const BITS_TO_A_BYTE  As Long = 8
Public Const BYTES_TO_A_WORD As Long = 4
Public Const BITS_TO_A_WORD  As Long = BYTES_TO_A_WORD * BITS_TO_A_BYTE
Public m_lOnBits(0 To 30) As Long
Public m_l2Power(0 To 30) As Long
Public Function MD5_Encrypt(ByVal sText As String) As String
MD5_Init
MD5_Encrypt = MD5(sText)
End Function
'*******************************************************************************
' Class_Initialize (SUB)
'
' DESCRIPTION:
' We will usually get quicker results by preparing arrays of bit patterns and
' powers of 2 ahead of time instead of calculating them every time, unless of
' course the methods are only ever getting called once per instantiation of the
' class.
'*******************************************************************************
Public Sub MD5_Init()
    ' Could have done this with a loop calculating each value, but simply
    ' assigning the values is quicker - BITS SET from RIGHT
    m_lOnBits(0) = 1            ' 00000000000000000000000000000001
    m_lOnBits(1) = 3            ' 00000000000000000000000000000011
    m_lOnBits(2) = 7            ' 00000000000000000000000000000111
    m_lOnBits(3) = 15           ' 00000000000000000000000000001111
    m_lOnBits(4) = 31           ' 00000000000000000000000000011111
    m_lOnBits(5) = 63   &nb