VB中实现MD5加密
'
' 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, 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
' Round 2
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
' Round 3
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
' Round 4
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)
