MD5加密算法在VB中的实现

MD5加密算法在VB中的实现

- 中国WEB开发者网络 (http://www.webasp.net)
-- 技术教程 (http://www.webasp.net/article/)
--- MD5加密算法在VB中的实现 (http://www.webasp.net/article/16/15017.htm)

-- 作者：未知
-- 发布日期： 2004-11-23

' MD5加密算法在VB中的实现

Option Explicit

Dim w1 As String, w2 As String, w3 As String, w4 As String

Function MD5F(ByVal tempstr As String, ByVal w As String, ByVal X As S
tring, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVa
l qdata As String, ByVal rots As Integer)
MD5F = BigMod32Add(RotLeft(BigMod32Add(BigMod32Add(w, tempstr), Bi
gMod32Add(Xin, qdata)), rots), X)
End Function

Sub MD5F1(w As String, ByVal X As String, ByVal y As String, ByVal z A
s String, ByVal Xin As String, ByVal qdata As String, ByVal rots As In
teger)
Dim tempstr As String

tempstr = BigXOR(z, BigAND(X, BigXOR(y, z)))
w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
End Sub

Sub MD5F2(w As String, ByVal X As String, ByVal y As String, ByVal z A
s String, ByVal Xin As String, ByVal qdata As String, ByVal rots As In
teger)
Dim tempstr As String

tempstr = BigXOR(y, BigAND(z, BigXOR(X, y)))
w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
End Sub

Sub MD5F3(w As String, ByVal X As String, ByVal y As String, ByVal z A
s String, ByVal Xin As String, ByVal qdata As String, ByVal rots As In
teger)
Dim tempstr As String

tempstr = BigXOR(X, BigXOR(y, z))
w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
End Sub

Sub MD5F4(w As String, ByVal X As String, ByVal y As String, ByVal z A
s String, ByVal Xin As String, ByVal qdata As String, ByVal rots As In
teger)
Dim tempstr As String

tempstr = BigXOR(y, BigOR(X, BigNOT(z)))
w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
End Sub

Function MD5_Calc(ByVal hashthis As String) As String
ReDim buf(0 To 3) As String
ReDim Xin(0 To 15) As String
Dim tempnum As Integer, tempnum2 As Integer, loopit As Integer, loopou
ter As Integer, loopinner As Integer
Dim a As String, b As String, c As String, d As String

' Add padding

tempnum = 8 * Len(hashthis)
hashthis = hashthis + Chr$(128) 'Add binary 10000000
tempnum2 = 56 - Len(hashthis) Mod 64

If tempnum2 < 0 Then
tempnum2 = 64 + tempnum2
End If

hashthis = hashthis + String$(tempnum2, Chr$(0))

For loopit = 1 To 8
hashthis = hashthis + Chr$(tempnum Mod 256)
tempnum = tempnum - tempnum Mod 256
tempnum = tempnum / 256
Next loopit

' Set magic numbers
buf(0) = "67452301"
buf(1) = "efcdab89"
buf(2) = "98badcfe"
buf(3) = "10325476"

' For each 512 bit section
For loopouter = 0 To Len(hashthis) / 64 - 1
a = buf(0)
b = buf(1)
c = buf(2)
d = buf(3)

' Get the 512 bits
For loopit = 0 To 15
Xin(loopit) = ""
For loopinner = 1 To 4
Xin(loopit) = Hex$(Asc(Mid$(hashthis, 64 * loopouter +
4 * loopit + loopinner, 1))) + Xin(loopit)
If Len(Xin(loopit)) Mod 2 Then Xin(loopit) = "0" + Xin
(loopit)
Next loopinner
Next loopit

' Round 1
MD5F1 a, b, c, d, Xin(0), "d76aa478", 7
MD5F1 d, a, b, c, Xin(1), "e8c7b756", 12
MD5F1 c, d, a, b, Xin(2), "242070db", 17
MD5F1 b, c, d, a, Xin(3), "c1bdceee", 22
MD5F1 a, b, c, d, Xin(4), "f57c0faf", 7
MD5F1 d, a, b, c, Xin(5), "4787c62a", 12
MD5F1 c, d, a, b, Xin(6), "a8304613", 17
MD5F1 b, c, d, a, Xin(7), "fd469501", 22
MD5F1 a, b, c, d, Xin(8), "698098d8", 7
MD5F1 d, a, b, c, Xin(9), "8b44f7af", 12
MD5F1 c, d, a, b, Xin(10), "ffff5bb1", 17
MD5F1 b, c, d, a, Xin(11), "895cd7be", 22
MD5F1 a, b, c, d, Xin(12), "6b901122", 7
MD5F1 d, a, b, c, Xin(13), "fd987193", 12
MD5F1 c, d, a, b, Xin(14), "a679438e", 17
MD5F1 b, c, d, a, Xin(15), "49b40821", 22

' Round 2
MD5F2 a, b, c, d, Xin(1), "f61e2562", 5
MD5F2 d, a, b, c, Xin(6), "c040b340", 9
MD5F2 c, d, a, b, Xin(11), "265e5a51", 14
MD5F2 b, c, d, a, Xin(0), "e9b6c7aa", 20
MD5F2 a, b, c, d, Xin(5), "d62f105d", 5
MD5F2 d, a, b, c, Xin(10), "02441453", 9
MD5F2 c, d, a, b, Xin(15), "d8a1e681", 14
MD5F2 b, c, d, a, Xin(4), "e7d3fbc8", 20
MD5F2 a, b, c, d, Xin(9), "21e1cde6", 5
MD5F2 d, a, b, c, Xin(14), "c33707d6", 9
MD5F2 c, d, a, b, Xin(3), "f4d50d87", 14
MD5F2 b, c, d, a, Xin(8), "455a14ed", 20
MD5F2 a, b, c, d, Xin(13), "a9e3e905", 5
MD5F2 d, a, b, c, Xin(2), "fcefa3f8", 9
MD5F2 c, d, a, b, Xin(7), "676f02d9", 14
MD5F2 b, c, d, a, Xin(12), "8d2a4c8a", 20

' Round 3
MD5F3 a, b, c, d, Xin(5), "fffa3942", 4
MD5F3 d, a, b, c, Xin(8), "8771f681", 11
MD5F3 c, d, a, b, Xin(11), "6d9d6122", 16
MD5F3 b, c, d, a, Xin(14), "fde5380c", 23
MD5F3 a, b, c, d, Xin(1), "a4beea44", 4
MD5F3 d, a, b, c, Xin(4), "4bdecfa9", 11
MD5F3 c, d, a, b, Xin(7), "f6bb4b60", 16
MD5F3 b, c, d, a, Xin(10), "bebfbc70", 23
MD5F3 a, b, c, d, Xin(13), "289b7ec6", 4
MD5F3 d, a, b, c, Xin(0), "e27fa", 11
MD5F3 c, d, a, b, Xin(3), "d4ef3085", 16
MD5F3 b, c, d, a, Xin(6), "04881d05", 23
MD5F3 a, b, c, d, Xin(9), "d9d4d039", 4
MD5F3 d, a, b, c, Xin(12), "e6db99e5", 11
MD5F3 c, d, a, b, Xin(15), "1fa27cf8", 16
MD5F3 b, c, d, a, Xin(2), "c4ac5665", 23

' Round 4
MD5F4 a, b, c, d, Xin(0), "f4292244", 6
MD5F4 d, a, b, c, Xin(7), "432aff97", 10
MD5F4 c, d, a, b, Xin(14), "ab9423a7", 15
MD5F4 b, c, d, a, Xin(5), "fc93a039", 21
MD5F4 a, b, c, d, Xin(12), "655b59c3", 6
MD5F4 d, a, b, c, Xin(3), "8f0ccc92", 10
MD5F4 c, d, a, b, Xin(10), "ffeff47d", 15
MD5F4 b, c, d, a, Xin(1), "85845dd1", 21
MD5F4 a, b, c, d, Xin(8), "6fa87e4f", 6
MD5F4 d, a, b, c, Xin(15), "fe2ce6e0", 10
MD5F4 c, d, a, b, Xin(6), "a3014314", 15
MD5F4 b, c, d, a, Xin(13), "4e0811a1", 21
MD5F4 a, b, c, d, Xin(4), "f7537e82", 6
MD5F4 d, a, b, c, Xin(11), "bd3af235", 10
MD5F4 c, d, a, b, Xin(2), "2ad7d2bb", 15
MD5F4 b, c, d, a, Xin(9), "eb86d391", 21

buf(0) = BigAdd(buf(0), a)
buf(1) = BigAdd(buf(1), b)
buf(2) = BigAdd(buf(2), c)
buf(3) = BigAdd(buf(3), d)
Next loopouter

' Extract MD5Hash
hashthis = ""
For loopit = 0 To 3
For loopinner = 3 To 0 Step -1
hashthis = hashthis + Chr(Val("&H" + Mid$(buf(loopit), 1 +
2 * loopinner, 2)))
Next loopinner
Next loopit

' And return it
MD5_Calc = hashthis
End Function

Function BigMod32Add(ByVal value1 As String, ByVal value2 As String) A
s String
BigMod32Add = Right$(BigAdd(value1, value2), 8)
End Function

Public Function BigAdd(ByVal value1 As String, ByVal value2 As String)
As String
Dim valueans As String
Dim loopit As Integer, tempnum As Integer

tempnum = Len(value1) - Len(value2)
If tempnum < 0 Then
value1 = Space$(Abs(tempnum)) + value1
ElseIf tempnum > 0 Then
value2 = Space$(Abs(tempnum)) + value2
End If

tempnum = 0
For loopit = Len(value1) To 1 Step -1
tempnum = tempnum + Val("&H" + Mid$(value1, loopit, 1)) + Val(
"&H" + Mid$(value2, loopit, 1))
valueans = Hex$(tempnum Mod 16) + valueans
tempnum = Int(tempnum / 16)
Next loopit

If tempnum <> 0 Then
valueans = Hex$(tempnum) + valueans
End If

BigAdd = Right(valueans, 8)
End Function

Public Function RotLeft(ByVal value1 As String, ByVal rots As Integer)
As String
Dim tempstr As String
Dim loopit As Integer, loopinner As Integer
Dim tempnum As Integer

rots = rots Mod 32

If rots = 0 Then
RotLeft = value1
Exit Function
End If

value1 = Right$(value1, 8)
tempstr = String$(8 - Len(value1), "0") + value1
value1 = ""

' Convert to binary
For loopit = 1 To 8
tempnum = Val("&H" + Mid$(tempstr, loopit, 1))
For loopinner = 3 To 0 Step -1
If tempnum And 2 ^ loopinner Then
value1 = value1 + "1"
Else
value1 = value1 + "0"
End If
Next loopinner
Next loopit
tempstr = Mid$(value1, rots + 1) + Left$(value1, rots)

' And convert back to hex
value1 = ""
For loopit = 0 To 7
tempnum = 0
For loopinner = 0 To 3
If Val(Mid$(tempstr, 4 * loopit + loopinner + 1, 1)) Then

tempnum = tempnum + 2 ^ (3 - loopinner)
End If
Next loopinner
value1 = value1 + Hex$(tempnum)
Next loopit

RotLeft = Right(value1, 8)
End Function

Function BigAND(ByVal value1 As String, ByVal value2 As String) As Str
ing
Dim valueans As String
Dim loopit As Integer, tempnum As Integer

tempnum = Len(value1) - Len(value2)
If tempnum < 0 Then
value2 = Mid$(value2, Abs(tempnum) + 1)
ElseIf tempnum > 0 Then
value1 = Mid$(value1, tempnum + 1)
End If

For loopit = 1 To Len(value1)
valueans = valueans + Hex$(Val("&H" + Mid$(value1, loopit, 1))
And Val("&H" + Mid$(value2, loopit, 1)))
Next loopit

BigAND = valueans
End Function

Function BigNOT(ByVal value1 As String) As String
Dim valueans As String
Dim loopit As Integer

value1 = Right$(value1, 8)
value1 = String$(8 - Len(value1), "0") + value1
For loopit = 1 To 8
valueans = valueans + Hex$(15 Xor Val("&H" + Mid$(value1, loop
it, 1)))
Next loopit

BigNOT = valueans
End Function

Function BigOR(ByVal value1 As String, ByVal value2 As String) As Stri
ng
Dim valueans As String
Dim loopit As Integer, tempnum As Integer

tempnum = Len(value1) - Len(value2)
If tempnum < 0 Then
valueans = Left$(value2, Abs(tempnum))
value2 = Mid$(value2, Abs(tempnum) + 1)
ElseIf tempnum > 0 Then
valueans = Left$(value1, Abs(tempnum))
value1 = Mid$(value1, tempnum + 1)
End If

For loopit = 1 To Len(value1)
valueans = valueans + Hex$(Val("&H" + Mid$(value1, loopit, 1))
Or Val("&H" + Mid$(value2, loopit, 1)))
Next loopit

BigOR = valueans
End Function

Function BigXOR(ByVal value1 As String, ByVal value2 As String) As Str
ing
Dim valueans As String
Dim loopit As Integer, tempnum As Integer

tempnum = Len(value1) - Len(value2)
If tempnum < 0 Then
valueans = Left$(value2, Abs(tempnum))
value2 = Mid$(value2, Abs(tempnum) + 1)
ElseIf tempnum > 0 Then
valueans = Left$(value1, Abs(tempnum))
value1 = Mid$(value1, tempnum + 1)
End If

For loopit = 1 To Len(value1)
valueans = valueans + Hex$(Val("&H" + Mid$(value1, loopit, 1))
Xor Val("&H" + Mid$(value2, loopit, 1)))
Next loopit

BigXOR = Right(valueans, 8)
End Function

' To Be Continue...

webasp.net