# 经典加密算法在VB中的实现：MD5

2010-03-30

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 Strin

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)
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
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(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
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
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