MD5算法(VB.NET)

'--------------------------------------标准算法实现--------------------------------------

Public Class OtherMD5

    Function MD5F(ByVal tempstr As String, ByVal w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
        MD5F = BigMod32Add(RotLeft(BigMod32Add(BigMod32Add(w, tempstr), BigMod32Add(Xin, qdata)), rots), X)
    End Function

    Sub MD5F1(ByRef w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
        Dim tempstr As String
        tempstr = BigOR(BigAND(X, y), BigAND(BigNOT(X), z))
        'tempstr = BigXOR(z, BigAND(X, BigXOR(y, z)))
        w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
    End Sub

    Sub MD5F2(ByRef w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
        Dim tempstr As String
        tempstr = BigOR(BigAND(X, z), BigAND(y, BigNOT(z)))
        'tempstr = BigXOR(y, BigAND(z, BigXOR(X, y)))
        w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
    End Sub

    Sub MD5F3(ByRef w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
        Dim tempstr As String
        tempstr = BigXOR(BigXOR(X, y), z)
        'tempstr = BigXOR(X, BigXOR(y, z))
        w = MD5F(tempstr, w, X, y, z, Xin, qdata, rots)
    End Sub

    Sub MD5F4(ByRef w As String, ByVal X As String, ByVal y As String, ByVal z As String, ByVal Xin As String, ByVal qdata As String, ByVal rots As Integer)
        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
        Dim buf(4) As String
        Dim Xin(16) As String
        Dim tempnum As Integer, tempnum2 As Integer, loopit As Integer, loopouter As Integer, loopinner As Integer
        Dim a As String, b As String, c As String, d As String, tempstr99 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 tempnum2
            hashthis = hashthis + Chr(0)
        Next loopit
        For loopit = 1 To 8
            hashthis = hashthis + Chr(tempnum Mod 256)
            tempnum = tempnum - tempnum Mod 256
            tempnum = tempnum / 256
        Next loopit

        buf(0) = "67452301"
        buf(1) = "efcdab89"
        buf(2) = "98badcfe"
        buf(3) = "10325476"

        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
                    'tempstr99 = Hex$(Asc(Mid$(hashthis, 64 * loopouter + 4 * loopit + loopinner, 1)))
                    'If Len(tempstr99) < 2 Then tempstr99 = "0" + tempstr99
                    'Xin(loopit) = Xin(loopit) + tempstr99
                    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

            ' 第一轮循环

            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)

            ' 第二轮循环
            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)

            ' 第三轮循环
            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), "eaa127fa", 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)

            ' 第四轮循环
            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

        hashthis = ""
        For loopit = 0 To 3
            For loopinner = 3 To 0 Step -1
                hashthis = hashthis + Mid(buf(loopit), 1 + 2 * loopinner, 2)
            Next loopinner
        Next loopit

        MD5_Calc = hashthis
    End Function

    Function BigMod32Add(ByVal value1 As String, ByVal value2 As String) As 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$(Math.Abs(tempnum)) + value1
        ElseIf tempnum > 0 Then
            value2 = Space$(Math.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
        For loopit = 1 To 8 - Len(value1)
            tempstr = tempstr + "0"
        Next loopit
        tempstr = tempstr + value1
        value1 = ""

        ' 转换成二进制形式
        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)

        ' 转换为十六进制
        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 String
        Dim valueans As String
        Dim loopit As Integer, tempnum As Integer

        tempnum = Len(value1) - Len(value2)
        If tempnum < 0 Then
            value2 = Mid$(value2, Math.Abs(tempnum) + 1)
        ElseIf tempnum > 0 Then
            value1 = Mid$(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
        Dim tempstr As String
        value1 = Right$(value1, 8)
        'value1 = String$(8 - Len(value1), "0") + value1
        For loopit = 1 To 8 - Len(value1)
            tempstr = tempstr + "0"
        Next loopit
        tempstr = tempstr + value1
        value1 = tempstr
        For loopit = 1 To 8
            valueans = valueans + Hex$(15 Xor Val("&H" + Mid$(value1, loopit, 1)))
        Next loopit

        BigNOT = valueans
    End Function

    Function BigOR(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
            valueans = Left$(value2, Math.Abs(tempnum))
            value2 = Mid$(value2, Math.Abs(tempnum) + 1)
        ElseIf tempnum > 0 Then
            valueans = Left$(value1, Math.Abs(tempnum))
            value1 = Mid$(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 String
        Dim valueans As String
        Dim loopit As Integer, tempnum As Integer
        tempnum = Len(value1) - Len(value2)
        If tempnum < 0 Then
            valueans = Left$(value2, Math.Abs(tempnum))
            value2 = Mid$(value2, Math.Abs(tempnum) + 1)
        ElseIf tempnum > 0 Then
            valueans = Left$(value1, Math.Abs(tempnum))
            value1 = Mid$(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

End Class

'--------------------------------------.NET算法实现--------------------------------------

Imports System.Security.Cryptography

Public Class MD5
    Public Function Md5hash_String(ByVal InputString As String) As String
        Dim code, MD5
        Dim dataToHash As Byte() = (New System.Text.ASCIIEncoding).GetBytes(InputString)
        Dim hashvalue As Byte() = CType(System.Security.Cryptography.CryptoConfig.CreateFromName("MD5"), System.Security.Cryptography.HashAlgorithm).ComputeHash(dataToHash)
        Dim i As Integer
        For i = 0 To 15 '选择32位字符的加密结果
            MD5 += Hex(hashvalue(i))
        Next
        Return MD5

    End Function

End Class