VB編程Windows屏幕保護(hù)密碼(1)

大家都知道，屏幕保護(hù)密碼最多為16個(gè)字符。微軟內(nèi)置了16字節(jié)的密鑰：48 EE 76 1D 67 69 A1 1B 7A 8C 47 F8 54 95 97 5F。Windows便用上述密鑰加密你輸入的密碼。其加密過(guò)程為：首先將你輸入的密碼字符逐位轉(zhuǎn)換為其16進(jìn)制的ASCⅡ碼值（小寫(xiě)字母先轉(zhuǎn)為大寫(xiě)字母），再依次與對(duì)應(yīng)密鑰逐位進(jìn)行異或運(yùn)算，把所得16進(jìn)制值的每一位當(dāng)作字符，轉(zhuǎn)換為其16進(jìn)制ASCII碼，并在其尾加上00作為結(jié)束標(biāo)志，存入注冊(cè)表HKEY_CURRENT_USERControl Paneldesktop下的二進(jìn)制鍵ScreenSave_Data中。
    懂得其加密原理后，便不難編程*我的屏幕保護(hù)密碼（即上網(wǎng)密碼）了。本人用VB6.0編制了一讀取注冊(cè)表中ScrrenSave_Data值的函數(shù)GetBinaryValue(Entry As String),讀出其值為31 43 41 33 33 43 35 35 33 34 32 31 00,去掉其結(jié)束標(biāo)志00，把余下字節(jié)轉(zhuǎn)換為對(duì)應(yīng)的ASCII字符，并把每?jī)蓚€(gè)字符組成一16進(jìn)制數(shù)：1C A3 3C 55 34 21，顯然，密碼為6位，將其與前6字節(jié)密鑰逐一異或后便得出密碼的ASCII碼（16進(jìn)制值）：54 4D 4A 48 53 48,對(duì)應(yīng)的密碼明文為T(mén)MJHSH，*成功！用它拔號(hào)一試，呵，立刻傳來(lái)Modem歡快的叫聲。
    附VB源程序：(程序中使用了窗體Form1，文本框Text1，命令按鈕Command1)
    窗體代碼：
    Option Explicit
    Dim Cryptograph As String
    Dim i As Integer
    Dim j As Integer
    Dim k As Integer
    Dim CryptographStr(32) As Integer
    Dim PWstr As String
    Dim PassWord As String
    Private Sub Command1_Click()
    PWstr = ""
    PassWord = ""
    Text1.Text =""
    Cryptograph = GetBinaryValue("ScreenSave_Data")
    k = Len(Cryptograph)
    For j = 1 To k － 1
     For i = 32 To 126
     If Mid(Cryptograph, j, 1) = Chr(i) Then
     CryptographStr(j) = i
     End If
     Next i
    Next j
    i = (k － 1) / 2 ‘密碼位數(shù)為(h－1)/2,根據(jù)位數(shù)選擇解密過(guò)程。
    Select Case i
    Case 16
     GoTo 16
    Case 15
     GoTo 15
    Case 14
     GoTo 14
    Case 13
     GoTo 13
    Case 12
     GoTo 12
    Case 11
     GoTo 11
    Case 10
     GoTo 10
    Case 9
     GoTo 9
    Case 8
     GoTo 8
    Case 7
     GoTo 7
    Case 6
     GoTo 6
    Case 5
     GoTo 5
    Case 4
     GoTo 4
    Case 3
     GoTo 3
    Case 2
     GoTo 2
    Case 1
     GoTo 1
    Case Else
     End
    End Select
    16: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(31)) & Chr(CryptographStr(32))) Xor &H5F)
    15: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(29)) & Chr(CryptographStr(30))) Xor &H97)
    14: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(27)) & Chr(CryptographStr(28))) Xor &H95)
    13: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(25)) & Chr(CryptographStr(26))) Xor &H54)
    12: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(23)) & Chr(CryptographStr(24))) Xor &HF8)
    11: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(21)) & Chr(CryptographStr(22))) Xor &H47)
    10: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(19)) & Chr(CryptographStr(20))) Xor &H8C)
    9: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(17)) & Chr(CryptographStr(18))) Xor &H7A)
    8: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(15)) & Chr(CryptographStr(16))) Xor &H1B)
    7: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(13)) & Chr(CryptographStr(14))) Xor &HA1)
    6: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(11)) & Chr(CryptographStr(12))) Xor &H69)
    5: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(9)) & Chr(CryptographStr(10))) Xor &H67)
    4: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(7)) & Chr(CryptographStr(8))) Xor &H1D)
    3: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(5)) & Chr(CryptographStr(6))) Xor &H76)
    2: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(3)) & Chr(CryptographStr(4))) Xor &HEE)
    1: PWstr = PWstr & Chr(("&H" & Chr(CryptographStr(1)) & Chr(CryptographStr(2))) Xor &H48)
    For i = i To 1 Step －1 ‘所得PWstr的值為密碼的倒序列，將其倒置便得出密碼。
     PassWord = PassWord & Mid(PWstr, i, 1)
    Next i
    Text1.Text = PassWord ‘在文本框內(nèi)顯示密碼。
    End Sub