用VB编写一个可以在ASP环境下调用的运行CMD命令的组件

答案：有时我们在管理服务器时为了安全起见会禁用Windows Scripting Host，这样能防止某些不法用户利用WSH生成一个WebShell，对服务器造成很大的安全隐患。但如果我们又想禁用WSH，又想使用自己的WebShell用于服务器的管理怎么办呢？这里介绍了一种实现ASP中运行CMD并显示结果的组件编程。希望对大家能有所帮助。

首先我们新建一个ActiveDLL工程，命名为ASPCMD，新建的类命名为CMDShell。在“Project“的“Referenct“中添加一个引用：Microsoft Active Server Pages Object Library。

然后我们的思路是使用Window API ShellExecute调用cmd.exe，将运行的结果保存到一个临时文本文件，然后读出这个文件的内容显示出来。

以下是工程ASPCMD的类CMDShell.cls的代码。

Option Explicit
Dim rp As Response
Dim rq As Request
Dim ap As Application
Dim sr As Server
Dim sn As Session
Private Declare Sub Sleep Lib "kernel32" (ByVal dwMilliseconds As Long)
Private Declare Function ShellExecute Lib "shell32.dll" Alias "ShellExecuteA" (ByVal hWnd As Long, ByVal lpOperation As String, ByVal lpFile As String, ByVal lpParameters As String, ByVal lpDirectory As String, ByVal nShowCmd As Long) As Long


Private Sub ShellEx(ByVal sLocation As String, ByVal sPara As String, Optional MaxedForm As Boolean = False)
    On Error GoTo errhandle:
    Dim lR As Long
    Dim Style As Long
    Dim hWnd As Long
    If MaxedForm Then
        Style = vbMaximizedFocus
    Else
        Style = vbNormalFocus
    End If
    
    lR = ShellExecute(hWnd, "open", sLocation, sPara, "", Style)
    If (lR < 0) Or (lR > 32) Then
        'success
    Else
        rp.Write "Error Occered when starting the program " & sLocation
    End If
errhandle:
    rp.Write "Error:" & Err.Description
End Sub

Public Sub OnStartPage(ByVal mysc As ScriptingContext)
     Set rp = mysc.Response
     Set rq = mysc.Request
     Set sr = mysc.Server
     Set ap = mysc.Application
     Set sn = mysc.Session
End Sub

Public Sub OnEndPage()
     Set rp = Nothing
     Set rq = Nothing
     Set sr = Nothing
     Set ap = Nothing
     Set sn = Nothing
End Sub

Private Function FileExists(Filename As String) As Boolean  
Dim i   As Integer
On Error Resume Next
i = Len(Dir$(Filename))
If Err Or i = 0 Then FileExists = False Else FileExists = True
End Function

Private Function IsOpen(Filename As String) As Boolean
 Dim fFile As Integer
 Dim msg As String
 fFile = FreeFile()
 On Error GoTo ErrOpen
 Open Filename For Binary Lock Read Write As fFile
 Close fFile
 Exit Function
ErrOpen:
 If Err.Number <> 70 Then
 msg = "Error # " & Str(Err.Number) & " was generated by " _
 & Err.Source & Chr(13) & Err.Description
 Else
 IsOpen = True
 End If
End Function

Public Sub Exec1(ByVal strCmd As String)
On Error GoTo errhandle:
    Dim myTimer As Integer
    myTimer = 0
    
    Dim strOut As String
    Dim strFname As String
   //生成一个临时文件
    If Len(App.Path) = 3 Then
        strFname = App.Path & "lhtmp.txt"
    Else
        strFname = App.Path & "\lhtmp.txt"
    End If
    //如果在运行前文件已存在则删除之
    If FileExists(strFname) Then
        Kill strFname
    End If
    
   //运行行用户的CMD命令，并将结果输出到临时文件中
   //注意cmd.exe的/c参数是指运行完一个命令后马上结束会话状态。等同于在windows的run中输入的CMD命令。
    Dim strPara As String
    strPara = "/c " & strCmd & ">" & strFname
    ShellEx "cmd.exe", strPara
    //等待生成输出文件
    Do While Not FileExists(strFname)
        Sleep 1000
        DoEvents
        myTimer = myTimer + 1
        If myTimer = 15 Then
            Exit Do
        End If
    Loop
    myTimer = 0
    //等待文件输出完毕
    Do While IsOpen(strFname)
        Sleep 1000
        DoEvents
        myTimer = myTimer + 1
        If myTimer = 15 Then
            Exit Do
        End If
    Loop
    
    //显示输出文件的内容
    Open strFname For Input As #1
    Do While Not EOF(1)
        Line Input #1, strOut
        rp.Write strOut & vbCrLf
    Loop
    Close #1
    Sleep 1000
    //删除临时文件
    Kill strFname
    Exit Sub
errhandle:
    rp.Write "error occured:" & Err.Description
End Sub

生成ASPCMD.dll，使用regsvr32 aspcmd.dll注册组件。

以下是调用该DLL的一个ASP程序例子：

<%@LANGUAGE="VBSCRIPT"%>
<style type="text/css">
<!--
.singleborder {
 border: 1px solid;
 background-color: #000000;
 font-family: Arial, Helvetica, sans-serif;
 color: #FFFFFF;
}
.noborder {
 border: 1px none;
 background-color: #000000;
 font-family: Arial, Helvetica, sans-serif;
 color: #FFFFFF;
}
body{background-color: #000000;SCROLLBAR-FACE-COLOR: #333333; FONT-SIZE: 12px; SCROLLBAR-HIGHLIGHT-COLOR: #000000; SCROLLBAR-SHADOW-COLOR: #000000; SCROLLBAR-3DLIGHT-COLOR: #000000; SCROLLBAR-ARROW-COLOR: #000000; SCROLLBAR-TRACK-COLOR: #000000;  SCROLLBAR-DARKSHADOW-COLOR: #000000
 font-family: Fixedsys;   font-size: 9pt}
-->
</style>
<form action="" method="post">
<input name="cmd" class="singleborder" value="<%=request.form("cmd")%>" size=102>
<input type="submit" class="singleborder" value="EXECUTE">
</form>
<%
if request.form("cmd")<>"" then
 set testme=server.createobject("aspcmd.cmdshell")
%>
<div class="noborder"><%=request.Form("cmd")%></div><br>
<textarea cols="120" rows="30" class="noborder">
<%=testme.exec1(request.form("cmd"))%></textarea>

<% set testme=nothing
end if
%>

以下是运行Ipconfig /all的结果：

Windows 2000 IP Configuration

 Host Name . . . . . . . . . . . . : ibm-wrk-02
 Primary DNS Suffix  . . . . . . . : 
 Node Type . . . . . . . . . . . . : Broadcast
 IP Routing Enabled. . . . . . . . : No
 WINS Proxy Enabled. . . . . . . . : No

Ethernet adapter 本地连接:

 Connection-specific DNS Suffix  . : 
 Description . . . . . . . . . . . : Intel(R) PRO/100 VM Network Connection
 Physical Address. . . . . . . . . : 00-08-02-BD-D7-EB
 DHCP Enabled. . . . . . . . . . . : No
 IP Address. . . . . . . . . . . . : 192.168.0.4
 Subnet Mask . . . . . . . . . . . : 255.255.255.0
 Default Gateway . . . . . . . . . : 192.168.0.1
 DNS Servers . . . . . . . . . . . : 202.106.196.115


 

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