监控USB设备插拔-阿里云开发者社区

最近做了UKey加密中设计到USB设备. 因UKEy是用来加密和执行PC与项目间通信加密的介质.从作用范围来讲不是传统意义上U盘作为存储介质来使用.其实熟悉网银驱动DR应该了解.在网银系统安全上一个最基本需求就是动态即时监控通信PC驱动以及设备列表通信变化.当然包括我们加密存储介质在PC上USB插拔.

思路一.在WinFrom中通过拦截Windows 消息机制来实现. 类似定义MEssageForm窗体. 假如用鼠标左击一下窗体, 系统会收到一条 WM_LBUTTONDOWN 消息;当鼠标抬起, 系统又会收到 WM_LBUTTONUP 消息.系统收到消息后, 会告诉窗体发生的事情, 然后窗体再做出反应; 当然窗体能否做出反应要看窗体是否有相应的响应代码. 同样也可以把USB设备插拔事件通过重写窗体WndProc(Ref Message m)方法拦截并处理.

首先引入命名空间:

using System.Management;
using System.Threading;
using System.Security.Permissions;

定义Device Management Event的枚举:

public enum DeviceEvent : int
{
DBT_CONFIGCHANGECANCELED = 0x0019,
DBT_CONFIGCHANGED=0x0018,
DBT_CUSTOMEVENT=0x8006,
DBT_DEVICEARRIVAL=0x8000,//USB Insert DEvice Statu
DBT_DEVICEQUERYREMOVE=0x8001,
DBT_DEVICEQUERYREMOVEFAILED=0x8002,
DBT_DEVICEREMOVEPENDING=0x8003,//USB Revoing.
DBT_DEVICEREMOVECOMPLETE=0x8004,//USB Remove Completed
DBT_DEVICETYPESPECIFIC=0x8005,
DBT_DEVNODES_CHANGED=0x0007,//Device List _Changed
DBT_QUERYCHANGECONFIG=0x0017,
DBT_USERDEFINED=0xFFFF
}

其中涉及到USB设备插拔的是DEVICEREMOVEPENDING/DEVICEREMOVECOMPLETE[删除] DEVICEARRIVAL[插入设备] 重写WinFProc实现窗体上对Windows MEssage进行拦截并重新处理:

[PermissionSet(SecurityAction.Demand, Name = "FullTrust")]
protected override void WndProc(ref Message m)
{
base.WndProc(ref m);
DeviceEvent lEvent;
lEvent = (DeviceEvent)m.WParam.ToInt32();
switch (lEvent)
{
case DeviceEvent.DBT_DEVICEARRIVAL://[Insert]
this.CheckDeviceStatus_Lable.BackColor = Color.Green;
this.CheckDeviceStatus_Lable.Text = "----Connection Device!----";
MessageBox.Show("Just Insert At Moment !", "Insert");
break;
case DeviceEvent.DBT_DEVICEREMOVECOMPLETE://[REmove]
this.CheckDeviceStatus_Lable.BackColor = Color.Red;
this.CheckDeviceStatus_Lable.Text = "------No Connection------";
MessageBox.Show("Remove Complete At Moment!", "Remove");
break;
case DeviceEvent.DBT_DEVNODES_CHANGED://[Device List Have Changed]
MessageBox.Show("Device List have been Changed!");
break;
default:
break;
}
}

首先USB在进行插拔即时如果没有存储介质即Disk或是无驱动的方式可能不能触发DeviceEvent.DBT_DEVICEREMOVECOMPLETE 和 DeviceEvent.DBT_DEVICEARRIVAL插把事件. 但是一点是可以确认的是.PC端只要接受USB设备.PC识别之后设备列表肯定会发生变化. 如果不是加密Key. u盘的盘符方式存在Disk存储介质.则没有问题.

当然需要移植这种基于From窗体系统Message拦截方法时发现这种可重用性就不高.换一种思路采用Windows底层方式WMI实现.

WMI以CIMOM为基础，CIMOM即公共信息模型对象管理器[Common Information Model Object Manager]，是一个描述操作系统构成单元的对象数据库，为MMC和脚本程序提供了一个访问操作系统构成单元的公共接口。有了WMI，工具软件和脚本程序访问操作系统的不同部分时不需要使用不同的API；相反，操作系统的不同部分都可以插入WMI，工具软件和WMI可以方便地读写WMI.

WMI 可以产生的系统级事件的一些更有用。每当创建 WMI 类的新实例；例如对于激发称为 __instancecreationevent 事件__instancedeletionevent 时将触发一个实例将被删除. 当然USB插拔时同样获得这个系统事件：

public void ControlUSBConnectionStatu()
{
ManagementEventWatcher getEventWatcher = null;
WqlEventQuery getEventQuery = null;
ManagementOperationObserver getObserver = new ManagementOperationObserver();
//Bind to Loacl Machine and Watch the PortConnection
ManagementScope getScope = new ManagementScope("root\\CIMV2");
getScope.Options.EnablePrivileges = true;//set requeired
try
{
getEventQuery = new WqlEventQuery();
getEventQuery.EventClassName = "__InstanceOperationEvent";
getEventQuery.WithinInterval = new TimeSpan(0, 0, 0, 1);
getEventQuery.Condition = @"TargetInstance ISA 'Win32_DiskDrive' ";
//[Disk must have DiskDrive fuck ]
//Event Watcher [Test Event and semd informatio to this message and create new informtion .]
getEventWatcher = new ManagementEventWatcher(getEventQuery);
getEventWatcher.EventArrived += new EventArrivedEventHandler(getEventWatcher_EventArrived);
getEventWatcher.Start();//Start Watch Event
}
catch (Exception se)
{ }
finally
{
// getEventWatcher.Stop();
}
}

当发生USB插拔并成功监听到事件时处理方法:

void getEventWatcher_EventArrived(object sender, EventArrivedEventArgs e)
{
ManagementBaseObject getBaseObject = (ManagementBaseObject)e.NewEvent;
if ((getBaseObject.ClassPath.ClassName == "__InstanceCreationEvent"))
{
//Usb Inserted
MessageBox.Show("USB Disk Inserted!");
}
else
{
//Usb Removed
MessageBox.Show("USB Device Removed!");
}
}

如上在定义时设置一个Condition[条件]:存在Disk Driver 磁盘驱动.如果类似某些UKey不存在磁盘驱动同时也无存储介质经过测试你会发现.加密的UKey插入如上的WMI监听事件并不能扑捉到USB插拔. 但是针对这种方式我们还有一种更为彻底的方式就是USB插拔唯一可以确定在PC识别必然变化的因素是系统设备列表发生更新.

WMI处理监听:

/// <summary>
/// 监听USB Device设备插拔事件完整操作.
/// WMI Handle Event Change Device List chenkai
/// </summary>
public void RegisterDeviceWMIEventStatu()
{
try
{
//Device List HAve Changed And Send Message
WqlEventQuery query = new WqlEventQuery("SELECT * FROM Win32_DeviceChangeEvent");
ManagementEventWatcher watcher = new ManagementEventWatcher(query);
watcher.EventArrived += new EventArrivedEventHandler(watcher_EventArrived);
watcher.Start(); // Start listening for events
}
catch (Exception se)
{ }
}

WMI监听处理函数:

void watcher_EventArrived(object sender, EventArrivedEventArgs e)
{
string geteventtype = e.NewEvent.GetPropertyValue("EventType").ToString();
ManagementBaseObject getEventObject = (ManagementBaseObject)e.NewEvent;
if (getEventObject != null)
{
//close Operator
this.CloseDeviceEqument();
}
}

其实这依然还是一种折中办法.因为导致PC端设备列表发生变化的因素有很多.如何判定是USB口发生设备变化.WMI依然没有让我们失望:

//WMI Control The USB Device Change Statu And Send Message to When IT‘s Changed/
public void ControlUSBDeviceSTatu()
{
try
{
WqlEventQuery query = new WqlEventQuery("select * from Win32_VolumeChangeEvent");
ManagementEventWatcher getwatcher = new ManagementEventWatcher(query);
getwatcher.EventArrived += new EventArrivedEventHandler(getwatcher_EventArrived);
getwatcher.Start();
}
catch (Exception se)
{ }
}