这几天由于工作需要，需要用C#开发一个设置文件夹共享，并为共享的文件夹设置共享权限的功能。在开发过程中发现了一些有趣的问题，
就是如果用程序的方式创建一个共享目录，那么就是无法直接用程序的方式设置它的共享权限。更为奇怪的是如果手动去改下下共享权限 （改前和改后的设置都一样），
就可以以程序的方式设置 共享权限了。
这里我贴出创建共享目录的代码
/// <returns></returns>
public static bool ShareFolder(string folderPath, string shareName, string description, out string returnMsg)
//默认的共享权限是Everyone
/*
如果oInParams[“Access”] 不设置或者设置为null，你就会奇怪的发现，当你先要用程序再去设置共享权限时就不行了（xp和2003下，win7,win2008缺可以）
*/
设置权限的普通方法：
/// 设置共享目录的共享权限
/// </summary>
/// <param name=”folderPath”>共享目录名</param>
/// <param name=”user”>共享权限用户</param>
/// <param name=”returnMsg”>返回消息</param>
/// <returns></returns>
public static bool SetPermission(string shareName, string user, out string returnMsg)
{
bool bRet = false;
returnMsg = “”;
//判断用户是否存在
if (!IsUserExists(user))
{
returnMsg = string.Format(“用于[{0}]不存在”, user);
return bRet;
}
// Step 1 – Getting the user Account Object
string sShareName =shareName;
ManagementObject oShareSecuritySetting= null;
ManagementObjectSearcher oSearcher = new ManagementObjectSearcher(“Select * from Win32_LogicalShareSecuritySetting where Name = ‘” + sharedName + “‘”);
//ManagementObjectSearcher oSearcher = new ManagementObjectSearcher(“Select * from Win32_LogicalShareSecuritySetting”);
ManagementObjectCollection oResultOfSearch = oSearcher.Get();
if (oResultOfSearch.Count > 0)
{
//The search might return a number of objects with same shared name. I assume there is just going to be one
foreach (ManagementObject sharedFolder in oResultOfSearch)
{
oShareSecuritySetting= sharedFolder;
break;
}
}
if (oShareSecuritySetting!= null)
{
ManagementBaseObject oSecurityDescriptorObject = oShareSecuritySetting.InvokeMethod(“GetSecurityDescriptor”, null, null);
if (oSecurityDescriptorObject != null)
{
if ((uint)(oSecurityDescriptorObject.Properties[“ReturnValue”].Value) == 0)
{
ManagementBaseObject oSecurityDescriptor = oSecurityDescriptorObject.Properties[“Descriptor”].Value as ManagementBaseObject;
// Step 2 — Access Control List from the security descriptor
int iExistingAcessControlEntriesCount = 0;
ManagementBaseObject[] oAccessControlList = oSecurityDescriptor.Properties[“DACL”].Value as ManagementBaseObject[];
if (oAccessControlList != null)
{
// Otherwise, resize the list to allow for all new users.
iExistingAcessControlEntriesCount = oAccessControlList.Length;
Array.Resize(ref oAccessControlList, oAccessControlList.Length + 1);
}
else
{
// If there aren’t any entries in access control list or the list is empty – create one
oAccessControlList = new ManagementBaseObject[1];
}
// Step 3 – Getting the user Account Object
string sUserDomain = Environment.UserDomainName;
ManagementObject oUserAccountObject = GetUserAccountObject(sUserDomain, user);
ManagementObject oSecurityIdentfierObject = new ManagementObject(string.Format(“Win32_SID.SID='{0}'”, (string)oUserAccountObject.Properties[“SID”].Value));
oSecurityIdentfierObject.Get();
// Step 4 – Create Trustee Object
ManagementObject oTrusteeObject = CreateTrustee(sUserDomain, user, oSecurityIdentfierObject);
// Step 5 – Create Access Control Entry
ManagementObject oAccessControlEntry = CreateAccessControlEntry(oTrusteeObject, false);
// Step 6 – Add Access Control Entry to the Access Control List
oAccessControlList[iExistingAcessControlEntriesCount] = oAccessControlEntry;
// Step 7 – Assign access Control list to security desciptor
oSecurityDescriptor.Properties[“DACL”].Value = oAccessControlList;
// Step 8 – Assign access Control list to security desciptor
ManagementBaseObject oParameterForSetSecurityDescriptor = oSharedFolder.GetMethodParameters(“SetSecurityDescriptor”);
oParameterForSetSecurityDescriptor[“Descriptor”] = oSecurityDescriptor;
oShareSecuritySetting.InvokeMethod(“SetSecurityDescriptor”, oParameterForSetSecurityDescriptor, null);
bRet = true;
}
else
{
returnMsg = string.Format(“共享目录[{0}]的安全描述符(SecurityDescriptorObject)的返回值错误！”, sShareName);
}
}
else
{
returnMsg = string.Format(“无法获取共享目录[{0}]的安全描述符(SecurityDescriptorObject)”, sShareName);
}
}
else
{
returnMsg = string.Format(“无法获取共享目录[{0}]的共享安全设置！”, sShareName);
}
return bRet;
}
/// 获取账户对象
/// </summary>
/// <param name=”domain”>用户的域名</param>
/// <param name=”alias”>用户名称别名</param>
/// <returns></returns>
private static ManagementObject GetUserAccountObject(string domain, string alias)
{
ManagementObject oUserAccountObject = null;
ManagementObjectSearcher oSearcher = new ManagementObjectSearcher(string.Format(“select * from Win32_Account where Name = ‘{0}’ and Domain='{1}'”, alias, domain));
ManagementObjectCollection oResultOfSearch = oSearcher.Get();
if (oResultOfSearch.Count > 0)
{
foreach (ManagementObject userAccount in oResultOfSearch)
{
oUserAccountObject = userAccount;
break;
}
}
return oUserAccountObject;
}
/// <summary>
/// 创建指定用户的信任项
/// </summary>
/// <param name=”domain”>域名</param>
/// <param name=”userName”>用户名</param>
/// <param name=”securityIdentifierOfUser”>用户的权限标识</param>
/// <returns></returns>
private static ManagementObject CreateTrustee(string domain, string userName, ManagementObject securityIdentifierOfUser)
{
ManagementObject oTrusteeObject = new ManagementClass(“Win32_Trustee”).CreateInstance();
oTrusteeObject.Properties[“Domain”].Value = domain;
oTrusteeObject.Properties[“Name”].Value = userName;
oTrusteeObject.Properties[“SID”].Value = securityIdentifierOfUser.Properties[“BinaryRepresentation”].Value;
oTrusteeObject.Properties[“SidLength”].Value = securityIdentifierOfUser.Properties[“SidLength”].Value;
oTrusteeObject.Properties[“SIDString”].Value = securityIdentifierOfUser.Properties[“SID”].Value;
return oTrusteeObject;
}
/// <summary>
/// 创建指定用户的访问控制项（Access Control Entry）对象
/// </summary>
/// <param name=”trustee”>用户的信任项对象</param>
/// <param name=”deny”>用户权限是拒绝还是允许</param>
/// <returns></returns>
private static ManagementObject CreateAccessControlEntry(ManagementObject trustee, bool deny)
{
ManagementObject oAceObject = new ManagementClass(“Win32_ACE”).CreateInstance();
oAceObject.Properties[“AccessMask”].Value = 0x1U | 0x2U | 0x4U | 0x8U | 0x10U | 0x20U | 0x40U | 0x80U | 0x100U | 0x10000U | 0x20000U | 0x40000U | 0x80000U | 0x100000U; // all permissions
oAceObject.Properties[“AceFlags”].Value = 0x0U; // no flags
oAceObject.Properties[“AceType”].Value = deny ? 1U : 0U; // 0 = allow, 1 = deny
oAceObject.Properties[“Trustee”].Value = trustee;
return oAceObject;
}
/// <summary>
/// 检查用户是否存在
/// </summary>
/// <param name=”user”></param>
/// <param name=”returnMsg”></param>
/// <returns></returns>
public static bool IsUserExists(string userName)
{
bool bRet = false;
DirectoryEntry oLocalMachine = null;
DirectoryEntry oNewUser = null;
try
{
oLocalMachine = new DirectoryEntry(“WinNT://” + Environment.MachineName);
oNewUser = oLocalMachine.Children.Find(userName, “user”);
bRet = true;
}
catch
{
bRet = false;
}
return bRet;
}
运行代码上面这段代码时你会发现
ManagementObjectSearcher oSearcher = new ManagementObjectSearcher(“Select * from Win32_LogicalShareSecuritySetting where Name = ‘” + sharedName + “‘”);
ManagementObjectCollection oResultOfSearch = oSearcher.Get();
if (oResultOfSearch.Count > 0)
{
//The search might return a number of objects with same shared name. I assume there is just going to be one
foreach (ManagementObject sharedFolder in oResultOfSearch)
{
oShareSecuritySetting= sharedFolder;
break;
}
}
这句代码片段是无法找到有效的oShareSecuritySetting。但是实际情况是文件夹是共享的而且有一个默认的Everyone的共享权限。这是为啥我找了很久也没答案。
鉴于无法获取oShareSecuritySetting这个“Win32_LogicalShareSecuritySetting”对象，下一步的权限设置也没法做了。
其实获取这个对象的最终目的是为了获取下面这个对象
这就头疼了，这些功能代码的目的就是为了使用程序去设置共享及共享权限，如果需要手动去设置下权限那不是有点隔靴搔痒了。
最后实在没办了，我只能想了个笨办法。既然手动创建的共享目录能够获取oSecurityDescriptor 这个对象，那能不能我把这个对象保存下来能，应为只要有了
最后想出来办法是用.net的序列化方法去序列化一个实现获取到的oSecurityDescriptor对象，把这个对象保存在一个文件里，下次在进行反序列化获取这个对象。
需要注意一点的是。无法获取oShareSecuritySetting只会发生在第一次创建共享目录的时候（注意：使用代码创建的），如果第一次为这个共享目录设置了共享权限，那么下次次再设置权限就没有障碍了。烦啊。。。
好了，还是说序列化吧，如下代码：
{
using (FileStream oFileStream = new FileStream(@”C:\LogicalShareSecuritySetting.dat”, FileMode.Create))
{
BinaryFormatter oFormatter = new BinaryFormatter();
oFormatter.Serialize(oFileStream, serObj);
}
}
这样就把这个对象永久保存在C:\LogicalShareSecuritySetting.dat这个文件里了，为了部署方便，我们可以把这个文件作为一个嵌入的资源嵌入在我们的程序中，下次我们就可以这样反序列化这个对象了：
private const string LOGICAL_SHARESECURITY_SETTING=“Namespace.LogicalShareSecuritySetting.dat”;
try
{
Assembly oAsm = Assembly.GetExecutingAssembly();
using (Stream oStream = oAsm.GetManifestResourceStream(LOGICAL_SHARESECURITY_SETTING))
{
BinaryFormatter oFormatter = new BinaryFormatter();
oSecurityDescriptor= oFormatter.Deserialize(oStream) as ManagementBaseObject;
}
}
catch
{ }
一旦反序列化成功这个oSecurityDescriptor，我们就可以为这个对象赋值一个我们想要的用户权限啦，如下：
{
ManagementBaseObject[] oAccessControlList = null;
oAccessControlList = new ManagementBaseObject[1];
// Step 3 – Getting the user Account Object
string sUserDomain = Environment.UserDomainName;
ManagementObject oUserAccountObject = GetUserAccountObject(sUserDomain, user); //这个user就是本地计算机的用户名，如Guest等。
ManagementObject oSecurityIdentfierObject = new ManagementObject(string.Format(“Win32_SID.SID='{0}'”, (string)oUserAccountObject.Properties[“SID”].Value));
oSecurityIdentfierObject.Get();
// Step 4 – Create Trustee Object
ManagementObject oTrusteeObject = CreateTrustee(sUserDomain, user, oSecurityIdentfierObject);
// Step 5 – Create Access Control Entry
ManagementObject oAccessControlEntry = CreateAccessControlEntry(oTrusteeObject, false);
// Step 6 – Add Access Control Entry to the Access Control List
oAccessControlList[0] = oAccessControlEntry;
// Step 7 – Assign access Control list to security desciptor
oSecurityDescriptor.Properties[“DACL”].Value = oAccessControlList;
}
一旦设置成功了，那么我们返回第一段设置共享目录代码的地方，记得不记得这段代码
oInParams[“Access”] = null; //默认的共享权限是Everyone
我们就可以吧获取的
OK，大家有兴趣试试。如果有什么更好的方法，请一定告诉我哦。我期待有更好的方式解决这个问题。
转载于:https://www.cnblogs.com/nerocool/archive/2011/02/16/1955481.html
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