按照提供的链接到http://www.hightechtalks.com/csharp/lsa-functions-276626.html上的代码
IntPtr GetSIDInformation(string account)
{
LSA_UNICODE_STRING[] names = new LSA_UNICODE_STRING[1];
LSA_TRANSLATED_SID2 lts;
IntPtr tsids = IntPtr.Zero;
IntPtr tdom = IntPtr.Zero;
names[0] = InitLsaString(account);
lts.Sid = IntPtr.Zero;
Console.WriteLine("String account: {0}", names[0].Length);
int ret = Win32Sec.LsaLookupNames2(lsaHandle, 0, 1, names, ref tdom, ref tsids);
if (ret != 0)
{
throw new Win32Exception(Win32Sec.LsaNtStatusToWinError(ret));
}
lts = (LSA_TRANSLATED_SID2) Marshal.PtrToStructure(tsids,
typeof(LSA_TRANSLATED_SID2));
Win32Sec.LsaFreeMemory(tsids);
Win32Sec.LsaFreeMemory(tdom);
return lts.Sid;
}
lts（一个LSA_TRANSLATED_SID2结构）包含一个指针，该指针指向通过调用Win32Sec.LsaFreeMemory释放的内存。在释放内存后使用指针是不好的做法，并且会产生不可预测的结果——它甚至可能“工作”。
通过使用 SecurityIdentifier 类（.Net 2 及更高版本）以及对不需要的代码进行少量清理来调整链接处的代码可以避免内存问题。
using System;
namespace Willys.LsaSecurity
{
using System.ComponentModel;
using System.Runtime.InteropServices;
using System.Security;
using System.Security.Principal;
using LSA_HANDLE = IntPtr;
[StructLayout(LayoutKind.Sequential)]
struct LSA_OBJECT_ATTRIBUTES
{
internal int Length;
internal IntPtr RootDirectory;
internal IntPtr ObjectName;
internal int Attributes;
internal IntPtr SecurityDescriptor;
internal IntPtr SecurityQualityOfService;
}
[StructLayout(LayoutKind.Sequential, CharSet = CharSet.Unicode)]
struct LSA_UNICODE_STRING
{
internal ushort Length;
internal ushort MaximumLength;
[MarshalAs(UnmanagedType.LPWStr)]
internal string Buffer;
}
sealed class Win32Sec
{
[DllImport("advapi32", CharSet = CharSet.Unicode, SetLastError = true), SuppressUnmanagedCodeSecurityAttribute]
internal static extern uint LsaOpenPolicy(
LSA_UNICODE_STRING[] SystemName,
ref LSA_OBJECT_ATTRIBUTES ObjectAttributes,
int AccessMask,
out IntPtr PolicyHandle
);
[DllImport("advapi32", CharSet = CharSet.Unicode, SetLastError = true), SuppressUnmanagedCodeSecurityAttribute]
internal static extern uint LsaAddAccountRights(
LSA_HANDLE PolicyHandle,
IntPtr pSID,
LSA_UNICODE_STRING[] UserRights,
int CountOfRights
);
[DllImport("advapi32")]
internal static extern int LsaNtStatusToWinError(int NTSTATUS);
[DllImport("advapi32")]
internal static extern int LsaClose(IntPtr PolicyHandle);
}
sealed class Sid : IDisposable
{
public IntPtr pSid = IntPtr.Zero;
public SecurityIdentifier sid = null;
public Sid(string account)
{
sid = (SecurityIdentifier) (new NTAccount(account)).Translate(typeof(SecurityIdentifier));
Byte[] buffer = new Byte[sid.BinaryLength];
sid.GetBinaryForm(buffer, 0);
pSid = Marshal.AllocHGlobal(sid.BinaryLength);
Marshal.Copy(buffer, 0, pSid, sid.BinaryLength);
}
public void Dispose()
{
if (pSid != IntPtr.Zero)
{
Marshal.FreeHGlobal(pSid);
pSid = IntPtr.Zero;
}
GC.SuppressFinalize(this);
}
~Sid()
{
Dispose();
}
}
public sealed class LsaWrapper : IDisposable
{
enum Access : int
{
POLICY_READ = 0x20006,
POLICY_ALL_ACCESS = 0x00F0FFF,
POLICY_EXECUTE = 0X20801,
POLICY_WRITE = 0X207F8
}
const uint STATUS_ACCESS_DENIED = 0xc0000022;
const uint STATUS_INSUFFICIENT_RESOURCES = 0xc000009a;
const uint STATUS_NO_MEMORY = 0xc0000017;
IntPtr lsaHandle;
public LsaWrapper()
: this(null)
{ }
// // local system if systemName is null
public LsaWrapper(string systemName)
{
LSA_OBJECT_ATTRIBUTES lsaAttr;
lsaAttr.RootDirectory = IntPtr.Zero;
lsaAttr.ObjectName = IntPtr.Zero;
lsaAttr.Attributes = 0;
lsaAttr.SecurityDescriptor = IntPtr.Zero;
lsaAttr.SecurityQualityOfService = IntPtr.Zero;
lsaAttr.Length = Marshal.SizeOf(typeof(LSA_OBJECT_ATTRIBUTES));
lsaHandle = IntPtr.Zero;
LSA_UNICODE_STRING[] system = null;
if (systemName != null)
{
system = new LSA_UNICODE_STRING[1];
system[0] = InitLsaString(systemName);
}
uint ret = Win32Sec.LsaOpenPolicy(system, ref lsaAttr,
(int) Access.POLICY_ALL_ACCESS, out lsaHandle);
if (ret == 0)
return;
if (ret == STATUS_ACCESS_DENIED)
{
throw new UnauthorizedAccessException();
}
if ((ret == STATUS_INSUFFICIENT_RESOURCES) || (ret == STATUS_NO_MEMORY))
{
throw new OutOfMemoryException();
}
throw new Win32Exception(Win32Sec.LsaNtStatusToWinError((int) ret));
}
public void AddPrivileges(string account, string privilege)
{
uint ret = 0;
using (Sid sid = new Sid(account))
{
LSA_UNICODE_STRING[] privileges = new LSA_UNICODE_STRING[1];
privileges[0] = InitLsaString(privilege);
ret = Win32Sec.LsaAddAccountRights(lsaHandle, sid.pSid, privileges, 1);
}
if (ret == 0)
return;
if (ret == STATUS_ACCESS_DENIED)
{
throw new UnauthorizedAccessException();
}
if ((ret == STATUS_INSUFFICIENT_RESOURCES) || (ret == STATUS_NO_MEMORY))
{
throw new OutOfMemoryException();
}
throw new Win32Exception(Win32Sec.LsaNtStatusToWinError((int) ret));
}
public void Dispose()
{
if (lsaHandle != IntPtr.Zero)
{
Win32Sec.LsaClose(lsaHandle);
lsaHandle = IntPtr.Zero;
}
GC.SuppressFinalize(this);
}
~LsaWrapper()
{
Dispose();
}
// helper functions
static LSA_UNICODE_STRING InitLsaString(string s)
{
// Unicode strings max. 32KB
if (s.Length > 0x7ffe)
throw new ArgumentException("String too long");
LSA_UNICODE_STRING lus = new LSA_UNICODE_STRING();
lus.Buffer = s;
lus.Length = (ushort) (s.Length * sizeof(char));
lus.MaximumLength = (ushort) (lus.Length + sizeof(char));
return lus;
}
}
}