Question

我使用以下C＃代码：

enum TOKEN_INFORMATION_CLASS
{
    TokenUser = 1,
    TokenGroups,
    TokenPrivileges,
    TokenOwner,
    TokenPrimaryGroup,
    TokenDefaultDacl,
    TokenSource,
    TokenType,
    TokenImpersonationLevel,
    TokenStatistics,
    TokenRestrictedSids,
    TokenSessionId,
    TokenGroupsAndPrivileges,
    TokenSessionReference,
    TokenSandBoxInert,
    TokenAuditPolicy,
    TokenOrigin
}

[StructLayout(LayoutKind.Sequential)]
public struct SID_AND_ATTRIBUTES
{
    public IntPtr Sid;
    public UInt32 Attributes;
}

[StructLayout(LayoutKind.Sequential)]
public struct TOKEN_GROUPS
{
    public UInt32 GroupCount;
    // Followed by this:
    [MarshalAs(UnmanagedType.ByValArray)]
    public SID_AND_ATTRIBUTES[] Groups;
}

internal class TokenInformationTools : ITokenInformationTools
{

    [DllImport("advapi32", SetLastError = true), SuppressUnmanagedCodeSecurityAttribute]
    static extern int OpenProcessToken(System.IntPtr processHandle, int desiredAccess, ref IntPtr tokenHandle);
    const int OpenProcessTokenFail = 0;

    [DllImport("advapi32.dll", SetLastError = true)]
    static extern int GetTokenInformation(IntPtr tokenHandle, TOKEN_INFORMATION_CLASS tokenInformationClass, IntPtr tokenInformation, int tokenInformationLength, out int returnLength);
    const int GetTokenInformationFail = 0;

    [DllImport("advapi32", CharSet = CharSet.Auto, SetLastError = true)]
    static extern bool ConvertSidToStringSid(IntPtr securityIdentifier, out string securityIdentifierName);

    [DllImport("kernel32.dll")]
    static extern uint GetLastError();

    public bool CheckForTokenGroup(string tokenGroupName)
    {
        var processHandle = Process.GetCurrentProcess().Handle;
        IntPtr tokenHandler = IntPtr.Zero;
        const int TOKEN_READ = 0x20008;
        if (OpenProcessToken(processHandle, TOKEN_READ, ref tokenHandler) != OpenProcessTokenFail)
        {
            int length = 0;
            var getTokenInformationReturnValue = GetTokenInformation(tokenHandler, TOKEN_INFORMATION_CLASS.TokenGroups, IntPtr.Zero, 0, out length);
            if (getTokenInformationReturnValue != GetTokenInformationFail)
            {
                var tokenInfo = Marshal.AllocHGlobal(length);
                if (GetTokenInformation(tokenHandler, TOKEN_INFORMATION_CLASS.TokenGroups, tokenInfo, length, out length) != GetTokenInformationFail)
                {
                    int groupCount = Marshal.ReadInt32(tokenInfo);
                    const int sizeDword = 4;
                    var pSaa = tokenInfo + sizeDword;
                    for (int i = 0; i < groupCount; i++)
                    {
                        var groupInfo = (SID_AND_ATTRIBUTES)Marshal.PtrToStructure((IntPtr)pSaa, typeof(SID_AND_ATTRIBUTES));
                        string sidAsString = string.Empty;
                        ConvertSidToStringSid(groupInfo.Sid, out sidAsString);
                        if (sidAsString == tokenGroupName)
                        {
                            Marshal.FreeHGlobal(tokenInfo);
                            return true;
                        }
                        pSaa += Marshal.SizeOf(typeof(SID_AND_ATTRIBUTES));
                    }
                }
                else
                {
                    var error = GetLastError();
                }
                Marshal.FreeHGlobal(tokenInfo);
            }
            else
            {
                var error = GetLastError();
            }
        }
        return false;
    }
}

问题是，第一次调用时getTokenInformationReturnValue为0。因此，如此处所述：https://docs.microsoft.com/en-us/windows/desktop/api/securitybaseapi/nf-securitybaseapi-gettokeninformation，这是错误情况：

If the function succeeds, the return value is nonzero.

GetLastError返回0，表示“ 操作成功完成。”。为此，https://docs.microsoft.com/de-de/windows/desktop/Debug/system-error-codes--0-499-

但是该功能似乎仍然可以工作。如果我忽略getTokenInformationReturnValue（以及对GetTokenInformation的以下调用的返回值），则一切似乎都按预期工作。

此代码是以下VBA代码的副本，其中GetTokenInformationFail的返回值不为0。

Enum TokenInformation
  TokenUser = 1
  TokenGroups = 2
End Enum

Private Const TOKEN_READ As Long = &H20008

Private Declare Sub CopyMemory Lib "kernel32" Alias "RtlMoveMemory" (pTo As Any, uFrom As Any, ByVal lSize As Long)
Private Declare Function GetCurrentProcess Lib "kernel32" () As Long
Private Const GetCurrentProcessFail As Long = 0

Private Declare Function OpenProcessToken Lib "advapi32.dll" (ByVal ProcessHandle As Long, ByVal DesiredAccess As Long, TokenHandle As Long) As Long
Private Const OpenProcessTokenFail As Long = 0
Private Declare Function GetTokenInformation Lib "advapi32.dll" (ByVal TokenHandle As Long, ByVal TokenInformationClass As Long, TokenInformation As Any, ByVal TokenInformationLength As Long, ReturnLength As Long) As Long
Private Const GetTokenInformationFail As Long = 0
Private Declare Function ConvertSidToStringSid Lib "advapi32.dll" Alias "ConvertSidToStringSidA" (ByVal lpSid As Long, lpString As Long) As Long
Private Declare Function LocalFree Lib "kernel32" (ByVal hMem As Long) As Long
Private Declare Function lstrlen Lib "kernel32" Alias "lstrlenA" (ByVal lpString As Long) As Long

Private Type SID_AND_ATTRIBUTES
  Sid             As Long
  Attributes      As Long
End Type

Private Type VB_TOKEN_GROUPS
  GroupCount      As Long
  Groups()        As SID_AND_ATTRIBUTES
End Type

Private Const SizeDword As Long = 4

Public Function fn_checkForTokenGroup(ByVal par_UserGroupSid As String) As Boolean

  Dim dPseudoProcessHandle As Long
  Dim dTokenHandler As Long
  Dim dNeeded As Long
  Dim dReadBuffer() As Byte
  Dim dStringBuffer As String
  Dim dStringPointer As Long
  Dim dGroupData As VB_TOKEN_GROUPS

  On Error GoTo fn_checkForTokenGroup_error

  fn_checkForTokenGroup = False

  dPseudoProcessHandle = GetCurrentProcess()
  If dPseudoProcessHandle <> GetCurrentProcessFail Then
    If OpenProcessToken(dPseudoProcessHandle, TOKEN_READ, dTokenHandler) <> OpenProcessTokenFail Then
      Call GetTokenInformation(dTokenHandler, TokenInformation.TokenGroups, ByVal 0, 0, dNeeded)
      ReDim dReadBuffer(0 To dNeeded)
      If GetTokenInformation(dTokenHandler, TokenInformation.TokenGroups, dReadBuffer(0), UBound(dReadBuffer), dNeeded) <> GetTokenInformationFail Then
        Call CopyMemory(dGroupData.GroupCount, dReadBuffer(0), SizeDword)
        ReDim dGroupData.Groups(0 To dGroupData.GroupCount - 1)
        Call CopyMemory(dGroupData.Groups(0), dReadBuffer(SizeDword), dGroupData.GroupCount * Len(dGroupData.Groups(0)))

        Dim i As Long
        For i = 0 To dGroupData.GroupCount - 1
          If ConvertSidToStringSid(dGroupData.Groups(i).Sid, dStringPointer) Then
            dStringBuffer = Space(lstrlen(dStringPointer))
            Call CopyMemory(ByVal dStringBuffer, ByVal dStringPointer, Len(dStringBuffer))
            Call LocalFree(dStringPointer)
            If (dStringBuffer = par_UserGroupSid) Then
              fn_checkForTokenGroup = True
              GoTo fn_checkForTokenGroup_endeSchleife:
            End If
          End If
        Next
fn_checkForTokenGroup_endeSchleife:

      End If
      Call CloseHandle(dTokenHandler)
    End If
    Call CloseHandle(dPseudoProcessHandle)
  End If

fn_checkForTokenGroup_exit:

  Exit Function

fn_checkForTokenGroup_error:
  Call msg_error_norm(ModuleName, "CheckForTokenGroup")
  GoTo fn_checkForTokenGroup_exit:
End Function

那么我的C＃代码有什么问题？我的声明有问题吗？

Answer 1

您不得使用 GetLastError 但是

 int nLastWin32Error = Marshal.GetLastWin32Error();

当返回值为0并测试此错误== ERROR_INSUFFICIENT_BUFFER （122）时，那么您可以致电 Marshal.AllocHGlobal

APICall GetTokenInformation返回错误值

1 个答案: