windows-server-2003/admin/wmi/wbem/providers/win32provider/common/session.cpp

//=============================================================================
// session.cpp -- implementation of session collection class.
//
//  Copyright (c) 1998-2002 Microsoft Corporation, All Rights Reserved
//=============================================================================



#include <nt.h>
#include <ntrtl.h>
#include <nturtl.h>
#include <ntobapi.h>

#define _WINNT_	// have what is needed from above

#pragma warning (disable: 4786)


#include "precomp.h"
#include <map>
#include <vector>
#include <comdef.h>
#include "chstring.h"
#include "session.h"
#include <ProvExce.h>
#include <AssertBreak.h>
#include <wbemcli.h>
#include <ntsecapi.h>

#ifdef _WIN32_WINNT
#define SECURITY_WIN32
#else
#define SECURITY_WIN16
#endif

#include <sspi.h>

#include "ctoken.h"

#include <autoptr.h>
#include <ScopeGuard.h>

typedef SECURITY_STATUS (SEC_ENTRY *PFN_LSA_ENUMERATE_LOGON_SESSIONS)
(
    OUT PULONG  LogonSessionCount,
    OUT PLUID*  LogonSessionList
);


typedef SECURITY_STATUS (SEC_ENTRY *PFN_LSA_GET_LOGON_SESSION_DATA)
(
    IN   PLUID                           LogonId,
    OUT  PSECURITY_LOGON_SESSION_DATA*   ppLogonSessionData
);


typedef NTSTATUS (*PFN_LSA_FREE_RETURN_BUFFER)
(
    IN PVOID Buffer
);



//*****************************************************************************
// CUserSessionCollection functions
//*****************************************************************************

CUserSessionCollection::CUserSessionCollection()
{
    Refresh();
}


CUserSessionCollection::CUserSessionCollection(
    const CUserSessionCollection& sescol)
{
    m_usr2ses.clear();

    USER_SESSION_ITERATOR sourceIter;

    for(sourceIter = sescol.m_usr2ses.begin();
        sourceIter != sescol.m_usr2ses.end();
        sourceIter++)
    {
        m_usr2ses.insert(
            USER_SESSION_MAP::value_type(        
                sourceIter->first,
                sourceIter->second));
    }

}



DWORD CUserSessionCollection::Refresh()
{
    DWORD dwRet = ERROR_SUCCESS;

    // Empty out previous contents...
    m_usr2ses.clear();

    dwRet = CollectSessions();

    return dwRet;
}



DWORD CUserSessionCollection::CollectSessions()
{
    DWORD dwRet = ERROR_SUCCESS;
    std::vector<CProcess> vecProcesses;
    SmartCloseHandle hProcess;
    SmartCloseHandle hToken;
    TOKEN_STATISTICS tokstats;
    PTOKEN_USER ptokusr = NULL;
    DWORD dwRetSize = 0L;
    PSID psidUsr = NULL;
    CHString chstrUsr;
    LUID luidSes;


    // Enable the debug privilege...
    EnablePrivilegeOnCurrentThread(SE_DEBUG_NAME);

    // Get a list of all running processes...
    dwRet = GetProcessList(vecProcesses);

    if(dwRet == ERROR_SUCCESS)
    {
        // For each member of the process list...
        for(long m = 0L; 
            m < vecProcesses.size(); 
            m++)
        {
            // open the process...
            ::SetLastError(ERROR_SUCCESS);
            dwRet = ERROR_SUCCESS;

            hProcess = ::OpenProcess(
                PROCESS_QUERY_INFORMATION,
                FALSE,
                vecProcesses[m].GetPID());

            if(hProcess == NULL)
            {
                dwRet = ::GetLastError();
            }

            // get the process token...
            if(hProcess != NULL &&
                dwRet == ERROR_SUCCESS)
            {
                ::SetLastError(ERROR_SUCCESS);
                dwRet = ERROR_SUCCESS;

                if(!::OpenProcessToken(
                    hProcess,
                    TOKEN_QUERY,
                    &hToken))
                {
                    dwRet = ::GetLastError();
                }
            }

            // get the token statistics...
            if(hToken != NULL &&
                dwRet == ERROR_SUCCESS)
            {
                ::SetLastError(ERROR_SUCCESS);
                dwRet = ERROR_SUCCESS;
                if(!::GetTokenInformation(
                    hToken,
                    TokenStatistics,
                    &tokstats,
                    sizeof(TOKEN_STATISTICS),
                    &dwRetSize))
                {
                    dwRet = ::GetLastError();
                }
            }

			//
			// smart token user
			//
			wmilib::auto_buffer < BYTE > smartptokusr;

            // get the token user sid...
            if(dwRet == ERROR_SUCCESS)
            {
                // the token user struct varries
                // in size depending on the size
                // of the sid in the SID_AND_ATTRIBUTES
                // structure, so need to allocate
                // it dynamically.
                if(!::GetTokenInformation(
                    hToken,
                    TokenUser,
                    NULL,
                    0L,
                    &dwRetSize))
                {
                    dwRet = ::GetLastError();
                }
                if(dwRet == ERROR_INSUFFICIENT_BUFFER)
                {
                    smartptokusr.reset ( new BYTE [ dwRetSize ] ) ;
					ptokusr = (PTOKEN_USER) smartptokusr.get () ;
                    DWORD dwTmp = dwRetSize;

					if(!::GetTokenInformation(
                            hToken,
                            TokenUser,
                            ptokusr,
                            dwTmp,
                            &dwRetSize))
                    {
                        dwRet = ::GetLastError();
                    }
					else
					{
						dwRet = ERROR_SUCCESS ;
					}
                }
            }
        
            if(ptokusr != NULL)
            {
                if(dwRet == ERROR_SUCCESS)
                {
                    psidUsr = (ptokusr->User).Sid;

                    // from the token statistics, get 
                    // the TokenID LUID of the session...
                    luidSes.LowPart = tokstats.AuthenticationId.LowPart;
                    luidSes.HighPart = tokstats.AuthenticationId.HighPart; 

                    // try to find the session of the 
                    // process in the multimap...
                    USER_SESSION_ITERATOR usiter;
                    
                    if(FindSessionInternal(
                        luidSes,
                        usiter))
                    {
                        // try to find the process id in the 
                        // session's process vector...
                        CSession sesTmp(usiter->second);
                        CProcess* procTmp = NULL;
                        bool fFoundIt = false;

                        for(long z = 0L; 
                            z < sesTmp.m_vecProcesses.size() && !fFoundIt;
                            z++)
                        {
                            if((DWORD)(sesTmp.m_vecProcesses[z].GetPID()) == 
                                vecProcesses[m].GetPID())
                            {
                                fFoundIt = true;
                            }
                        }
                    
                        // If we didn't find the process in the
                        // session's list of processes, add it in...
                        if(!fFoundIt)
                        {
                            (usiter->second).m_vecProcesses.push_back(
                                CProcess(vecProcesses[m]));
                        }
                    }
                    else // no such session in the map, so add an entry
                    {
                        // Create new CSession(tokenid LUID), and 
                        // add process to the session's process vector...         
                        CSession sesNew(luidSes);
                        sesNew.m_vecProcesses.push_back(
                            vecProcesses[m]);

                        // add CUser(user sid) to map.first and the 
                        // CSession just created to map.second...
                        CUser cuTmp(psidUsr);
                        if(cuTmp.IsValid())
                        {
                            m_usr2ses.insert(
                                USER_SESSION_MAP::value_type(
                                    cuTmp,
                                    sesNew));
                        }
                        else
                        {
                            LogErrorMessage2(
                                L"Token of process %d contains an invalid sid", 
                                vecProcesses[m].GetPID());
                        }
                    }
                }
            }
        } // next process
    }

    // There may have been sessions not associated
    // with any processes.  To get these, we will
    // use LSA.
    CollectNoProcessesSessions();

    return dwRet;
}


void CUserSessionCollection::Copy(
    CUserSessionCollection& out) const
{
    out.m_usr2ses.clear();

    USER_SESSION_ITERATOR meIter;

    for(meIter = m_usr2ses.begin();
        meIter != m_usr2ses.end();
        meIter++)
    {
        out.m_usr2ses.insert(
            USER_SESSION_MAP::value_type(        
                meIter->first,
                meIter->second));
    }
}


// Support enumeration of users.  Returns
// a newly allocated copy of what was in
// the map (caller must free).
CUser* CUserSessionCollection::GetFirstUser(
    USER_SESSION_ITERATOR& pos)
{
    CUser* cusrRet = NULL;

    if(!m_usr2ses.empty())
    {
        pos = m_usr2ses.begin();
        cusrRet = new CUser(pos->first);
    }
    
    return cusrRet;
}

// Returns a newly allocated CUser*, which
// the caller must free.
CUser* CUserSessionCollection::GetNextUser(
    USER_SESSION_ITERATOR& pos)
{
    // Users are the non-unique part of 
    // the map, so we need to go through
    // the map until the next user entry
    // comes up.
    CUser* usrRet = NULL;

    while(pos != m_usr2ses.end())
    {
        CHString chstrSidCur;
        pos->first.GetSidString(chstrSidCur);
    
        pos++;

        if(pos != m_usr2ses.end())
        {
            CHString chstrSidNext;
            pos->first.GetSidString(chstrSidNext);

            // Return the first instance where
            // the next user is different from 
            // the current one.
            if(chstrSidNext.CompareNoCase(chstrSidCur) != 0)
            {
                usrRet = new CUser(pos->first);
                break;
            }
        }
    }

    return usrRet;        
}


// Support enumeration of sessions
// belonging to a particular user.
CSession* CUserSessionCollection::GetFirstSessionOfUser(
    CUser& usr,
    USER_SESSION_ITERATOR& pos)
{
    CSession* csesRet = NULL;

    if(!m_usr2ses.empty())
    {
        pos = m_usr2ses.find(usr);
        if(pos != m_usr2ses.end())
        {
            csesRet = new CSession(pos->second);
        }
    }
    return csesRet;
}


CSession* CUserSessionCollection::GetNextSessionOfUser(
    USER_SESSION_ITERATOR& pos)
{
    // Sessions are the unique part of 
    // the map, so we just need to get 
    // the next one as long as pos.first
    // matches usr...
    CSession* sesRet = NULL;

    if(pos != m_usr2ses.end())
    {
        CHString chstrUsr1;
        CHString chstrUsr2;
        
        (pos->first).GetSidString(chstrUsr1);

        pos++;
        
        if(pos != m_usr2ses.end())
        {
            (pos->first).GetSidString(chstrUsr2);
            if(chstrUsr1.CompareNoCase(chstrUsr2) == 0)
            {
                sesRet = new CSession(pos->second);
            }
        }
    }

    return sesRet;
}



// Support enumeration of all sessions.  Returns a 
// newly allocated CSession*, which the caller
// must free.
CSession* CUserSessionCollection::GetFirstSession(
    USER_SESSION_ITERATOR& pos)
{
    CSession* csesRet = NULL;

    if(!m_usr2ses.empty())
    {
        pos = m_usr2ses.begin();
        csesRet = new CSession(pos->second);
    }
    return csesRet;
}

// Returns a newly allocated CSession* that the
// caller must free.
CSession* CUserSessionCollection::GetNextSession(
    USER_SESSION_ITERATOR& pos)
{
    // Sessions are the unique part of 
    // the map, so we just need to get 
    // the next one...
    CSession* sesRet = NULL;

    if(pos != m_usr2ses.end())
    {
        pos++;
        if(pos != m_usr2ses.end())
        {
            sesRet = new CSession(pos->second);
        }
    }

    return sesRet;
}


// Support finding a particular session.
// This internal version hands back an iterator
// on our member map that points to the found
// instance if found (when the function returns
// true.  If the function returns
// false, the iterator points to the end of our
// map.
bool CUserSessionCollection::FindSessionInternal(
    LUID& luidSes,
    USER_SESSION_ITERATOR& usiOut)
{
    bool fFoundIt = false;

    for(usiOut = m_usr2ses.begin();
        usiOut != m_usr2ses.end();
        usiOut++)
    {
        LUID luidTmp = (usiOut->second).GetLUID();
        if(luidTmp.HighPart == luidSes.HighPart &&
           luidTmp.LowPart == luidSes.LowPart)
        {
            fFoundIt = true;
            break;
        }
    }

    return fFoundIt;
}


// Support finding a particular session - external
// callers can call this one, and are given a new
// CSession* they can play with.
CSession* CUserSessionCollection::FindSession(
    LUID& luidSes)
{
    CSession* psesRet = NULL;
    USER_SESSION_ITERATOR pos;
    
    if(FindSessionInternal(
        luidSes,
        pos))
    {
        psesRet = new CSession(pos->second);
    }

    return psesRet;
}

CSession* CUserSessionCollection::FindSession(
    __int64 i64luidSes)
{
    LUID luidSes = *((LUID*)(&i64luidSes));
    return FindSession(luidSes);
}


// Support enumeration of processes
// belonging to a particular user.  Returns
// newly allocated CProcess* which the caller
// must free.
CProcess* CUserSessionCollection::GetFirstProcessOfUser(
    CUser& usr,
    USER_SESSION_PROCESS_ITERATOR& pos)
{
    CProcess* cprocRet = NULL;
    CHString chstrUsrSidStr;
    CHString chstrTmp;

    if(!m_usr2ses.empty())
    {
        usr.GetSidString(chstrUsrSidStr);
        pos.usIter = m_usr2ses.find(usr);
        while(pos.usIter != m_usr2ses.end())
        {
            // Get the sid string of the user we
            // are at and see whether the strings
            // are the same (e.g., whether this is a
            // session associated with the specified
            // user)...
            (pos.usIter)->first.GetSidString(chstrTmp);
            if(chstrUsrSidStr.CompareNoCase(chstrTmp) == 0)
            {
                // Now check that the session of the user
                // we are on has processes...
                if(!(((pos.usIter)->second).m_vecProcesses.empty()))
                {
                    pos.procIter = 
                        ((pos.usIter)->second).m_vecProcesses.begin();
                    cprocRet = new CProcess(*(pos.procIter));
                }
                else
                {
                    // the session for this user has
                    // no processes, so go to the next 
                    // session...
                    (pos.usIter)++;
                }
            }
        }
    }

    return cprocRet;
}


// Returns a newly allocated CProcess* that the
// caller must free.
CProcess* CUserSessionCollection::GetNextProcessOfUser(
    USER_SESSION_PROCESS_ITERATOR& pos)
{
    CProcess* cprocRet = NULL;
    CHString chstrCurUsr;
    CHString chstrNxtSesUsr;

    if(pos.usIter != m_usr2ses.end())
    {
        (pos.usIter)->first.GetSidString(chstrCurUsr);

        while(pos.usIter != m_usr2ses.end())
        {
            // First try to get the next process
            // within the current session.  If we
            // were at the end of the list of processes
            // for the current session, go to the
            // next session...
            (pos.procIter)++;

            // Of course, if we have moved on
            // to a different user, then stop.
            (pos.usIter)->first.GetSidString(chstrNxtSesUsr);
            if(chstrCurUsr.CompareNoCase(chstrNxtSesUsr) == 0)
            {
                if(pos.procIter == 
                    ((pos.usIter)->second).m_vecProcesses.end())
                {
                    (pos.usIter)++;
                }
                else
                {    
                    cprocRet = new CProcess(*(pos.procIter));    
                }
            }
        }
    }

    return cprocRet;
}



// Support enumeration of all processes.  Returns
// newly allocated CProcess* which the caller
// must free.
CProcess* CUserSessionCollection::GetFirstProcess(
    USER_SESSION_PROCESS_ITERATOR& pos)
{
    CProcess* cprocRet = NULL;

    if(!m_usr2ses.empty())
    {
        pos.usIter = m_usr2ses.begin();
        while(pos.usIter != m_usr2ses.end())
        {
            if(!(((pos.usIter)->second).m_vecProcesses.empty()))
            {
                pos.procIter = 
                    ((pos.usIter)->second).m_vecProcesses.begin();
                cprocRet = new CProcess(*(pos.procIter));
            }
            else
            {
                (pos.usIter)++;
            }
        }
    }

    return cprocRet;
}


// Returns a newly allocated CProcess* that the
// caller must free.
CProcess* CUserSessionCollection::GetNextProcess(
    USER_SESSION_PROCESS_ITERATOR& pos)
{
    CProcess* cprocRet = NULL;

    while(pos.usIter != m_usr2ses.end())
    {
        // First try to get the next process
        // within the current session.  If we
        // were at the end of the list of processes
        // for the current session, go to the
        // next session...
        (pos.procIter)++;
        if(pos.procIter == 
            ((pos.usIter)->second).m_vecProcesses.end())
        {
            (pos.usIter)++;
        }
        else
        {    
            cprocRet = new CProcess(*(pos.procIter));    
        }
    }

    return cprocRet;
}


// This helper enumerates the current set of processes
// and ads each process id as a DWORD in the vector.
DWORD CUserSessionCollection::GetProcessList( std::vector<CProcess>& vecProcesses ) const
{
    DWORD dwRet = ERROR_SUCCESS;

    // First, load up ntdll...
    HMODULE hLib = NULL;
    PFN_NT_QUERY_SYSTEM_INFORMATION pfnNtQuerySystemInformation = NULL;

    hLib = LoadLibraryW(L"NTDLL.DLL");
    if(hLib != NULL)
    {
		//
		// auto FreeLibrary
		//
		ON_BLOCK_EXIT ( FreeLibrary, hLib ) ;

        // Get proc address of NtQuerySystemInformation...
        pfnNtQuerySystemInformation = (PFN_NT_QUERY_SYSTEM_INFORMATION)
                                GetProcAddress(
                                    hLib,
                                    "NtQuerySystemInformation");
        
        if(pfnNtQuerySystemInformation != NULL)
        {
            // Ready to rock.  Enable debug priv...
            EnablePrivilegeOnCurrentThread(SE_DEBUG_NAME);
            
            DWORD dwProcessInformationSize = 0;
	        SYSTEM_PROCESS_INFORMATION* ProcessInformation = NULL;

			//
			// smart ProcessInformation
			//
			wmilib::auto_buffer < BYTE > SmartProcessInformation;

			// Get the process information...

            BOOL fRetry = TRUE;
			while(fRetry)
			{
				dwRet = pfnNtQuerySystemInformation(
					SystemProcessInformation,
					ProcessInformation,
					dwProcessInformationSize,
					NULL);

				if(dwRet == STATUS_INFO_LENGTH_MISMATCH)
				{
					dwProcessInformationSize += 32768;

                    SmartProcessInformation.reset ( new BYTE [ dwProcessInformationSize ] );
					ProcessInformation = (SYSTEM_PROCESS_INFORMATION*)SmartProcessInformation.get () ;
				}
				else
				{
					fRetry = FALSE;
				}
			}

            // If we got the process information, process it...
            if(ProcessInformation != NULL &&
                dwRet == ERROR_SUCCESS)
            {
                SYSTEM_PROCESS_INFORMATION* CurrentInformation = NULL;
                DWORD dwNextOffset;
                CurrentInformation = ProcessInformation;
                bool fContinue = true;
                while(CurrentInformation != NULL &&
                        fContinue)
                {
                    {
                        CProcess cptmp(
                            HandleToUlong(CurrentInformation->UniqueProcessId),
                            (CurrentInformation->ImageName).Buffer);

                        vecProcesses.push_back(cptmp);
                    }

                    dwNextOffset = CurrentInformation->NextEntryOffset;
                    if(dwNextOffset)
                    {
                        CurrentInformation = (SYSTEM_PROCESS_INFORMATION*) 
                            (((BYTE*) CurrentInformation) + dwNextOffset);
                    }
                    else
                    {
                        fContinue = false;
                    }
                }
            }
        }
	}
    else
    {
        LogErrorMessage(L"Failed to load library ntdll.dll");
    }

    return dwRet;
}

// Implementation lifted from dllutils.cpp.
DWORD CUserSessionCollection::EnablePrivilegeOnCurrentThread(
    LPCTSTR szPriv) const
{
    SmartCloseHandle    hToken = NULL;
    TOKEN_PRIVILEGES    tkp;
    BOOL                bLookup = FALSE;
    DWORD               dwLastError = ERROR_SUCCESS;

    // Try to open the thread token.  
    if (::OpenThreadToken(
            GetCurrentThread(), 
            TOKEN_ADJUST_PRIVILEGES | TOKEN_QUERY, 
            FALSE, 
            &hToken))
    {

        {
            bLookup = ::LookupPrivilegeValue(
                NULL, 
                szPriv, 
                &tkp.Privileges[0].Luid);
        }
        if (bLookup)
        {
            tkp.PrivilegeCount = 1;
            tkp.Privileges[0].Attributes = SE_PRIVILEGE_ENABLED;

            // Clear the last error.
            SetLastError(0);

            // Turn it on
            ::AdjustTokenPrivileges(
                hToken, 
                FALSE, 
                &tkp, 
                0,
                (PTOKEN_PRIVILEGES) NULL, 
                0);

            dwLastError = GetLastError();
        }
    }
	else
	{
		dwLastError = ::GetLastError();
	}

    // We have to check GetLastError() because 
    // AdjustTokenPrivileges lies about
    // its success but GetLastError() doesn't.
    return dwLastError;
}



bool CUserSessionCollection::IsSessionMapped(
    LUID& luidSes)
{
    bool fRet = false;

    USER_SESSION_ITERATOR usiter;
    usiter = m_usr2ses.begin();
    for(usiter = m_usr2ses.begin(); 
        usiter != m_usr2ses.end() && !fRet;
        usiter++)
    {
        LUID luidTmp = (usiter->second).GetLUID();
        if(luidTmp.HighPart == luidSes.HighPart &&
           luidTmp.LowPart == luidSes.LowPart)
        {
            fRet = true;
        }
    }

    return fRet;                                                   
}


bool CUserSessionCollection::IsSessionMapped(
    __int64 i64luidSes)
{
    LUID luidSes = *((LUID*)(&i64luidSes));
    return IsSessionMapped(luidSes);
}


// Collects sessions that have no associated
// process.  Uses LSA to enumerate sessions,
// then checks to see if we have each session
// already.  If we don't, adds it to our map.

DWORD CUserSessionCollection::CollectNoProcessesSessions()
{
    DWORD dwRet = ERROR_SUCCESS;
    ULONG ulLogonSessionCount = 0L;
    PLUID pluidLogonSessions = NULL;
    HMODULE hLib = NULL;
    PFN_LSA_ENUMERATE_LOGON_SESSIONS pfnEnumLogonSessions = NULL;
    PFN_LSA_GET_LOGON_SESSION_DATA pfnGetLogonSessionData = NULL;
    PFN_LSA_FREE_RETURN_BUFFER pfnLsaFreeReturnBuffer = NULL;

    // Doing a load library here rather than using the
    // resource manager, as SECURITYAPI.CPP defines us
    // to point to SECURITY.DLL, not SECUR32.DLL for the
    // W2K case.  

    hLib = ::LoadLibraryW(L"SECUR32.DLL");
    if(hLib)
    {
		//
		// auto FreeLibrary
		//
		ON_BLOCK_EXIT ( FreeLibrary, hLib ) ;

        pfnEnumLogonSessions = 
            (PFN_LSA_ENUMERATE_LOGON_SESSIONS) ::GetProcAddress(
                hLib,
                "LsaEnumerateLogonSessions");

        pfnGetLogonSessionData = 
            (PFN_LSA_GET_LOGON_SESSION_DATA) ::GetProcAddress(
                hLib,
                "LsaGetLogonSessionData");

        pfnLsaFreeReturnBuffer = 
            (PFN_LSA_FREE_RETURN_BUFFER) ::GetProcAddress(
                hLib,
                "LsaFreeReturnBuffer");

        if(pfnEnumLogonSessions &&
            pfnGetLogonSessionData &&
            pfnLsaFreeReturnBuffer)
        {    
            dwRet = pfnEnumLogonSessions(
                &ulLogonSessionCount,
                &pluidLogonSessions);
    
            if(dwRet == ERROR_SUCCESS &&
                pluidLogonSessions)
            {
				//
				// auto destructor for logon session
				//
				ON_BLOCK_EXIT ( pfnLsaFreeReturnBuffer, pluidLogonSessions ) ;

                for(ULONG u = 0L;
                    u < ulLogonSessionCount && dwRet == ERROR_SUCCESS;
                    u++)
                {
                    PSECURITY_LOGON_SESSION_DATA pSessionData = NULL;
                    dwRet = pfnGetLogonSessionData(
                        &pluidLogonSessions[u], 
                        &pSessionData);

                    if(dwRet == ERROR_SUCCESS &&
                        pSessionData)
                    {
						//
						// smart session data
						//
						ON_BLOCK_EXIT ( pfnLsaFreeReturnBuffer, pSessionData ) ;

                        // See if we have the session already...
                        if(!IsSessionMapped(pSessionData->LogonId))
                        {
                            // and if not, add it to the map.
                            CSession sesNew(pSessionData->LogonId);
                            CUser cuTmp(pSessionData->Sid);
                            CHString chstrTmp;
                            
                            if(cuTmp.IsValid())
                            {
                                cuTmp.GetSidString(chstrTmp);
                
                                m_usr2ses.insert(
                                    USER_SESSION_MAP::value_type(
                                        cuTmp,
                                        sesNew));
                            }
                            else
                            {
                                LUID luidTmp = sesNew.GetLUID();
                                LogMessage3(
                                    L"GetLogonSessionData returned logon data for session "
                                    L"luid %d (highpart) %u (lowpart) containing an invalid SID", 
                                    luidTmp.HighPart,
                                    luidTmp.LowPart);
                            }
                        }

                        // While we are here, add in various
                        // session properties lsa has been kind
                        // enough to provide for us.
                        USER_SESSION_ITERATOR usiter;
                        usiter = m_usr2ses.begin();
                        bool fFound = false;
                        while(usiter != m_usr2ses.end() &&
                            !fFound)
                        {
                            LUID luidTmp = pSessionData->LogonId;
                            __int64 i64Tmp = *((__int64*)(&luidTmp));

                            if((usiter->second).GetLUIDint64() ==
                                i64Tmp)
                            {
                                fFound = true;
                            }
                            else
                            {
                                usiter++;
                            }
                        }
                        if(fFound)
                        {
                            WCHAR wstrTmp[_MAX_PATH] = { '\0' };
                            if((pSessionData->AuthenticationPackage).Length < (_MAX_PATH - 1))
                            {
                                wcsncpy(
                                    wstrTmp, 
                                    (pSessionData->AuthenticationPackage).Buffer, 
                                    (pSessionData->AuthenticationPackage).Length);

                                (usiter->second).m_chstrAuthPkg = wstrTmp;
                            }
                            
                            (usiter->second).m_ulLogonType = 
                                pSessionData->LogonType;

                            (usiter->second).i64LogonTime = 
                                *((__int64*)(&(pSessionData->LogonTime)));
                        }
                    }
                }                
            }
        }
    }
    else
    {
        LogErrorMessage(L"Failed to load library SECUR32.dll");
    }

	return dwRet; 
}


//*****************************************************************************
// CSession functions
//*****************************************************************************

CSession::CSession(
    const LUID& luidSessionID)
{
    m_luid.LowPart = luidSessionID.LowPart;
    m_luid.HighPart = luidSessionID.HighPart;
    m_ulLogonType = 0;
    i64LogonTime = 0;
}

CSession::CSession(
    const CSession& ses)
{
    m_luid.LowPart = ses.m_luid.LowPart;
    m_luid.HighPart = ses.m_luid.HighPart;
    m_chstrAuthPkg = ses.m_chstrAuthPkg;
    m_ulLogonType = ses.m_ulLogonType;
    i64LogonTime = ses.i64LogonTime;

    m_vecProcesses.clear();
    for(long lPos = 0; 
        lPos < ses.m_vecProcesses.size(); 
        lPos++)
    {
        m_vecProcesses.push_back(
            ses.m_vecProcesses[lPos]);

    }
}


LUID CSession::GetLUID() const
{
    return m_luid;   
}

__int64 CSession::GetLUIDint64() const
{
    __int64 i64LuidSes = *((__int64*)(&m_luid));
    return i64LuidSes;    
}

CHString CSession::GetAuthenticationPkg() const
{
    return m_chstrAuthPkg;
}


ULONG CSession::GetLogonType() const
{
    return m_ulLogonType;
}


__int64 CSession::GetLogonTime() const
{
    return i64LogonTime;
}




// Functions to support enumeration of
// processes associated with this session.
// Returns a newly allocated CProcess* that
// the caller must free.
CProcess* CSession::GetFirstProcess(
    PROCESS_ITERATOR& pos)
{
    CProcess* procRet = NULL;
    if(!m_vecProcesses.empty())
    {
        pos = m_vecProcesses.begin();
        procRet = new CProcess(*pos);
    }
    return procRet;
}


// Returns a newly allocated CProcess* that
// the caller must free.
CProcess* CSession::GetNextProcess(
    PROCESS_ITERATOR& pos)
{
    CProcess* procRet = NULL;

    if(pos >= m_vecProcesses.begin() &&
       pos < m_vecProcesses.end())
    {
        pos++;
        if(pos != m_vecProcesses.end())
        {
            procRet = new CProcess(*pos);
        }
    }

    return procRet;
}



void CSession::Copy(
    CSession& sesCopy) const
{
    sesCopy.m_luid.LowPart = m_luid.LowPart;
    sesCopy.m_luid.HighPart = m_luid.HighPart;
    sesCopy.m_chstrAuthPkg = m_chstrAuthPkg;
    sesCopy.m_ulLogonType = m_ulLogonType;
    sesCopy.i64LogonTime = i64LogonTime;

    sesCopy.m_vecProcesses.clear();
    for(long lPos = 0; 
        lPos < m_vecProcesses.size(); 
        lPos++)
    {
        sesCopy.m_vecProcesses.push_back(
            m_vecProcesses[lPos]);

    }
}


// This function impersonates the 
// explorer process in the session's
// process array, if it is present.
// (If it isn't, impersonates the
// first process in the process array.)
// Returns the handle of token of the  
// thread we started from for easy  
// reversion, orINVALID_HANDLE_VALUE if  
// we couldn't impersonate.  The caller  
// must close that handle.
HANDLE CSession::Impersonate()
{
    HANDLE hCurToken = INVALID_HANDLE_VALUE;

	// Find the explorer process...
    DWORD dwImpProcPID = GetImpProcPID();
    if(dwImpProcPID != -1L)
    {
		//
		// smart CloseHandle
		//
		ScopeGuard SmartCloseHandleFnc = MakeGuard ( CloseHandle, hCurToken ) ;

        bool fOK = false;

        if(::OpenThreadToken(
            ::GetCurrentThread(), 
            TOKEN_QUERY | TOKEN_DUPLICATE | TOKEN_IMPERSONATE , 
            TRUE, 
            &hCurToken))
        {
            SmartCloseHandle hProcess;
            hProcess = ::OpenProcess(
                PROCESS_QUERY_INFORMATION,
                FALSE,
                dwImpProcPID);

            if(hProcess)
            {
                // now open its token...
                SmartCloseHandle hExplorerToken;
                if(::OpenProcessToken(
                        hProcess,
                        TOKEN_READ | TOKEN_QUERY | TOKEN_DUPLICATE | TOKEN_IMPERSONATE,
                        &hExplorerToken))
                {
					CProcessToken cpt ( hExplorerToken );
					if ( cpt.IsValidToken () )
					{
						TOKEN_TYPE type;
						if ( cpt.GetTokenType ( type ) )
						{
							if ( TokenPrimary == type )
							{
								CToken ct;
								if ( ct.Duplicate ( cpt, FALSE ) )
								{
									// Set the thread token...
									if(::SetThreadToken(NULL, ct.GetTokenHandle ()))
									{
										fOK = true;                        
									}
								}
							}
							else
							{
								// Set the thread token...
								if(::SetThreadToken(NULL, cpt.GetTokenHandle ()))
								{
									fOK = true;                        
								}
							}
						}
					}
                }
            }
        }

		SmartCloseHandleFnc.Dismiss () ;
        if (!fOK)
        {
            if(hCurToken != INVALID_HANDLE_VALUE)
            {
                ::CloseHandle(hCurToken);
                hCurToken = INVALID_HANDLE_VALUE;
            }    
        }
    }

    return hCurToken;
}


DWORD CSession::GetImpProcPID()
{
    DWORD dwRet = -1L;

    if(!m_vecProcesses.empty())
    {
        bool fFoundExplorerExe = false;

        for(long m = 0;
            m < m_vecProcesses.size() && 
             !fFoundExplorerExe;)
        {
            if(m_vecProcesses[m].GetImageName().CompareNoCase(
                L"explorer.exe") == 0)
            {
                fFoundExplorerExe = true;
                break;
            }
            else
            {
                m++;
            }
        }

        if(!fFoundExplorerExe)
        {
            m = 0;
        }

        dwRet = m_vecProcesses[m].GetPID();
    }

    return dwRet;
}



bool CSession::IsSessionIDValid(
        LPCWSTR wstrSessionID)
{
    bool fRet = true;
    
    if(wstrSessionID != NULL &&
        *wstrSessionID != L'\0')
    {
        for(const WCHAR* pwc = wstrSessionID;
            *pwc != NULL && fRet;
            pwc++)
        {
            fRet = iswdigit(*pwc);
        } 
    }
    else
    {
        fRet = false;
    }
            
    return fRet;
}


//*****************************************************************************
// CProcess functions
//*****************************************************************************

CProcess::CProcess() 
  :  m_dwPID(0) 
{
}


CProcess::CProcess(
    DWORD dwPID,
    LPCWSTR wstrImageName)
  :  m_dwPID(dwPID)
{
    m_chstrImageName = wstrImageName;
}


CProcess::CProcess(
    const CProcess& process)
{
    m_dwPID = process.m_dwPID;
    m_chstrImageName = process.m_chstrImageName;
}

CProcess::~CProcess()
{
}


DWORD CProcess::GetPID() const
{
    return m_dwPID;
}

CHString CProcess::GetImageName() const
{
    return m_chstrImageName;
}


void CProcess::Copy(
        CProcess& out) const
{
    out.m_dwPID = m_dwPID;
    out.m_chstrImageName = m_chstrImageName;
}




//*****************************************************************************
// CUser functions
//*****************************************************************************


CUser::CUser(
    PSID pSid)
  :  m_sidUser(NULL),
     m_fValid(false)
{
    if(::IsValidSid(pSid))
    {
        DWORD dwSize = ::GetLengthSid(pSid);
        m_sidUser = NULL;
        m_sidUser = malloc(dwSize);
        if(m_sidUser == NULL)
        {
		    throw CHeap_Exception(
                CHeap_Exception::E_ALLOCATION_ERROR);
        }
        else
        {
	        ::CopySid(
                dwSize, 
                m_sidUser, 
                pSid);

            m_fValid = true;
        }
    }
}



CUser::CUser(
    const CUser& user)
{
    DWORD dwSize = ::GetLengthSid(user.m_sidUser);
    m_sidUser = malloc(dwSize);

    if(m_sidUser == NULL)
    {
		throw CHeap_Exception(
            CHeap_Exception::E_ALLOCATION_ERROR);
    }

	::CopySid(
        dwSize, 
        m_sidUser, 
        user.m_sidUser);

    m_fValid = user.m_fValid;

}



CUser::~CUser()
{
    if(m_sidUser) 
    {
        free(m_sidUser);
        m_sidUser = NULL;
    }
}


bool CUser::IsValid()
{
    return m_fValid;
}


void CUser::Copy(
    CUser& out) const
{
    if(out.m_sidUser) 
    {
        free(out.m_sidUser);
        out.m_sidUser = NULL;
    }

    DWORD dwSize = ::GetLengthSid(m_sidUser);
    out.m_sidUser = malloc(dwSize);

    if(out.m_sidUser == NULL)
    {
		throw CHeap_Exception(
            CHeap_Exception::E_ALLOCATION_ERROR);
    }

	::CopySid(
        dwSize, 
        out.m_sidUser, 
        m_sidUser);

    out.m_fValid = m_fValid;
}


// Implementation lifted from sid.cpp.
void CUser::GetSidString(CHString& str) const
{
    ASSERT_BREAK(m_fValid);

    if(m_fValid)
    {
        // Initialize m_strSid - human readable form of our SID
	    SID_IDENTIFIER_AUTHORITY *psia = NULL;
        psia = ::GetSidIdentifierAuthority( m_sidUser );

	    // We assume that only last byte is used (authorities between 0 and 15).
	    // Correct this if needed.
	    ASSERT_BREAK( psia->Value[0] == psia->Value[1] == 
                      psia->Value[2] == psia->Value[3] == 
                      psia->Value[4] == 0 );

	    DWORD dwTopAuthority = psia->Value[5];

	    str.Format( L"S-1-%u", dwTopAuthority );
	    CHString strSubAuthority;
	    int iSubAuthorityCount = *( GetSidSubAuthorityCount( m_sidUser ) );
	    for ( int i = 0; i < iSubAuthorityCount; i++ ) {

		    DWORD dwSubAuthority = *( GetSidSubAuthority( m_sidUser, i ) );
		    strSubAuthority.Format( L"%u", dwSubAuthority );
		    str += _T("-") + strSubAuthority;
	    }
    }
}