How to read and write the HKEY_CURRENT_USER registry in a Windows service program

In the service program you want to read and write to the contents of the registry HKEY_CURRENT_USER, and will not return a failure, but it is always invalid. The reasons are:

1. The service runs under System permissions, not any one user

2.hkey_current_user stores the current user's information ================> causes the data in the service to be read HKEY_CURRENT_USER the actual operation of the user who is not currently logged on.

So if I want to manipulate the key value within the HKEY_CURRENT_USER, I have to impersonate the current user to read it.

There are several ways to do this:

1. Create a user process to operate the registry, using the CreateProcessAsUser function to do

2. Let the current thread impersonate the security context of the currently logged-on user (lets the calling thread impersonate, the security context of a logged-on user). You can do this using the ImpersonateLoggedOnUser function.

The first method needs to use another program, feeling more troublesome.

The second method is shown below:

BOOL Gettokenbyname (HANDLE &htoken,lptstr lpname) {    if(!lpname)returnFALSE; HANDLE Hprocesssnap=NULL; BOOL BRet=FALSE; PROCESSENTRY32 pe32= {0}; Hprocesssnap= CreateToolhelp32Snapshot (th32cs_snapprocess,0); if(Hprocesssnap = =Invalid_handle_value)return(FALSE); Pe32.dwsize=sizeof(PROCESSENTRY32); if(Process32First (Hprocesssnap, &pe32)) {           Do        {            if(!_tcscmp (_TCSUPR (Pe32.szexefile), _TCSUPR (lpname))) {HANDLE hprocess=openprocess (PROCESS_QUERY_INFORMATION,FALSE,PE32.TH32PROCESSID); BRet= OpenProcessToken (hprocess,token_all_access,&htoken);                 CloseHandle (hprocess);                 CloseHandle (HPROCESSSNAP); return(BRet); }        }         while(Process32Next (Hprocesssnap, &pe32)); BRet=FALSE; }     Else{BRet=FALSE;     } closehandle (HPROCESSSNAP); return(BRet);}////Get user SID//BOOLGetaccountsid (LPTSTR accountname, PSID *Sid) {PSID PSID=NULL; DWORD Cbsid=0; LPTSTR DomainName=NULL; DWORD Cbdomainname=0;    Sid_name_use SidNameUse; BOOL Bdone=FALSE; Try    {        if(!LookupAccountName (NULL, AccountName, PSID,&Cbsid, DomainName,&Cbdomainname,&sidnameuse)) {PSID=(PSID) malloc (CBSID); DomainName= (LPTSTR) malloc (Cbdomainname *sizeof(TCHAR)); if(!psid | |!DomainName) {                Throw; }            if(!LookupAccountName (NULL, AccountName, PSID,&Cbsid, DomainName,&Cbdomainname,&sidnameuse)) {                Throw; } bdone=TRUE; }    }    Catch(...) {        // Nothing    }    if(DomainName) {free (DomainName); }    if(!bdone &&PSID)    {free (PSID); }    if(bdone) {*sid =PSID; }    returnBdone;}//impersonate the current user environment to set the default printervoidSimulatecurrentusersetdefaultprinter () {HANDLE Htoken=NULL;  Do     {        if(! Gettokenbyname (htoken,_t ("EXPLORER. EXE")))        {             Break; }        //impersonate the security context of the logged-on user        if(FALSE = =ImpersonateLoggedOnUser (Htoken)) {             Break; }        //Get user nameTCHAR Szusername[max_path]; DWORD Dwusernamelen=MAX_PATH; if(FALSE = = GetUserName (szUserName, &Dwusernamelen))  Break; //We're done here, so don't forget to return to the original security context.        if(FALSE = =RevertToSelf ()) Break; //Get SidPSID PSID =NULL;        LPWSTR SID; Getaccountsid (szUserName,&PSID);//Get is a structConvertsidtostringsid (PSid, &sid);//get the SID string from the struct//Set default printer information//SetDefaultPrinter (pssd_printer_name);HKEY HKEY; intI=0;//operation Result: 0==succeedwchar_t Lswregvalue[max_path]; stringcchprintf (Lswregvalue, MAX_PATH, L"%s,winspool,%s", Pssd_printer_name, pssd_printer_port_name); wchar_t Lswkeypath[max_path]= {0}; stringcchprintf (Lswkeypath, MAX_PATH, L"%s\\software\\microsoft\\windows nt\\currentversion\\windows", sid); if(RegOpenKeyEx (HKEY_USERS, Lswkeypath,0, key_all_access, &hkey) = =error_success) {            if(RegSetValueEx (hkey,l"Device", NULL,REG_SZ, (ConstLPBYTE) Lswregvalue, (Wcslen (lswregvalue) +1) *sizeof(wchar_t))! =error_success) {i=1;        } regclosekey (HKey); }        Else{i=1; }        if(1==i) {OutputDebugStringW (L"STST: Failed to set default printer"); }        Else{sendnotifymessage (Hwnd_broadcast, Wm_settingchange,0,0); }    }  while(false); if(NULL! =htoken) CloseHandle (Htoken);}

How to read and write the HKEY_CURRENT_USER registry in a Windows service program