1 /* Copyright (C) 2002-2005 RealVNC Ltd.  All Rights Reserved.
2  *
3  * This is free software; you can redistribute it and/or modify
4  * it under the terms of the GNU General Public License as published by
5  * the Free Software Foundation; either version 2 of the License, or
6  * (at your option) any later version.
7  *
8  * This software is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11  * GNU General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public License
14  * along with this software; if not, write to the Free Software
15  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307,
16  * USA.
17  */
18 
19 // -=- Currentuser.cxx
20 
21 #include <stdlib.h>
22 #include <rfb/LogWriter.h>
23 #include <rfb_win32/CurrentUser.h>
24 #include <rfb_win32/Service.h>
25 #include <lmcons.h>
26 #include <wtsapi32.h>
27 
28 using namespace rfb;
29 using namespace win32;
30 
31 static LogWriter vlog("CurrentUser");
32 
33 
34 const TCHAR* shellIconClass = _T("Shell_TrayWnd");
35 
enumWindows(HWND hwnd,LPARAM lParam)36 BOOL CALLBACK enumWindows(HWND hwnd, LPARAM lParam) {
37   TCHAR className[16];
38   if (GetClassName(hwnd, className, sizeof(className)) &&
39       (_tcscmp(className, shellIconClass) == 0)) {
40     vlog.debug("located tray icon window (%s)", (const char*)CStr(className));
41     DWORD processId = 0;
42     GetWindowThreadProcessId(hwnd, &processId);
43     if (!processId)
44       return TRUE;
45     Handle process = OpenProcess(MAXIMUM_ALLOWED, FALSE, processId);
46     if (!process.h)
47       return TRUE;
48     if (!OpenProcessToken(process, MAXIMUM_ALLOWED, (HANDLE*)lParam))
49       return TRUE;
50     vlog.debug("obtained user token");
51     return FALSE;
52   }
53   return TRUE;
54 }
55 
enumDesktops(LPTSTR lpszDesktop,LPARAM lParam)56 BOOL CALLBACK enumDesktops(LPTSTR lpszDesktop, LPARAM lParam) {
57   HDESK desktop = OpenDesktop(lpszDesktop, 0, FALSE, DESKTOP_ENUMERATE);
58   vlog.debug("opening \"%s\"", lpszDesktop);
59   if (!desktop) {
60     vlog.info("desktop \"%s\" inaccessible", (const char*)CStr(lpszDesktop));
61     return TRUE;
62   }
63   BOOL result = EnumDesktopWindows(desktop, enumWindows, lParam);
64   if (!CloseDesktop(desktop))
65     vlog.info("unable to close desktop: %ld", GetLastError());
66   return result;
67 }
68 
69 
CurrentUserToken()70 CurrentUserToken::CurrentUserToken() {
71   if (isServiceProcess()) {
72     // Try to get the user token using the Terminal Services APIs
73     WTSQueryUserToken(-1, &h);
74   } else {
75     // Try to open the security token for the User-Mode process
76     if (!OpenProcessToken(GetCurrentProcess(), GENERIC_ALL, &h)) {
77       DWORD err = GetLastError();
78       if (err != ERROR_CALL_NOT_IMPLEMENTED)
79         throw rdr::SystemException("OpenProcessToken failed", err);
80       h = INVALID_HANDLE_VALUE;
81     }
82   }
83 }
84 
85 
ImpersonateCurrentUser()86 ImpersonateCurrentUser::ImpersonateCurrentUser() {
87   RegCloseKey(HKEY_CURRENT_USER);
88   if (!isServiceProcess())
89     return;
90   if (!token.canImpersonate())
91     throw rdr::Exception("Cannot impersonate unsafe or null token");
92   if (!ImpersonateLoggedOnUser(token)) {
93     DWORD err = GetLastError();
94     if (err != ERROR_CALL_NOT_IMPLEMENTED)
95       throw rdr::SystemException("Failed to impersonate user", GetLastError());
96   }
97 }
98 
~ImpersonateCurrentUser()99 ImpersonateCurrentUser::~ImpersonateCurrentUser() {
100   if (!RevertToSelf()) {
101     DWORD err = GetLastError();
102     if (err != ERROR_CALL_NOT_IMPLEMENTED)
103       exit(err);
104   }
105   RegCloseKey(HKEY_CURRENT_USER);
106 }
107 
108 
UserName()109 UserName::UserName() : TCharArray(UNLEN+1) {
110   DWORD len = UNLEN+1;
111   if (!GetUserName(buf, &len))
112     throw rdr::SystemException("GetUserName failed", GetLastError());
113 }
114 
115 
UserSID()116 UserSID::UserSID() {
117   CurrentUserToken token;
118   if (!token.canImpersonate())
119     return;
120   setSID(Sid::FromToken(token.h));
121 }
122