Microsoft KB Archive/252490

= How To Use ADSI to Query the Global Catalog for a UPN =

Article ID: 252490

Article Last Modified on 10/12/2007

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APPLIES TO


 * Microsoft Windows 2000 Server
 * Microsoft Windows 2000 Advanced Server
 * Microsoft Windows 2000 Professional Edition
 * Microsoft Active Directory Service Interfaces 2.0
 * Microsoft Active Directory Service Interfaces 2.5

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This article was previously published under Q252490



SUMMARY
A User Principal Name (UPN) is composed of a user account logon name and the user principal name suffix joined by the "@" sign. The UPN allows for a simplified logon. Most commonly, the UPN is the user's e-mail address. Because the user principal name provides the ability to perform a single logon anywhere in the enterprise, the UPN is required to be unique across the entire Microsoft Windows 2000 forest. This is achieved by querying the Global Catalog for an existing user with that UPN.

This article contains code samples written in Microsoft Visual Basic and Microsoft Visual C++ that demonstrate how to query the Global Catalog for a UPN.



MORE INFORMATION
Before setting a UPN for a new or existing user, the Global Catalog should be queried. The Active Directory Users and Computers Microsoft Management Console (MMC) snap-in queries the Global Catalog, as should any other application making modifications to the UPN. Although querying the Global Catalog does not absolutely guarantee that a UPN is unique across the enterprise, it is a recommended practice that greatly reduces the chances of duplication. Following is a Microsoft Visual Basic/VBScript code example that uses Active Directory Services Interfaces (ADSI) Lightweight Directory Access Protocol (LDAP) provider to query the Global Catalog for a UPN:

'The following lines are commented for use in VBScript Dim oConnection 'As ADODB.Connection Dim oRecordset 'As ADODB.Recordset Dim strQuery 'As String Dim strUPN 'As String Dim oCont 'As IADsContainer Dim oGC 'As IADs Dim strADsPath 'As String

'TO DO : Change the UPN to fit your environment strUPN = "User1@Corp.com"

'Find the Global Catalog server Set oCont = GetObject("GC:") For Each oGC In oCont strADsPath = oGC.ADsPath Next

Set oConnection = CreateObject("ADODB.Connection") Set oRecordset = CreateObject("ADODB.Recordset") oConnection.Provider = "ADsDSOObject" 'The ADSI OLE-DB provider

oConnection.Open "ADs Provider" strQuery = "<" & strADsPath & ">;(&(objectClass=user)(objectCategory=person)(userprincipalName=" & strUPN & "));userPrincipalName,cn,distinguishedName;subtree" Set oRecordset = oConnection.Execute(strQuery)

If oRecordset.EOF And oRecordset.BOF Then MsgBox "No duplicate UPN found" Else While Not oRecordset.EOF MsgBox oRecordset.Fields("userPrincipalName") & " found!" & vbLf & oRecordset.Fields("cn") & " located at " & oRecordset.Fields("distinguishedName") oRecordset.MoveNext Wend End If

Set oCont = Nothing Set oGC = Nothing Set oRecordset = Nothing Set oConnection = Nothing

Following is a similar example for use in Microsoft Visual C++:


 * 1) define UNICODE
 * 2) define _UNICODE
 * 3) include 
 * 4) include 

HRESULT FindUPN(LPOLESTR bstrUPN);

int wmain(int argc, wchar_t *argv[]) {   LPOLESTR lpstrUPN=NULL; //Initialize COM CoInitialize(NULL); HRESULT hr = S_OK; if(argc != 2) {       wprintf(L"This program will query the GC for the existence of a UPN\n"); wprintf(L"Please enter the UPN to search for\n");

}   else {       lpstrUPN = argv[1]; hr = FindUPN(lpstrUPN); if (FAILED(hr)) wprintf(L"Search failed with hr: %d\n", hr); }   // Uninitialize COM CoUninitialize; return 0; }

HRESULT FindUPN(LPOLESTR pszUPN) {   HRESULT hr = E_FAIL; HRESULT hrGC = S_OK; VARIANT var; ULONG lFetch; // Interface Pointers IDirectorySearch *pGCSearch = NULL; IADsContainer *pContainer = NULL; IUnknown *pUnk = NULL; IEnumVARIANT *pEnum = NULL; IDispatch *pDisp = NULL; IADs *pADs = NULL; //Bind to Global Catalog hr = ADsOpenObject(L"GC:", //NT 4.0, Win9.x client must include the servername, e.g GC://myServer        NULL,        NULL,        ADS_SECURE_AUTHENTICATION, //Use Secure Authentication        IID_IADsContainer,        (void**)&pContainer); if (SUCCEEDED(hr)) {       hr = pContainer->get__NewEnum( &pUnk ); if (SUCCEEDED(hr)) {           hr = pUnk->QueryInterface( IID_IEnumVARIANT, (void**) &pEnum ); if (SUCCEEDED(hr)) {               // Now Enumerate--there should be only one item. hr = pEnum->Next( 1, &var, &lFetch ); if (SUCCEEDED(hr)) {                   while( hr == S_OK ) {                       if ( lFetch == 1 ) {                           pDisp = V_DISPATCH(&var); hr = pDisp->QueryInterface( IID_IDirectorySearch, (void**)&pGCSearch); hrGC = hr; }                       VariantClear(&var); hr = pEnum->Next( 1, &var, &lFetch ); };               }            }            if (pEnum) pEnum->Release; }       if (pUnk) pUnk->Release; }   if (pContainer) pContainer->Release; if (FAILED(hrGC)) {       if (pGCSearch) pGCSearch->Release; return hrGC; }   //Create search filter WCHAR rgSearchFilter[1024]; wsprintf(rgSearchFilter,L"(&(objectCategory=person)(objectClass=user)(userPrincipalName=%s))", pszUPN); //Search entire subtree from root. ADS_SEARCHPREF_INFO SearchPrefs; SearchPrefs.dwSearchPref = ADS_SEARCHPREF_SEARCH_SCOPE; SearchPrefs.vValue.dwType = ADSTYPE_INTEGER; SearchPrefs.vValue.Integer = ADS_SCOPE_SUBTREE; DWORD dwNumPrefs = 1; // COL for iterations ADS_SEARCH_COLUMN col; // Handle used for searching ADS_SEARCH_HANDLE hSearch; // Set the search preference hr = pGCSearch->SetSearchPreference( &SearchPrefs, dwNumPrefs); if (FAILED(hr)) return hr; // Set attributes to return CONST DWORD dwAttrNameSize = 3; LPOLESTR pszAttribute[dwAttrNameSize] = {L"cn",L"distinguishedName",L"userPrincipalName"}; // Execute the search hr = pGCSearch->ExecuteSearch(rgSearchFilter,       pszAttribute,        dwAttrNameSize,        &hSearch        ); if ( SUCCEEDED(hr) ) {           if(pGCSearch->GetFirstRow(hSearch) ==  S_ADS_NOMORE_ROWS ) {           wprintf(L"There is no UPN with that value\n"); }       else   //The UPN was found {           do            { // loop through the array of passed column names, // print the data for each column for (DWORD x = 0; x < dwAttrNameSize; x++) {                   // Get the data for this column hr = pGCSearch->GetColumn( hSearch, pszAttribute[x], &col ); if ( SUCCEEDED(hr) ) {                       // Print the data for the column and free the column // Note the attributes we asked for are type CaseIgnoreString. wprintf(L"%s: %s\r\n",pszAttribute[x],col.pADsValues->CaseIgnoreString); pGCSearch->FreeColumn( &col ); }                   else wprintf(L"<%s property is not a string>",pszAttribute[x]); }               wprintf(L"--\n"); }           while( pGCSearch->GetNextRow( hSearch) != S_ADS_NOMORE_ROWS ); }       // Close the search handle to clean up        pGCSearch->CloseSearchHandle(hSearch);

}    if (pGCSearch) pGCSearch->Release; return hr; }

