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Verifying Client Access to a Requested Resource in C++

Call the AccessCheck method of the IAzClientContext interface to check if the client has access to one or more operations. A client might have membership in more than one role, and an operation might be assigned to more than one task, so Authorization Manager checks for all roles and tasks. If any role to which the client belongs contains any task that contains an operation, access to that operation is granted.

To check access for only a single role to which the client belongs, set the RoleForAccessCheck property of the IAzClientContext interface.

When initializing the authorization policy store for access check, you must pass zero as the value of the lFlags parameter of the IAzAuthorizationStore::Initialize method.

The following example shows how to check a client's access to an operation. The example assumes that there is an existing XML policy store named MyStore.xml in the root directory of drive C, that this store contains an application named Expense and an operation named UseFormControl, and that the variable hToken contains a valid client token.


#include <windows.h>
#include <stdio.h>
#include <azroles.h>

void CheckAccess(ULONGLONG hToken)
{
    IAzAuthorizationStore* pStore = NULL;
    IAzApplication* pApp = NULL;
    IAzClientContext* pClientContext = NULL;
    IAzOperation* pOperation = NULL;
    BSTR storeName = NULL;
    BSTR appName = NULL;
    BSTR operationName = NULL;
    BSTR objectName = NULL;
    LONG operationID;
    HRESULT hr;
    VARIANT varOperationIdArray;
    VARIANT varOperationId;
    VARIANT varResultsArray;
    VARIANT varResult;
    void MyHandleError(char *s);

    VARIANT myVar;
    VariantInit(&myVar);//.vt) = VT_NULL;

    //  Initialize COM.
    hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
    if (!(SUCCEEDED(hr)))
        MyHandleError("Could not initialize COM.");

    //  Create the AzAuthorizationStore object.
    hr = CoCreateInstance(
   /*"b2bcff59-a757-4b0b-a1bc-ea69981da69e"*/
         __uuidof(AzAuthorizationStore),
         NULL,
         CLSCTX_ALL,
   /*"edbd9ca9-9b82-4f6a-9e8b-98301e450f14"*/
         __uuidof(IAzAuthorizationStore),
         (void**)&pStore);
    if (!(SUCCEEDED(hr)))
        MyHandleError("Could not create AzAuthorizationStore object.");

    //  Allocate a string for the  policy store.
    if(!(storeName = SysAllocString(L"msxml://c:\\myStore.xml")))
        MyHandleError("Could not allocate string.");
    
    //  Initialize the store.
    hr = pStore->Initialize(0, storeName, myVar);
    if (!(SUCCEEDED(hr)))
        MyHandleError("Could not initialize store.");

    //  Create an application object.
    if (!(appName = SysAllocString(L"Expense")))
        MyHandleError("Could not allocate application name string.");
    hr = pStore->OpenApplication(appName, myVar, &pApp);
    if (!(SUCCEEDED(hr)))
        MyHandleError("Could not open application.");

    //  Create a client context from a token handle.
    hr = pApp->InitializeClientContextFromToken(hToken, myVar,
   &pClientContext);
    if (!(SUCCEEDED(hr)))
        MyHandleError("Could not create client context.");

    //  Set up parameters for access check.

    //  Set up the object name.
    if (!(operationName = SysAllocString(L"UseFormControl")))
        MyHandleError("Could not allocate operation name string.");

    //  Get the ID of the operation to check.
    hr = pApp->OpenOperation(operationName, myVar, &pOperation);
    if (!(SUCCEEDED(hr)))
        MyHandleError("Could not open operation.");

    hr = pOperation->get_OperationID(&operationID);
    if(!(SUCCEEDED(hr)))
        MyHandleError("Could not get operation ID.");

    //  Create a SAFEARRAY for the operation ID.
    varOperationIdArray.parray = SafeArrayCreateVector(VT_VARIANT, 0, 1);

    //  Set SAFEARRAY type.
    varOperationIdArray.vt = VT_ARRAY | VT_VARIANT;

    //  Create an array of indexes.
    LONG* index = new LONG[1];
    index[0] = 0;

    //  Populate a SAFEARRAY with the operation ID.
    varOperationId.vt = VT_I4;
    varOperationId.lVal = operationID;

    hr = SafeArrayPutElement(varOperationIdArray.parray, index,
   &varOperationId);
    if(!(SUCCEEDED(hr)))
        MyHandleError("Could not put operation ID in array.");

    if(!(objectName = SysAllocString(L"UseFormControl")))//used for audit
        MyHandleError("Could not allocate object name string.");

    //  Check access.
    hr = pClientContext->AccessCheck(
        objectName,
        myVar,
        varOperationIdArray,
        myVar,               // use default application scope
        myVar,
        myVar,
        myVar,
        myVar,
        &varResultsArray);

    if (!(SUCCEEDED(hr)))
        MyHandleError("Could not complete access check.");

    hr = SafeArrayGetElement(varResultsArray.parray, index, &varResult);
    if (!(SUCCEEDED(hr)))
        MyHandleError("Could not get result from array.");

    if (varResult.lVal == 0)
        printf("Access granted.\n");
    else
        printf("Access denied.\n");
    

    //  Clean up resources.
    pStore->Release();
    pApp->Release();
    pClientContext->Release();
    pOperation->Release();
    SysFreeString(storeName);
    SysFreeString(appName);
    SysFreeString(operationName);
    SysFreeString(objectName);
    VariantClear(&myVar);
    VariantClear(&varOperationIdArray);
    VariantClear(&varOperationId);
    VariantClear(&varResultsArray);
    VariantClear(&varResult); 
    CoUninitialize();
}

void MyHandleError(char *s)
{
    printf("An error occurred in running the program.\n");
    printf("%s\n",s);
    printf("Error number %x\n.",GetLastError());
    printf("Program terminating.\n");
    exit(1);
}


 

 

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