IMetadataInfo::GetVrToken Method

 

Retrieves an IHttpTokenEntry interface for the impersonation account that is configured for a virtual directory.

Syntax

virtual IHttpTokenEntry* GetVrToken(  
   VOID  
) = 0;  

Parameters

This method takes no parameters.

Return Value

A pointer to an IHttpTokenEntry interface.

Remarks

When creating a virtual directory in IIS that points to a network share, you can specify the impersonation user name and password that IIS will use to connect to the network share when IIS processes requests. You can then use the GetVrToken method to retrieve an IHttpTokenEntry interface for the impersonated user.

Example

The following code example demonstrates how to use the GetVrToken method to create an HTTP module that retrieves an IHttpTokenEntry interface for the impersonation account that is configured for a virtual directory. The module converts the user token to a string and returns the string to the Web client.

#define _WINSOCKAPI_
#include <windows.h>
#include <sal.h>
#include <httpserv.h>
#define _WIN32_WINNT 0x0500
#include <sddl.h>

// Create the module class.
class MyHttpModule : public CHttpModule
{
public:
    REQUEST_NOTIFICATION_STATUS
    OnBeginRequest(
        IN IHttpContext * pHttpContext,
        IN IHttpEventProvider * pProvider
    )
    {
        UNREFERENCED_PARAMETER( pProvider );

        // Retrieve a pointer to the IMetadataInfo interface.
        IMetadataInfo * pMetadataInfo = pHttpContext->GetMetadata();

        // Test for an error.
        if (NULL != pMetadataInfo)
        {
            // Retrieve the token key for the metadata interface.
            IHttpTokenEntry * pHttpTokenEntry = pMetadataInfo->GetVrToken();
            // Test for an error.
            if (NULL != pHttpTokenEntry)
            {
                // Clear the existing response.
                pHttpContext->GetResponse()->Clear();
                // Set the MIME type to plain text.
                pHttpContext->GetResponse()->SetHeader(
                    HttpHeaderContentType,"text/plain",
                    (USHORT)strlen("text/plain"),TRUE);
                // Retrieve the SID for the user associated with the metadata.
                PSID pSid = pHttpTokenEntry->GetSid();
                // Test for an error.
                if (NULL==pSid)
                {
                    // Return a message to the client that the SID is null.
                    WriteResponseMessage(pHttpContext,
                        "The metadata SID is ","null");
                }
                else
                {
                    // Test whether the SID is valid.
                    if (FALSE == IsValidSid(pSid))
                        // Return a message to the client that the SID is invalid.
                        WriteResponseMessage(pHttpContext,
                        "The metadata SID is ","invalid");
                    else
                    {
                        LPTSTR pszSid;
                        // Convert the SID to a string.
                        if (TRUE == ConvertSidToStringSid(pSid,&pszSid))
                        {
                            // Return a message to the client with the SID.
                            WriteResponseMessage(pHttpContext,
                                "The metadata SID is ",pszSid);
                        }
                    }
                }
                // End additional processing.
                return RQ_NOTIFICATION_FINISH_REQUEST;
            }
        }
        // Return processing to the pipeline.
        return RQ_NOTIFICATION_CONTINUE;
    }

private:

    // Create a utility method that inserts a name/value pair into the response.
    HRESULT WriteResponseMessage(
        IHttpContext * pHttpContext,
        PCSTR pszName,
        PCSTR pszValue
    )
    {
        // Create an HRESULT to receive return values from methods.
        HRESULT hr;
        
        // Create a data chunk.
        HTTP_DATA_CHUNK dataChunk;
        // Set the chunk to a chunk in memory.
        dataChunk.DataChunkType = HttpDataChunkFromMemory;
        // Buffer for bytes written of data chunk.
        DWORD cbSent;

        // Set the chunk to the first buffer.
        dataChunk.FromMemory.pBuffer =
            (PVOID) pszName;
        // Set the chunk size to the first buffer size.
        dataChunk.FromMemory.BufferLength =
            (USHORT) strlen(pszName);
        // Insert the data chunk into the response.
        hr = pHttpContext->GetResponse()->WriteEntityChunks(
            &dataChunk,1,FALSE,TRUE,&cbSent);
        // Test for an error.
        if (FAILED(hr))
        {
            // Return the error status.
            return hr;
        }

        // Set the chunk to the second buffer.
        dataChunk.FromMemory.pBuffer =
            (PVOID) pszValue;
        // Set the chunk size to the second buffer size.
        dataChunk.FromMemory.BufferLength =
            (USHORT) strlen(pszValue);
        // Insert the data chunk into the response.
        hr = pHttpContext->GetResponse()->WriteEntityChunks(
            &dataChunk,1,FALSE,TRUE,&cbSent);
        // Test for an error.
        if (FAILED(hr))
        {
            // Return the error status.
            return hr;
        }

        // Return a success status.
        return S_OK;
    }
};

// Create the module's class factory.
class MyHttpModuleFactory : public IHttpModuleFactory
{
public:
    HRESULT
    GetHttpModule(
        OUT CHttpModule ** ppModule, 
        IN IModuleAllocator * pAllocator
    )
    {
        UNREFERENCED_PARAMETER( pAllocator );

        // Create a new instance.
        MyHttpModule * pModule = new MyHttpModule;

        // Test for an error.
        if (!pModule)
        {
            // Return an error if the factory cannot create the instance.
            return HRESULT_FROM_WIN32( ERROR_NOT_ENOUGH_MEMORY );
        }
        else
        {
            // Return a pointer to the module.
            *ppModule = pModule;
            pModule = NULL;
            // Return a success status.
            return S_OK;
        }            
    }

    void Terminate()
    {
        // Remove the class from memory.
        delete this;
    }
};

// Create the module's exported registration function.
HRESULT
__stdcall
RegisterModule(
    DWORD dwServerVersion,
    IHttpModuleRegistrationInfo * pModuleInfo,
    IHttpServer * pGlobalInfo
)
{
    UNREFERENCED_PARAMETER( dwServerVersion );

    // Set the request notifications and exit.
    return pModuleInfo->SetRequestNotifications(
        new MyHttpModuleFactory,
        RQ_BEGIN_REQUEST,
        0
    );
}

Your module must export the RegisterModule function. You can export this function by creating a module definition (.def) file for your project, or you can compile the module by using the /EXPORT:RegisterModule switch. For more information, see Walkthrough: Creating a Request-Level HTTP Module By Using Native Code.

You can optionally compile the code by using the __stdcall (/Gz) calling convention instead of explicitly declaring the calling convention for each function.

Requirements

Type Description
Client - IIS 7.0 on Windows Vista
- IIS 7.5 on Windows 7
- IIS 8.0 on Windows 8
- IIS 10.0 on Windows 10
Server - IIS 7.0 on Windows Server 2008
- IIS 7.5 on Windows Server 2008 R2
- IIS 8.0 on Windows Server 2012
- IIS 8.5 on Windows Server 2012 R2
- IIS 10.0 on Windows Server 2016 Technical Preview
Product - IIS 7.0, IIS 7.5, IIS 8.0, IIS 8.5, IIS 10.0
- IIS Express 7.5, IIS Express 8.0, IIS Express 10.0
Header Httpserv.h

See Also

IMetadataInfo Interface