ISCPSecureExchange2::TransferContainerData2

The TransferContainerData2 method transfers container file data to the secure content provider. The secure content provider breaks down the container internally and reports which parts of the content are available as they are extracted from the container. This method extends ISCPSecureExchange::TransferContainerData by accepting a progress callback on which the secure content provider can send progress notifications for any of the steps it needs to carry out.

Syntax

HRESULT TransferContainerData2(BYTE*pData,DWORDdwSize,IWMDMProgress3*pProgressCallback,UINT*pfuReadyFlags,BYTEabMac[WMDM_MAC_LENGTH]);

Parameters

pData

[in]  Pointer to a buffer holding the current data being transferred from the container file. This parameter must be included in the input message authentication code and must be encrypted.

dwSize

[in]  DWORD that contains the number of bytes in the buffer. This parameter must be included in the input message authentication code.

pProgressCallback

[in]  Progress callback on which the secure content provider can report progress of any steps that it might need to carry out. The step will be identified by the EventId parameter of IWMDMProgress3 methods.

pfuReadyFlags

[out]  Flag indicating which parts of the container file are ready to be read. This parameter is included in the output message authentication code. The following flags indicate what is ready.

abMac

[in, out]  Array of eight bytes containing the message authentication code for the parameter data of this method. (WMDM_MAC_LENGTH is defined as 8.)

Return Values

If the method succeeds, it returns S_OK. If it fails, it returns an HRESULT error code.

Remarks

Windows Media Device Manager calls this method repeatedly, transferring data from the container file to the secure content provider. Windows Media Device Manager eventually calls this method with dwSize set to zero to indicate that it has no more data to transfer. As the secure content provider collects the data and extracts the various objects from it, it reports back to Windows Media Device Manager which objects, if any, are available after each call. If no objects are available, the secure content provider returns S_OK with the pfuReadyFlags parameter set to zero. When the secure content provider has determined that it requires no further processing and/or modification of the file being transferred, the flag WMDM_SCP_NO_MORE_CHANGES is returned. Windows Media Device Manager can then directly transfer the remainder of the file to the device.

Object data is transferred from the secure content provider by calling the ObjectData method. Windows Media Device Manager calls ObjectData repeatedly until it returns zero in the second parameter, dwBytesWrite.

The TransferComplete method is called by Windows Media Device Manager to signal the end of a secure transfer of data.

Windows Media Device Manager passes the application-provided progress callback to the secure content provider in the pProgressCallback parameter. The secure content provider can use this parameter to provide progress notification for any steps that it needs to carry out. The step itself is identified by EventId, which is the first parameter of the methods of IWMDMProgress3. A specific secure content provider implementation will define EventId values for applications to use.

Requirements

Header: Defined in WMSCP.idl.

Library: mssachlp.lib

See Also

• ISCPSecureExchange Interface
• ISCPSecureExchange::ObjectData
• ISCPSecureExchange2 Interface
• IWMDMProgress3 Interface