ISCPSecureQuery::ExamineData
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The ExamineData method determines rights and responsibility for the content by examining data that Windows Media Device Manager passes to this method.
Syntax
HRESULT ExamineData(UINTfuFlags,LPWSTRpwszExtension,BYTE*pData,DWORDdwSize,BYTEabMac[WMDM_MAC_LENGTH]);
Parameters
fuFlags
[in] Flags describing the data offered to the secure content provider to make decisions. The following flags can be present.
| Flag | Description |
| WMDM_SCP_EXAMINE_DATA | The pData parameter points to data to be examined. |
pwszExtension
[in] Pointer to the file name extension to be examined if the secure content provider asks for an extension in the GetDataDemands call.
pData
[in] Pointer to the data at the beginning of the file to be examined. This parameter must be included in the input message authentication code and must be encrypted.
dwSize
[in] DWORD that contains the length, in bytes, of the data to be examined. This parameter must be included in the input message authentication code.
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
The method returns an HRESULT. Possible values include, but are not limited to, those in the following table.
| Return code | Description |
| S_OK | The method succeeded. The secure content provider is responsible for this content. |
| WMDM_E_CALL_OUT_OF_SEQUENCE | This method was called out of sequence. GetDataDemands must be called first. |
| WMDM_E_MAC_CHECK_FAILED | The message authentication code is not valid. |
| WMDM_E_MOREDATA | Windows Media Device Manager must call this method again with another packet of data. The size of the packet is determined by the pdwMinExamineData parameter in the GetDataDemands method. |
| S_FALSE | The secure content provider is not responsible for this content. Terminate interaction with the secure content provider. |
| E_INVALIDARG | A parameter is invalid or is a NULL pointer. |
| E_FAIL | An unspecified error occurred. |
Remarks
This method is called after the GetDataDemands method. The secure content provider uses the information passed in this method to determine whether it is responsible for the content. The fuFlags parameter is consulted to determine which data has been presented for examination. The pData parameter points to the beginning of the rights and responsibility data. The dwSize parameter contains the length, in bytes, of the rights and responsibility data.
If the WMDM_SCP_EXAMINE_DATA flag is set, then the pDataBuffer parameter contains dwDataLength of bytes for the secure content provider to examine.
If this method does not return S_OK or WMDM_E_MOREDATA, then Windows Media Device Manager does not make any further calls to this secure content provider.
Requirements
Header: Defined in WMSCP.idl.
Library: mssachlp.lib
See Also