IAMCertifiedOutputProtection::KeyExchange
| Microsoft DirectShow 9.0 |
IAMCertifiedOutputProtection::KeyExchange
This topic applies only to Windows XP Service Pack 2 or later.
The KeyExchange method returns the graphics driver's certificate.
Syntax
HRESULT KeyExchange(
GUID *pRandom,
BYTE **VarLenCertGH,
DWORD *pdwLengthCertGH
);
Parameters
pRandom
[out] Receives a 128-bit random number, generated by the graphics driver. Use this value in the IAMCertifiedOutputProtection::SessionSequenceStart method.
VarLenCertGH
[out] Receives a pointer to a buffer containing the graphics driver's certificate. The method allocates the memory for the buffer. The caller must release the memory by calling CoTaskMemFree.
pdwLengthCertGH
[out] Receives the length of the buffer returned in VarLenCertGH.
Return Values
Returns an HRESULT value. Possible values include the following.
| Return Code | Description |
| S_OK | Success. |
| E_UNEXPECTED | Invalid state. Possibly the application passed unexpected data, or called IAMCertifiedOutputProtection methods in the wrong order. If this error occurs, the application should release the current instance of the VMR. |
| VFW_E_NO_COPP_HW | The display device does not support COPP; or the VMR has not connected to a display device yet. |
Remarks
The graphics driver's certificate contains the driver's public encryption key.
If this method returns E_UNEXPECTED, the application should create a new COPP session by releasing the VMR, creating a new instance of the VMR, and calling KeyExchange again on the new instance.
Requirements
Header: Declared in Strmif.h; include Dshow.h.
Library: Use Strmiids.lib.
See Also