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CSecureChannelClient::EncryptParam

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The EncryptParam method uses the session key of the secure authenticated channel to encrypt the data contained in a parameter.

Syntax

HRESULT EncryptParam(
  BYTE*  pbData,
  DWORD  dwDataLen
);

Parameters

  pbData

Pointer to the first byte of a data buffer containing the parameter that is to be encrypted.

  dwDataLen

Pointer to a DWORD specifying the length of the buffer to which pbData points.

Return Values

The method returns an HRESULT. All the interface methods in Windows Media Device Manager and service provider can return any of the following classes of error codes:

  • Standard COM error codes
  • Windows error codes converted to HRESULT values
  • Windows Media Device Manager error codes

For a complete list of possible error codes, see Error Codes.

Possible values include, but are not limited to, those in the following table.

Return code Description
S_OK The method succeeded.
E_INVALIDARG A parameter is invalid or is a NULL pointer.
E_FAIL An unspecified error occurred.

Remarks

Call the EncryptParam method to encrypt certain parameters before calling functions in other components.

Encrypt only the parameters that are specified as requiring encryption. See Secure Authenticated Channel Interface for a table of methods that must use the message authentication code algorithm and encrypted parameters.

Example Code

// Create the MAC to send to ExamineData.
CSecureChannelClient *pSCClient = NULL;
UINT fuTempFlags;
pSCClient->MACInit(&hMAC);
fuTempFlags = WMDM_SCP_EXAMINE_DATA;
pSCClient->MACUpdate(hMAC, (BYTE*)(&fuTempFlags), sizeof(fuTempFlags));
pSCClient->MACUpdate(hMAC, (BYTE*)(pData), dwExSize);
pSCClient->MACUpdate(hMAC, (BYTE*)(&dwExSize), sizeof(dwExSize));
pSCClient->MACFinal(hMAC, abTempMAC);

// Encrypt the pData Parameter.
pSCClient->EncryptParam(pData, dwExSize);

Requirements

Header: Include scclient.h.

Library: mssachlp.lib

See Also