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Initialize DRM Import Example

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[The feature associated with this page, Windows Media Format 11 SDK, is a legacy feature. It has been superseded by Source Reader and Sink Writer. Source Reader and Sink Writer have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use Source Reader and Sink Writer instead of Windows Media Format 11 SDK, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The following code example illustrates how to initialize a DRM writer object for DRM Import:

HRESULT InitializeImport( IWMDRMWriter3 *pDRMWriter )
{
    // Set this value to the desired number of bytes in an encrypted 
    //  session key.
    const int MODULUS_SIZE = 32;

    HRESULT hr = S_OK;
    WMDRM_IMPORT_INIT_STRUCT ImportInit;

    BYTE *pbEncryptedSessionKey = NULL;
    DWORD cbEncryptedSessionKey = 0;

    WMDRM_IMPORT_SESSION_KEY *pSessionKey = NULL;
    DWORD cbSessionKey = 0;

    WMDRM_IMPORT_CONTENT_KEY *pContentKey = NULL;
    DWORD cbContentKey = 0;
        
    // Allocate memory for the encrypted session key.
    pbEncryptedSessionKey = new BYTE[ MODULUS_SIZE ];
    if( NULL == pbEncryptedSessionKey )
    {
        hr = E_OUTOFMEMORY;
        goto EXIT;
    }
    cbEncryptedSessionKey = MODULUS_SIZE;

    hr = CreateSessionKey( &pSessionKey, &cbSessionKey );
    if( FAILED( hr ) ) goto EXIT;

    if( cbSessionKey > MODULUS_SIZE )
    if( FAILED( hr ) ) goto EXIT;

    hr = CreateContentKey( &pContentKey, &cbContentKey );
    if( FAILED( hr ) ) goto EXIT;

    // TODO: Encrypt the content key with the session Key.    
    // TODO: Encrypt the session key with the machine certificate public key.   

    ImportInit.dwVersion = 0;
    ImportInit.pbEncryptedSessionKeyMessage = pbEncryptedSessionKey;
    ImportInit.cbEncryptedSessionKeyMessage = cbEncryptedSessionKey;
    ImportInit.pbEncryptedKeyMessage = (BYTE*)pContentKey;
    ImportInit.cbEncryptedKeyMessage = cbContentKey;

    hr = pDRMWriter->SetProtectStreamSamples( &ImportInit );
    if( FAILED( hr ) ) goto EXIT;

EXIT:

    SAFE_ARRAY_DELETE( pContentKey );
    SAFE_ARRAY_DELETE( pSessionKey );

    return( hr );
}

Create Content Key Example

Create Session Key Example

DRM Import Examples