PFND3D11_1DDI_DECRYPTIONBLT callback function (d3d10umddi.h)

Writes encrypted data to a protected surface. This function is called only if D3D11_1DDI_CONTENT_PROTECTION_CAPS_DECRYPTION_BLT is set in the Caps member of the D3D11_1DDI_VIDEO_CONTENT_PROTECTION_CAPS structure.

Syntax

PFND3D11_1DDI_DECRYPTIONBLT Pfnd3d111DdiDecryptionblt;

void Pfnd3d111DdiDecryptionblt(
  D3D10DDI_HDEVICE hDevice,
  D3D11_1DDI_HCRYPTOSESSION hCryptoSession,
  D3D10DDI_HRESOURCE hSrcResource,
  D3D10DDI_HRESOURCE hDstResource,
  const D3D11_1DDI_ENCRYPTED_BLOCK_INFO *pEncryptedBlockInfo,
  UINT ContentKeySize,
  const VOID *pContentKey,
  UINT IVSize,
  const VOID *pIV
)
{...}

Parameters

hDevice

A handle to the display device (graphics context).

hCryptoSession

A handle to the driver's private data for the cryptographic session. This handle was created by the Direct3D runtime and passed to the driver in the call to the CreateCryptoSession function.

hSrcResource

A handle to the resource that contains the source data.

hDstResource

A pointer to the resource where the encrypted data is to be written.

pEncryptedBlockInfo

A pointer to a D3D11_1DDI_ENCRYPTED_BLOCK_INFO structure that describes the portions of the buffer that are encrypted.

ContentKeySize

The size, in bytes, of the content key.

pContentKey

A pointer to a block of memory that contains the content key that is required to decrypt the bit-block transfer (bitblt) data.

If pContentKey is not set to NULL, the buffer data is encrypted by using the specified content key. The data for this key is encrypted by using the session key with the AES-ECB algorithm.

If pContentKey is NULL, the graphics adapter does not require a separate content key to decrypt the data. In this case, the session key is used to decrypt the data.

IVSize

The size, in bytes, of the initialization vector (IV).

pIV

A pointer to a block of memory that contains the initialization vector that is required to decrypt the bitblt data. For more information, see the Remarks section.

Return value

None

Remarks

For 128-bit AES-CTR encryption, the pIV parameter points to a D3D11_1DDI_AES_CTR_IV structure that is allocated by the application. However, the actual contents of this structure are filled in by the driver or graphics adapter. When the first IV is generated, the driver or adapter initializes the IV member of this structure to a random number. For each subsequent IV, the caller increments the IV member, ensuring that the value always increases. This procedure enables the application to validate that the same IV is never used more than once with the same key pair.

For other encryption types, a different structure might be used, or the encryption might not use an IV.

Requirements

See also

D3D11_1DDI_AES_CTR_IV

D3D11_1DDI_ENCRYPTED_BLOCK_INFO

D3D11_1DDI_VIDEO_CONTENT_PROTECTION_CAPS