EFI_RNG_PROTOCOL.GetRNG

Article
03/23/2023

Retrieves a Random Number Generation (RNG) value.

Syntax

typedef EFI_STATUS (EFIAPI *EFI_RNG_GET_RNG) (
    IN  struct _EFI_RNG_PROTOCOL    *This,
    IN  EFI_RNG_ALGORITHM           *RNGAlgorithm, OPTIONAL
    IN  UINTN                       RNGValueLength,
    OUT UINT8                       *RNGValue
    );

Parameters

This
[in] A pointer to the EFI_RNG_PROTOCOL instance.

RNGAlgorithm
[in] A pointer to the EFI_RNG_ALGORITHM which identifies the RNG algorithm to use. If this parameter is NULL, the default algorithm supported by the driver will be used.

RNGValueLength
[in] The length, in bytes, of the buffer returned by RNGValue.

RNGValue
[in] Pointer to a buffer that will contain the RNG value. The value is allocated by this function using EFI_BOOT_SERVICES->AllocatePool(), and it is the caller's responsibility to free this memory by using EFI_BOOT_SERVICES->FreePool().

Remarks

The minimum size of RNGValue is 32 bytes.

Return value

Returns one of the following status codes.

Status code	Description
EFI_SUCCESS	The function successfully returned an RNG value.
EFI_INVALID_PARAMETER	RNGAlgorithm is NULL when several algorithms are possible.
EFI_UNSUPPORTED	The algorithm specified by RNGAlgorithm is not supported by this driver.
EFI_DEVICE_ERROR	An RNG value could not be retrieved because of a hardware or firmware error.
EFI_NOT_READY	There is not enough entropy data available.
EFI_OUT_OF_RESOURCES	The driver is unable to allocate memory for the RNG value.

Requirements

Header: User generated

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