audk/MdePkg/Include/Library/ArmTrngLib.h

107 lines
3.4 KiB
C

/** @file
Arm TRNG interface library definitions (Cf. [1]).
Copyright (c) 2021 - 2022, Arm Limited. All rights reserved.<BR>
SPDX-License-Identifier: BSD-2-Clause-Patent
@par Reference(s):
- [1] Arm True Random Number Generator Firmware, Interface 1.0,
Platform Design Document.
(https://developer.arm.com/documentation/den0098/latest/)
- [2] NIST Special Publication 800-90B, Recommendation for the Entropy
Sources Used for Random Bit Generation.
(https://csrc.nist.gov/publications/detail/sp/800-90b/final)
@par Glossary:
- TRNG - True Random Number Generator
**/
#ifndef ARM_TRNG_LIB_H_
#define ARM_TRNG_LIB_H_
/** Get the version of the Arm TRNG backend.
A TRNG may be implemented by the system firmware, in which case this
function shall return the version of the Arm TRNG backend.
The implementation must return NOT_SUPPORTED if a Back end is not present.
@param [out] MajorRevision Major revision.
@param [out] MinorRevision Minor revision.
@retval RETURN_SUCCESS The function completed successfully.
@retval RETURN_INVALID_PARAMETER Invalid parameter.
@retval RETURN_UNSUPPORTED Backend not present.
**/
RETURN_STATUS
EFIAPI
GetArmTrngVersion (
OUT UINT16 *MajorRevision,
OUT UINT16 *MinorRevision
);
/** Get the UUID of the Arm TRNG backend.
A TRNG may be implemented by the system firmware, in which case this
function shall return the UUID of the TRNG backend.
Returning the Arm TRNG UUID is optional and if not implemented,
RETURN_UNSUPPORTED shall be returned.
Note: The caller must not rely on the returned UUID as a trustworthy Arm TRNG
Back end identity
@param [out] Guid UUID of the Arm TRNG backend.
@retval RETURN_SUCCESS The function completed successfully.
@retval RETURN_INVALID_PARAMETER Invalid parameter.
@retval RETURN_UNSUPPORTED Function not implemented.
**/
RETURN_STATUS
EFIAPI
GetArmTrngUuid (
OUT GUID *Guid
);
/** Returns maximum number of entropy bits that can be returned in a single
call.
@return Returns the maximum number of Entropy bits that can be returned
in a single call to GetArmTrngEntropy().
**/
UINTN
EFIAPI
GetArmTrngMaxSupportedEntropyBits (
VOID
);
/** Returns N bits of conditioned entropy.
See [2] Section 2.3.1 GetEntropy: An Interface to the Entropy Source
GetEntropy
Input:
bits_of_entropy: the requested amount of entropy
Output:
entropy_bitstring: The string that provides the requested entropy.
status: A Boolean value that is TRUE if the request has been satisfied,
and is FALSE otherwise.
@param [in] EntropyBits Number of entropy bits requested.
@param [in] BufferSize Size of the Buffer in bytes.
@param [out] Buffer Buffer to return the entropy bits.
@retval RETURN_SUCCESS The function completed successfully.
@retval RETURN_INVALID_PARAMETER Invalid parameter.
@retval RETURN_UNSUPPORTED Function not implemented.
@retval RETURN_BAD_BUFFER_SIZE Buffer size is too small.
@retval RETURN_NOT_READY No Entropy available.
**/
RETURN_STATUS
EFIAPI
GetArmTrngEntropy (
IN UINTN EntropyBits,
IN UINTN BufferSize,
OUT UINT8 *Buffer
);
#endif // ARM_TRNG_LIB_H_