| /** @file | |
| RNG Driver to produce the UEFI Random Number Generator protocol. | |
| The driver will use the new RDRAND instruction to produce high-quality, high-performance | |
| entropy and random number. | |
| RNG Algoritnms defined in UEFI 2.4: | |
| - EFI_RNG_ALGORITHM_SP800_90_CTR_256_GUID - Supported | |
| (RDRAND implements a hardware NIST SP800-90 AES-CTR-256 based DRBG) | |
| - EFI_RNG_ALGORITHM_RAW - Supported | |
| (Structuring RDRAND invocation can be guaranteed as high-quality entropy source) | |
| - EFI_RNG_ALGORITHM_SP800_90_HMAC_256_GUID - Unsupported | |
| - EFI_RNG_ALGORITHM_SP800_90_HASH_256_GUID - Unsupported | |
| - EFI_RNG_ALGORITHM_X9_31_3DES_GUID - Unsupported | |
| - EFI_RNG_ALGORITHM_X9_31_AES_GUID - Unsupported | |
| Copyright (c) 2013, Intel Corporation. All rights reserved.<BR> | |
| (C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR> | |
| This program and the accompanying materials | |
| are licensed and made available under the terms and conditions of the BSD License | |
| which accompanies this distribution. The full text of the license may be found at | |
| http://opensource.org/licenses/bsd-license.php | |
| THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS, | |
| WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED. | |
| **/ | |
| #include "RdRand.h" | |
| // | |
| // Supported RNG Algorithms list by this driver. | |
| // | |
| EFI_RNG_ALGORITHM mSupportedRngAlgorithms[] = { | |
| EFI_RNG_ALGORITHM_SP800_90_CTR_256_GUID, | |
| EFI_RNG_ALGORITHM_RAW | |
| }; | |
| /** | |
| Returns information about the random number generation implementation. | |
| @param[in] This A pointer to the EFI_RNG_PROTOCOL instance. | |
| @param[in,out] RNGAlgorithmListSize On input, the size in bytes of RNGAlgorithmList. | |
| On output with a return code of EFI_SUCCESS, the size | |
| in bytes of the data returned in RNGAlgorithmList. On output | |
| with a return code of EFI_BUFFER_TOO_SMALL, | |
| the size of RNGAlgorithmList required to obtain the list. | |
| @param[out] RNGAlgorithmList A caller-allocated memory buffer filled by the driver | |
| with one EFI_RNG_ALGORITHM element for each supported | |
| RNG algorithm. The list must not change across multiple | |
| calls to the same driver. The first algorithm in the list | |
| is the default algorithm for the driver. | |
| @retval EFI_SUCCESS The RNG algorithm list was returned successfully. | |
| @retval EFI_UNSUPPORTED The services is not supported by this driver. | |
| @retval EFI_DEVICE_ERROR The list of algorithms could not be retrieved due to a | |
| hardware or firmware error. | |
| @retval EFI_INVALID_PARAMETER One or more of the parameters are incorrect. | |
| @retval EFI_BUFFER_TOO_SMALL The buffer RNGAlgorithmList is too small to hold the result. | |
| **/ | |
| EFI_STATUS | |
| EFIAPI | |
| RngGetInfo ( | |
| IN EFI_RNG_PROTOCOL *This, | |
| IN OUT UINTN *RNGAlgorithmListSize, | |
| OUT EFI_RNG_ALGORITHM *RNGAlgorithmList | |
| ) | |
| { | |
| EFI_STATUS Status; | |
| UINTN RequiredSize; | |
| if ((This == NULL) || (RNGAlgorithmListSize == NULL)) { | |
| return EFI_INVALID_PARAMETER; | |
| } | |
| RequiredSize = sizeof (mSupportedRngAlgorithms); | |
| if (*RNGAlgorithmListSize < RequiredSize) { | |
| Status = EFI_BUFFER_TOO_SMALL; | |
| } else { | |
| // | |
| // Return algorithm list supported by driver. | |
| // | |
| if (RNGAlgorithmList != NULL) { | |
| CopyMem (RNGAlgorithmList, mSupportedRngAlgorithms, RequiredSize); | |
| Status = EFI_SUCCESS; | |
| } else { | |
| Status = EFI_INVALID_PARAMETER; | |
| } | |
| } | |
| *RNGAlgorithmListSize = RequiredSize; | |
| return Status; | |
| } | |
| /** | |
| Produces and returns an RNG value using either the default or specified RNG algorithm. | |
| @param[in] This A pointer to the EFI_RNG_PROTOCOL instance. | |
| @param[in] RNGAlgorithm A pointer to the EFI_RNG_ALGORITHM that identifies the RNG | |
| algorithm to use. May be NULL in which case the function will | |
| use its default RNG algorithm. | |
| @param[in] RNGValueLength The length in bytes of the memory buffer pointed to by | |
| RNGValue. The driver shall return exactly this numbers of bytes. | |
| @param[out] RNGValue A caller-allocated memory buffer filled by the driver with the | |
| resulting RNG value. | |
| @retval EFI_SUCCESS The RNG value was returned successfully. | |
| @retval EFI_UNSUPPORTED The algorithm specified by RNGAlgorithm is not supported by | |
| this driver. | |
| @retval EFI_DEVICE_ERROR An RNG value could not be retrieved due to a hardware or | |
| firmware error. | |
| @retval EFI_NOT_READY There is not enough random data available to satisfy the length | |
| requested by RNGValueLength. | |
| @retval EFI_INVALID_PARAMETER RNGValue is NULL or RNGValueLength is zero. | |
| **/ | |
| EFI_STATUS | |
| EFIAPI | |
| RngGetRNG ( | |
| IN EFI_RNG_PROTOCOL *This, | |
| IN EFI_RNG_ALGORITHM *RNGAlgorithm, OPTIONAL | |
| IN UINTN RNGValueLength, | |
| OUT UINT8 *RNGValue | |
| ) | |
| { | |
| EFI_STATUS Status; | |
| if ((RNGValueLength == 0) || (RNGValue == NULL)) { | |
| return EFI_INVALID_PARAMETER; | |
| } | |
| Status = EFI_UNSUPPORTED; | |
| if (RNGAlgorithm == NULL) { | |
| // | |
| // Use the default RNG algorithm if RNGAlgorithm is NULL. | |
| // | |
| RNGAlgorithm = &gEfiRngAlgorithmSp80090Ctr256Guid; | |
| } | |
| // | |
| // NIST SP800-90-AES-CTR-256 supported by RDRAND | |
| // | |
| if (CompareGuid (RNGAlgorithm, &gEfiRngAlgorithmSp80090Ctr256Guid)) { | |
| Status = RdRandGetBytes (RNGValueLength, RNGValue); | |
| return Status; | |
| } | |
| // | |
| // The "raw" algorithm is intended to provide entropy directly | |
| // | |
| if (CompareGuid (RNGAlgorithm, &gEfiRngAlgorithmRaw)) { | |
| // | |
| // When a DRBG is used on the output of a entropy source, | |
| // its security level must be at least 256 bits according to UEFI Spec. | |
| // | |
| if (RNGValueLength < 32) { | |
| return EFI_INVALID_PARAMETER; | |
| } | |
| Status = RdRandGenerateEntropy (RNGValueLength, RNGValue); | |
| return Status; | |
| } | |
| // | |
| // Other algorithms were unsupported by this driver. | |
| // | |
| return Status; | |
| } | |
| // | |
| // The Random Number Generator (RNG) protocol | |
| // | |
| EFI_RNG_PROTOCOL mRngRdRand = { | |
| RngGetInfo, | |
| RngGetRNG | |
| }; | |
| /** | |
| The user Entry Point for the Random Number Generator (RNG) driver. | |
| @param[in] ImageHandle The firmware allocated handle for the EFI image. | |
| @param[in] SystemTable A pointer to the EFI System Table. | |
| @retval EFI_SUCCESS The entry point is executed successfully. | |
| @retval EFI_NOT_SUPPORTED Platform does not support RNG. | |
| @retval Other Some error occurs when executing this entry point. | |
| **/ | |
| EFI_STATUS | |
| EFIAPI | |
| RngDriverEntry ( | |
| IN EFI_HANDLE ImageHandle, | |
| IN EFI_SYSTEM_TABLE *SystemTable | |
| ) | |
| { | |
| EFI_STATUS Status; | |
| EFI_HANDLE Handle; | |
| // | |
| // Install UEFI RNG (Random Number Generator) Protocol | |
| // | |
| Handle = NULL; | |
| Status = gBS->InstallMultipleProtocolInterfaces ( | |
| &Handle, | |
| &gEfiRngProtocolGuid, | |
| &mRngRdRand, | |
| NULL | |
| ); | |
| return Status; | |
| } |