/** @file\r
Support routines for RDRAND instruction access.\r
\r
-Copyright (c) 2013, Intel Corporation. All rights reserved.<BR>\r
+Copyright (c) 2013 - 2018, Intel Corporation. All rights reserved.<BR>\r
+(C) Copyright 2015 Hewlett Packard Enterprise Development LP<BR>\r
This program and the accompanying materials\r
are licensed and made available under the terms and conditions of the BSD License\r
which accompanies this distribution. The full text of the license may be found at\r
WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.\r
\r
**/\r
+#include <Library/RngLib.h>\r
\r
#include "RdRand.h"\r
#include "AesCore.h"\r
\r
-//\r
-// Bit mask used to determine if RdRand instruction is supported.\r
-//\r
-#define RDRAND_MASK 0x40000000\r
-\r
-/**\r
- Determines whether or not RDRAND instruction is supported by the host hardware.\r
-\r
- @retval EFI_SUCCESS RDRAND instruction supported.\r
- @retval EFI_UNSUPPORTED RDRAND instruction not supported.\r
-\r
-**/\r
-EFI_STATUS\r
-EFIAPI\r
-IsRdRandSupported (\r
- VOID\r
- )\r
-{\r
- EFI_STATUS Status;\r
- UINT32 RegEax;\r
- UINT32 RegEbx;\r
- UINT32 RegEcx;\r
- UINT32 RegEdx;\r
- BOOLEAN IsIntelCpu;\r
-\r
- Status = EFI_UNSUPPORTED;\r
- IsIntelCpu = FALSE;\r
- \r
- //\r
- // Checks whether the current processor is an Intel product by CPUID.\r
- //\r
- AsmCpuid (0, &RegEax, &RegEbx, &RegEcx, &RegEdx);\r
- if ((CompareMem ((CHAR8 *)(&RegEbx), "Genu", 4) == 0) &&\r
- (CompareMem ((CHAR8 *)(&RegEdx), "ineI", 4) == 0) &&\r
- (CompareMem ((CHAR8 *)(&RegEcx), "ntel", 4) == 0)) {\r
- IsIntelCpu = TRUE;\r
- }\r
-\r
- if (IsIntelCpu) {\r
- //\r
- // Determine RDRAND support by examining bit 30 of the ECX register returned by CPUID.\r
- // A value of 1 indicates that processor supports RDRAND instruction.\r
- //\r
- AsmCpuid (1, 0, 0, &RegEcx, 0);\r
-\r
- if ((RegEcx & RDRAND_MASK) == RDRAND_MASK) {\r
- Status = EFI_SUCCESS;\r
- }\r
- }\r
-\r
- return Status;\r
-}\r
-\r
-/**\r
- Calls RDRAND to obtain a 16-bit random number.\r
-\r
- @param[out] Rand Buffer pointer to store the random result.\r
- @param[in] NeedRetry Determine whether or not to loop retry.\r
-\r
- @retval EFI_SUCCESS RDRAND call was successful.\r
- @retval EFI_NOT_READY Failed attempts to call RDRAND.\r
-\r
-**/\r
-EFI_STATUS\r
-EFIAPI\r
-RdRand16 (\r
- OUT UINT16 *Rand,\r
- IN BOOLEAN NeedRetry\r
- )\r
-{\r
- UINT32 Index;\r
- UINT32 RetryCount;\r
-\r
- if (NeedRetry) {\r
- RetryCount = RETRY_LIMIT;\r
- } else {\r
- RetryCount = 1;\r
- }\r
-\r
- //\r
- // Perform a single call to RDRAND, or enter a loop call until RDRAND succeeds.\r
- //\r
- for (Index = 0; Index < RetryCount; Index++) {\r
- if (RdRand16Step (Rand)) {\r
- return EFI_SUCCESS;\r
- }\r
- }\r
- \r
- return EFI_NOT_READY;\r
-}\r
-\r
-/**\r
- Calls RDRAND to obtain a 32-bit random number.\r
-\r
- @param[out] Rand Buffer pointer to store the random result.\r
- @param[in] NeedRetry Determine whether or not to loop retry.\r
-\r
- @retval EFI_SUCCESS RDRAND call was successful.\r
- @retval EFI_NOT_READY Failed attempts to call RDRAND.\r
-\r
-**/\r
-EFI_STATUS\r
-EFIAPI\r
-RdRand32 (\r
- OUT UINT32 *Rand,\r
- IN BOOLEAN NeedRetry\r
- )\r
-{\r
- UINT32 Index;\r
- UINT32 RetryCount;\r
-\r
- if (NeedRetry) {\r
- RetryCount = RETRY_LIMIT;\r
- } else {\r
- RetryCount = 1;\r
- }\r
-\r
- //\r
- // Perform a single call to RDRAND, or enter a loop call until RDRAND succeeds.\r
- //\r
- for (Index = 0; Index < RetryCount; Index++) {\r
- if (RdRand32Step (Rand)) {\r
- return EFI_SUCCESS;\r
- }\r
- }\r
- \r
- return EFI_NOT_READY;\r
-}\r
-\r
-/**\r
- Calls RDRAND to obtain a 64-bit random number.\r
-\r
- @param[out] Rand Buffer pointer to store the random result.\r
- @param[in] NeedRetry Determine whether or not to loop retry.\r
-\r
- @retval EFI_SUCCESS RDRAND call was successful.\r
- @retval EFI_NOT_READY Failed attempts to call RDRAND.\r
-\r
-**/\r
-EFI_STATUS\r
-EFIAPI\r
-RdRand64 (\r
- OUT UINT64 *Rand,\r
- IN BOOLEAN NeedRetry\r
- )\r
-{\r
- UINT32 Index;\r
- UINT32 RetryCount;\r
-\r
- if (NeedRetry) {\r
- RetryCount = RETRY_LIMIT;\r
- } else {\r
- RetryCount = 1;\r
- }\r
-\r
- //\r
- // Perform a single call to RDRAND, or enter a loop call until RDRAND succeeds.\r
- //\r
- for (Index = 0; Index < RetryCount; Index++) {\r
- if (RdRand64Step (Rand)) {\r
- return EFI_SUCCESS;\r
- }\r
- }\r
- \r
- return EFI_NOT_READY;\r
-}\r
-\r
/**\r
Calls RDRAND to fill a buffer of arbitrary size with random bytes.\r
\r
OUT UINT8 *RandBuffer\r
)\r
{\r
- EFI_STATUS Status;\r
- UINT8 *Start;\r
- UINT8 *ResidualStart;\r
- UINTN *BlockStart;\r
- UINTN TempRand;\r
- UINTN Count;\r
- UINTN Residual;\r
- UINTN StartLen;\r
- UINTN BlockNum;\r
- UINTN Index;\r
-\r
- ResidualStart = NULL;\r
- TempRand = 0;\r
-\r
- //\r
- // Compute the address of the first word aligned (32/64-bit) block in the \r
- // destination buffer, depending on whether we are in 32- or 64-bit mode.\r
- //\r
- Start = RandBuffer;\r
- if (((UINT32)(UINTN)Start % (UINT32)sizeof(UINTN)) == 0) {\r
- BlockStart = (UINTN *)Start;\r
- Count = Length;\r
- StartLen = 0;\r
- } else {\r
- BlockStart = (UINTN *)(((UINTN)Start & ~(UINTN)(sizeof(UINTN) - 1)) + (UINTN)sizeof(UINTN));\r
- Count = Length - (sizeof (UINTN) - (UINT32)((UINTN)Start % sizeof (UINTN)));\r
- StartLen = (UINT32)((UINTN)BlockStart - (UINTN)Start);\r
- }\r
-\r
- //\r
- // Compute the number of word blocks and the remaining number of bytes.\r
- //\r
- Residual = Count % sizeof (UINTN);\r
- BlockNum = Count / sizeof (UINTN);\r
- if (Residual != 0) {\r
- ResidualStart = (UINT8 *) (BlockStart + BlockNum);\r
- }\r
-\r
- //\r
- // Obtain a temporary random number for use in the residuals. Failout if retry fails.\r
- //\r
- if (StartLen > 0) {\r
- Status = RdRandWord ((UINTN *) &TempRand, TRUE);\r
- if (EFI_ERROR (Status)) {\r
- return Status;\r
- }\r
- }\r
+ BOOLEAN IsRandom;\r
+ UINT64 TempRand[2];\r
\r
- //\r
- // Populate the starting mis-aligned block.\r
- //\r
- for (Index = 0; Index < StartLen; Index++) {\r
- Start[Index] = (UINT8)(TempRand & 0xff);\r
- TempRand = TempRand >> 8;\r
- }\r
-\r
- //\r
- // Populate the central aligned block. Fail out if retry fails.\r
- //\r
- Status = RdRandGetWords (BlockNum, (UINTN *)(BlockStart));\r
- if (EFI_ERROR (Status)) {\r
- return Status;\r
- }\r
- //\r
- // Populate the final mis-aligned block.\r
- //\r
- if (Residual > 0) {\r
- Status = RdRandWord ((UINTN *)&TempRand, TRUE);\r
- if (EFI_ERROR (Status)) {\r
- return Status;\r
+ while (Length > 0) {\r
+ IsRandom = GetRandomNumber128 (TempRand);\r
+ if (!IsRandom) {\r
+ return EFI_NOT_READY;\r
}\r
- for (Index = 0; Index < Residual; Index++) {\r
- ResidualStart[Index] = (UINT8)(TempRand & 0xff);\r
- TempRand = TempRand >> 8;\r
+ if (Length >= sizeof (TempRand)) {\r
+ WriteUnaligned64 ((UINT64*)RandBuffer, TempRand[0]);\r
+ RandBuffer += sizeof (UINT64);\r
+ WriteUnaligned64 ((UINT64*)RandBuffer, TempRand[1]);\r
+ RandBuffer += sizeof (UINT64);\r
+ Length -= sizeof (TempRand);\r
+ } else {\r
+ CopyMem (RandBuffer, TempRand, Length);\r
+ Length = 0;\r
}\r
}\r
\r
This function takes multiple random numbers through RDRAND without intervening\r
delays to ensure reseeding and performs AES-CBC-MAC over the data to compute the\r
seed value.\r
- \r
+\r
@param[out] SeedBuffer Pointer to a 128bit buffer to store the random seed.\r
\r
@retval EFI_SUCCESS Random seed generation succeeded.\r
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