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Diffstat (limited to 'MdeModulePkg/Library/BaseRngLibTimerLib/RngLibTimer.c')
-rw-r--r--MdeModulePkg/Library/BaseRngLibTimerLib/RngLibTimer.c440
1 files changed, 220 insertions, 220 deletions
diff --git a/MdeModulePkg/Library/BaseRngLibTimerLib/RngLibTimer.c b/MdeModulePkg/Library/BaseRngLibTimerLib/RngLibTimer.c
index 28ff46c71f..4d3b1617de 100644
--- a/MdeModulePkg/Library/BaseRngLibTimerLib/RngLibTimer.c
+++ b/MdeModulePkg/Library/BaseRngLibTimerLib/RngLibTimer.c
@@ -1,220 +1,220 @@
-/** @file
- BaseRng Library that uses the TimerLib to provide reasonably random numbers.
- Do not use this on a production system.
-
- Copyright (c) 2023, Arm Limited. All rights reserved.
- Copyright (c) Microsoft Corporation.
- SPDX-License-Identifier: BSD-2-Clause-Patent
-**/
-
-#include <Base.h>
-#include <Uefi.h>
-#include <Library/BaseLib.h>
-#include <Library/BaseMemoryLib.h>
-#include <Library/DebugLib.h>
-#include <Library/TimerLib.h>
-#include <Guid/RngAlgorithm.h>
-
-#define DEFAULT_DELAY_TIME_IN_MICROSECONDS 10
-
-/**
- Using the TimerLib GetPerformanceCounterProperties() we delay
- for enough time for the PerformanceCounter to increment.
-
- If the return value from GetPerformanceCounterProperties (TimerLib)
- is zero, this function will return 10 and attempt to assert.
- **/
-STATIC
-UINT32
-CalculateMinimumDecentDelayInMicroseconds (
- VOID
- )
-{
- UINT64 CounterHz;
-
- // Get the counter properties
- CounterHz = GetPerformanceCounterProperties (NULL, NULL);
- // Make sure we won't divide by zero
- if (CounterHz == 0) {
- ASSERT (CounterHz != 0); // Assert so the developer knows something is wrong
- return DEFAULT_DELAY_TIME_IN_MICROSECONDS;
- }
-
- // Calculate the minimum delay based on 1.5 microseconds divided by the hertz.
- // We calculate the length of a cycle (1/CounterHz) and multiply it by 1.5 microseconds
- // This ensures that the performance counter has increased by at least one
- return (UINT32)(MAX (DivU64x64Remainder (1500000, CounterHz, NULL), 1));
-}
-
-/**
- Generates a 16-bit random number.
-
- if Rand is NULL, then ASSERT().
-
- @param[out] Rand Buffer pointer to store the 16-bit random value.
-
- @retval TRUE Random number generated successfully.
- @retval FALSE Failed to generate the random number.
-
-**/
-BOOLEAN
-EFIAPI
-GetRandomNumber16 (
- OUT UINT16 *Rand
- )
-{
- UINT32 Index;
- UINT8 *RandPtr;
- UINT32 DelayInMicroSeconds;
-
- ASSERT (Rand != NULL);
-
- if (Rand == NULL) {
- return FALSE;
- }
-
- DelayInMicroSeconds = CalculateMinimumDecentDelayInMicroseconds ();
- RandPtr = (UINT8 *)Rand;
- // Get 2 bytes of random ish data
- for (Index = 0; Index < sizeof (UINT16); Index++) {
- *RandPtr = (UINT8)(GetPerformanceCounter () & 0xFF);
- // Delay to give the performance counter a chance to change
- MicroSecondDelay (DelayInMicroSeconds);
- RandPtr++;
- }
-
- return TRUE;
-}
-
-/**
- Generates a 32-bit random number.
-
- if Rand is NULL, then ASSERT().
-
- @param[out] Rand Buffer pointer to store the 32-bit random value.
-
- @retval TRUE Random number generated successfully.
- @retval FALSE Failed to generate the random number.
-
-**/
-BOOLEAN
-EFIAPI
-GetRandomNumber32 (
- OUT UINT32 *Rand
- )
-{
- UINT32 Index;
- UINT8 *RandPtr;
- UINT32 DelayInMicroSeconds;
-
- ASSERT (Rand != NULL);
-
- if (NULL == Rand) {
- return FALSE;
- }
-
- RandPtr = (UINT8 *)Rand;
- DelayInMicroSeconds = CalculateMinimumDecentDelayInMicroseconds ();
- // Get 4 bytes of random ish data
- for (Index = 0; Index < sizeof (UINT32); Index++) {
- *RandPtr = (UINT8)(GetPerformanceCounter () & 0xFF);
- // Delay to give the performance counter a chance to change
- MicroSecondDelay (DelayInMicroSeconds);
- RandPtr++;
- }
-
- return TRUE;
-}
-
-/**
- Generates a 64-bit random number.
-
- if Rand is NULL, then ASSERT().
-
- @param[out] Rand Buffer pointer to store the 64-bit random value.
-
- @retval TRUE Random number generated successfully.
- @retval FALSE Failed to generate the random number.
-
-**/
-BOOLEAN
-EFIAPI
-GetRandomNumber64 (
- OUT UINT64 *Rand
- )
-{
- UINT32 Index;
- UINT8 *RandPtr;
- UINT32 DelayInMicroSeconds;
-
- ASSERT (Rand != NULL);
-
- if (NULL == Rand) {
- return FALSE;
- }
-
- RandPtr = (UINT8 *)Rand;
- DelayInMicroSeconds = CalculateMinimumDecentDelayInMicroseconds ();
- // Get 8 bytes of random ish data
- for (Index = 0; Index < sizeof (UINT64); Index++) {
- *RandPtr = (UINT8)(GetPerformanceCounter () & 0xFF);
- // Delay to give the performance counter a chance to change
- MicroSecondDelay (DelayInMicroSeconds);
- RandPtr++;
- }
-
- return TRUE;
-}
-
-/**
- Generates a 128-bit random number.
-
- if Rand is NULL, then ASSERT().
-
- @param[out] Rand Buffer pointer to store the 128-bit random value.
-
- @retval TRUE Random number generated successfully.
- @retval FALSE Failed to generate the random number.
-
-**/
-BOOLEAN
-EFIAPI
-GetRandomNumber128 (
- OUT UINT64 *Rand
- )
-{
- ASSERT (Rand != NULL);
- // This should take around 80ms
-
- // Read first 64 bits
- if (!GetRandomNumber64 (Rand)) {
- return FALSE;
- }
-
- // Read second 64 bits
- return GetRandomNumber64 (++Rand);
-}
-
-/**
- Get a GUID identifying the RNG algorithm implementation.
-
- @param [out] RngGuid If success, contains the GUID identifying
- the RNG algorithm implementation.
-
- @retval EFI_SUCCESS Success.
- @retval EFI_UNSUPPORTED Not supported.
- @retval EFI_INVALID_PARAMETER Invalid parameter.
-**/
-EFI_STATUS
-EFIAPI
-GetRngGuid (
- GUID *RngGuid
- )
-{
- if (RngGuid == NULL) {
- return EFI_INVALID_PARAMETER;
- }
-
- CopyMem (RngGuid, &gEdkiiRngAlgorithmUnSafe, sizeof (*RngGuid));
- return EFI_SUCCESS;
-}
+/** @file
+ BaseRng Library that uses the TimerLib to provide reasonably random numbers.
+ Do not use this on a production system.
+
+ Copyright (c) 2023, Arm Limited. All rights reserved.
+ Copyright (c) Microsoft Corporation.
+ SPDX-License-Identifier: BSD-2-Clause-Patent
+**/
+
+#include <Base.h>
+#include <Uefi.h>
+#include <Library/BaseLib.h>
+#include <Library/BaseMemoryLib.h>
+#include <Library/DebugLib.h>
+#include <Library/TimerLib.h>
+#include <Guid/RngAlgorithm.h>
+
+#define DEFAULT_DELAY_TIME_IN_MICROSECONDS 10
+
+/**
+ Using the TimerLib GetPerformanceCounterProperties() we delay
+ for enough time for the PerformanceCounter to increment.
+
+ If the return value from GetPerformanceCounterProperties (TimerLib)
+ is zero, this function will return 10 and attempt to assert.
+ **/
+STATIC
+UINT32
+CalculateMinimumDecentDelayInMicroseconds (
+ VOID
+ )
+{
+ UINT64 CounterHz;
+
+ // Get the counter properties
+ CounterHz = GetPerformanceCounterProperties (NULL, NULL);
+ // Make sure we won't divide by zero
+ if (CounterHz == 0) {
+ ASSERT (CounterHz != 0); // Assert so the developer knows something is wrong
+ return DEFAULT_DELAY_TIME_IN_MICROSECONDS;
+ }
+
+ // Calculate the minimum delay based on 1.5 microseconds divided by the hertz.
+ // We calculate the length of a cycle (1/CounterHz) and multiply it by 1.5 microseconds
+ // This ensures that the performance counter has increased by at least one
+ return (UINT32)(MAX (DivU64x64Remainder (1500000, CounterHz, NULL), 1));
+}
+
+/**
+ Generates a 16-bit random number.
+
+ if Rand is NULL, then ASSERT().
+
+ @param[out] Rand Buffer pointer to store the 16-bit random value.
+
+ @retval TRUE Random number generated successfully.
+ @retval FALSE Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+GetRandomNumber16 (
+ OUT UINT16 *Rand
+ )
+{
+ UINT32 Index;
+ UINT8 *RandPtr;
+ UINT32 DelayInMicroSeconds;
+
+ ASSERT (Rand != NULL);
+
+ if (Rand == NULL) {
+ return FALSE;
+ }
+
+ DelayInMicroSeconds = CalculateMinimumDecentDelayInMicroseconds ();
+ RandPtr = (UINT8 *)Rand;
+ // Get 2 bytes of random ish data
+ for (Index = 0; Index < sizeof (UINT16); Index++) {
+ *RandPtr = (UINT8)(GetPerformanceCounter () & 0xFF);
+ // Delay to give the performance counter a chance to change
+ MicroSecondDelay (DelayInMicroSeconds);
+ RandPtr++;
+ }
+
+ return TRUE;
+}
+
+/**
+ Generates a 32-bit random number.
+
+ if Rand is NULL, then ASSERT().
+
+ @param[out] Rand Buffer pointer to store the 32-bit random value.
+
+ @retval TRUE Random number generated successfully.
+ @retval FALSE Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+GetRandomNumber32 (
+ OUT UINT32 *Rand
+ )
+{
+ UINT32 Index;
+ UINT8 *RandPtr;
+ UINT32 DelayInMicroSeconds;
+
+ ASSERT (Rand != NULL);
+
+ if (NULL == Rand) {
+ return FALSE;
+ }
+
+ RandPtr = (UINT8 *)Rand;
+ DelayInMicroSeconds = CalculateMinimumDecentDelayInMicroseconds ();
+ // Get 4 bytes of random ish data
+ for (Index = 0; Index < sizeof (UINT32); Index++) {
+ *RandPtr = (UINT8)(GetPerformanceCounter () & 0xFF);
+ // Delay to give the performance counter a chance to change
+ MicroSecondDelay (DelayInMicroSeconds);
+ RandPtr++;
+ }
+
+ return TRUE;
+}
+
+/**
+ Generates a 64-bit random number.
+
+ if Rand is NULL, then ASSERT().
+
+ @param[out] Rand Buffer pointer to store the 64-bit random value.
+
+ @retval TRUE Random number generated successfully.
+ @retval FALSE Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+GetRandomNumber64 (
+ OUT UINT64 *Rand
+ )
+{
+ UINT32 Index;
+ UINT8 *RandPtr;
+ UINT32 DelayInMicroSeconds;
+
+ ASSERT (Rand != NULL);
+
+ if (NULL == Rand) {
+ return FALSE;
+ }
+
+ RandPtr = (UINT8 *)Rand;
+ DelayInMicroSeconds = CalculateMinimumDecentDelayInMicroseconds ();
+ // Get 8 bytes of random ish data
+ for (Index = 0; Index < sizeof (UINT64); Index++) {
+ *RandPtr = (UINT8)(GetPerformanceCounter () & 0xFF);
+ // Delay to give the performance counter a chance to change
+ MicroSecondDelay (DelayInMicroSeconds);
+ RandPtr++;
+ }
+
+ return TRUE;
+}
+
+/**
+ Generates a 128-bit random number.
+
+ if Rand is NULL, then ASSERT().
+
+ @param[out] Rand Buffer pointer to store the 128-bit random value.
+
+ @retval TRUE Random number generated successfully.
+ @retval FALSE Failed to generate the random number.
+
+**/
+BOOLEAN
+EFIAPI
+GetRandomNumber128 (
+ OUT UINT64 *Rand
+ )
+{
+ ASSERT (Rand != NULL);
+ // This should take around 80ms
+
+ // Read first 64 bits
+ if (!GetRandomNumber64 (Rand)) {
+ return FALSE;
+ }
+
+ // Read second 64 bits
+ return GetRandomNumber64 (++Rand);
+}
+
+/**
+ Get a GUID identifying the RNG algorithm implementation.
+
+ @param [out] RngGuid If success, contains the GUID identifying
+ the RNG algorithm implementation.
+
+ @retval EFI_SUCCESS Success.
+ @retval EFI_UNSUPPORTED Not supported.
+ @retval EFI_INVALID_PARAMETER Invalid parameter.
+**/
+EFI_STATUS
+EFIAPI
+GetRngGuid (
+ GUID *RngGuid
+ )
+{
+ if (RngGuid == NULL) {
+ return EFI_INVALID_PARAMETER;
+ }
+
+ CopyMem (RngGuid, &gEdkiiRngAlgorithmUnSafe, sizeof (*RngGuid));
+ return EFI_SUCCESS;
+}
generated by cgit v1.2.3 (git 2.39.0) at 2026-09-08 23:52:42 +0300