MdePkg/Library/DxeRngLib/DxeRngLib.c

   1 /** @file
   2  Provides an implementation of the library class RngLib that uses the Rng protocol.
   3
   4  Copyright (c) Microsoft Corporation. All rights reserved.
   5  SPDX-License-Identifier: BSD-2-Clause-Patent
   6
   7 **/
   8 #include <Uefi.h>
   9 #include <Library/UefiBootServicesTableLib.h>
  10 #include <Library/DebugLib.h>
  11 #include <Library/RngLib.h>
  12 #include <Protocol/Rng.h>
  13
  14 /**
  15   Routine Description:
  16
  17   Generates a random number via the NIST
  18   800-9A algorithm.  Refer to
  19   http://csrc.nist.gov/groups/STM/cavp/documents/drbg/DRBGVS.pdf
  20   for more information.
  21
  22   @param[out] Buffer      Buffer to receive the random number.
  23   @param[in]  BufferSize  Number of bytes in Buffer.
  24
  25   @retval EFI_SUCCESS or underlying failure code.
  26 **/
  27 STATIC
  28 EFI_STATUS
  29 GenerateRandomNumberViaNist800Algorithm (
  30   OUT UINT8  *Buffer,
  31   IN  UINTN  BufferSize
  32   )
  33 {
  34   EFI_STATUS        Status;
  35   EFI_RNG_PROTOCOL  *RngProtocol;
  36
  37   RngProtocol = NULL;
  38
  39   if (Buffer == NULL) {
  40       DEBUG((DEBUG_ERROR, "%a: Buffer == NULL.\n", __FUNCTION__));
  41       return EFI_INVALID_PARAMETER;
  42   }
  43
  44   Status = gBS->LocateProtocol (&gEfiRngProtocolGuid, NULL, (VOID **)&RngProtocol);
  45   if (EFI_ERROR (Status) || RngProtocol == NULL) {
  46       DEBUG((DEBUG_ERROR, "%a: Could not locate RNG prototocol, Status = %r\n", __FUNCTION__, Status));
  47       return Status;
  48   }
  49
  50   Status = RngProtocol->GetRNG (RngProtocol, &gEfiRngAlgorithmSp80090Ctr256Guid, BufferSize, Buffer);
  51   DEBUG((DEBUG_INFO, "%a: GetRNG algorithm CTR-256 - Status = %r\n", __FUNCTION__, Status));
  52   if (!EFI_ERROR (Status)) {
  53     return Status;
  54   }
  55
  56   Status = RngProtocol->GetRNG (RngProtocol, &gEfiRngAlgorithmSp80090Hmac256Guid, BufferSize, Buffer);
  57   DEBUG((DEBUG_INFO, "%a: GetRNG algorithm HMAC-256 - Status = %r\n", __FUNCTION__, Status));
  58   if (!EFI_ERROR (Status)) {
  59     return Status;
  60   }
  61
  62   Status = RngProtocol->GetRNG (RngProtocol, &gEfiRngAlgorithmSp80090Hash256Guid, BufferSize, Buffer);
  63   DEBUG((DEBUG_INFO, "%a: GetRNG algorithm Hash-256 - Status = %r\n", __FUNCTION__, Status));
  64   if (!EFI_ERROR (Status)) {
  65     return Status;
  66   }
  67   // If all the other methods have failed, use the default method from the RngProtocol
  68   Status = RngProtocol->GetRNG (RngProtocol, NULL, BufferSize, Buffer);
  69   DEBUG((DEBUG_INFO, "%a: GetRNG algorithm Hash-256 - Status = %r\n", __FUNCTION__, Status));
  70   if (!EFI_ERROR (Status)) {
  71     return Status;
  72   }
  73   // If we get to this point, we have failed
  74   DEBUG((DEBUG_ERROR, "%a: GetRNG() failed, staus = %r\n", __FUNCTION__, Status));
  75
  76   return Status;
  77 }// GenerateRandomNumberViaNist800Algorithm()
  78
  79
  80 /**
  81   Generates a 16-bit random number.
  82
  83   if Rand is NULL, return FALSE.
  84
  85   @param[out] Rand     Buffer pointer to store the 16-bit random value.
  86
  87   @retval TRUE         Random number generated successfully.
  88   @retval FALSE        Failed to generate the random number.
  89
  90 **/
  91 BOOLEAN
  92 EFIAPI
  93 GetRandomNumber16 (
  94   OUT UINT16  *Rand
  95   )
  96 {
  97   EFI_STATUS Status;
  98
  99   if (Rand == NULL)
 100   {
 101     return FALSE;
 102   }
 103
 104   Status = GenerateRandomNumberViaNist800Algorithm ((UINT8 *)Rand, sizeof(UINT16));
 105   if (EFI_ERROR (Status)) {
 106     return FALSE;
 107   }
 108   return TRUE;
 109 }
 110
 111 /**
 112   Generates a 32-bit random number.
 113
 114   if Rand is NULL, return FALSE.
 115
 116   @param[out] Rand     Buffer pointer to store the 32-bit random value.
 117
 118   @retval TRUE         Random number generated successfully.
 119   @retval FALSE        Failed to generate the random number.
 120
 121 **/
 122 BOOLEAN
 123 EFIAPI
 124 GetRandomNumber32 (
 125   OUT UINT32 *Rand
 126   )
 127 {
 128   EFI_STATUS Status;
 129
 130   if (Rand == NULL) {
 131     return FALSE;
 132   }
 133
 134   Status = GenerateRandomNumberViaNist800Algorithm ((UINT8*)Rand, sizeof(UINT32));
 135   if (EFI_ERROR (Status)) {
 136     return FALSE;
 137   }
 138   return TRUE;
 139 }
 140
 141 /**
 142   Generates a 64-bit random number.
 143
 144   if Rand is NULL, return FALSE.
 145
 146   @param[out] Rand     Buffer pointer to store the 64-bit random value.
 147
 148   @retval TRUE         Random number generated successfully.
 149   @retval FALSE        Failed to generate the random number.
 150
 151 **/
 152 BOOLEAN
 153 EFIAPI
 154 GetRandomNumber64 (
 155   OUT UINT64 *Rand
 156   )
 157 {
 158   EFI_STATUS Status;
 159
 160   if (Rand == NULL) {
 161     return FALSE;
 162   }
 163
 164   Status = GenerateRandomNumberViaNist800Algorithm ((UINT8*)Rand, sizeof(UINT64));
 165   if (EFI_ERROR (Status)) {
 166     return FALSE;
 167   }
 168   return TRUE;
 169 }
 170
 171 /**
 172   Generates a 128-bit random number.
 173
 174   if Rand is NULL, return FALSE.
 175
 176   @param[out] Rand     Buffer pointer to store the 128-bit random value.
 177
 178   @retval TRUE         Random number generated successfully.
 179   @retval FALSE        Failed to generate the random number.
 180
 181 **/
 182 BOOLEAN
 183 EFIAPI
 184 GetRandomNumber128 (
 185   OUT UINT64 *Rand
 186   )
 187 {
 188   EFI_STATUS Status;
 189
 190   if (Rand == NULL) {
 191     return FALSE;
 192   }
 193
 194   Status = GenerateRandomNumberViaNist800Algorithm ((UINT8*)Rand, 2 * sizeof(UINT64));
 195   if (EFI_ERROR (Status)) {
 196     return FALSE;
 197   }
 198   return TRUE;
 199 }