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
  68   // If all the other methods have failed, use the default method from the RngProtocol
  69   Status = RngProtocol->GetRNG (RngProtocol, NULL, BufferSize, Buffer);
  70   DEBUG ((DEBUG_INFO, "%a: GetRNG algorithm Hash-256 - Status = %r\n", __FUNCTION__, Status));
  71   if (!EFI_ERROR (Status)) {
  72     return Status;
  73   }
  74
  75   // If we get to this point, we have failed
  76   DEBUG ((DEBUG_ERROR, "%a: GetRNG() failed, staus = %r\n", __FUNCTION__, Status));
  77
  78   return Status;
  79 }// GenerateRandomNumberViaNist800Algorithm()
  80
  81 /**
  82   Generates a 16-bit random number.
  83
  84   if Rand is NULL, return FALSE.
  85
  86   @param[out] Rand     Buffer pointer to store the 16-bit random value.
  87
  88   @retval TRUE         Random number generated successfully.
  89   @retval FALSE        Failed to generate the random number.
  90
  91 **/
  92 BOOLEAN
  93 EFIAPI
  94 GetRandomNumber16 (
  95   OUT UINT16  *Rand
  96   )
  97 {
  98   EFI_STATUS  Status;
  99
 100   if (Rand == NULL) {
 101     return FALSE;
 102   }
 103
 104   Status = GenerateRandomNumberViaNist800Algorithm ((UINT8 *)Rand, sizeof (UINT16));
 105   if (EFI_ERROR (Status)) {
 106     return FALSE;
 107   }
 108
 109   return TRUE;
 110 }
 111
 112 /**
 113   Generates a 32-bit random number.
 114
 115   if Rand is NULL, return FALSE.
 116
 117   @param[out] Rand     Buffer pointer to store the 32-bit random value.
 118
 119   @retval TRUE         Random number generated successfully.
 120   @retval FALSE        Failed to generate the random number.
 121
 122 **/
 123 BOOLEAN
 124 EFIAPI
 125 GetRandomNumber32 (
 126   OUT UINT32  *Rand
 127   )
 128 {
 129   EFI_STATUS  Status;
 130
 131   if (Rand == NULL) {
 132     return FALSE;
 133   }
 134
 135   Status = GenerateRandomNumberViaNist800Algorithm ((UINT8 *)Rand, sizeof (UINT32));
 136   if (EFI_ERROR (Status)) {
 137     return FALSE;
 138   }
 139
 140   return TRUE;
 141 }
 142
 143 /**
 144   Generates a 64-bit random number.
 145
 146   if Rand is NULL, return FALSE.
 147
 148   @param[out] Rand     Buffer pointer to store the 64-bit random value.
 149
 150   @retval TRUE         Random number generated successfully.
 151   @retval FALSE        Failed to generate the random number.
 152
 153 **/
 154 BOOLEAN
 155 EFIAPI
 156 GetRandomNumber64 (
 157   OUT UINT64  *Rand
 158   )
 159 {
 160   EFI_STATUS  Status;
 161
 162   if (Rand == NULL) {
 163     return FALSE;
 164   }
 165
 166   Status = GenerateRandomNumberViaNist800Algorithm ((UINT8 *)Rand, sizeof (UINT64));
 167   if (EFI_ERROR (Status)) {
 168     return FALSE;
 169   }
 170
 171   return TRUE;
 172 }
 173
 174 /**
 175   Generates a 128-bit random number.
 176
 177   if Rand is NULL, return FALSE.
 178
 179   @param[out] Rand     Buffer pointer to store the 128-bit random value.
 180
 181   @retval TRUE         Random number generated successfully.
 182   @retval FALSE        Failed to generate the random number.
 183
 184 **/
 185 BOOLEAN
 186 EFIAPI
 187 GetRandomNumber128 (
 188   OUT UINT64  *Rand
 189   )
 190 {
 191   EFI_STATUS  Status;
 192
 193   if (Rand == NULL) {
 194     return FALSE;
 195   }
 196
 197   Status = GenerateRandomNumberViaNist800Algorithm ((UINT8 *)Rand, 2 * sizeof (UINT64));
 198   if (EFI_ERROR (Status)) {
 199     return FALSE;
 200   }
 201
 202   return TRUE;
 203 }