CryptoPkg: OpensslLib: Use RngLib to generate entropy in rand_pool

[mirror_edk2.git] / CryptoPkg / Library / OpensslLib / rand_pool.c

/** @file\r
  OpenSSL_1_1_1b doesn't implement rand_pool_* functions for UEFI.\r
  The file implement these functions.\r
\r
  Copyright (c) 2019, Intel Corporation. All rights reserved.<BR>\r
  SPDX-License-Identifier: BSD-2-Clause-Patent\r
\r
**/\r
\r
#include "crypto/rand.h"\r
#include <openssl/aes.h>\r
\r
#include <Uefi.h>\r
#include <Library/RngLib.h>\r
\r
/**\r
  Calls RandomNumber64 to fill\r
  a buffer of arbitrary size with random bytes.\r
  This is a shim layer to RngLib.\r
\r
  @param[in]   Length        Size of the buffer, in bytes,  to fill with.\r
  @param[out]  RandBuffer    Pointer to the buffer to store the random result.\r
\r
  @retval TRUE        Random bytes generation succeeded.\r
  @retval FALSE       Failed to request random bytes.\r
\r
**/\r
STATIC\r
BOOLEAN\r
EFIAPI\r
RandGetBytes (\r
  IN UINTN         Length,\r
  OUT UINT8       *RandBuffer\r
  )\r
{\r
  BOOLEAN     Ret;\r
  UINT64      TempRand;\r
\r
  Ret = FALSE;\r
\r
  if (RandBuffer == NULL) {\r
    DEBUG((DEBUG_ERROR, "[OPENSSL_RAND_POOL] NULL RandBuffer. No random numbers are generated and your system is not secure\n"));\r
    ASSERT (RandBuffer != NULL); // Since we can't generate random numbers, we should assert. Otherwise we will just blow up later.\r
    return Ret;\r
  }\r
\r
\r
  while (Length > 0) {\r
    // Use RngLib to get random number\r
    Ret = GetRandomNumber64 (&TempRand);\r
\r
    if (!Ret) {\r
      return Ret;\r
    }\r
    if (Length >= sizeof (TempRand)) {\r
      *((UINT64*) RandBuffer) = TempRand;\r
      RandBuffer += sizeof (UINT64);\r
      Length -= sizeof (TempRand);\r
    }\r
    else {\r
      CopyMem (RandBuffer, &TempRand, Length);\r
      Length = 0;\r
    }\r
  }\r
\r
  return Ret;\r
}\r
\r
/*\r
 * Add random bytes to the pool to acquire requested amount of entropy\r
 *\r
 * This function is platform specific and tries to acquire the requested\r
 * amount of entropy by polling platform specific entropy sources.\r
 *\r
 * This is OpenSSL required interface.\r
 */\r
size_t\r
rand_pool_acquire_entropy (\r
  RAND_POOL *pool\r
  )\r
{\r
  BOOLEAN        Ret;\r
  size_t         Bytes_needed;\r
  unsigned char *Buffer;\r
\r
  Bytes_needed = rand_pool_bytes_needed (pool, 1 /*entropy_factor*/);\r
  if (Bytes_needed > 0) {\r
    Buffer = rand_pool_add_begin (pool, Bytes_needed);\r
\r
    if (Buffer != NULL) {\r
      Ret = RandGetBytes (Bytes_needed, Buffer);\r
      if (FALSE == Ret) {\r
        rand_pool_add_end (pool, 0, 0);\r
      }\r
      else {\r
        rand_pool_add_end (pool, Bytes_needed, 8 * Bytes_needed);\r
      }\r
    }\r
  }\r
\r
  return rand_pool_entropy_available (pool);\r
}\r
\r
/*\r
 * Implementation for UEFI\r
 *\r
 * This is OpenSSL required interface.\r
 */\r
int\r
rand_pool_add_nonce_data (\r
  RAND_POOL *pool\r
  )\r
{\r
  UINT8 data[16];\r
  RandGetBytes (sizeof(data), data);\r
\r
  return rand_pool_add (pool, (unsigned char*)&data, sizeof(data), 0);\r
}\r
\r
/*\r
 * Implementation for UEFI\r
 *\r
 * This is OpenSSL required interface.\r
 */\r
int\r
rand_pool_add_additional_data (\r
  RAND_POOL *pool\r
  )\r
{\r
  UINT8 data[16];\r
  RandGetBytes (sizeof(data), data);\r
\r
  return rand_pool_add (pool, (unsigned char*)&data, sizeof(data), 0);\r
}\r
\r
/*\r
 * Dummy Implementation for UEFI\r
 *\r
 * This is OpenSSL required interface.\r
 */\r
int\r
rand_pool_init (\r
  VOID\r
  )\r
{\r
  return 1;\r
}\r
\r
/*\r
 * Dummy Implementation for UEFI\r
 *\r
 * This is OpenSSL required interface.\r
 */\r
VOID\r
rand_pool_cleanup(\r
  VOID\r
  )\r
{\r
}\r
\r
/*\r
 * Dummy Implementation for UEFI\r
 *\r
 * This is OpenSSL required interface.\r
 */\r
VOID\r
rand_pool_keep_random_devices_open (\r
  int keep\r
  )\r
{\r
}\r